GENETIC-ANALYSIS FOR PARTIAL RESISTANCE TO AN IRANIAN STRAIN OF BACTERIAL LEAF STREAK (XANTHOMONAS-CAMPESTRIS PV HORDEI) IN BARLEY

Seven barley genotypes with high genetic variability for resistance to bacterial leaf streak (Xanthomonas campestris pv. hordei) were crosse d in diallel fashion to determine the inheritance of resistance to thi s disease. Two experiments were undertaken in a controlled growth cham ber using a complete-block design with four replicates. Each replicate consisted of a row of 20 seedlings per parent or F-1 hybrid. An Irani an strain of bacterial leaf streak was used for inoculation of 12-day- old seedlings. Results showed that the cultivars 'Express' and 'Morex' and the Iranian pure line Iran-3a had a high partial resistance in bo th experiments. Diallel analysis showed highly significant general and specific combining abilities. 'Morex' and Iran-3a were the best combi ners for partial resistance to bacterial leaf streak in barley and cou ld be successfully used for breeding purposes.