THIS ISSUE AT A GLANCE

Page Article

3 The Biggest Problems or InformationNeeds With Respect to Tree Seed for theProvince of Québec

4 An Example of the Need to M ainta inGenetic Diversity

5 What are the Biggest Problems orInformation Needs With Respect to TreeSeed in Saskatchewan?

5 Potential Areas for Future Tree SeedResearch

7 Cone Induction and Seed ProductionNeeds

8 Priority Areas in Seed Biology Research

11 Tree Seed Workshop O verview

14 Is Western Larch a Poor Seed Producerin Natural Stands and Seed Orchards?

19 Seed Production in 2004 From J.D.Irving, Limited’s Parkindale SeedOrchard

19 Non-specific Pollination MechanismsMay Create Obstacles for ProperSeeding in Juniperus

20 IUFRO Seed Physiology and TechnologyResearch Group Meeting

21 National Tree Seed Centre

22 Woody Plant Seed Manual

22 Upcoming Meetings

22 Selected References

CANADIAN TREE IMPROVEMENT ASSOCIATION/ASSOCIATION CANADIENNE POUR L’AMÉLIORATION DES ARBRES

Tree Seed Working Group

NEWS BULLETIN

No. 40 December 2004

PROBLEMS AND INFORMATION NEEDS FOR TREE SEED

CHAIR’S ‘ARMCHAIR’ REPORT

Hello! It is my pleasure to welcome you to the 40th

Edition of the CTIA Tree Seed Working Group(TSWG) News Bulletin. Before reminiscing aboutour heritage I’d like to thank everyone whoattended and participated in the CTIA meeting thispast summer. I have received a great deal ofpositive feedback concerning the meeting andworkshops. A synopsis of the Tree Seed workshopis presented in an enclosed article, but I would liketo thank, up front, all of the speakers who madepresentations on ‘Quality Assurance in the SeedHandling System” as well as everyone involved inour lively discussions.

The Tree Seed Working Group began in 1983after successful seed workshops at the 18 th

(Duncan) and 19th (Toronto) CTIA meetings. Thegroup has consistently produced two NewsBulletins a year for the past 20 years and hashosted tree seed workshops at most CTIAmeetings over this time span. The group hasmaintained the following four objectives over its21-year history: To promote tree seed scienceand technology through:

1) seed research from bud initiation to seedutilization,2) identification of seed problems relating to treeimprovement and forest management,3) the exchange of information on seed relatedproblems, and by4) advising on implementation practices

The objectives still seem relevant and help todefine the scope of our Working Group. A largenumber of people have contributed to the TSWGin terms of articles, workshop presentations, andtheir dedication to tree seed science andtechnology. Firstly, I would like to identify andthank our past TSW G chairs:

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Ben Wang Chair 1983 to 1985Yves Lamontagne Chair 1985 to 1987Graham Powell Chair 1987 to 1991Guy Caron Chair 1991 to 1997Howard Frame Chair 1997 to 2000

The chairs may provide the face of the organization,but the group’s success is on the backbone of theTSWG News Bulletin Editor. We have had someexcellent editors over the years and theircontributions have been incredible. Thank you.

George Edwards Editor 1983 to 1985Hugh Schooley Editor 1985 to 1995Ron Smith Editor 1995 to 2002Dale Simpson Editor 2002 to present

There are many more individuals who have dedicatedenergies towards the TSWG. I cannot identify all, butI would like to acknowledge a few other individuals:

Peter De Groot has been involved in the TSWG fromNews Bulletin #2 (at least) and co-ordinated the Coneand Seed Insects Working Party (CSIWP) for manyyears. The TSWG also had a Tree Seed Processingand Testing Working Party that was headed by DaveBewick and then myself. These working parties weredissolved in 2000 not because these topics areunimportant, but because the working parties werenot active and these subjects can be handledeffectively under the TSWG umbrella.

You may wonder who is the Tree Seed WorkingGroup? The answer is basically anyone with aninterest in tree seed science and technology whoparticipates in our News Bulletin or our workshops.Currently the News Bulletin is distributed to about250 individuals and about 40 libraries. The audienceis primarily those working in Canada, but about 7%of the News Bulletins go to workers in the UnitedStates and an additional 9% goes to a variety of otherCountries throughout the world.

Before presenting my two-cents on this edition’stheme I’d like to announce that the theme for NewsBulletin #41 is “Cone and Seed Pests”. This iscertainly an important topic that is having a hugeimpact in BC seed orchards. It is currently consideredour greatest impediment to meeting seed demandsover the next decade. The BC Pest Managementgroup with the Tree Improvement Branch has agreedto help write and solicit articles. Please contribute tokeeping the News Bulletin active, current, andNational in scope. Deadline for articles is May 20,2005. Thank you.

The theme of this News Bulletin is “What are yourbiggest problems or information needs withrespect to tree seed?” It allows for some reflectionon what we need to do to move forward in keepingtree seed science current in a rapidly changing world.I will elaborate on a few ideas starting from a big

picture view to some specifics that I believe arecritical. My biggest concern is in the number ofpeople who are actually working in the area of treeseed science and technology. This is not new andmost of us can remember Ron Smith’s 1998commentary in News Bulletin #29 “Tree SeedResearch: Is anyone doing any?”. We haveexperienced a large drain in Canada with theretirements of George Edwards, Robert Farmer,Carole Leadem, John Owens, Ben Wang, and JoeWebber who were leaders in our field for manyyears. The area does not attract many new peopleand this is not because we have answered all thepertinent questions, especially with the rapidlychanging genetic base of our seed. The fieldcurrently does not present a very promising futurefor students and they cannot compete for researchdollars with state-of-the art molecular techniques.

I do not want it to appear like I am againstmolecular biology, but I strongly think there is aneed for a multi-pronged approach to solving treeseed problems. With more science being on thecutting edge of technology the gap betweenresearch and operational implementation iswidening. The results of scientific research cannotalways be easily implemented into operations andtechnology transfer does not receive strongsupport today. I strongly believe that we areloosing our prong of how to deal with questionsrelated to seed anatomy and morphology. Thesetopics are rarely taught in Universities as theredoes not ‘appear’ to be practical applications andover time our expertise in this area will disappear.There is some great work happening inconjunction with Simon Fraser University and thePlant Biotechnology Institute in Saskatoon usingMRI technology as a method of visualizing waterand oil distribution in seeds, so there is hope.Look forward to more information on thisvaluable technology in the next issue.

In addition to not enough basic scientificresearchers, technology transfer personnel, andoperational researchers I don’t think we are veryefficient in accessing research that has alreadybeen performed. I keep coming back to a quotefrom Dr. Jeffery Burley in an article entitled Therestoration of research, in which he states“Research information and practical experience ofthe management of forests and trees haveaccumulated for over a century; however, muchresearch has been repetitive in ignorance ofearlier work, much has been ignored by currentpolicy-makers or resource managers, and muchhas not addressed current issues”. I think this hitsseveral key points, but the one I’d like toemphasize is the need to better appreciate andhave more awareness of research that has alreadybeen performed, considering its benefits as well asits limitations in tree seed science today. The

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electronic age and reliance on electronic literaturesearches that primarily focus on the last decade (ortwo) ignore a large foundation of tree seed scienceand technology. I’m hoping to take a bite out of thisgeneral issue over the next year – stay tuned.

Moving to more specific needs I have a few topics toput forth as problems or needs:

1) We need a good method of quantifying seeddormancy. Fortunately a paper is in press thataddresses this topic and should provide a standardmethod for quantifying seed dormancy. For those atthe 2002 Tree Seed Workshop in Edmonton youobtained a sneak preview on the topic.

2) Many jurisdictions are moving towards greater useof seed orchard produced seed. The transition ishappening quickly and it raises a variety of questions(or should). We should continue to be diligent inaddressing questions of after-effects, familyvariability, and better quantifying what exactly weproduce in seed lots from imperfectly random mating.

3) The last item I would like to highlight is pests anda better understanding of fungi and insects that reducethe efficiency of our operations. Specifically moreinformation on basic biology of coneworms(Dioryctria spp.) and the route and properties ofFusarium spp. contamination are priorities.

Thank you to everyone who has contributed to our40 th anniversary edition. Have a Happy and Safeholiday season.

Dave KoloteloChairperson

EDITOR’S NOTES

Welcome to the 40th issue of the TSWG’s NewsBulletin! I had the good fortune to be invited to givea paper at the Tree Seed Workshop held prior to the19 th CTIA in Toronto in 1983 and participated in themeeting that followed which formalized theformation of the Tree Seed Working Group. The firstissue of the News Bulletin was published December1983. Now 20+ years and 40 News Bulletins later theGroup continues to thrive and be active. It is an honorto be involved.

I am sure you will find something of interest in thisissue. There are several shorter submissions dealingwith the theme as well as a couple of longer articles.You will also find a number of general interest andnewsy articles. It is this diversity that I thinkcontinues to make the News Bulletin interesting and

successful.

At this time I want to wish you all a JoyousHoliday Season and the Best for the New Year.

Dale SimpsonEditor

TREE SEED WORKING GROUP

ChairpersonDave Kolotelo

BC Ministry of ForestsTree Seed Centre

18793 - 32nd AvenueSurrey, BC V4P 1M5

Tel.: (604) 541-1683 x 228Fax.: (604) 541-1685

E-m ail: Dave.Kolotelo@gems7.gov.bc.ca

EditorDale Simpson

Natural Resources CanadaCanadian Forest ServiceAtlantic Forestry Centre

P.O. Box 4000Fredericton, NB E3B 5P7

Tel.: (506) 452-3530Fax.: (506) 452-3525

E-m ail: Dale.Simpson@nrcan.gc.ca

Comments, suggestions, and contributions for theNews Bulletin are welcomed by the Chairpersonor Editor.

THE BIGGEST PROBLEMS ORINFORMATION NEEDS WITH RESPECTTO TREE SEED FOR THE PROVINCE OF

QUÉBEC

The Ministère des Ressources naturelles, de laFaune et des Parcs from Québec provides all thetree seeds used for seedling production. Québec’sobjective for 2005 is to produce 80% of all theseedlings from improved sources. About 135million seedlings are planted each year. Seventypercent of the coniferous seedlings are producedin 20 private nurseries with the balance producedin 6 government-owned nurseries. All coniferousand hardwood seeds are processed and stored atthe provincial Tree Seed Center in Berthier.

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The major coniferous species used for seedlingproduction are, in decreasing order: black spruce(Picea mariana), jack pine (Pinus banksiana), whitespruce (P. glauca), Norway spruce (P. abies), easternwhite pine (P. strobus), red pine (P. resinosa), balsamfir (Abies balsamea), and eastern larch (Larixlaricina). Those species are produced from seeds,mainly in containers. Black spruce, white spruce,Norway spruce, and hybrid larch are also producedfrom cuttings.

Over 1 million hardwood seedlings are also producedfrom 15 species. The principle hardwood speciesgrown are: yellow birch (Betula alleghaniensis), redoak (Quercus rubra), sugar maple (Acer saccharum),and white ash (Fraxinus americana). About 1.5million hybrid poplar cuttings are produced per year.

