Oat BYDV and Crown
Rust
Herb Ohm and
Joseph Anderson
Purdue University/USDA-ARS
Lafayette, IN 47907-1150
Objectives of The Purdue University/USDA-ARS Small Grains Program include development of spring oat germplasm that is resistant to barley yellow dwarf virus and crown rust.
A number of BYDV resistant donor lines have been used to combine resistance primarily Avena sativa and one accession of Avena sterilis (Table 1). Advanced lines have been developed which have scores of 2 to 2.5 on a 0-to 9 scale (Table 1). Future efforts to increase this level of resistance will utilize other sources of resistance such as A. strigosa or even more distantly related sources such as Thinopyrum intermedium. Experiments are underway to examine the ability of wheat pollen to germinate in oat flowers to determine the feasibility of transferring wheatgrass-wheat translocations that carry YDV resistance into oat.
Currently an F4:5 RI population of approximately 200 lines that are segregating for slow crown rusting and YDV resistance are in field analyses. These lines were inoculated in May 2002 with a mixture of BYDV-PAV and CYDV-RPV to characterize the genetic basis of YDV. This same material will be analyzed for slow crown rust resistance through natural infection.
One approach to identifying ways to interfere with the ability of YDV to cause disease in oats is to identify genes whose expression is altered upon infection with YDV. Using a suppressive subtraction hybridization technique cDNA clones are being generated which will be screened for altered expression patterns following infection and also at various time-points after infection.
Table 1. Sources of YDV resistance and assessment of advanced lines contained resistance from these sources.
Combining YDV resistance from: YDV (0-9)
Classic 3.0
Jay 4.0
IL95-1555 3.0
ND880107 3.5
A. sterilis line (Morocco) 3.5
WI X7822-3 3.0
WI X6984-3 3.5
Clintland 64 (ck) 8.5
Best advanced lines in 2001 yield trials
971A9-7-4-1 2.5
973A38-3-6 2.5
9763A18-9-1 2.5