Inheritance of tolerance to barley yellow dwarf virus in oats

Summary Advanced generation random lines from crosses of tolerant x susceptible parents were studied to determine the inheritance of tolerance to barley yellow dwarf virus (BYDV) in oats Avena sativa L. Clintland 64, a susceptible oat cultivar, was crossed with the BYDV tolerant oat lines Otee, FF64/74, M921 and CI4492. Randomly selected lines were advanced to F5 or F6 by single seed descent and were tested for their reaction to BYDV at Palmerston North, New Zealand and Winnipeg, Manitoba and Ste-Foy, Quebec, Canada.The reactions of the lines to BYDV infection from each cross at the three test sites fall into a relatively continuous distribution. Two to four quantitatively inherited genes appear to contribute to the tolerance of the four tolerant oats. At Palmerston North, Clintland 64 expressed some tolerance to the virus.The correlation between the three sites was significant (P=0.01) for all crosses, ranging from 0.36 to 0.69, according to the particular cross considered. This correlation is sufficient to justify more international testing of oats for BYDV tolerance.Contribution Nos. 1163.