Seed research in Québec is conducted both by theTree Seed Center and the Direction de la rechercheforestière. Our interests are wide but mainly our goalsare to: 1) Improve seed orchard production by usingelectrostatic pollination. Preliminary results for blackspruce show that the number of seeds produced bycones pollinated with the electrostatic pistol can bedoubled. 2) Facilitate cone harvest with top pruning.Tests have started in second-generation black spruceand white spruce seed orchards. 3) Improveextraction methods at the Tree Seed Center toincrease seed lot quality. For example, since 2001,mean germination rate of white spruce seed lotsincreased from 85 to 93%. 4) Improve seedstratification methods for some hardwood species(white ash, black ash (F. nigra), black maple (A.nigrum), and American basswood (Tilia americana)).5) Determine sowing factors to optimize theutilization of seeds for seedling production. Thesefactors will allow adequate nursery sowing and willavoid seed waste. 6) Determine a germination testfrequency for each coniferous species in order toreduce the number of seed germination tests done atthe Tree Seed Center without reducing the quality ofthe results.

For general information, see the ministry web site:http://www.mrnfp.gouv.qc.ca/english/forest/quebec/quebec-system-management-plants.jsp (in English)http://www.mrnfp.gouv.qc.ca/forets/entreprises/entreprises-semences.jsp (in French, more exhaustive)

Fabienne ColasMinistère des Ressources natu relles, de la Faune etdes Parcs, Direction de la recherche forestière 2700,rue EinsteinSainte-Foy, QCG1P 3W8E-m ail: fabienne.colas@mrnfp.gouv.qc.ca

Michèle BettezMinistère des Ressources naturelles, de la Fauneet des ParcsCentre de semences forestières de Berthier1690, chemin Grande-CôteBerthier, QCJ0K 1A0E-m ail: michele.bettez@mrnfp.gouv.qc.ca

AN EXAMPLE OF THE NEED TOMAINTAIN GENETIC DIVERSITY

From evolutionary, population adaptation, andclimate change adaptation perspectives, I thinkone of the main issues for seed collection activitiesis the maintenance of genetic diversity with aspecial focus on the type of diversity beingmaintained. Seed orchards are an excellent ideafor maintaining genetic diversity and as a basis forallowing natural selection to determine the geneticand adaptive constitution of the next generation.However, for the past 10 years, I've beenfocussing on the conservation of genetic diversityin marginal natural populations along the northernmargins of their geographic range under theassumption that these populations may be the bestgenetic sources for northward migration in theevent of anticipated climate warming. Oneproblem in these smaller, isolated, marginalpopulations is inbreeding and its often deleteriouseffects on reproductive capacity. However, suchpopulations may also be very active areas ofevolution of the species because of the activity andconsequences of evolutionary forces such asinbreeding, drift, and natural selection. I think theloss of these populations through harvesting(before we can take advantage of the generationsof natural selection, mild inbreeding, and geneticdrift that have often produced the best-adaptedgenotypes for continuing northward migration)should be seen as a serious issue by the treeimprovement community. I would like to see thetree improvement community voice theircollec tive concern and support for themaintenance of a representative sample of theseolder, natural populations at their northern rangemargins in recognition of their potential value asimportant genetic resources and seed sources foradaptation under anticipated climate change.

With many in the forestry community now talkingabout how forests will adapt to climate change, Ithink it's a great time to be working with seedissues because these seed issues are a fundamentalaspect of how well the forest sector and forestsadapt to climate change.

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Alex MosselerNatural Resources CanadaCanadian Forest ServiceAtlantic Forestry CentreP.O. Box 4000Fredericton, NB E3B 5P7E-m ail: Alex.Mosseler@nrcan.gc.ca

WHAT ARE THE BIGGEST PROBLEMS ORINFORMATION NEEDS WITH RESPECT TO

TREE SEED IN SASKATCHEWAN?

Unless a person has been working within the realm oftree improvement or had experience with seedorchards, there lacks a general understanding of wildtree seed development. Many times silviculturists areforced to collect seed without proper information. Forexample, taking a helicopter to nearby areas wherethere are sufficient cones in order to hopefully fill thequota of seed needs for the up-coming year.

More often than not, a clear plan of objectives doesnot exist when it comes to maintaining or ensuringthat there is a supply of quality seed. This can beeffected by one or more of the reasons below: 1) Future Forest Planning – knowing the volume ofseed by species that is needed for a future period oftime. 2) Collecting from “quality” stands - seed collectionstands should be sought out in advance andmonitored for seed yields. Perhaps a protection zonecan be put around these areas. Often stands areselected for their closeness to roads and not enoughemphasis is put on tree quality (is it growing straight,is it prone to disease?). 3) Proper timing of cone collection. Improperunderstanding of embryo development. Collectingcones at the wrong time can result in poor qualityseed. 4) Collection methods. These days there arenumerous ways to collect cones and often costdictates which method is used. Hiring of untrainedcrews or improper training of the crews also affectsthe success of the collection. 5) Quality Control Measures of the entire process(from finding stands to storage of seed). If there areno guidelines then there are no standards to measureagainst.

Therefore, what is needed to advance tree seedscience?1) Current education material/information forinexperienced to learn from. Perhaps short courses forcompany personnel. A regional perspective wouldneed to be maintained.2) Companies/Government need to hire qualified

individuals with silviculture experience.3) Develop regional quality control measuresutilizing information obtained from people withexperience.

Deb WeedonSaskatchewan Environment – Forest ServiceBox 3003, McIntosh MallPrince Albert, SK S6V 6G1E-m ail: Dweedon@serm.gov.sk.ca

POTENTIAL AREAS FOR FUTURE TREESEED RESEARCH

Sum mary

There is considerable scope for tree seed researchto improve the reliability and success rates of allthree methods of woodland establishment: 1)nursery sowing plus transplanting of seedlings, 2)direct sowing, and 3) natural regeneration.

Nursery and direct sowing would bothsignificantly benefit from higher quality seed.Higher germination percentages, quicker and moreuniform emergence, and seed better able togerminate over a wider range of conditions arethree potential improvements. Methods to prolongthe storage life of recalcitrant seeds and betterremoval of dead and dying seeds are two others.

Improved, faster and more versatile seedpretreatments for overcoming seed dormancywould not only provide major benefits in the areasof nursery and direct sowing but also in the qualityassurance realm of seed testing. An ultimate aimfor tree seed research should be the developmentof techniques to enable tree seeds to be pretreated,dried back to normal storage moisture contents,stored for any period of time and yet still be in anon-dormant state. Then they could be suppliedfrom dry-storage and be ready for immediatesowing.

Many woodland managers would prefer to usemore natural processes in the creation andmaintenance of uneven-aged or continuous-coverforests. Identifying the fates of naturally dispersedand direct sown tree seeds, predicting seedlongevity in soil seed banks, plus a betterunderstanding about what makes tree seedsgerminate or not, (particularly the phenomenon ofseed dormancy) would significantly improvesuccess rates for both natural regeneration anddirect sowing.

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Introduction

There are generally three methods used to establishtrees from seeds: 1) nursery sowing followed bytransplanting seedlings to their final planting site, 2)direct sowing where seeds are sown onto the final siteof the proposed crop, and 3) natural regeneration (ormore accura te ly, ‘human -assis ted n atura lr e g e n e r a t i o n ’ ) w h e r e ‘ n a t u r a l ’colonisation/establishment from seed banks ispromoted by a number of artificial, pre-plannedoperations such as leaving seed trees, applyingcarefully timed ground disturbance, minimising seedpredation, and protecting seedlings from weedcompetition and browsing.

Throughout the world, there are significant problemsin the establishment of forest trees via all of thesemethods. Even weed seed characteristics are muchbetter understood than those of trees because greaterresearch efforts have been directed for longer periodsof time towards controlling weed problems in foodcrops than towards improving afforestation andreforestation techniques. Consequently, the qualityand performance of most tree seeds lags about 50years behind agricultural, horticultural, vegetable, andflower seeds. Some of the more significant tree seedproblems, which are potentially amenable to researchsolutions, are considered below in the chronologicalsequence in which they occur.

Flowering/Fruiting

Tree seed production is highly erratic. In some yearstrees produce lots of seeds, in others virtually none.But there are no cost-effective methods forstimulating consistent seed production in anythingother than seed orchard systems. Seed supply istherefore a problem especially for species with seedsthat cannot be stored.

Methods for assessing flowering and fruiting innatural stands are not only extremely subjective, butthey are also still in their infancy and only availablefor a relatively few species. The development of moreobjective flowering/fruiting assessments wouldenable advance prediction of ‘good’ versus ‘bad’ seedyears, lead to fewer uneconomical seed collections,and increase the chances of successfully managingsubsequent phases of ‘human-assisted, naturalregeneration’.

Processing

Trees habitually produce large proportions of emptyand dead seeds, and insect and fungal infections arenot uncommon. With the exception of removingempty seeds, processing techniques for separatinglive, healthy seeds from unproductive ones are

relatively inefficient and only applicable to a fewspecies. As a consequence, few countries evenattempt to remove dead seeds from any of theirseed lots. Hence germination percentages for treeseed lots can be quite low, and unlikecommercially available agricultural, vegetable,and flower seed lots there are no minimumgermination standards. Better removal of dead anddying seeds would lead to higher germinationpercentages, more efficient nursery production,and increased opportunities for direct seeding.Improved detection and control of seed borneinsects and fungi would reduce seed/seedlinglosses in nurseries.

Seed Storage and Longevity

The seeds of many tropical rainforest and sometemperate tree species such as oaks (Quercus),chestnuts (Aesculus and Castanea), and sycamore(Acer pseudoplatanus) are extremely perishable.They are shed at a high moisture content and arekilled by very little drying. Such seeds cannot bestored without significant deterioration over veryshort time-scales (e.g., weeks to months) and areoften referred to as recalcitrant. The seeds of thesespecies usually tend to be large and as aconsequence of their size and perishability theyare by far the most expensive tree seeds (on a perlive seed basis). Methods are urgently sought toprolong the storage life of such rapidlydeteriorating seeds, both for conservation andcommercial reasons.

In contrast to seeds with recalcitrant properties,the majority of tree seeds can be dried and storedrelatively successfully and are said to be orthodox.However, whereas the seed longevity of manyagricultural and horticultural crops can bepredicted at different moisture contents and underdifferent temperature regimes from mathematicalformulae, most tree seed storage is doneempirically. Research is required on these treespecies to not only enable the maximum potentiallongevity of seeds to be predicted in commercialseed stores and ex-situ conservation facilities, butalso to monitor/predict seed deterioration innatural seed banks to improve the chances ofsuccessfully managing natural regeneration.

A small minority of tree seeds appear to fall intoan intermediate storage category betweenorthodox and recalcitrant. Preliminary evidencesuggests that these seeds are less tolerant of dryingand shorter-lived than the majority of seeds withorthodox storage characteristics. But they are notas desiccation sensitive or highly perishable asrecalcitrant seeds. Early indications are that Acerplatanoides, Calocedrus decurrens, Fagussylvatica, some true-firs (Abies spp.) and some

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cedars (Cedrus spp.) may fall into this category.

Seed Dormancy, Pretreatment, Testing andPropagation

Agricultural, horticultural, vegetable, and flowerseeds are nearly all supplied from dry storage readyfor immediate sowing. Hence most farmers,horticulturists, and gardeners are used to buyingseeds, planting them, (perhaps watering them) andwatching them grow into plants. Unfortunately,virtually all tree seeds exhibit dormancy. Dormantseeds are live, fully mature, and perfectly healthy.But even when they are provided with apparentlyideal conditions for germination (ample water, goodaeration, and a suitable temperature) they obstinatelyrefuse to germinate. To overcome this dormancy,most tree seeds require some form of artificial, pre-sowing treatment. Unfortunate ly, effectiv epretreatments are not known for many species; inother instances, pretreatments are only effective onsome seed lots or a small proportion of seeds in anyparticular seed lot. Even for seeds wherepretreatments are considered to be relatively good,they are nearly always awkward to carry out, takemonths or even years to complete, and requirefrequent monitoring.

