Apple powdery mildew resistance genes in Iranian wild apple genotypes

Apple (Malus domestica Borkh) is one of the most valuable agricultural products in the Rosaceae family because of its high nutritional and economic value. Powdery mildew of apple which is caused by Podosphaera leucotricha, is one of the primary fungal diseases with an extensively negative impact on the quality and quantity of apple production. In recent years, the use of resistant cultivars for controlling powdery mildew of apple has been considered. For this purpose, the candidate resistance genes Pl1, Pld, Plbj, and RGA (Resistance Gene Analogs) were detected in 47 genotypes of wild apples collected from West Azerbaijan, Golestan, Fars, Chaharmahal va Bakhtiari and Isfahan provinces. The presence of NBS-LRR conserved domains and P-loop NTPase motif in NBS-LRR-like protein, which encode by the RGA in N-terminal, were confirmed in wild apple (Malus orientalis) genotypes of Iran. Pl1 resistance gene was detected in all collected samples in this research except one. Pld gene just was observed in three out of the 47 samples, and the Plbj resistance gene was detected in just 13 samples of all wild genotypes collected from cold areas of Azerbaijan and Isfahan provinces; the sequences of this gene was introduced to the Global database. Detection of resistance genes and RGAs can help in developing resistant apple varieties in future.