IDENTIFICATION OF POWDERY-MILDEW-RESISTANCE GENES IN COMMON WHEAT (TRITICUM-AESTIVUM L) .6. WHEAT CULTIVARS GROWN IN CHINA

A total of 26 common wheat cultivars and advanced breeding lines grown in China were tested with a set of 11 differential powdery-mildew iso lates. Seven cultivars were susceptible. Another seven cultivars showe d the response pattern of resistance gene Pm2, either individually or in combination with genes Pm3d or Pm4a. Five cultivars expressed the r esistance of gene Pm46 singly or in combination with Pm6. Another four cultivars exhibited the response patterns of genes Pm5, Pm6 and Pm8, respectively. Three cultivars, which included one breeding line with a pair of substituted chromosomes from Haynaldia villosa, presumably ca rrying the resistance gene Pm21, showed resistance-response patterns t o all the isolates tested.