Screening of Iranian potato germplasm for resistance to PVY and PVX

Potato virus Y (PVY) and Potato virus X (PVX) are the most important potato-infecting agent causing yield loss and tuber quality reduction. In this study, an experiment was conducted in Karaj, Iran, to investigate the effects of mentioned viruses on the yield and resistance level of 33 potato genotypes. The experiment was performed based on randomized complete design in factorial format under two levels viruses with three replications. The results revealed that the viral infection had a significant impact on mean yield, seed yield (tuber size 35-55), ware yield (tuber size > 55 mm), and non-marketable yield (tuber size< 35). Based on cluster analysis for PVY, cluster VII was considered maximum resistant genotypes to PVY in terms mean absorption and yield, while cluster VI was identified susceptible genotypes in to PVY. According to cluster analysis of PVX virus, cluster I was considered highest resistant genotypes in terms mean absorption and yield and cluster III were maximum susceptible genotypes to PVX infection. Results of this study showed that genotype G23 with a mean-absorption of 0.01 and 0.032 for PVY and PVX, respectively, and mean yield of 4.1 kg/m2 was considered as a highly resistant genotype to both viruses. The concurrent selection of genotypes for high yield and resistant to both viruses (PVX and PVY) can facilitate potato breeding programs.