Jain, SunitaSapna2016-11-182016-11-182008http://krishikosh.egranth.ac.in/handle/1/86337The present study was undertaken to investigate the lipid peroxidation and antioxidant pathway in specific leaves of resistant and sensitive cultivars of Brassica juncea L. infected with Albugo candida. Following inoculation of third leaf with Albugo candida spores higher electrolyte leakage, MDA and H2O2 content indicating enhanced lipid peroxidation was observed in sensitive cultivar Varuna. Activity of H2O2 scavenging enzyme viz. peroxidase and catalase increased in both the cultivars but more pronounced enhancement was found in resistant cultivar except super oxide dismutase, as its activity was found to increase in Varuna but declined sharply in RH781. The activity of Halliwell- Asada pathway enzymes i.e. ascorbate peroxidase and glutathione reductase enhanced in both the cultivars but the elevation was more in RH781. Ascorbate and reduced glutathione level increased specifically in RH781 whereas, oxidized glutathione was found to be higher in Varuna signifying more oxidative damage. The study shows noticeable enhancement in lipid peroxidation, activities of enzymes of antioxidant pathway and ascorbate and glutathione content in third leaf on 3 DAI. Thereafter, the increase was more in second leaf as compared to fourth leaf in both the varieties indicating that transduction of pathogen attack signal might be towards the upper leaves via phloem than the lower leaves.enPlanting, Pigeonpeas, Crossing over, Rapd, Genotypes, Genetics, Dna, Polymorphism, Diseases, Developmental stagesThesis