In vitro induction of mutation in cotton (Gossypium hirsutum L.) and isolation of mutants with improved yield and fiber characters

This paper describes a protocol to develop cotton mutant lines with improved yield and fiber characters. Immature ovules [(15-day post-anthesis ovules (dap)] were irradiated with 10-50 Gy gamma rays and treated with 1-5 mM EMS and SA to investigate the stimulatory effects of mutagenic treatments. During the subsequent field trials, the mutant lines showed significant variations from control lines. Lower dose/concentration of mutagenic treatments effectively stimulate the agronomical characters like early flowering, plant height, number of bolls, yield of seed cotton, ginning percent, seed index, harvest index and fiber characters while exposure at higher dose/concentration results in lowering the value of the parameters. Consequently, we use this approach to induce genetic variability for obtaining novel mutant cotton cultivars. Among the 19 different mutant lines isolated from the study, M7 showed higher morphological variations in terms of yield characters such as plant height, number of bolls, yield of seed cotton, ginning percent and fiber characters. Significant increase in cellulose content was also noted in mutant lines, whereas moderate increase was observed in total fiber units of the mutant lines. The selected cotton mutant lines for cultivars were investigated systematically; these lines significantly increased the potential for agronomical enhancement of cotton yield.