XVI International Botanical Congess

Barley yellow dwarf virus cause annually high losses in yield worldwide. Resistance breeding is the only one way how to prevent infection. One efficient gene Yd2 has been discovered. We tested set of barley cultivars and lines (Czech, ICARDA and CIMMYT origin) in field tests using aphid from greenhouse rearing and PAV isolate to evaluate field resistance and the most interesting lines were used for variability study. Using microsatellite and AFLP we grouped icadra materials, cimmyt materials were more close to Czech feeding quality barley cultivars. Two Czech cultivars show up moderate resistancy. It was proven by YLM marker, that they do not possess Yd2 gene. According to segregation analysis three genes are involved in the regulation. Using the same marker (YLM) we found Yd2 in most of the CIMMYT and ICARDA resistant materials.