Screening of wild apples (Malus orientalis Uglitz.) to Scab and Powdery mildew along an altitudinal gradient in the west of Hyrcanian forest

The use of wild germplasm and identification of resistant genotypes is an effective strategy to reduce the economic damage caused by the occurrence of fungal diseases in domesticated cultivars. In this study, three populations of wild apples in the west of Hyrcanian forest, Siahbil, Masal and Asalem were selected and the presence of resistance genes of two fire and powdery mildew diseases in trees were considered along an altitudinal gradients. After DNA extraction, screening for the presence of 9 resistance genes (six genes: Vf, Vr, Vr1, Vr2, Vm and Vbj and the three genes: Pl-1, Pl-w and Pl-d associated with Scab and powdery mildew diseases, respectively) was done. The results showed that all of the six genes studied in all three populations (except for the Vf gene in the Siahbil population) were present and the genes. Vr and Vf had the highest and lowest levels of presence in the studied trees, respectively. Also, for powdery mildew, Pl-d gene was observed in all three populations. Pl-w gene was present in some trees of Asalem population, while Pl-1 gene was not found in any of the trees. Our study showed the high prevalence of candidate genes for resistance to scab disease and the rare presence of candidate resistance genes to Powdery mildew in western populations of wild apple in Hyrcanian forest. This indicates a high vulnerability of the populations studied, especially populations located at lower altitudes in facing to an outbreak of powdery mildew in apple habitats.