Variations in seed protein content of cotton (Gossypium hirsutum L.) mutant lines by in vivo and in vitro mutagenesis

The present work describes the influence of gamma irradiation (GR), ethyl methane sulphonate (EMS) and sodium azide (SA) treatment on yield and protein content of selected mutant lines of cotton. Seeds of MCU 5 and MCU 11 were exposed to gamma rays (GR), ethyl methane sulphonate (EMS) and sodium azide (SA). Lower dose of gamma irradiation (100-500 Gy), 10-50 mM EMS and SA at lower concentration effectively influences in improving the yield and protein content. Significant increase in yield (258.9 g plant^-1) and protein content (18.63 mg g^-1 d. wt.) as compared to parental lines was noted in M₂ generations. During the subsequent field trials, number of mutant lines varied morphologically in terms of yield as well as biochemical characters such as protein. The selected mutant lines were bred true to their characters in M₃ and M₄ generations. The significant increase in protein content and profiles of the mutant lines with range of 10.21-18.63 mg g^-1. The SDS-PAGE analysis of mutant lines revealed 9 distinct bands of different intensities with range of 26-81 kDa. The difference in intensity of bands was more (41, 50 and 58 kDa) in the mutant lines obtained from in vitro mutation than in vivo mutation. Significance of such stimulation in protein content correlated with yielding ability of the mutant lines of cotton in terms of seed weight per plant. The results confirm that in cotton it is possible to enhance the both yield and biochemical characters by in vivo and in vitro mutagenic treatments.