Assessment of Late Blight Resistance in Indian Potato Cultivars and Associated Biochemical Changes During Disease Development

The present study was focused on screening of Indian potato cultivars [‘Kufri Khyati’ (KK), ‘Kufri Chipsona 1’ (CS-1), and ‘Kufri Pukhraj’ (KP)] for late blight resistance followed by an investigation of biochemical changes during infection. The varied level of disease resistance in potato cultivars was found to be associated with tested biochemical markers. Late blight progression was found to reduce total protein content and increase proline accumulation prominently in sensitive (KP) and moderately sensitive (CS-1) cultivars, whereas minimal changes were observed in the resistant cultivar (KK). The highest melonaldehyde (MDA) content (a marker of lipid peroxidation) was recorded in KP, where about 93% of plants showed necrosis after 7 days of inoculation. The activities of antioxidant enzymes also varied in potato cultivars during pathogenic interaction. The superoxide dismutase activity was observed to increase in all the cultivars till day 4 of inoculation. After that, it remained constant in cultivar KK while a decrease in the activity was observed in cultivars KP and CS-1. Although, an increment in the peroxidase and ascorbate peroxidase activities were observed in KK, yet catalase, glutathione reductase, and polyphenol peroxidase activities were found to decrease during the early phases of infection. Throughout the experiment, the highest levels of activities of all the antioxidant enzymes studied were recorded in cultivar KK, showing their significant role in disease resistance. The identified blight resistance linked biochemical markers can be effectively utilised in development of blight resistant potato cultivars.