بررسی تعداد ژن، شناسایی و نحوه توارث ژنهای مقاومت مرحله گیاهچه ای و گیاه کامل در تعدادی از ژنوتیپ های امیدبخش و چند رقم تجاری گندم استان فارس نسبت به زنگ زرد

Stripe rust caused by Puccinia striiformis f. sp. tritiei (Pst) is the most important disease of wheat in many wheat growing areas in Iran. A good knowledge about genetic basis of resistance in commercial or newly released wheat cultivars and in selected elite lines to the disease is a worthwhile objective in breeding programs. This study was carried out to identify the number of resistance genes and mode of inheritance to stripe rust among selected elite genotypes of 1379-1381 and several commercial wheat cu1tivars. The wheat elite genotypes and cultivars were crossed to susceptible parent Avocet S. For each cross five hybrid seeds were considered to produce F 1 seeds of which two F 1 populations were grown to produce F2 and F3 generations in the successive years. Two F3 families from each cross each including about 120 lines together whit control and differential cultivars were grown in the field and inoculated with Pst pathotype 166E138 A+ (the dominant stripe rust race in Fars province) in late winter and early spring. The responses were recorded when the reaction on flag leaf of susceptible control (Bolani) was 100S. In addition one F3 family of cross M-79-7/Avocets and all parents (The above selected elite genotypes and commercial cultivars of wheat) along with control cultivars were examined to the same Pst pathotype at the seedling stage in the greenhouse. Based on the responses, the F3 families were categorized to three classes as non- segregating resistant, segregating and non-segregating susceptible. The results showed that most of elite genotypes except M-79-7, M-80-4, M-80-5 and M-81-18 and also cultivars included Darab2, star, S-78-11 and S-79-10 had susceptible reaction to the used Pst pathotype at the seedling stage, but at the adult plant stage, the majority of elite genotypes except M-81-3 and M-79-17 that were susceptible, had moderately resistance to moderately susceptible reactions. Darab2, S-78-11 and S-79-10 were moderately susceptible. NickNejad and Star were resistant and susceptible respectively Genetic analysis showed that elite genotypes including M-79-4, M-79-5, M-79-18, M-80-13, M-80-20, M-81-5, and the cultivar Darab 2, and elite genotypes 8-78-11 and 8-79-10 each had one adult plant resistance (APR) gene. The elite genotypes M-80-6, M-80-12, M-81-8, M-81-13, M-81-15 were shown to confer two APR genes. The resistance in elite genotypes M-79-17, M-81-18, M-80-4 and M-80-5 and cultivar NickNejad each was controlled by two dominant genes that at least one of them is operated at the seedling stage. More studies are required to elucidate whether the second resistance gene comes from seedling stage or it is just effective at the adult plant stage. The elite genotype M-79-7 had one seedling and one adult plant resistance gene. The elite genotypes M-79-13 and M-81-3 and the cultivar Star were shown to lack any resistance genes at both seedling and adult plant stages.

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گندم ها ، توارث ژنتیکی ، زنگ ها (بیماری) ، ژنوتیپ ها ، مقاومت به بیماری