Better, faster, and more versatile seed pretreatmentsfor overcoming seed dormancy would provide severalmajor benefits: 1) improved measurement of seedquality and forecasting accuracy of nurseryemergence from seed test results, 2) increasedopportunities for adopting precision sowing andcontainer production methods, 3) more consistentproduction of higher quality nursery stock at lowercost, and 4) greater chances of success for directsown tree seeds. The increased understanding of treeseed dormancy, pretreatment techniques, andgermination characteristics which would accompanythe above research would also significantly improvethe predictability and hence management of naturalregeneration.

An ultimate aim of tree seed research should be thedevelopment of techniques to enable tree seeds to bepretreated, dried back to normal storage moisturecontents, stored for any period of time, and yet still bein a non-dormant state and ready for immediatesowing. This is no more than is taken for granted withthe seeds of virtually every other crop.

Peter GoslingForestry Commission Research AgencyAlice Holt LodgeFarnham, Surrey

GU10 4LH, UKE-m ail: peter.gosling@forestry.gsi.gov.uk

CONE INDUCTION AND SEEDPRODUCTION NEEDS

Seed orchard effectiveness has been greatlyimproved thanks to research in flower stimulation,pollen management and artificial pollination.However, deployment of orchard seed lotsrequires further information on many issues. In myopinion, the most important are inductiont r e a t m e n t f r e q u e n c y , f l o w e rinduction/differentiation process, ovule and seeddevelopment, and seed extraction.

In the last 20 years, progress was made on therefinement of flower stimulation techniques(regarding timing, technique of application, doseof active ingredient). As these techniques havegenerally additive effects the best results areobtained with combined treatments. The successrate and the gains achieved can be consideredsatisfactory though they still depend on siteconditions, genotype, and physiological age. Forexample, combining root-pruning, girdling,Gibberellin4/7 application, and nitrogen fertilizersproved to be the most successful treatment inFrench Douglas-fir (Pseudotsuga menziesii)meadow orchards. However, repeated treatmentsand frequent cone production weaken the trees.Trees treated several times often show needledamage, reduced vigor, and they do not respond aswell as untreated individuals to subsequenttreatments. Our data suggest that biennialapplication may not be compatible withsustainable seed production. Is it preferable to usehighly effective treatments every third or fourthyear or a less stressful treatment every secondyear? No answer can be found in the literaturebecause the experiments cover too short a periodof time. New experiments should be establishedfor this specific purpose.

The last great advance made in the understandingof the mechanisms involved in flower initiation isrelated to the discovery of the effectiveness ofGibberellin4/7 in the Pinaceae. It was nearly 30years ago. Basic research should continue in thatfield.

Initiating flower primordia is one thing, producinglarge quantities of seeds is another one. Non-

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negligible loss of flowers, ovules, and seeds has beenreported in many papers. Efforts should be devoted toresearch aiming at increasing seed efficiency (actualnumber of full seeds per cone / potential number ofseeds). That implies a better understanding of thepollination mechanism and embryo development. Asinsects seem to play a leading role in flower, ovule,and seed abortion, at least in pines, cooperation withentomologists should be reinforced. M oreover,simple treatments such as irrigation, fertilization, andgirdling that increase carbohydrate availability in thecrown portion where the cones develop proved toimprove seed traits. More information is needed onthe effect of nutrition on seed development.

Taking into account the numerous efforts devoted toseed production enhancement, every possible meansmust be used to reduce seed loss in the final stage,that is seed extraction. W e know that a lot of viableseeds remain in the cones of recalcitrant species likeEuropean larch (Larix decidua). Moreover, theextraction rate varies from one clone to another andincreases the natural deviation from panmixia. Forthese reasons, it is desirable to improve theeffectiveness of the seed extraction machinery used inseed plants (or at least to assess the % of potentialseeds actually extracted).

Ideally, seed orchards have a panmictic matingsystem. That means that all the genotypes produce thesame number of gametes, that these gametes mate atrandom, and that there is no selfing and no pollencontamination. In fact, there are always deviations topanmixia and their extent depends on floweringconditions. Some countries have adopted a protocolfor rating seed orchard seed lots. The genetic quality(genetic gain, effective population size) of each seedlot is assessed according to the parental gametecontributions. The development of such protocolsshould be encouraged.

Gwenaël PhilippeCemagrefForest Planting Stock and Genetic ResourcesResearch UnitDomaine des Barres 45290 Nogent-sur-VernissonFranceE-m ail: gwenael.philippe@cemagref.fr

PRIORITY AREAS IN SEED BIOLOGYRESEARCH

Introduction

Not enough is known about the biological processes

involved in seed germination. Despite the workdone on seed provenance testing and treebreeding, there has been relatively little work onseed biology. When it comes to seeds, there aremany ‘information gaps’. However, identifyingthe ‘biggest problems and information needs’presents more of a challenge.

A failure to consider seed biology ignores thepotential contribution of seeds to research. Forinstance, the evolution of conifers represents over200 million years of successful defense againstdisease, insects, and environmental stress.Although the genetic code is fully present inconifer seeds very little of the genetic ‘memory’ isutilized. Once seed defenses are unraveled, wecould have a powerful tool that will enable us tofully utilize the natural defenses of trees.

The production of seed by trees is irregular; hencethere is the necessity to store seeds forregeneration purposes. The loss of seed viabilityover time adds to the cost of storage and hindersregeneration efforts. Of course, users still preferyoung, fresh seed. With age, stored seed maygerminate and grow more slowly, compared toyoung, fresh seed. Beyond a certain age, seedslose viability and have to be tested to ensure theyreach minimum standards.

Oxidative Stress, Antioxidants and SeedSenescence

Living, respiring, organisms require oxygen tostay alive and germinating seeds consume largeamounts of it. Oxygen is not a stable element andforms toxic free radicals when organisms areunder stress. Oxidative stress and free radicalformation may diminish seed longevity and itsability to germinate but it has been found, in agedwhite pine seed, that the use of antioxidants canpartly reverse seed deterioration (Blake 2002a).

Even small variations in the most commonly usedseed treatments may inhibit germination and causeslow growth. For example, repeated seed wettingand drying are variously reported to increase,decrease or have no effect on germination,depending on the study. Although pre-sowingtreatments, e.g., pre-germination and ‘fluiddrilling’, have been advocated, their benefits arenot always apparent. Although there are reports ofearly root emergence and faster seedlingestablishment following repeated wetting anddrying cycles, other workers have failed to findany real benefit from dehydration treatments.Also, drought-hardening seed treatments (e.g.,immersion in an osmoticum such as mannitol orPEG) were reported to increase seedling hardiness,but the dramatic slowing of growth reduced any

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competitive advantage.

The seed stage is the most desiccation-tolerant part ofthe life cycle of a tree, however, seed viability anddesiccation tolerance decline greatly under warmmoist storage. Desiccation tolerance is maximal in theseed but declines during germination, along with areduction in lipid-soluble antioxidants. Seed viabilityrequires active biosynthesis of phospholipids. Highviability, in young, fresh, mature seeds, coincideswith maximum phospholipid synthesis. As seeds age,viability declines and there is a loss of membraneintegrity that carries-over into the seedling stage.Membrane leakage occurs in aging seeds when freeradicals degrade membrane lipids. In the desiccation-intolerant seeds of silver maple (Acer saccharinum),membrane leakage was found to increase during seeddehydration (Pucacka 1989).

Use of Antioxidant Seed Treatments

The synthetic antioxidant Ambiol enhances the lowgermination rate observed in artificially-aged seeds,including those exposed to radiation (Vichnevetskaiaand Roy 1999). Ambiol also increased germinationrate and early seedling growth in black spruce (Piceamariana) (Borsos-Matovina and Blake 2001). Asingle seed pre-treatment with Ambiol (0.1, 1 or 10mg/L) accelerated seed germination (by 25%),hastened emergence, and also protected seedlingsagainst drought and extreme temperatures. Treatedcanola seed was twice as likely to have emerged 10days after treatment (Vichnevetskaia and Roy 1999).Not only were anti-oxidant treated seedlings morestress tolerant, but they also grew faster. Ambiolpretreatment of seeds was found to ‘switch-on’ genesynthesis (Vichnevetskaia and Roy 1999) and genescould be ‘switched-off’ by a subsequent treatmentwith either a general protein synthesis inhibitor(cyclohexamide) or a specific inhibitor of RNA-synthesis (actinomycin-D) (Kritenko and Blake,unpublished data).

The Role of Seed Phenols

The role of phenols in stratification and germinationrequires more study. Phenols are often thought to bemerely by-products of metabolism, but they may alsostimulate or inhibit plant growth and development.Washing of stone pine (Pinus cembra) seeds resultedin more rapid germination which was attributed toleaching of inhibitors from the seed coat (Martinez-Honduvilla and Santos-Ruiz 1978). Germination wasstimulated as much by removal of the seed coat as bystratification. However, the beneficial effects of seedcoat removal may result from an increase in oxygenand water uptake by seeds; so a role for phenols hasstill to be confirmed.

Stratification improves the speed and uniformityof germination in some species, but manyquestions remain. Not all greenhouse operatorsstratify conifer seeds of boreal conifers, as amatter of course.

Stress-signaling compounds are often phenoliccompounds, (e.g., salicylic acid). Phenols aremajor constituents of pine seeds and levels ofphenolic acids decline significantly in the seedcoat during stratification (Murphy and Noland1981a).

Although they play a role in stratification andplant defence reactions, the role of seed phenolsremains unclear. The activity of the PAL(phenylalanine ammonia-lyase) enzyme (whichinitiates phenol production), is highly correlatedwith germination, growth, and development. Incontrast to treatments, such as soaking and storingseeds at room temperature, which lowered PALactivity, stratification caused PAL activity toincrease by 50% after a two-week lag period(Murphy and Noland 1980).

Levels of phenolic acids, including cinnamic acid,p-coumarin acid, and ferulic acid, were relativelylow in dormant sugar pine seeds, but increasedsubstantially in the embryos during stratificationat 5°C. The active synthesis of phenols in sugarpine embryos did not support an inhibitory role forphenols in germination (Murphy and Noland1981b).

Reaction to Mild Doses of UV-B Reveals PlantDefence Reactions

Not only are phenols active in plan t defence, butthey also play a role in growth and development.W e u se d U V - B a n d Am bio l (a 5-hydroxybenzimidazole derivative), as modelsystems to study the role of phenols in plantdefence reactions. Ambiol was added as a 24-hourseed soak, in a range of concentrations (0.01 to 10mg/L).

Low (ambient) doses of UV-B are known tostimulate the production of the enzyme PAL,which is the first step in activation of the phenol-synthesis pathway. We used a PAL-inhibitor (AIP– 2-aminoindan-2-phosphonic acid) to block theearliest stage in phenol formation in plants.Hardiness induction was compared in UV-B-treated and untreated plants, with and withoutAIP. UV-B increased hardiness but the stimulationwas reversed by AIP (i.e., plants treated with UV-B + AIP were unable to tolerate drought orextreme temperatures). In the absence of AIP, UV-B treatment caused phenols to accumulate, whichincreased plant hardiness to extreme temperatures.

