Antioxidants elevates the resistance to Cercospora canescens in interspecific cross of Vigna radiata (Kopergaon) × Vigna mungo (Pant Urd 31)

Abstract

Cercospora leaf spot (CLS) caused by Cercospora canescens is one of the most important foliar diseases responsible for 30%–75% yield losses in mungbean. CLS is induced by the photo-activated toxin cercosporin. The most operative measure of managing the disease is the use of resistant varieties. The objective of present study was to determine the changes in the antioxidants status of mung-bean plant to differential responses of Cercospora leaf spot under field conditions. The present study attempted to quantify the antioxidant activities against C. canescens infection in resistant RILs of inter specific cross of Vigna radiata (Kopergaon) × Vigna mungo (PU31). It was found that antioxidants such as superoxide dismutase (SOD) and catalase (CAT) enzymes were actively involved in scavenging ROS in both resistant and susceptible recombinant inbred lines (RILs) after CLS infection. Throughout the infection, the activity of both the enzymes were higher in resistant than in susceptible RILs. The malondialdehyde (MDA) accumulated at a significantly low concentration in resistant RILs and higher in susceptible ones. Statistically, area under disease progress curve (AUDPC) and MDA showed a significant positive correlation whereas, there was a negative correlation between AUDPC and SOD and CAT activity. The disease components such as lesion number and total lesion size were variable in RILs with different disease reactions. The study identified few RILs resistant to Cercospora leaf spot infection in response to utilization of the antioxidant system to confer Cercospora leaf spot resistance in mungbean by detoxifying cercosporin induced reactive oxygen species.