Induction of morphological mutations in okra (Abelmoschus esculentus L.) through gamma rays and EMS

Abstract

Induced mutagenesis has become an effective tool to improve a crop through creation of variability. Genetically pure, uniform and dry seeds of okra (Abelmoschus esculentus L.) variety P-8 were treated with physical mutagen gamma rays (35kR, 40kR, 45kR, 50kR, 55kR, 60 kR, 65kR, 70kR, 75kR, 80kR and 85kR) and chemical mutagen Ethyl Methane Sulphonate (0.2%, 0.4%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.4% and 1.6%) and their combination treatments to assess the extent of macro-mutations induced in the M2 generation and their scope for future use in plant improvement programme. The irradiated seeds were sown in the M1 field and harvested in bulk to raise M2 generation in Augmented Design. Wide spectrum of morphological macro mutants including variation in the leaf size, leaf shape and leaf colour etc were observed in M2 generation. Among the morphological macro mutants (round, rosette and lobed leaf type); lobed leaf types was observed in highest frequency followed by rosette and round type. Lobed and round leaf types were maximum in 75kR whereas rosette leaf types were maximum in both the treatments ie. 75kR+1.4% EMS and 85kR+1.4% EMS.