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Since the PAL-inhibitor (AIP) also prevented phenolsynthesis, this suggests that phenol formation(quercitin, kaempferol and anthocyanin) is arequirement for plant hardiness. The UV-B-filteringeffects of the glass and plastics used in commercialgreenhouses could explain why transplants are oftenunthrifty (Teklemariam and Blake 2004).

UV-B and antioxidants both ‘switch-on’ plantdefence genes. We used UV-B, as a model system, todetermine whether there is a common basis in plantsthat enables them to withstand a variety of differenttypes of stress (such a mechanism, which is called‘Systemic Acquired Resistance’, or SAR, has beensuggested to underlie plant resistance to stress). PALwas found to activate phenol synthesis and certainphenols were identified as ‘signaling’ compounds,that appear to initiate plant defence reactions tostress. The SAR concept would explain why plantsexposed to one stress (UV-B) acquire resistance toother types of stress (Teklemariam and Blake 2003;Teklemariam and Blake 2004).

Membrane Protection

Stress acts at the level of the cell membrane.Membrane protection, once activated, would increasethe tolerance of high and low temperatures. Anincrease in stress resistance (and reduction inmembrane leakage), was observed in UV-B-pretreated seeds. This resulted from PAL-inducedphenol production. The PAL-inhibitor, AIP reversedthe beneficial effects of mild UV-B treatment onplant hardiness. This confirmed the importance ofPAL synthesis in membrane hardiness and stresstolerance (Teklemariam and Blake 2004).

Seed Pretreatments Enhance Growth and StressTolerance

Experimental verification of the benefits of sometypes of seed pre-treatment (e.g., fluid drilling, seedwetting and drying) is often absent. However, manystudies show that a single (24-hour) seed-soak, witheither Ambiol or natural plant extract (BioProtect)increases and stimulates germination, growth andstress tolerance (Blake 2002a). Antioxidants wereshown to spare membranes, protect photosynthesisand enhance growth under drought (Rajasekaran andBlake 1999), which provides an explanation for theimproved environmental resistance that was observedfollowing seed pretreatment with the antioxidant(Rajasekaran and Blake 2002).

Operational Use of a Natural Antioxidant(BioProtect) in Canada: Field Results

Since 2002, over 4 million seedlings have beentreated with the natural plant extract, BioProtect. This

product has been used in reforestation projectsfrom New Brunswick to British Columbia. Wehave not attempted to track the performance of allthese seedlings, but feedback from forest companyand nursery personnel has been positive. Of coursefield performance is the only real indicator of thevalue of any product or procedure that is used inthe nursery. Therefore we have produced a shortreview of several trials that were established todemonstrate the effectiveness of the naturalantioxidant, BioProtect.

In 2001, trials were established using blackspruce, white spruce (Picea glauca), and jack pine(Pinus banksiana) in Thunder Bay and Dryden,Ontario. Early results (fall 2001) indicated thatBioProtect had resulted in improvements in fieldperformance.

In the fall of 2004, one of these trials at ThunderBay was re-measured. For white spruce, treatedseedlings were slightly taller and 28% larger instem volume. Survival for BioProtect treatedseedlings was 85% compared to 76% for untreatedseedlings. For black spruce, BioProtect seedlingswere 20% taller and 60% larger in stem volumeafter 4 growing seasons. In addition, survival was94% compared to 68% for untreated seedlings. Foradditional information on seed treatments andtheir effectiveness, please refer to our web site:www.ambiolinc.com .

Conclusions

The effects of seed deterioration are carried overinto the seedling stage. The use of poor seedprovenances or inappropriate seed treatmentsslows the growth of transplanted seedlings. Oncegrowth slows and membranes start to leak,seedlings become uncompetitive. In stressedseedlings, oxidation reactions alter protein andRNA synthesis and these changes cause lipidperoxidation and membrane leakage (using themalondialdehye (MDA) assay) (Teklemariam andBlake 2004).

The use of antioxidants is a form of seed‘chemotherapy’ which benefits aged seed (Blake2002b). Such a treatment is cheaper and moreeffective than seed testing. The antioxidantAmbiol ‘switches-on’ dormant genes and theresul ting synthesis of PAL accele ratesgermination. Early seed germination and fasterseedling growth were observed followingantioxidant treatment and the growth advantagecarries over into the field. Treated seedlings werelarger, more tolerant of drought, and of high andlow temperatures. Antioxidant treatment alsoprotected seedlings against some greenhousediseases, including damping-off. The advantages

11

of a single, antioxidant seed treatment were stillapparent four years after transplanting to the field. Agrowth advantage that lasts through the greenhousestage and through the first four years of growth in thefield could last over the life cycle of a tree.

These results, when taken together, suggest that treescan acquire ‘systemic acquired resistance’ (SAR).The membrane sparing ability of antioxidants and amild dose of UV-B suggest a mechanism that couldbe used to harden seedlings to most, if not all, typesof stress (Genaud and Metraux, 1999). Althoughmany of the effects of antioxidants resemble those ofambient UV-B, more study is required to fullyunderstand the nature of systemic resistance (SAR).Research into the process by which the seed developsits extreme environmental resistance and passes itsstress resistance onto seedlings and trees, is obviouslya high priority.

Literature Cited

Blake, T.J. 2002a. Antioxidant and naturalbiostimulant enhancement of seedlinggrowth and stress tolerance in coniferseedlings. BC Min.For., Seed SeedlingExtension Topics 14:10–17.

Blake, T.J. 2002b. Oxidative stress, antioxidants andprospects for seed chemotherapy. Can. TreeImp. Assoc., Tree Seed Work. Group, NewsBull. 36:7–10.

Borsos-Matovina, V.; Blake, T.J. 2001. Seedtreatment with the antioxidant Ambiolenhances membrane protection in seedlingsexposed to drought and low temperatures.Trees 15:163–167.

Genaud, T.; Metraux, J.P. 1999. Cross talk in plantcell signaling: structure and function of thegenetic network. Trends Plant Sci.4:503–507.

Martinez-Honduvilla, C.J.; Santos-Ruiz, A. 1978.Germination inhibitors in the pine seed coat.Planta 141:141–144.

Murphy, J.B.; Noland, T. 1980. Activity of L-phenylalan ine ammo nia-lyase du ringstratification and germination of sugar pineseeds . Z eo t . Fur Pf lanzenphys io l.97:161–169.

Murphy, J.B.; Noland, T.L. 1981a. Changes inphenolic acids and abscisic acid in sugar pineseed coats during stratification. Physiol.Plant. 52:370–374.

Murphy, J.B.; Noland, T. 1981b. Changes inphenolic acid and abscisic acid in sugarpine embryos and megagametophytesduring stratification. Physiol. Plant.52:375–379.

Pucacka, S. 1989. The effect of desiccation onviability and phospholipids compositionof Acer saccharinum L. seeds. Trees3:144–148.

Rajasekaran, L.R.; Blake, T.J. 1999. New plantgrowth regulators protect photosynthesisand enhance growth under drought of jackpine seedlings. J. Plant Growth Reg.18:175–181

Rajasekaran, L.R.; Blake, T.J. 2002. Seedpretreatment using a derivative of 5-hydroxynezimidazole (AMBIOL) pre-acclimates carrot seedlings to drought.Can. J. Plant Sci. 82:195–202.

Teklemariam, T.A.; Blake, T.J. 2004. Op. Cit.

Vichnevetskaia, K.D.; Roy, D.N. 1999. Oxidativestress and antioxidative defence with anemphasis on plant antioxidants. Envir.Rev. 7:31–51.

Terry BlakeUniversity of TorontoFaculty of Forestry33 Willcocks StreetToronto, ON M5S 3B3E-m ail: terryblake@sympatico.ca

Wayne Sm ithAmbiol Inc.32 Parklea DriveToronto, ON M 4G 2J6

TREE SEED WORKSHOP OVERVIEW

At the 29 th meeting of the CTIA, the Tree SeedWorking Group presented a workshop on “QualityAssurance in the Seed Handling System”. Twoadditional speakers (George Edwards and ConorO’Reilly) also presented volunteer papers. I’llpresent an overview of the talks and try and recallthe issues raised. If I’ve missed something, pleaseelaborate on it in the next News Bulletin.

I introduced the workshop topic and defined

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Quality Assurance [QA] quite broadly as “ theevaluation, monitoring, and management ofinformation and practices related to activities withinthe seed handling system”. QA evolved frommanufacturing with the goal of reducing variability.In forestry, variability plays an important role inensuring trees survive to rotation age. Emphasisshould be on reducing process variability andmeasurement subjectivity (= standardization). Thevariation we are faced with in cones and seeds is aprice we pay for maintaining genetic variability. Thisdifferentiates us from the agricultural and beddingplant seed industries where genetic variability isminimized and classical QA is more appropriate.This needs to be appreciated as we borrowtechnologies from these industries. I have done somereading on the topic and would like to suggest sevenQA ‘truisms’ to help initiate or improve your system:

1) Focus on customer satisfaction ,2) Concentrate on reducing process variability,3) Decisions should be based on data,4) Root causes of problems should be sought

out by disciplined investigation,5) Data recording must be performed

consistently,6) Barriers between departments need to be

broken down, and7) QA needs to provide significant added value

and it needs to demonstrate it effectively tomanagement.

Here is an overview of the speakers and topicscovered during the workshop. I planned to have ahalf-day workshop, but we ended up finishing atabout 3:30. I’m not sure if that’s an organizationalfailure or success, but I was pleased with thepresentations and lively discussions we had on avariety of topics. I’ll try and cover some of the mainpoints, but here are the presenters – Thank you verymuch:

Chris Walsh Crop Maintenance andCollection in Seed Orchards

Al Foley Quality Assurance in Coneand Seed Processing

Dale Simpson Quality Assurance in SeedTesting

Donna Palamarek Quality Assurance in SeedStorage

Dave Kolotelo Quality Assurance in SeedPreparation

Susan Thorpe and Fernando Rey Qu ality Assurance in the

Nursery

George Edwards Thermo-kinetics of waterabsorption, with special reference to Noblefir seeds

Conor O’Reilly Effect of moisture content duringpre-treatment or storage on the germination

response of alder, birch, and oak seeds. In the orchard setting, QA was presented from theperspective of having a good cone crop – Whatnext? What considerations are important? Chriscovered a variety of considerations and I’llunderline the main activities he presented. Theimportance of regular orchard maintenance fromthe standpoint of safety and increased efficiencywas emphasized. Maintaining tree health andprotection from cone and seed pests were topicsdiscussed. During crop development, having anestimate of crop size aids in the administration andorganization required to run a biologically soundand efficient collection. Having a cone collectionstrategy in place involves identification of croptrees; a strategy for picking (most BC collectionsare picked on a clonal basis) and ensuring allequipment is ready. The timing of collection iscritical and varies by clone. An overview of theindicator system used at Kalamalka seed orchardswas reviewed (see News Bulletin #38 foradditional details on harvest efficiency and thecone axis test). Cone collection methods and conestorage and shipment methods were reviewed. Thebottom line was that vigilance pays dividends!!

Al discussed the Ontario Seed Plant and hisresponsibility in organizing cone collections forthe province. This is currently difficult as theprovince’s seed inventory is distributed at variouslocations and the full inventory of seed isunknown. This situation will probably change inthe near future. Ontario is still performing a largeamount of aerial seeding and this demandaccounts for a large proportion of the conecollections. Seed processing for direct seedingneed not be to the same high standards as seedused for container sowing. The importance of cashflow from the sale of spent cones was discussed.This raised one of our lively discussionsconcerning diligence in ensuring that insects arenot being exported with cones. Al indicated thatan 80°C treatment was being used to eradicatepests.

