The experiment was carried out during rabi 2018-19 in the experimental field of College of Agriculture, Central Agricultural University, Imphal. Seeds of two Indian mustard genotypes CAULC- 2 and NRCHB-101 were exposed to three doses of gamma rays (1000, 1100 and 1200 Gy), three concentrations of ethyl methanesulphonate (0.3, 0.5 and 0.7%) and their combination (1000Gy+0.5%, 1100Gy+0.5% and 1200Gy+0.5%). The treated seeds along with the control were laid out in Randomised Block Design with three replications to raise M1 generation. To determine the biological damage in M1 generation, parameters like seed germination, seedling height, plant survival and pollen fertility were taken into account. Reduction in germination and survival percentage, seedling height and pollen fertility was observed in the mutagen treated population. The reduction was more pronounced in combined treatments. The reduction in these traits is caused due to cytological and physiological changes in the cell of the plants.

Biological damage, ethyl methanesulphonate, gamma ray, Indian mustard.

From the present investigation, it was concluded that biological damage increased with increasing dose or concentration of mutagens in M1 generation of Indian mustard. Seed germination, survival, pollen fertility and seedling height were higher at lower dose or concentration of the mutagens, which was due to the fact that biological damage (in terms of lethality, injury and sterility) increase with increasing dose or concentration of mutagens. Gamma rays and EMS, alone as well as in combination, are able to induce mutations in Indian mustard.

T. Julia, E.V.D. Sastry, N. Brajendra Singh, Th. Renuka and N. Reetisana (2022). Study of Biological Damage in M1 Generation of Indian Mustard (Brassica juncea L. Czern and Coss). Biological Forum – An International Journal, 14(2): 634-637.