Genetic analysis for some agro-physiological traits to improve drought tolerance in cotton

Abstract

Now a days, lack of fresh water availability is a major issue for crop production worldwide. Cotton is highly sensitive to drought stress with respect to seed cotton yield and fibre quality. In this study, 30 F1 crosses along with their 13 parents were evaluated for agro-physiological traits like seed cotton yield (SCY), osmotic potential (OP), water potential (WP), pressure potential (PP), chlorophyll fluorescence (CF) and proline contents (PC) under normal irrigation (947.42 mm) as well as water-deficit condition (693.42 mm). The data were analysed for better parent heterosis (BPH), general combining ability (GCA), specific combining ability (SCA) and gene action through line × tester analysis. The analysis of parents and F1 data showed the non-additive type of gene action for all the traits under both conditions. FH-159 and IR-6 revealed good GCA estimates for PP, CF and PC under water deficit condition The FH-159 × KZ-191 was recorded as the best specific combiner for PP, CF, SCY and WP under water deficit condition. High GCA estimates for SCY, WP and OP were found for FH-207 under normal as well as under water deficit condition. The highest SCA for PC under water deficit condition was found for VH-289 × NS-131. High value of BPH was recorded in VH-289 × AA-703 for OP, PP and CF under water deficit condition Whereas; under normal irrigation high BPH was recorded in FH-159 × KZ-191 for SCY, WP and OP. Meanwhile, the crosses FH-207 × NS-131, S-15 × AA-703 and FH-329 × NS-131 showed higher BPH for SCY under water deficit condition. These crosses can be grown to further generations to attempt selection for higher SCY under water limited condition. Furthermore, non-additive gene action for all traits suggested the development of hybrids in cotton to improve drought tolerance using these traits.