Gamma Rays, EMS and Sodium Azide Induced Genetic Variability for Quantitative Traits in Ajara Ghansal Non-Basmati Aromatic Rice

Full text: Ajara Ghansal, a local non-basmati aromatic rice cultivar (landrace) adapted to the agro-climatic conditions of Ajara Taluk of Kolhapur, Maharashtra, India possesses a good aroma and good cooking qualities, thus is a very good potential for domestic market. However, it has a low yield potential. Five hundred (500) Ajara Ghansal seeds were subjected to mutagenic treatments using gamma rays, Ethyl methanesulphonate (EMS) and Sodium Azide (SA) separately to induce genetic variability. M₁ seeds were harvested and planted in a plant-to-row basis to develop M₂ generation. Among M₂ populations, several mutations were identified: semi-dwarf plant height, early maturity, and good yield, as well as lodging resistance. Dwarf mutants with shorter culms were identified in plants derived from treatments with 0.8%, 1.0% and 1.2% EMS and 200Gy. Early maturing mutants were detected in EMS treatments (1.0 and 1.2%), SA (0.006%) and 200Gy treatments with 135-137 days of maturity as compared to control (160 days). Mutants with higher number of tillers were also identified in EMS (1.0%), SA (0.006%) and 150Gy, with numbers ranging from 61 to 70 per plant as compared to 19 tillers/plant in control. Mutants with increased panicle length ranging from 24.30 to 28.89cm were observed form treatments using EMS (1.0 and 1.2%), SA (0.006%) and 150 and 200Gy as compared to control (23.03cm). Mutants with higher yield/plant were detected under EMS (1.0%), SA (0.006%) and 150Gy treatments which showed higher yield/plant (138-349g/plant) as compared to control (58g/plant). Lodging resistant mutants were recorded in EMS (1.0 and 1.2%), SA (0.006%) and 150Gy treatments at the time of harvesting; where control plants have shown complete lodging. Among the mutagenic treatments, 1.0% and 1.2% treatments of EMS and 150Gy treatment of gamma rays were found to be the most effective treatments for induction of desirable mutants. (author)