بررسی ارزیابی واکنش ژنتیپ های جو مربوط به آزمایشات مقایسه عملکرد پیشرفته و امیدبخش نسبت به بیماری زنگ زرد جو

Barley stripe rust (caused by Puccinia striiformis f. sp. hordei) is an important disease of cultivated barley in several parts of the world which can cause yield losses due to severe epidemics. In some parts of Iran, it is increasing on susceptible cultivars/lines. Production and use of resistant lines (particularly durable resistance) will be the best control method in order to prevent the disease epidemics and to decrease yield losses. In this research, 216 barley genotypes of Advanced and Elite Yield Trials (particularly for cold, moderate and north areas) were evaluated in Ardabil and Mashhad in 2007-2008 cropping season. Each line was sown in two 1m long rows and spaced 30cm apart. The susceptible cultivar Afzal was planted at 10 lines intervals and also as borders of the nursery. Experiment was conducted under natural infection condition. Mist and flooding irrigation were used to improve disease development. Infection type (IT) of each entry was scored based on Roelfs et al, method at adult plant stage when disease widely developed on susceptible check (50S). The percentage of infected leaf area (disease severity) was also scored using the modified Cobb s scale at the same time. Coefficients of infection (CI) were calculated by combination of IT and disease severity. The results of Ardabil site showed that 46,43, 8,33, 30,95, 3,58 and 10,71% of genotypes were immune or resistant (O or R), moderately resistant (MR), moderately susceptible (MS), moderately susceptible to susceptible (MS-S) and susceptible (S) respectively. Among the genotypes evaluated in Ardabil, 77,4% of entries with CI<16 were selected. Unfavorable condition in Mashhad limited proper disease development. Key words: Barley, Yellow Rust, Resistance Evaluation.

Keywords:

جو (گیاه) , ارقام , ژنوتیپ ها , پوکسینیا استری ایفورمیس , زنگ ها (بیماری) , مقاومت به بیماری