The structure and breeding behaviour of a translocation involving the transfer of mildew resistance from Avena barbata Pott. into the cultivated oat

Summary The gene for mildew resistance has been succesfully transferred into the cultivated oat from the wild oat species Avena barbata by means of an irradiation-induced translocation. The translocation has been shown to involve the long arm of chromosome ST21 of A. sativa, the short arm, the centromere and a segment of the long arm of the barbata chromosome.The transmission of the translocation is normal in the cultivar Manod in which it was originally isolated. When the translocation was transferred into other cultivars of oats, transmission through the male gametes was found to be impaired in some genotypic backgrounds. However, there was no evidence that the translocation had any deleterious effect on development and fertility in a range of cultivars.The translocation was shown to involve an exchange between nonhomoeologous chromosomes.The behaviour of the translocation in diverse genotypes indicated that the translocation was a new source of mildew resistance that could be easily used in a breeding programme.