Seed longevity and vigour studies in different types of Indian mustard

An experiment was conducted at ICAR-Indian Agricultural Research Institute, New Delhi (2017-18) to study the possible reason for reduced seed vigour in Indian quality mustard genotypes during storage for the first time. Freshly harvested seeds, one year, two year aged seeds and controlled deteriorated seeds of freshly harvested seeds of conventional and quality Indian mustard were used for the study. Reactive oxygen species (ROS), i.e. hydrogen peroxide (H2O2) and superoxide radical (O2 .-) were estimated along with enzymatic antioxidants such as catalase and peroxidase and redox couples ratio (ASC/DHA and GSH/GSSG) in all the nine genotypes of different age group and correlated with germination percentage, mean germination time and seed vigour indices. The experiment revealed that during storage, the amount of ROS accumulation goes on increasing and both enzymatic and non-enzymatic antioxidants goes on decreasing. In comparison to conventional genotypes, quality genotypes were found to contain significantly lower level of antioxidants and significantly higher level of ROS content during the storage period. Germination percentage as well as seed vigour indices were negatively correlated with ROS and positively correlated with enzymatic and non-enzymatic antioxidants. This experiment revealed that reduced vigour in quality genotypes could be due to faster deterioration during the storage due to increased production of ROS.