institute for crop science and plant breeding
TRANSCRIPT
Bavarian State Research Center for Agriculture
Institute for Crop Science and Plant Breeding
50%
60%
70%
80%
90%
100%
combination
I
combination
IIa
combination
I
combination
IIb
location PU location AES
Cross-pollination rates
90.0%n=107
79.6%n=104
94.3%n=88
90.7%n=43
vertical line = standard deviation
Cross-pollination rates
90.0%n=107
79.6%n=104
94.3%n=88
90.7%n=43
vertical line = standard deviation
R² = 0,9176
1
2
3
4
5
6
7
8
9
1 2 3 4 5
Vitality during germination and seedling cultivation
(scoring marks, 1 = very weak to 9 = very strong)
R² = 0.918
I1-lines
2012
I2-lines
2013
I3-lines
2014
I4-lines
2015/16
vertical line = standard deviation; n = 8
(highly) inbred parents
open pollination
Seeds produced by cross-pollination
plant population in the field
seed fraction F1 > inbred
lower vitality, reduced growth
inbred descendant
F1-
In
breed
Michael Penzkofer, Stefan Seefelder, Heidi Heuberger
What is the percentage of cross-pollinated seeds respectively inbred seeds in cross-pollinated populations? Is an inbreeding depression identifiable for inbred lines, that is, do inbred plants exhibit lower vitality?
A
B
A
B
A B
Contact:
Bavarian State Research Center for Agriculture (LfL),
Institute for Crop Science and Plant Breeding
(IPZ3d), Vöttinger Str. 38, 85354 Freising,
[email protected], www.LfL.bayern.de.
• Selected va ler i an p l an ts (e l i tes) w ere propagated in -v i t ro (c loning ) .
• Homozy gous ly present DNA - based marker bands ( AFLP) w ere examined in the f i rst inbred generat ion ( I 1) .
• Si x e l i tes w ere ident i f ied that d i f fer in at least one h omozyg ous ba nd an d w ere used in three pa i r combinat ions ( I - I Ia / I Ib) .
• The mat ing c lones w ere p lant ed together in a poly - cross - system at two locat ions (PU - AES) .
• The seeds w ere taken separate ly f rom each p l ant an d e leven descendants f rom each p lant w ere analyzed .
• In seve ra l s teps , inbred l ines w ith d i f ferent leve ls of inbreeding ( I 1 t o I 4) w ere generated .
• A t each leve l of inbreeding a performance test w as carr ied out in the f ie ld , eva lu at ing the character ist ics e . g . v i ta l i ty dur ing germinat ion an d seedl ing cu lt ivat ion, crop coverage and v i ta l i ty in f ie ld , as w el l as rootstock w eight .
B
A
References: BECKER, B., 2011: Pflanzenzüchtung. Eugen Ulmer, Stuttgart BERNÁTH, J., 1997: Cultivation of Valerian. In HOUGHTON, P. H. (ed.), Valerian The Genus Valeriana, harwood academic publishers, United Kingdom, 77-100 HEEGER, E. F., 1956: Handbuch des Arznei- und Gewürzpflanzenbaues. Deutscher Bauernverlag, Berlin.
The observed high cross-pollination rates show the preference for cross-pollination, however autogamy is possible. (Similar reported in HEEGER, 1956 and BERNÁTH, 1997).
Thus, the first and important condition for a hybrid variety from open pollination, without male-sterility system would be met.
The detected inbreeding depression in inbred lines means that possibly formed inbred descendants will 'disappear' in field, saying that they will take a small fraction in the harvested material.
Hybrid-breeding can only be exploited fully, if inbred lines are used (BECKER, 2011). Therefore, another inbred step in the F1 hybrid seed production will probably create plants with a much higher inbreeding depression.
Basically the validity applies only for the tested clone combinations. Most likely, other clones or lines will behave similarly; however, in the end, the cross pollination rate of the developed hybrid variety must be determined.