ارزيابي مقاومت گياهچه اي تعدادي از لاين هاي پيشرفته گندم نان نسبت به زنگ زرد

Evaluation of seedling resistance of some advanced lines of bread wheat to yellow rust

Thirty nine advanced breeding lines of wheat were inoculated at seedling stage with four pathotypes of wheat yellow rust 6E130A+, 6E134A+, 134E148A+ and 166E42A+ and then infection type and latent period were scored. A high correlation coefficient was found between infection type and latent period and the correlation increased with the increase of potentiality of the pathogen to cause the disease. Most of the lines appeared to be resistant to at least one of the pathotypes. Many lines showed incomplete resistance of which M-80-3, M-78-9 and M-78-16 demonstrated longer latent period. M-78-18 lacked seedling resistance and was susceptible to all four pathotypes, however, M-78-4 and M-80-4 appeared to be completely resistant to all four pathotypes. Cluster analysis was performed on the basis of the resistance reaction of the lines to all pathotypes. The lines were divided into five groups. The similarity of the individuals within each group was mostly based on their number of complete resistance in response to different pathotypes.