Seed testing was reviewed by Dale with respect tothe International Seed Testing Association (ISTA)rules. Emphasis was on using techniques that giveresults that are as repeatable as possible. Theinitial critical step is to obtain a random,representative sample of the seed lot. The sampleis used to determine moisture content(destructively), purity, 1000-seed weight, andgermination. Germination tests are conducted toestimate the proportion of seed that will producea normal seedling. Depending on species, seedsthat are dormant need to be treated, generally by aperiod of moist chilling, before being germinationtested. Viability tests are also useful to quicklyindicate if seeds are capable of germinating.

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Donna pointed out that the main functions of seedstorage are to: provide favourable conditions tominimize loss of seed quality, maintain correctidentity and location, and protect from harm and/orloss. The Alberta Public Lands and Forests Divisioncurrently has about 1 700 individual seed lots for atotal of 42 000 kg of seed in storage. Theunderground seed storage facility at the Alberta TreeImprovement and Seed Centre (ATISC) is maintainedat -18ºC and is monitored 24/7 for temperaturefluctuations, mechanical failure, power loss, andunauthorized entry. Seed lots are tested prior tostorage for moisture content, germination, 1000-seedweight, and purity. Ideally, seed lots should havemoisture contents between 4 and 8%. Seed is storedin heat-sealed, 5-mil plastic bags and placed in waxedcardboard boxes. Bags are labeled inside and out andreplaced every 10 years. Boxes are labeled on theoutside. Government seed lots are retested every 4 to5 years for germination and moisture content.

ATISC has a research seed germplasm conservationprogram, which is mainly comprised of single treecollections used for tree improvement research.There are 5 500 seed lots with the average lot sizebeing about 20 grams. The bulk of this seed is storedin a walk-in cooler in the ATISC technical building.Where amounts allow, duplicate storage ofirreplaceable lots is maintained in the undergroundstorage facility.

Seed pretreatments were reviewed by Dave in termsof the seed requirements for germination: adequatemoisture, alleviating dormancy, and at the nurserytemperature sums. If adequate moisture is notcontained in seeds, stratification will not be effectiveand germination will not occur. Species differ in theirmaximum and ‘optimal’ stratification moisturecontents. If surface drying is employed followingsoaking it is very important that only moisture on theseed coat is removed. This is to ensure seed flowsfreely (a seeder requirement), pathogen build-up islimited, and oxygen is readily accessible to theembryo. Another one of our lively discussionsfollowed regarding soak durations, surface drying,and the time it takes for moisture to reach theembryo. If in doubt, dissect some seeds (withoutdestroying the embryo) – do the embryos bend(imbibed) or break (dry)? Additional work is neededon tracking the uptake of moisture into seeds in termsof the actual route and the rate of uptake underoperational conditions. Stratification requirementscan vary greatly by species, individual seed lots, andeven families. More work is needed in quantifyingthis variability. Operators should understand thebenefits of stratification – not only in overcomingdormancy, but also in speeding up germination (anddecreasing the window for pests to attack thesucculent tissues of germinants), increasinguniformity and the vigour of the seed. Vigour is theability of the seed to germinate under sub-optimal

conditions.

Susan and Fernando covered nursery aspects.Inputs of concern to the nursery are seed qualityand quantity, seed cost, and seed condition(cleanliness, presence of insect/disease damage).Some nurseries also pretreat their sowing requestsand may employ seed cleaning (sink:floatseparations) during seed imbibition. The nurseryis concerned about and must consider: sowingequipment and performance monitoring, amountand type of grit, handling of seeded blocks, andtemperatures to use for germination. Susandiscussed the key performance indicators forCanadian Forest Products Ltd. including cavityfill, seed use efficiency, thinning labour costs, andsowing labour costs. Impressive gains (6% ingermination) were illustrated through the use ofstyrogrit versus convential grit material. Fernandodiscussed the “order’-based informa tionmanagement system (PREM IS) that is being usedat Pelton Reforestation Ltd.. This records pertinentseed information and is a tool used to increase theseed to seedling efficiency ratio.

George presented work on thermo-kinetics ofwater absorption. The three phases of waterabsorption and the impact of temperature on therate and maximum level of imbibition wereexplained. Results on Noble fir indicate thatalthough faster imbibition is accomplished withhigher water temperatures a greater maximummoisture content is achieved with lower watertemperatures. Differences between filled andempty seeds were discussed. For more details referto the original paper (Edwards, D.G.W . 1971. Thekinetics of water absorption in stratifying andnonstratifying noble fir (Abies procera Rehd.)seeds. Can. J. For. Res. 1:235–240).

The final speaker of the day was Conor O’Reillywho presented the paper indicated on the agenda.Two co-authors should also be recognized here –Norberta Atrip and Colin Doody. Conor traveledall the way from Ireland and I think it isappropriate to include the entire abstract here.

Alder (Alnus glutinosa (L.) Gaertn.), birch (Betulapubescens Ehrh.), and pedunculate oak (Quercusrobur L.) now form an important part of theplanting program in Ireland. However, seedgermination in the nursery bed is often low and/orslow. To this end, the effect of seed moisturecontent (MC) during pre-treatment on thegermination performance of these species wasinvestigated. Alder and birch have orthodox seedcharacteristics (easy to store provided M C <12% ),whereas oak is difficult to store successfully(relatively high MC levels must be maintainedduring storage). Seeds of each species wereadjusted to various MC levels and stored at 4°C

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for various periods. Acorns were also stored at -3 and1 °C. The optimum or target MC (TMC) duringprechilling was about 30% in alder and 35% in birch.Germination increased following up to 24 weeks ofprechilling for seeds at TMC levels in alder and 12weeks in birch, significantly better than achievedusing the standard method (fully imbibed for shorterperiods). Thereafter, germination remained almostunchanged for seeds that received up to 36 weeks ofprechilling, whereas the fully imbibed seedsdeteriorated or germinated prematurely. In oak,acorns adjusted to the highest MC level (46%) andstored for 4–6 months at -3°C had the highestgermination (76%) while the non-soaked controls andthose adjusted to 37% MC has the lowest values(17% for both treatments). Interestingly, the controlacorns had significantly lower germination than seedsthat were soaked and then dried back to similarlevels.

Thank you for everyone who participated. W e arecurrently looking at the East Coast for 2006 andTannis Beardmore and myself are hoping to co-ordinate a joint workshop with the IUFRO SeedPhysiology and Technology research group. It isnever too early to start putting the buzz in yourmanager,s ears for travel requests (.

I’ll leave you with my favourite little desktop saying:Data is not Information

Information is not KnowledgeKnowledge is not Wisdom

Dave Kolotelo

IS WESTERN LARCH A POOR SEEDPRODUCER IN NATURAL STANDS AND

SEED ORCHARDS?

Introduction

Western larch (Larix occidentalis Nutt.) is the largestof the North American larches and has limiteddistributions growing at moderate elevations in thedry interior of the Pacific Northwest. Its distributionextends from SE British Columbia (BC) southward inthe Cascade Mountains of Washington and Oregonand in the Inland Empire forest regions of NEWashington, Northern Idaho, Northwest Montana andin the NE corner of Oregon (Fowells 1965, Schmidtand Shearer 1995). It is considered to be a pioneerspecies that becomes established, before other moreshade tolerant species, in areas where there has beenfire, slides, volcanic activity, glaciation or other

disturbances. Most disturbances appear veryquickly whereas glaciation may take centuries, butall leave very similar and dramatic landscapes.

Glaciation has been part of the Pacific Northwestecology for the last 16 000 years with the lastglaciers about 12 000 years ago after which theareas became colonized by herb-dominatedspecies and sub-alpine forests. The presence ofsummer rains may have prevented fires andfavored Pseudotsuga, but not larch. However, wecannot be sure which species dominated becauserecent fossil evidence is based on pollen depositsand fossil Pseudotsuga and larch pollen are notdistinguishable (Owens and Simpson 1986,Whitlock 1995). Presently, western larch thrives inrelatively cool temperatures averaging 7°Cannually but ranging from 47°C to -37°C with afrost-free period of 60 to 160 days and an annualrainfall averaging 760 mm, only 20% of whichfalls during the active growing season (Schmidtand Shearer 1995).

Western larch is a seral rather than a climaxspecies because of its intolerance for shade. Itusually grows in mixed stands that includeDouglas-fir (Pseudotsuga menziesii), lodgepolepine (Pinus contorta), Interior spruce (Piceaglauca x engelmannii), sub-alpine fir (Abieslasiocarpa), and, on drier sites, ponderosa pine (P.ponderosa) (Fowells 1965, Schmidt and Shearer1995). Several studies in the past have suggestedthat western larch may be a poor seed producerbut this conclusion may have resulted from studiesbeing done on rather isolated individuals or thosegrowing in harsh environments (Owens andMolder 1979a). Other studies of trees in pottedseed orchards have also concluded that westernlarch, under those conditions, produces few filledseeds, often only 10 to 20 per cone (Owens et al.1994) and as low as 2 to 3 filled seeds per cone(Webber and Ross 1995). Similar low filled seedsper cone have been observed in potted orchards inwestern Oregon (Richard Snedzko USFS, CottageGrove, Oregon, pers.com.). The generalizationthat larch is a low seed producer also comes fromresearch on other species including L. laricina(tamarack), L. decidua (European), L. kaempferi(Japanese), and L. siberica (Siberian). In most ofthese studies the main factors believed to causeloss of filled seeds were the infrequency ofsuccessful pollination, low pollen fertility, andearly embryo abortion. In contrast, another reportindicated that western larch was one of the bestseed producers in the Mountain West (Schmidtand Shearer 1995).

Conflicting results, such as these, have causedconcern about establishing western larch seedorchards that may have unacceptably low filledseed production. In order to address these

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concerns, two studies were done in 2003, one in anestablished clonal soil-based seed orchard in theOkanagan Valley of BC and another in five naturalstands in the Inland Empire in the Northwestern U.S.The purposes of the studies were to compare conemorphology, determine the seed potential per cone,the filled and empty seeds per cone, and the possiblecauses of filled seed loss in clonal seed orchards andnatural stands of western larch.

Methods and Materials

W estern larch genetics research an d treeimprovement programs began in the United States inthe mid-1970’s and in BC in 1987. A western larchseed orchard was established near Lewiston, Idaho inthe mid-1970’s and another at the Kalamalka SeedOrchard (KSO) near Vernon, BC in 1987 (Jaquish etal. 1995). Both began to produce some seed conesafter about 6 years and are now coming into fullproduction. Both orchards are reasonably wellisolated from natural stands of western larch.

At the KSO in the late summer of 2003, five maturecones were sampled from each of 10 clones that wereopen pollinated by orchard pollen. Each cone wassealed in a coin envelope and the cones from eachclone were sealed in a paper bag. Most cones openedin the envelopes and seeds from that cone remainedin the envelope. Data were taken on conemorphology, including cone length, cone weight,total cone scales, sterile cone scales (those lackingany winged structures), fertile scales (those bearingwinged structures), and seed potential (fertile scalesx 2). After weighing each cone and its seeds, thenumbers of fertile scales and sterile scales werecounted and the seeds of various sizes were placed onthe sticky surface of strapping tape attached to asmall board. All but the smallest seeds were thensliced longitudinally with a double-edged razor blade(broken in half for safety) and the cut seeds wereobserved using a dissecting microscope. The numberof filled seeds, empty seeds, early-aborted seeds, late-aborted seeds, and insect or disease damaged seedswere counted and the seed efficiency was calculated(SEF, the number of filled seeds/seed potential).

