correlation of bacterial leaf blight symptoms with presence of sr2 bob bowden seifollah p. kiani...
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Correlation of bacterial leaf blight symptoms with presence of Sr2
Bob BowdenSeifollah P. KianiEduard Akhunov
Yr Mist Chamber Conditions
10-15°C, 100% relative humidity for 14-16 hours
Symptoms From Yr Mist Chamber
Bacterial Leaf Blight caused by Pseudomonas syringae pv. syringae
Photo by Bill Willis, KSU
Crosses for BLB Mapping
• Jagger/Thunder CL, n=295, F5 RILs• KS84HW196/Jagger, n=190, F5 RILs
PBC and SM Ratings
0 = no melanism 1 = low; few tillers have mild symptoms2 = moderate; many tillers have mild to
moderate symptoms3 = strong; most tillers have moderate
to strong symptoms
Association Mapping of PBC and SM
Correlation CoefficientsPBC SM BLB
PBC 1.00 0.72*** 0.39***
SM 0.72*** 1.00 0.53***
BLB 0.39*** 0.53*** 1.00
Sr2 STM559(Hayden et al, 2004)
0.49*** 0.44*** 0.29***
Sr2 csSr2(Mago et al, 2010)
0.66*** 0.48*** 0.18*
* p<0.01** p<0.001*** p<0.0001N=221 or 222
Lines with PBC, SM, and BLB• Arlin• Bennett• C004393• Erhardt• KS84HW196• Snowmass• Thunder CL• Wendy
• 2174• Avalanche• BondCL• Centerfield• OK05303• OK04507• OK04415• OK04111• OK06318• HV9W03-1551WP• HV9W03-1596R• MTS0713• Sturdy2K• TAM302
csSr2 (+) csSr2 (-)
SM, PBC, and BLBon 2174
Inoculations for S. nodorum
Summary
• Certain varieties develop symptoms similar to BLB when placed in a dew chamber overnight.
• Inoculation with P. syringae is not required.• BLB-like symptom scores correlate with PBC and SM
scores as well as Sr2 markers• Some Oklahoma varieties like 2174 seem to express
low to moderate BLB, PBC, and SM, but do not carry the diagnostic allele for csSr2 marker (Mago et al, 2010)
• A gene conferring susceptibility to BLB-like lesions appears to be linked to Sr2 on chromosome arm 3BS.