DEVELOPMENT AND MOLECULAR CYTOGENETIC ANALYSIS OF WHEAT-HAYNALDIA VILLOSA 6VS 6AL TRANSLOCATION LINES SPECIFYING RESISTANCE TO POWDERY MILDEW/

Several Triticum aestivum L.-Haynaldia villosa disomic 6VS/6AL translo cation lines with powdery mildew resistance were developed from the hy bridization between common wheat cultivar Yangmai 5 and alien substitu tion line 6V(6A). Mitotic and meiotic C-banding analysis, aneuploid an alysis with double ditelosomic stocks, in situ hybridization, as well as the phenotypic assessment of powdery mildew resistance, were used t o characterize these lines. The same translocated chromosome, with bre akpoints near the centromere, appears to be present in all the lines, despite variation among the lines in their morphology and agronomic ch aracteristics. The resistance gene, conferred by H. villosa and design ated as Pm21, is a new and promising source of powdery mildew resistan ce in wheat breeding.