GENETIC ASSOCIATION OF GENE BDV1 FOR TOLERANCE TO BARLEY YELLOW DWARF VIRUS WITH GENES LR34 AND YR18 FOR ADULT-PLANT RESISTANCE TO RUSTS IN BREAD WHEAT

Genetic association between the gene Bdv1, which confers slow yellowing to barley yellow dwarf (BYD) in adult plants, and genes Lr34 and Yr18, which confer partial adult plant resistance to leaf rust and stripe rust, respectively, was investigated. Nearly 115 random F3 and Fs lines, derived from the crosses of susceptible cultivar Jupateco 73S with resistant (symptomatically tolerant for BYD) cultivars Jupateco 73R and Condor, and the parents were evaluated for reaction to the three diseases in separate experiments. Resistance to each disease in Jupateco 73R and Condor is conferred by a single gene. Using a joint classification of the F3 and F5 lines for the three diseases indicated that genes Lr34, Yr18, and Bdv1 are either very closely linked or under pleiotropic genetic control. Because Lr34 is known to be located on the long arm of chromosome 7D, it was concluded that Bdv1 is also located on the same chromosome arm. It is suggested that Condor, Jupateco 73R, or Anza be used as a tester genotype for Bdv1, as well as for Lr34 and Yr18. The three genes are common in the wheat germ plasm of the International Maize and Wheat Improvement Center.