Chromosomal regions associated with barley yellow dwarf virus resistance in oat

Recombinant inbred lines from the oat ( Avena sativa L.) population Kanota x Ogle were analyzed in order to detect quantitative trait loci for Barley Yellow Dwarf resistance. Plants were scored for BYD symptoms in three locat ions (Urbana-Illinois, Ithaca-New York, and a greenhouse), and in four year s (1992, 1993, 1994, and 1995). All plants were inoculated with infected ap hids at the three-leaf stage, and the scores were recorded at the early flo wering stage. Twenty one chromosomal regions distributed over 16 different linkage groups were associated with BYD resistance. Most regions came from Kanota, while only five were contributed by Ogle. A multiple linear model w as fitted for each BYDV isolate in order to evaluate the best combination o f markers for selection in a backcross breeding program. In IL the best mod el explained 19%, 5%, and 17% of the genetic variation for 1992, 1993 and 1 994, respectively. The best model for NY explained 16% of the genetic varia tion in 1992 and 8% in 1993. The best model for the greenhouse explained 46 % and 44% of the genetic variation in 1994 and 1995, respectively. These mo dels will allow genotypic selection for BYD resistance to the extent that t he markers are linked to the QTL.