عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this study, response of 18 bread wheat cultivars were evaluated in interaction with five Mycosphaerella graminicola isolates from five provinces in seedling stage. In this experiment, the seeds were treated by 0, 0.75 and 1 mM concentrations of salicylic acid. According to the analysis of variance, significant difference (p<0.01) was observed between cultivars, isolates an SA concentration levels. Also consistent with the results of the analysis of variance, interaction between cultivar-isolate, cultivar-concentration and isolate-concentration had significant difference, which indicates that there are specific interactions between these interactivities. Seventy-eight percent of cultivars were susceptible in interaction with all of the isolates and eleven isolate-specific resistances were observed among other cultivars. Marvdasht with three isolate-specific resistance were the most resistant cultivars in this study and after Marvdasht , Hirmand and Toos, with three isolate-specific resistance but high levels of pycnidia coverage percentage compared with Marvdasht had the next ranks. Based on the virulence, all isolates fall into four different groups and S1 were virulent on most cultivares, but none of the isolates were avirulent on all cultivars. Comparition of pycnidia coverage average represents a significant reduction in the area of pycnidia coverage in 1mM concentration of SA compared to the zero and 0.75 mM levels. The 1mM concentration had greatest impact on symptoms reduction.