Resistance evaluation of eleven potato varieties against potato leaf-roll virus and physiological responses to virus infection

Abstract

Abstract Potato leaf-roll virus (PLRV) is a prevalent and serious viral disease affecting potato production. Like other viruses, controlling PLRV through selective breeding and planting resistant varieties is the most effective and economical measure. However, in China, commercial potato cultivars have not been well characterized for resistance to PLRV. This study evaluated the resistance of eleven potato varieties and found that infection rates varied significantly among the varieties (ranging from 21–90.7%). Two varieties (Kexin NO.1 and DongNong 308) showed strong resistance to PLRV, while HuTou exhibited tolerance, and NeiShu NO.7, LongShu NO.3, and ZhongShu NO.11 showed moderate resistance. Atlantic and Desiree showed moderate susceptibility, whereas Shepody, Faverita, and Russet Burbank were susceptible to PLRV. Moreover, the study investigated the activities of the Nitric oxide (NO) and antioxidant enzymes, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the leaves of different varieties during infection with PLRV, revealing significantly higher levels of NO, SOD, and POD in PLRV-inoculated resistant and moderately resistant varieties compared to susceptible and non-inoculated plants. Moreover, CAT activities were lower in susceptible varieties and decreased significantly in susceptible genotypes than non-inoculated plants. These findings suggest that antioxidant enzymes may play an essential role in the defense mechanism of potato plants against viral infections, emphasizing the practical importance of selective breeding to develop PLRV-resistant potato varieties.