great plains wheat virus survey mary burrows extension plant pathology specialist montana state...
TRANSCRIPT
Great Plains Wheat Virus Survey
Mary BurrowsExtension Plant Pathology Specialist
Montana State University, Bozeman, MT
Overview
• How we got into this• Data from 2008 & 2009• Outcomes• DD maps• Future of survey
Wheat viruses were bad in our state this year
Ours too!
Ours too!
(me) Hmm…this may be an opportunity to do some virology
(Jim Stack) Hmm…this may be an opportunity to show how the GPDN network can collaborate
2006 NPDN meeting, GPDN state reports
Increase in regional virus incidence?
Vector
Host
Pathogen Environment( New York Times)
Process• The diagnosticians were interested to find out
what viruses were in their states (TriMV had just been identified in KS)
• Jim Stack volunteered to pay for the kits• Agdia put together kits for WSMV, TriMV, HPV,
BYDV-PAV and CYDV-RPV• 2008-2010: processing samples that come into
the clinic as part of routine diagnostics and surveys (depending on the state)
• 2010: DD mapping
Survey Protocol• Symptomatic or asymptomatic wheat samples
coming into the diagnostic labs• Symptomatic winter wheat fields
– State-wide wheat disease surveys– Other samples as part of regular extension activities by
specialists• Samples processed via ELISA by the state lab or
sent to MT• Samples were saved for further research activities
(Charlie Rush, TX; Jacque Fletcher, OK; Steve Wegulo/Roy French, NE)
Data from each wheat sample• Presence/absence and type of virus (ELISA) • Symptom severity and incidence (visual
scale) • Date of sampling • Growth stage of plant • Geographical location (GPS if available)• Entered into PDIS as well as an Excel
spreadsheet for ease of analyzing data
What will we learn from a wheat virus survey?
• What the most prevalent viruses are in wheat• Where wheat viruses are distributed• Whether TriMV is present outside of KS (the
answer is yes)• Impressions of:
– Timing of infection– Incidence– Single or co-infections, relation to symptomatology– Affect of viruses on yield– Cropping system/management effects on wheat
viruses– Variety resistance/tolerance
2008 n WSMV WMoV TriMVColorado 51 61 10 10Kansas 53 62 38 30Montana 23 43 9 0Nebraska 66 39 8 27North Dakota 44 40 12 0Oklahoma 93 27 30 6South Dakota 96 28 7 2Texas 307 83 41 57Wyoming 21 38 19 24Total 754 47 19 17
2009Colorado 145 50 24 21Kansas 62 14 0 2Montana 150 29 4 7Nebraska 100 14 16 44North Dakota 92 52 12 .Oklahoma 77 49 17 18South Dakota 44 27 14 .Texas 322 44 4 14Wyoming 21 10 19 0Total 1013 32 12 20
% of samples testing positive
2008 n WSMV + WMoV WSMV + TriMV WMoV + TriMV All miteColorado 51 8 8 0 0Kansas 53 15 21 13 8Montana 23 9 0 0 0Nebraska 66 8 18 5 5North Dakota 44 9 0 0 0Oklahoma 93 16 4 3 3South Dakota 96 7 2 1 1Texas 307 37 53 28 26Wyoming 21 5 10 10 0Total 754 13 13 13 5
2009Colorado 145 70 67 46 6Kansas 62 14 16 2 0Montana 150 3 5 1 1Nebraska 100 31 57 60 3North Dakota 92 63 . . .Oklahoma 77 66 68 36 0South Dakota 44 41 . . .Texas 322 48 58 18 2Wyoming 21 76 14 10 0Total 1013 46 46 29 2
2008 n BYDV-PAV CYDV-RPV All aphidColorado 51 10 4 0Kansas 53 6 2 0Montana 23 9 0 0Nebraska 66 5 3 2North Dakota 44 2 0 0Oklahoma 93 16 3 2South Dakota 96 3 0 0Texas 307 14 2 0Wyoming 21 0 0 0Total 754 7 2 0
2009Colorado 145 32 8 5Kansas 62 10 0 0Montana 150 1 2 1Nebraska 100 8 14 1North Dakota 92 6 9 0Oklahoma 77 65 4 4South Dakota 44 5 . .Texas 322 20 0 0Wyoming 21 5 0 0Total 1013 17 4 1
Number of viruses in sample2008 n 0 1 2 3 4 5
Colorado 51 22 63 16 0 0 0Kansas 53 8 55 30 8 0 0Montana 23 48 43 9 0 0 0Nebraska 66 47 29 20 5 0 0North Dakota 44 57 34 9 0 0 0Oklahoma 93 49 28 17 3 2 0
South Dakota 96 68 23 7 1 0 0Texas 307 8 23 37 28 4 0Wyoming 21 43 33 24 0 0 0Total 754 39 37 19 5 1 0
2009Colorado 145 33 41 14 11 0 1Kansas 62 82 15 3 0 0 0Montana 150 67 24 7 1 0 0Nebraska 100 36 41 17 6 0 0North Dakota 92 39 48 8 4 0 0Oklahoma 77 10 34 48 8 0 0South Dakota 44 66 23 11 0 0 0Texas 322 46 34 14 4 2 0Wyoming 21 76 14 10 0 0 0Total 1013 49 29 18 4 0 0
Outcomes• Information on prevalence and species of wheat viruses in the
Great Plains region• WMoV and TriMV in all states → not regulated pests• Germplasm used for several research projects (MT, NE, OK, etc.)
