Gamma ray induced cytomorphological variations in Sesbania cannabina Poir

Seeds of Sesbania cannabina cultivar ND-1 were subjected to different doses of gamma irradiation (20, 40, 60 and 80 KR) and irradiation effects on seed germination, survival, and several morphological and cytological characters of adult plants were studied. The irradiated seeds were tested for lethal doses at which 50% of the seeds germinated (LD50) i.e. 40 KR dose. Plants grown from the gamma ray-treated seeds showed variation regarding their morphological and cytological characters. The plant height, stem girth, number of leaves per plant, and pod length decreased as the doses of irradiation increased. However, internode length increased with increasing doses of irradiation. Meiotic analysis revealed the presence of various types of chromosomal abnormalities at all phases. Meiotic aberrations increased according to the doses of irradiation. A reduction in pollen fertility was also noticed. (author)