Assessing the impact of gamma rays and EMS mutagens in M1 generation of sunflower (Helianthus annuus. L) on germination, plant survival

The seeds of the two genotypes, TAS-82 and MORDEN, were exposed to five doses of gamma radiation at Bhabha Atomic research Centre (BARC), Trombay, Mumbai, also with three doses of EMS for which treatment was given at PGI, Dr. PDKV Akola, to study the impact of mutagenesis on germination, plant survival and lethality. About 100 seeds from each dose were placed in a laboratory conditions for germination test. The percent germination, plant survival, lethality and pollen sterility calculated from treated seeds at field conditions as per doses sown at the Oilseed research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, in a Randomised block design with Three replications. The observations regarding percent germination, plant survival, lethality as compared to control were recorded. The seed germination and plant survival parameters for all the doses differed significantly, indicating strong the impact of mutagenic doses on these characters. In laboratory condition, in both genotypes observed a progressive decrease in germination percentage, with the increase in gamma ray doses and EMS doses. The LD50 was observed at 400Gy dose for TAS-82 and MORDEN genotype. The highest reduction in plant survival in M1 generation under field condition was found at 400Gy dose (41.11% in TAS-82 and 33.88% in MORDEN) compared to both their controls. In general, a dose dependent relationship between biological damage (%) and the type of mutagen used was observed.