شناسایی منابع مقاومت ژنتیکی در برابر نماتد سیستی غلاتHeterodera filipjevi (Madzhidov) Stelter 1984 در برخی ارقام گندم، جو و چاودار

The cereal cyst nematodes, Heterodera avenae group, are devastating root nematode parasites of cereals and have a global distribution. These sedentary endoparasitic nematodes cause significant economic yield losses in most of the countries in all over the world, particularly where the rain-fed cereal cultivations are predominant. Among cereal cyst nematodes H. avenae, H. filipjevi and H. latipons are considered as the most important species in West Asia, North Africa and Mediterranean countries.Among the management approaches of the cyst nematodes using resistant cultivars is the most effective way for managing nematodes and prevent their damage in high and low value cropping systems. Several genes belonging to Cre gene group from either hexaploid wheat or its relatives have been identified as sources of resistance against cereal cyst nematodes. The objective of this research was to identify resistance sources in some wheat, barley and rye cultivars that are commonly cultivated in northwest of Iran. The seeds of 35 cultivars of wheat, barley and rye as well as Aegilops tauschii and Aegilops cylindrica screened in this study were provided by Seed and Plant Improvement Institute Karaj, Iran. The seeds of different cultivars were planted in greenhouse condition in 2017 and at four-leaf stage, fresh leaves from each cultivar were collected and stored in deepfreeze in order to extract the DNA. For DNA extraction leaves were ground to a powder using a mortar containing liquid nitrogen and following the CTAB procedure. To determine the presence of Cre genes in the cultivars, three primer pairs namely Crecon, Xgwm301-2D and Xgwm147-6B were used to amplify segments of Cre1, Cre3 and Cre8 genes, respectively. PCR reaction was consisted of one cycle of 1 min at 94˚C followed by 35 cycles of 1 min at 94˚C, 1 min at 56˚C, 1 min at 72˚C and a final cycle of 7 min at 72˚C. PCR products were run on a 0.8% agarose gel (100V, 45 min), stained with ethidium bromide, visualized on gel documentation and photographed. The results of this study showed that all the wheat cultivars studied here possessed Cre 1 gene that is one of the resistance genes against H. filipjevi. However, none of the barley and rye cultivars had this gene. Cre 8 and Cre 3 genes were not found in any of wheat, barley and rye cultivars. Also, the results indicated that A. tauschii carries all the three Cre genes in its genetic background, but A. cylindrical lacks Cre 1 and Cre 8 genes except Cre 3.