In the late summer of 2003, at least five cones fromeach of five trees were collected from five differentnatural stands in the Inland Empire. Unfortunately,cone collections were done differently by those doingthe collections at the different sites. Consequently,the number of cones collected per tree varied and inmost cases all of the cones were placed in one bagresulting in a mix of seeds from many cones. This didnot allow careful analysis of seeds relating to aparticular cone nor statistical analysis as wasintended. All seeds from the cones of one tree wereplaced on the strapping tape, sliced, observed,counted and categorized in the same manner as those

from KSO.

The data for cone size and morphology andcategories of seeds from natural stands and KSOwere tabulated and the standard deviationdetermined.

Results

Cones from KSO averaged 3.5 cm (2.6–4.2 cm)and cone weight averaged 3.4 g (2.3–4.5 g). Totalscales averaged 69 (50–82), sterile scales 7(2–10), and fertile scales 67 (52–115). The seedpotential averaged 123 (103–148), filled seeds percone 55 (16–90), empty seeds 63 (29–104), early-aborted seeds 0.4 (0–1.8), late-aborted seeds 5(1–10), insect- and disease-damaged seeds 0.1(0–0.4), and rudimentary seeds 0.4 (0–1.8). TheSEF averaged 44% (15–70%), meaning that 44%of the ovules on the fertile scales weresuccessfully pollinated, fertilized and developedinto viable seeds (Table 1).

Cones from the five natural stands in the InlandEmpire averaged 3 cm (2.7–3.4 mm) and coneweight averaged 2.8 g (2–3.2 g), but this wasminus many of the seeds that had been shed intothe common bag. Total scales averaged 62(56–73), sterile scales 16 (9–25), and fertile scales46 (39–64). The seed potential averaged 90(69–127), filled seeds 38 (23–64), empty seeds 45(37–61), early-aborted seeds 3 (0.4–9), late-aborted seeds 6 (3–11), insect- and disease-damaged seeds 4 (1–10), and rudimentary seeds 3(0.4–8.8). The SEF was 42% (31–52%), meaningthat about 42% of ovules on the fertile scales weresuccessfully pollinated, fertilized, and developedinto viable seeds (Table 2).

Discussion

Two conclusions seem evident at a glance, andwithout elaborate statistics: firstly, western larchcan be a good seed producer in natural stands (38filled seeds per cone, 42% SEF) and secondly, itcan be a better seed producer (54 seeds per cone,44% SEF) when placed in a well managed soil-based seed orchard in a suitable dry environment.

For most members of the Pinaceae, 30 to 50 seedsper cone and a SEF of over 30% is average orbetter than average and is much better than speciesin most other conifer families (Owens 1991).However, in western larch, the number of conesper tree may fall short of other species in thePinaceae and certainly fall short of some in otherfamilies, such as the Cupressaceae. Thereproductive success of a tree is a combination ofthe number of filled seeds per cone times the

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Table 1. Cone and seed analysis of five cones from each of ten western larch clones at Kalamalka Seed Orchard in 2003

Clone Cone Cone Total Sterile Fertile Seed Filled Empty Rudi- Early Late Insect/ Total SEF

length weight scales scales scales potential seeds seeds mentory abortion abortion d isease seeds %

(cm) (g)

A 4.2 4.5 73 8 64 127 60 65 0 0 2 0 127 47

B 3.6 3.8 79 6 74 148 50 96 0.4 0.2 2 0.2 147 34

C 4.0 4.2 74 5 69 138 74 58 0.2 0.2 6 0 133 54

D 3.9 4.2 69 10 56 112 63 39 0.2 0 10 0.4 113 56

E 3.4 3.1 68 4 61 121 43 77 0.4 0.4 1 0 121 30

F 3.4 3.0 72 8 115 129 90 29 0 1.8 8 0.2 129 70

G 3.0 2.3 59 10 53 106 51 46 1.2 0.4 8 0 107 48

H 3.6 3.3 73 2 71 141 34 104 1.8 0 3 0 143 24

I 2.7 2.2 64 10 53 106 16 88 0 1.2 1 0 106 15

J 3.5 3.2 62 9 52 103 62 31 0 0 10 0.2 103 60

Avg. 3.53 3.38 69.3 7.2 66.8 123 .1 54.3 63.3 0.42 0.42 5.1 0.1 122 .9 43.8

SE 0.38 0.68 6.01 2.81 18.7 16.03 20.63 27.2 0.59 0.59 3.53 0.137 15.49 17.4

Table 2. Cone and seed analysis of 29 trees from five Western Larch sites in the Inland Empire in 2003.

Site No. No. Cone Cone Total Sterile Fertile Seed Filled Empty Rudi- Early Late Insect/ Total SEF

trees cones length weight scales scales scales potential seeds seeds mentory abort. abort. disease seed %

(cm) (g)

PC 5 50 3.0 2.6 62 12 50 99 47 43 2.1 2.0 6 3.0 103 52

IEPC 5 50 3.4 3.1 73 9 64 127 64 61 8.8 9.0 11 10.0 164 51

Goos 5 25 2.8 2.0 60 25 35 69 25 37 0.4 0.4 5 1.4 69 32

BCC 9 47 2.7 3.2 56 14 42 76 31 39 1.7 2.0 3 1.0 78 42

HE 5 70 3.1 3.0 59 20 39 77 23 43 2.0 2.0 4 5.0 79 31

Total 29 242

Avg. 3.0 2.78 62 16 46 89.6 38 44.6 3.0 3.08 5.8 4.08 99 42

SD 2.74 0.49 6.52 6.44 11.47 23.74 17.3 9.53 3.31 3.38 3.11 3.67 38.7 10

PC, Plum Creek, Montana; IEPC, Idaho; Goos, Goosman, W ashington; BCC, Idaho; HE, High Elevation, Washington

number of cones per tree (Owens 1991). Fewercones per tree in larch results from the coneposition and method of cone initiation – theynormally occur on dwarf or short shoots that areone or more years old, thus limited by previousvegetative growth (Owens and Molder 1979 a, b).This differs from many other conifers in whichmost cones develop from newly initiated axillaryapices (Owens and Blake 1985). We may enhancecone production in seed orchards and sometimesin seed-production areas in young natural standsby using cultural treatments and application ofplant growth regulators (Bonnet-Masembert 1982,Ross 1991, Philipson 1996). Cones are also lostduring development due to frost, insects, disease,and other less obvious reasons. These factors canusually be managed in seed orchards.

Cone morphology is important in seed production.In natural stands and seed orchards, larger conestend to have more scales, more fertile scales, andfewer sterile scales resulting in a higher seedpotential. This commonly results in more filledseed per cone, although not necessarily a greaterSEF. Therefore, simply collecting larger conesmay result in collecting more filled seed. Sincecone size was a clonal trait in this study, there maybe some gain in seed production by selecting seedorchard clones having larger cones. The number offertile scales averaged about 67 and was over 50for all 10 seed orchard clones but averaged only46 in natural stands. Larger cones that bear morefertile scales may partly result from better culturaltreatments in seed orchards. This increased theseed potential in seed orchard clones (123compared to 90 in natural stands) and was

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probably the most important factor in increasingfilled seeds in seed orchard trees.

The increase in fertile scales was partly due to anincrease in total cone scales but also due to adecrease in number of sterile scales. Ovuleinitiation and early development occur in the latesummer and fall before pollination (Owens andMolder 1979 c) and physiological o renvironmental conditions acting at that time maypromote more ovule initiation and more pre-dormancy ovule development producing morefertile ovules per cone at pollination.

The causes for seed losses are varied and dependon the species, its reproductive biology, and thesite in which the trees are grown. Like most othergenera in the Pinaceae, western larch has a one-year reproductive cycle (actually about 17 monthsfrom cone initiation until seed maturity) in whichpollination, and cone and seed maturity occurwithin 5 to 6 months – from about April untilSeptember (Owens 1995). During this short time,fertile ovules within a cone may be pollinated,fertilized and develop into filled, viable seed orform a variety of non-viable seeds. Some of thecauses for the loss of filled seeds have beendetermined for western larch (Owens et al. 1994)and were used in this study to estimate the relativeimportance of different causes in reducing filledseed production.

A filled seed is a fully developed and roundedseed with a well-developed seed coat. When slicedthe seed contains a yellow embryo that fills about80% of the shiny white megagametophyte. Theseare likely viable seeds (Kolotelo 1979).

Empty seeds are very common and may result inthe loss of about half of the seeds in natural stands(50% of seed potential) and in seed orchard (51%of seed potential). Empty seeds appear the same asfilled seeds externally but when sliced, emptyseeds contain only a collapsed brown sac, which isthe aborted megagametophyte. Empty seeds inlarch may result from two different causes: 1)Ovules that were not pollinated develop normallyuntil the time of fertilization. At fertilization boththe seed coat and megagametophyte are welldeveloped and the megagametophyte has a veryhigh water content. This development occurswhether the ovule was or was not pollinated. Inlarch (Owens et al. 1994) and Douglas-fir (Orr-Ewing 1957) pollinated and non-pollinated ovulesdevelop normally until about the time offertilization then non-pollinated ovules that aretherefore not fe rtilized abo rt and themegagametophyte dehydrates leaving only thecollapsed sac, which is the fibrous megasporemembrane (Owens et al. 1994). In contrast, themegagmetophyte in a fertilized ovule converts its

watery contents mostly into storage proteins andlipids that fill the megagametophyte cells enclosedby the megaspore membrane and the embryodevelops within the megagametophyte (Owens etal. 1994). 2) A second cause of empty seeds is thatmost megagametophytes, in which the eggs areself-pollinated, abort about the time of fertilizationand result in empty seeds that appear the same asthose that were not pollinated (Orr-Ewing 1957,Hagman and Mikkola 1963, Mergen et al. 1965,Owens et al. 2004).

Wings may develop on scales without a visibleovule attached. These may have had tiny ovulesbut they aborted before or about the time ofpollination. Other wings may bear small ovulesthat aborted at later stages. Rudimentary seeds areovules that aborted soon after the time ofpollination and remained as a very small abortedovule (“seed”) attached to a well-developed seedwing. Early ovule abortion results in small “seeds”with a thin, partially developed seed coat attachedto a well-developed seed wing. The abovestructures form a gradient from undevelopedovules to partially developed “seeds” for whichthere may be different causes, such as frostdamage at pollination or early pre-fertilizationself-incompatibility (Owens et al. 1994). W e knowvery little about the latter in larch but it appears tooccur in other conifers.

Late abortion occurs during embryo developmentand may result in seeds with poorly developedembryos and shrunken megagametophytes. Theseare thought to result form late acting self-incompatibility (self-inviability) and the seeds areusually not viable. All of these causes result insmall amounts of potentially filled seeds being lostduring development, in total usually only 5 to 10%of seeds. In seed orchards, these losses may bereduced by increasing cross-pollination throughsupplemental pollinations, reducing the risk offrost damage by sprinkling with water, andmaintaining good soils and nutrition of trees.

Cone and seed insects and diseases are not welldocumented for larch (Hedlin et al. 1980,Sutherland et al. 1987). Damage was slight atKSO but accounted for about 4% of filled seedloss in the natural stands. It varied considerablyamong stands and this was more than the tabulateddata show since in some stands some cones couldnot be analyzed because they were nearlydestroyed by insects feeding on cones and seeds.In seed orchards losses may be reduced throughspraying of insecticides as was done at KSO.However, in seed orchards insect pests anddiseases, that we do not yet associate with larch,may appear and spread from other species in theorchard, especially those having very similar seedcones and reproductive biology, such as Douglas-

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fir.

