شناسایی نشانگرهای ISSR آگاهی بخش مرتبط با تحمل به سفیدک پودری در گیاه بالغ جو

Powdery mildew (Blumeria graminis f. Sp. Hordei) is one of the most destructive foliar diseases in barley that cause yield reduction worldwide.  DNA molecular markers can be used to study the genetic diversity and better understanding of genetic predisposition to disease resistance to powdery mildew in barley at early growth stage.  Selection of resistance and tolerance need to identify molecular markers associated with disease.  In present study, genetic and phenotypic variations and also molecular markers linked to tolerance to powdery mildew in 34 of cultivated and wild barley genotypes were investigated.  Using 16 ISSR ma rkers in total amplified 125 alleles that 124 (99.27%) of that were identified as polymorphic alleles.  Number of amplified alleles ranged from 5 to 10 with an average 7.93 was different for each primer.  Polymorphic Information Content (PIC) were varied from 0.17 (15) to 0.44 (LBMB-B) and also Molecular Index (MI) varied from 0.84 (primer No. 809) to 3.85 (UBC836).  Resistance and susceptible genotypes show the highest genetic distance, however, resistance and tolerant genotypes show the lowest genetic distance.  Multiple regression analysis (stepwise) between trait resistances amplified 125 alleles identified six fragments 1000 bp (primer No. 826), 700 bp (LBMB), 1500 bp (ISSR10), 300 bp (primer No. 826), 1000 bp (UBC840) and 1000 bp (primer No. 12), respectively.  Results indicated that ISSR markers are suitable for screening of barley germplasm tolerant to powdery mildew disease.