and successful collaborations• Manuscript in Plant Health Progress and APSnet Feature article• Raised awareness of wheat viruses in our cropping systems• Model for data sharing among states in GPDN region and NPDN• Interest in conducting wheat virus surveys in additional NPDN
regions• Continued collaborations and greater understanding of cereal
virus epidemiology and management.• Use of NPDN mapping functions and degree day models to deliver
up-to-date information on wheat viruses during the 2010 cropping season and predict their occurrence (symptom development).
Current status• Survey ongoing in 2010• Samples feeding into research on TriMV in Nebraska
(Wegulo), other states as requested• Bi-weekly updates to SPHDs, SPROs, and
diagnosticians on virus status in GPDN
6/2/2010 Wheat Virus Summary State WSMV TriMV HPV BYDV-PAV CYDV-RPV
North Dakota + + + Montana + +
South Dakota + + + Nebraska + + + Wyoming Suspected Colorado
Kansas + + Oklahoma + + + + +
Texas + + + +
Other research activities (MT)• Dai Ito: Winter, spring wheat, barley variety trials
– Fall inoculations inefficient (~10% vs >50%) – probably due to cold temperatures and lack of systemic infection in the fall rather than winterkill
– Widely planted winter wheat varieties in MT loose ~18% yield due to WSMV, spring wheats loose ~30%
– Varieties vary in susceptibility as measured by symptom severity, incidence, and yield loss – one does not predict the other
– Barley is resistant to mechanical inoculation by WSMV (susceptible to TriMV)
• Greenhouse trials of winter wheat and weeds from 5 Great Plains states
Susceptibility to WSMV as measured by % incidence in varieties from 5 Great Plains states
0
0.2
0.4
0.6
0.8
1
1.2
ID MT NE OK TX
State
Inci
denc
e (%
)
a ab b
c
Susceptibility to WSMV as measured by relative ELISA absorbance value in varieties from 5 Great Plains states
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
ID MT NE OK TX
State
Rel a
bs (%)
a
bab
a a
Weeds vary in susceptibility to WSMV as measured by relative absorbance value
Wheat streak mosaic virus (WSMV) transmission by the wheat curl mite (WCM) from grassy weeds to wheat
Scientific name Common name Mite host WSMV host
Transmission of WSMV to wheat
by WCM
Aegilops cylindricae Jointed goatgrass Yes Yes Yes
Agropyron repens Quackgrass Yes No No
Avena fatua Wild oat No Yes No
Bromus japonicus Japanese brome Yes Yes Yes
Bromus secalinus Cheat grass Yes Yes Yes
Bromus tectorum Downy brome Yes Yes Yes
Echinochloa crus-galli Barnyardgrass Yes Yes Yes
Secale cereale Feral rye or rye Yes Yes Yes
Setaria viridis Green foxtail Yes Yes Yes
=conflicts with literature
Other research activities (MT)• Zach Miller: Weed/grassy weed interactions
as influenced by stress: nitrogen, WSMV
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
10to16 17to22 23to54 55to99 >100
Nitrogen Availability (lbs/ac)
WS
MV
In
cid
en
ce
Cheatgrass
Green Foxtail
Wild Oat
Winter Wheat
AcknowledgementsDai Ito, Zach Miller, Matt Moffet, Linnea SkoglundGPDN: Jim Stack & all state reps
and diagnosticiansMSU County Extension Agents