Sum mary

Western larch cones, although small, have manyscales and a high proportion of fertile scales thusa high filled seed potential (over 120 seeds percone). The filled seeds per cone and SEF are quitehigh in both natural stands and the clonal seedorchard compared to many other genera within thePinaceae. The high number of filled seeds percone may be increased in seed orchards overnatural stands by about 40% as a result of goodorchard management. Empty seeds are the maincause for loss of filled seeds in western larch andthey may result from the lack of successfulpollination by fertile pollen or self-pollination,both of which result in megagametophyte abortionabout the time of fertilization. The empty seedsresulting from both causes look the sameexternally and internally. These causes may bereduced in seed orchards by supplementalpollinations using a polymix of highly fertilepollen. With the high potential for filled seedproduction in conventional soil-based seedorchards, it is hard to recommend potted orchardsfor western larch, as the latter have had a shorthistory of low filled seed production with nodefinitive known causes.

Literature Cited

Bonnet-Masembert, M. 1982. Effect of growthregulators, girdling, and mulching onflowering of young European and Japaneselarches under field conditions. Can. J. For.Res. 12: 270–279.

Fowells, H. J. 1965. Silvics of forest trees of theUnited States. USDA For. Serv., Agric.Hndbk. No. 271, 762 p.

Hagman, M.; Mikkola, L. 1963. Observations oncross-, self- and interspecific pollinations inPinus peuce Griseb. Silvae Genet. 12:73–76.

Hedlin, A.F.; Yates III, H.O.; Tover, D.C.; Ebel,B.H.; Koerber, T.W.; Merkel, E.P. 1980.Cone and seed insects of North Americanconifers. Can. For. Serv., USDA For. Serv.,Secretaría de Agricultura y RecursosHidráulicos, Mexico.

Jaquish, B.; Howe, G.; Fins, L.; Rust, M. 1995.Western larch tree improvement programsin the Inland Empire and British Columbia.Pages 420–460. in W.C. Schmidt and K.J.M c D o n a l d , c o m p s . E c o lo g y a ndmanagement of Larix forests: A lookahead. USDA For. Serv., Intermountain

Res. Stat., Gen. Tech. Rep. GTR-Int-319.

Koletelo, D. 1997. Anatomy and morphology ofconifer tree seed. BC Min. For., NurseryTech. Series. 1.1, Victoria, BC, 62 p.

Mergen, F.; Burley, J.; Furnival, G.M. 1965.Embryo and seedling development in Piceaglauca (Moench) Voss after self- and wind-pollination. Silvae Genet. 14:188–194.

Orr-Ewing, A.L. 1957. A cytological study of theeffects of self-pollination on Pseudotsugamenziesii (Mirb) Franco. Silvae Genet.6:179–185.

Owens, J.N. 1991. Flowering and seed set. Pages247–271. in A.S. Raghavendra, ed.Physiology of Trees. John Wiley, Inc. NY.

Owens, J.N. 1995. Reproductive biology of larch.Pages 97–109. in W.C. Schmidt and K.J.M c D on a l d , c o m p s . E c o l o g y a ndmanagement of Larix forests: A lookahead. USDA For. Serv., IntermountainRes. Stat., Gen. Tech. Rep. GTR-Int-319.

Owens, J.N.; Blake, M.D. 1985. Forest tree seedproduction. A review of literature andrecommendations for the future. Can. For.Serv., Info. Rep. PI-X-53, 161 p.

Owens, J.N.; Molder, M. 1979a. Bud developmentin Larix occidentalis. I. Growth anddevelopment of vegetative long-shoot andvegetative short-shoot buds. Can. J. Bot.57:687–700.

Owens, J.N.; Molder, M. 1979b. Buddevelopment in Larix occidentalis. II. Conedifferentiation and early development. Can.J. Bot. 57:1557–1572.

Owens, J.N.; Molder, M. 1979c. Sexualreproduction of Larix occidentalis. Can. J.Bot. 57:2673–2690.

Owens, J.N.; Simpson, S.J. 1986. Pollen ofconifers native to British Columbia. Can. J.For. Res. 16:955–967.

Owens, J.N.; Morris, S.J.; Catalano, G.L. 1994.How the pollination mechanism andprezygotic and postzygotic events affectseed production in Larix occidentalis. Can.J. For. Res. 24:917–927.

Owens, J.N.; Bennett, J.; L’Hirondelle, S. 2004.Pollination and cone morphology affectcone and seed production in lodgepole pineseed orchards. Can. J. For. Res. (in press)

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Philipson, J.J. 1996. Effects of girdling andgibberellin A4/7 on flowering of Europeanand Japanese larch grafts in an outdoorclone bank. Can. J. For. Res. 26: 355–359.

Ross, S.D. 1991. Promotion of flowering inWestern Larch by girdling and gibberellinA4/7 and recommendations for selectionand treatment of seed trees. BC Min. For.,Res. Note No. 105, Victoria, BC, 13 p.

Schmidt, W.C.; Shearer, R.C. 1995. Larixoccidentalis: A pioneer of the NorthAmerican West. Pages 33–37. in W.C.Schmidt and K.J. McDonald, comps.Ecology and management of Larix forests:A look ahead. USDA For. Serv.,Intermountain Res. Stat., Gen. Tech. Rep.GTR-Int-319.

Sutherland, J.R.; Miller, T.; Quinard, R.S., eds.1987. Cone and seed diseases of NorthAmerican conifers. North Amer. For.Comm., Pub. No. 1., Victoria, BC, 77 p.

Webber, J.E.; Ross, S.D. 1995. Flower inductionand pollen viability for western larch. Pages395–402. in W.C. Schmidt and K.J.M c D o n a l d , c om p s . E c o l o g y an dmanagement of Larix forests: A look ahead.USDA For. Serv., Intermountain Res. Stat.,Gen. Tech. Rep. GTR-Int-319.

Whitlock, C. 1995. The history of Larixoccidentalis during the last 20,000 years ofenvironmental change. Pages 83–90. inW.C. Schmidt and K.J. McDonald, comps.Ecology and management of Larix forests:A look ahead. USDA For. Serv.,Intermountain Res. Stat., Gen. Tech. Rep.GTR-Int-319.

John N. Owens and Thanong Kittirat69/35 Sukhumvit Rd.Dtumbon Na JomteinAmphur SattahipChonburi 20250, ThailandE-m ail: jowens@ptty2.loxinfo.co.th

SEED PRODUCTION IN 2004 FROM J.D.IRVING, LIMITED’S PARKINDALE SEED

ORCHARD

This has been our best year for seed production at

the Parkindale Seed Orchard. The followingquantities of cones were collected with theapproximate expected seed yield: second-generation black spruce – 95 hL / 23 million seed,first-generation white spruce – 185 hL / 40 millionseed (we only picked 40% of the cones), first-generation Norway spruce – 126 hL / 15 millionseed, and first-generation white pine – 14 hL / 750000 seed which was picked from ramets that areless than 5 years old.

This was the first year to use lift equipment tocollect Norway spruce cones. Ladders were nottall enough to reach the top of these trees. All ofthe older first-generation blocks will require liftequipment within the next few years. The rametsare 10+ m tall as we do not top the trees.

We began extracting the seed from these cones inlate October and should be done by the end ofJanuary 2005. We will also do some customcleaning (210 hL), for the P.E.I. ProvincialGovernment and Nexfor Fraser Papers. Theextracting and cleaning process will keep 2 hourlyemployees busy until the end of March 2005.

On the nursery side, we struck 2 million Norwayand white spruce cuttings this year. These camefrom potted hedges, grown from crosses made inthe top 20% of our first- generation white spruceclones and weevil resistant Norway spruce. Wealso transplanted over 100 000 somatic embryosthis year. Emblings could replace most of therooted cutting production within the next fewyears.

Hart KunzeJ.D. Irving, LimitedSussex Tree Nursery181 Aiton RoadSussex, NB E4G 2V5E-m ail: Kunze.Hartmut@jdirving.com

NON-SPECIFIC POLLINATIONMECHANISMS MAY CREATE

OBSTACLES FOR PROPER SEEDING INJUNIPERUS

Angiosperms have a specialized receptive area forpollen receptivity because pollen does not havedirect access to the ovules. In contrast,gymnosperm ovules are exposed to theenvironment and pollen lands on the micropylewhere it is drawn in to the ovule by the micropylardrop as it is reabsorbed. The micropylar fluid is a

20

dilute sugar solution with the presence of proteins.The composition of the micropylar fluid has beenanalysed only in a limited number of species.

Under natural conditions, pollen from variousspecies as well as insect eggs and abiotic material(dust, etc.) may land on the micropylar drop. Theeffect of particles of different sizes on thepollination mechanism of Juniperus oxycedrusssp. oxycedrus was investigated within a researchproject funded by APAT (Italian EnvironmentalProtection Agency). The study dealt with thereproductive efficiency of three Juniperus speciesgrowing in the Mediterranean environment ofItaly.

Branches with mature female cones were cut andplaced in vases of water and kept at roomtemperature. When micropylar drops appeared onthe cones, pollination trials were conducted with:1) viable pollen of the same species, 2) non-viablepollen of the same species killed by exposure to120°C for 1 hour, and 3) silica gel dust of differentsizes (10–15, 40–63, and 63–200 µm).

The diameter of the micropylar drops (assumed tobe spherical) was measured under a stereomicroscope before and at different times afterpollination and volumes were calculated. Thedeposition of pollen as well as any kind ofpowdery material lead to a decrease in size of thepollination drop. Variation in diameter is to beinterpreted as partial or total reabsorption and thusthe ‘recognition’ of pollen by the micropylar drop.Unpollinated micropylar drops usually persist inthe branches kept in the laboratory for 12 dayswith few changes in volume due to temperatureand other environmental factors.

Results indicated a non-significant variation inunpollinated drops, while a significant decrease involume was observed when viable pollen, non-viable pollen, silica gel 10-15 µm, and silica gel40-63 µm were applied on the micropylar drops.In the case of viable and non-viable pollen, thevolume of the micropylar drop decreased to 0(total reabsorption) while there was only a partialreabsorption in the case of silica gel.

These studies reveal that the pollinationmechanism in Juniperus oxycedrus ssp. oxycedrusis highly non-specific. The micropylar drop isreabsorbed into the ovule even in response to non-viable pollen and inorganic particles of similarsize to Juniperus pollen. Since deposition of non-viable pollen induced total reabsorption of themicropylar drop, it led to a decrease in the lengthof the period of female receptivity. In fact, thepollination drop is normally secreted again thenext day. Silica gel particles caused partialreabsorption of the drop, thus decreasing the

probability of pollen capture. The combination ofthese two effects may explain the poor viable seedproduction observed in different populations ofjunipers.

This lack of specific capacity to recognize its ownpollen is a detriment to the pollination process ofJuniperus, especially if the plants are exposed tosources of particulate matter, dust, etc. Theecological implications are more evident if weconsider that many airborne inorganic particlesarise from human activities such as vehiclestraffic, industry and crushing or grindingoperations. Knowledge of the existence of thisobstacle can, however, be helpful to overcome theproblem itself.

