Vol.:(0123456789) 1 3 Indian Phytopathology (2018) 71:519–528 https://doi.org/10.1007/s42360-018-0101-4 RESEARCH ARTICLE Antioxidants elevates the resistance to Cercospora canescens in interspecifc cross of Vigna radiata (Kopergaon) × Vigna mungo (Pant Urd 31) Anuj Kumar Maurya 1  · Sudhir Navathe 1  · Chinmayee Mohapatra 1  · Ramesh Chand 1 Received: 26 April 2018 / Revised: 26 July 2018 / Accepted: 5 December 2018 / Published online: 10 December 2018 © Indian Phytopathological Society 2018 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 diferential responses of Cercospora leaf spot under feld conditions. The present study attempted to quantify the antioxidant activities against C. canescens infection in resistant RILs of inter specifc 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 signifcantly low concentration in resistant RILs and higher in susceptible ones. Statistically, area under disease progress curve (AUDPC) and MDA showed a signifcant 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 diferent disease reactions. The study identifed 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. Keywords Cercospora leaf spot · Cercosporin · Reactive oxygen species · Host plant resistance · Mungbean Introduction Mungbean (Vigna radiata L.) Wilczek (2n = 22), belong- ing to the family Leguminosae (sub family: Fabaceae) is an important grain legume of South East Asia, Africa, South America and Australia (Shanmugasundram 2007). The crop originated in South-East Asia and Indian sub- continent (Smartt 1984). It is a quality pulse due to its high protein content (23.86%), vitamins (B complex), energy (347 kcal/100 g) and excellent digestibility, especially when combined with cereals (Rachie and Roberts 1974; Thiru- maran and Seralathan 1988). Cercospora leaf spot (CLS) caused by Cercospora canescens (Ellis and Martin) is one of the major biotic constraints of mung bean production under warm and humid climatic conditions (Poehlman 1991; Misra and Bhattacharyya 2002; Kumar and Reena 2007). The CLS is characterized by angular spots with reddish bor- der and brown to grayish center (Fig. 1). The strain of C. canescens (MTCC-10835) produces atypical symptom and characterized as necrotic, irregular spore-producing spots, grey at center and without water soaked chlorotic margins (Chand et al. 2012, 2015). The abiotic factors like tempera- ture 25–30 °C and high relative humidity (98–100%) favor maximum spore germination and disease development in Electronic supplementary material The online version of this article (https://doi.org/10.1007/s42360-018-0101-4) contains supplementary material, which is available to authorized users. * Ramesh Chand rc_vns@yahoo.co.in Sudhir Navathe sudhir.agro123@gmail.com Chinmayee Mohapatra chinmayee09109@gmail.com 1 Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh 221 005, India