S. Mugnaini, M. Nepi , E. PaciniDipartimento Scienze Ambientali G. SarfattiUniversità di SienaVia Mattioli 453100 Siena, Italy

B. PiottoAgenzia per la Protezione dell’Ambiente e serviziTecnici (APAT)Dipartimento Difesa della NaturaVia Curtatone 300185 Rome, ItalyE-m ail: piotto@apat.it

IUFRO SEED PHYSIOLOGY ANDTECHNOLOGY RESEARCH GROUP

MEETING

The IUFRO (International Union of ForestResearch Organizations) Seed Physiology andTechnology Research Group (2.09.00) meetingwas held the 19 to 24 September at NanjingForestry University, Nanjing, Peoples Republic ofChina. The Nanjing Forestry University and theSouthern Tree Seed Inspection Center, StateForestry Administration hosted this meeting. TheNanjing Forestry University is a rapidly growinginstitution with interests in both seed technologyand research.

The meeting was divided into two components;one where general presentations were made andthe other consisted of field trips. The researchpresented was broad covering genetics,physiology, biochemistry, ecology, morphology,and innovative seed dissemination andgermination technologies. The proceeding werepublished and a few copies are still available upon

21

request to Dr Yu Fangyuan (fyyu@njfu.edu.cn).The field trips took us through the areasurrounding Nanjing. We visited ancient burialtombs, shrines, temples, and monuments to SunYet Sen.

The next IUFRO Seed Physiology andTechnology Research Group will be held inconjunction with the 2006 CTIA meeting.

Tannis Beardm oreNatural Resources CanadaCanadian Forest ServiceP.O. Box 4000Fredericton, NB E3B 5P7E-m ail: tbeardmo@nrcan.gc.ca

NATIONAL TREE SEED CENTRE

Seed Centre staff have been involved in a numberof activities and projects over the past year. Alarge investigatory experiment was initiated thefall of 2003 to evaluate various combinations anddurations of warm and cold to promote growth ofthe immature embryo and alleviate dormancy ofblack ash (Fraxinus nigra) seed. One series hadvarying durations of warm followed by cold and asecond series had varying durations of threetemperature treatments; cold followed by warmfollowed by cold. The experiment also examinedthe use of peat and kimpak to evaluate theirimpact as stratification media and ability to limitgrowth of mold on the seed. Data have beencollected and await analyses. Another experimentfocused on sugar maple (Acer saccharum) toevaluate the impact of seed source on germinationof seed subjected to several soaking times, chillingdurations, and germination temperatures. Part oneof this experiment was conducted in 2003 usingseed collected the fall of 2002 and Part two usedthe same seed lots after the seed had been instorage at -20°C for 12 months to evaluate theimpact storage may have on alleviating dormancy.The data have been collected and await analyses.

This was a good seed production year and themonths of September and October were busilyspent making collections. Collections are nowfocused on obtaining seed from at least 15 wellspaced individual trees in a population. These typeof collections are more useful for researchers andtake into account tree to tree variation in seedyield and quality. Over 500 collections were madewhich is a huge effort considering the smallnumber of staff. The winter months will be more

challenging in order to process and test all thismaterial in a timely fashion. A number ofcollections were made in cooperation with severalresearch projects. Species involved were: chokecherry (Punus virginiana var. virginiana), pincherry (P. pensylvanica), mountain maple (A.spicatum), striped maple (A. pensylvanicum),white spruce (Picea glauca), black ash, red ash (F. pensylvanica), and white ash (F. americana).

Elongation of Black Ash Embryos

Although black ash embryos are morphologicallycomplete at the time of seed dispersal, seeds willnot germinate at this time because the embryo isboth immature and dormant. The embryo mustdouble in length prior to germination. A numberof treatments were evaluated, for a seniorundergraduate forestry thesis, to determine whichwas most effective in promoting embryoelongation.

Two seed lots were used to evaluate the impact ofthree treatments: 1) presence or absence of thepericarp, 2) duration of incubation, and 3)incubation temperature. The pericarp was removedfrom one-half of the seeds. Seeds were soaked for24 hours prior to incubation for 2, 4, 6, 8, 10, 12,and 15 weeks under constant temperatures of 15°Cand 20°C in Conviron germination cabinets.

Of the three treatments, pericarp removal had asignificant impact on embryo elongation.Incubation for 12 weeks was sufficient forpromoting maximum embryo elongation for seedswith no pericarp while 15 weeks was insufficientfor seeds with the pericarp intact. Embryoelongation at 15°C was generally greater for bothpericarp treatments. A longer period of time wasrequired for maximum embryo elongation at 20°C.The overall results showed that removing thepericarp and incubating the seeds for 12 weeks at15°C produced an average embryo length of 16mm. Leaving the pericarp intact and incubatingthe seeds for 15 weeks at both temperaturesproduced an average embryo length of 12–13 mm(Horsman 2004).

Horsman, G. 2004. Development of immatureblack ash embryos under two temperatures.Un publ. BScF thesis, Univ. NewBrunswick, 25 p.

Dale Sim pson and Bernard DaigleNatural Resources CanadaCanadian Forest ServiceAtlantic Forestry Centre

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P.O. Box 4000Fredericton, NB E3B 5P7E-m ail: Dale.Simpson@nrcan.gc.ca

WOODY PLANT SEED MANUAL

A number of years ago Frank Bonner, formerly ofthe USDA in Starkville, Mississippi, undertookthe task to completely update “Seeds of woodyplants in the United States” published in 1974.Well it has been a monumental piece of work asyou can imagine. In the interim, until the newmanual is published, completed genera have beenmade available on the web. The most reliable siteto use in order to download these is from theNational Tree Seed Laboratory’s web sitehttp://www.ntsl.fs.fed.us/ . Follow the link fromthe main page.

Frank informed me that the manual has beencompleted and is currently in layout. He expectsthe galleys to be proofed soon and the book to bepublished in 2005. This should prove to be apopular publication and I expect all of you willwant to purchase a copy for your bookshelf. Iknow I can hardly wait!

Dale Simpson

UPCOMING MEETINGS

ISTA Ordinary Meeting 2005April 25-28, 2005 Bangkok, ThailandContact: www.seedtest.org

8th International Workshop on Seeds“Germinating New Ideas”May 8-13, 2005 Brisbane, AustraliaContact: info@seedbio2005.asn.au

AOSA/SCST Annual MeetingJune 15-22, 2005 Saskatoon, Saskatchewan Contact: aosaoffice@earthlink.net

SELECTED REFERENCES

A few papers that are somewhat thoughtprovoking as we consider our greatest problemsand needs. Certainly not an exhaustive list, so ifyou have a personal favourite forward it to Daveor Dale.

Burley, J. 2004. The restoration of research. For.Ecol. Manage. 201:83–88.

Colombo, S.J.; Parker, W.C. 1999. Does Canadianforestry need physiology research? For.Chron. 75:667–674.

Cote, M.-A.; Kneeshaw, D.; Bouthillier, L.;Messier, C. 2001. Increasing partnershipsbetween scientists and forest managers:Lessons from an ongoing interdisciplinaryproject in Quebec. For. Chron. 77:85–89.

Dumroese, K.; Wenny, D.L. 2003. Installing apractical research project and interpretingresults. Tree Plant. Notes 50:18–22.

Edwards, D.G.W. (compiler) 2000. Forest treeseeds at the end of the 20 th century: Majoraccomplishments and needs. A state of theknowledge report on forest tree seeds.IUFRO Unit 2.09.00 Seed physiology andtechnology. 9 p.[Please note the location of this document haschanged since being announced in NewsB u l l e t i n # 3 1 . T h e n e w l i n k i s :http://www.iufro.org/iufro/iufronet/d2/wu20900/skr20900.htm]

Hahn, G.J. 2002. Deming and the proactivestatistician. Am. Stat. 56:290–298.

Moller, P.M.; Jennions, M.D. 2001. Testing andadjusting for publication bias. Trends Ecol.Evol. 16:580–586.

Nilsson, G.; Luckert, M.K.; Armstrong, G.W.;Hauer, G.K.; Messmer, M.J. 2004.Approaches to setting research priorities:Considering the benefits of reducinguncertainty. For. Chron. 80:384–390.

Sprague, L.G.; Sprague, C.R. 1976. ManagementScience? Interfaces 7:57–62.

Warren, W.G. 1986. On the presentation ofstatistical analysis: Reason or ritual. Can. J.For. Res. 16:1185–1191.

Wolff, M.F. 1986. Motivating research scientiststo reach for the eagles. Res. Manage.29:8–10.

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RECENT PUBLICATIONS

Ahtikoski, A.; Pulkkinen, P. 2003. Cost-benefitanalysis of using orchard or stand seed inScots pine sowing, the case of northernFinland. New For. 26:247–262.

Burczyk, J.; Lewandowski, A.; Chalupka, W.2004. Local pollen dispersal and distantgene flow in Norway spruce (Picea abies(L.) K arst .) . For. Ecol . Manage .197(1-3):39–48.

Chandler, L.M.; Owens, J.N. 2004. Thepollination mechanism of Abies amabilis.Can. J. For. Res. 34:1071–1080.

Connor, K. 2004. Update on oak seed qualityresearch: Hardwood recalcitrant seeds.Pages 111–116. in USDA For. Ser., Proc.RMRS-P-33.

Daws, M.I.; Gamene, C.S.; Glidewel, S.M.;Pritchard, H.W. 2004. Seed mass variationpotentially masks a single critical watercontent in recalcitrant seeds. Seed Sci. Res.14:185–195.

Granger, A.R. 2004. Gene flow in cherryorchards. Theor. Appl. Gen. 108:497–500.

Gomez-Casero, M.T.; Hidalgo, P.J.; Garcia-Mozo,H.; Dominguez, E.; Galan, C. 2004. Pollenbiology in four Mediterranean Quercusspecies. Grana 43(1):22–30.

Gonzalez-Ochoa, A.I.; Lopez-Serrano, F.R.; de lasHeras, J. 2004. Does post-fire forestmanagement increase tree growth and coneproduction in Pinus halepensis? For. Ecol.Manage. 188(1-3):235–247.

Krannitz, P.G.; Duralia, T.E. 2004. Cone and seedproduction in Pinus ponderosa: A review.West. N. Amer. Nat. 64(2):208–218.

Krouchi, F.; Derridj, A.; Lefevre, F. 2004. Yearand tree effect on reproductive organisationof Cedrus atlantica in a natural forest.For. Ecol. Manage. 197(1-3):81–189.

Mente, R.F.; Brack-Hanes, S.D. 2004.Developmental patterns and growth curvesfor ovulate and seed cones of Pinus clausa(Chapm. ex Engelm.) Vasey ex sargo. andPinus ellioitii, Engelm. (Pinaceae). FloridaScientist 67(1):36–42.

Nel, A.; van Staden, J. 2003. Micro-fibrepollination bags and high viability Pinuspatula pollen enhance cone survival and

seed set during controlled pollination. SouthAfrican J. Bot. 69:469–475.

Pakkad, G.; Elliott, S.; Blakesley, D. 2004.Selection of Prunus cerasoides D. Don seedtrees for forest restoration. New For.28:1–9.

Radeloff, V.C.; Mladenoff, D.J.; Guries, R.P.;Boyce, M.S. 2004. Spatial patterns of coneserotiny in Pinus banksiana in relation tofire disturbance. For. Ecol. Manage.189(1-3):133–141.

Raimondi, N.; Kermode, A.R. 2004. Seedlinggrowth and establishment in natural standso f y e l l o w - c e d a r ( C h a m a e c y p a r i snootkatensis) seedlings derived from the useof modified seed dormancy-breakingtreatments. New For. 27:55–67.

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