Heterosis and combining ability studies in upland cotton for fibre characters

Abstract

The present investigation was undertaken to identify best parents and hybrids and also to study the genetic potential o f thirteen Gossypium hirsutum Sines in evolving superior fibre quality genotypes coupled with jassid resistance* The study indicated the predominance of non-additive gene effects for 2.5 per cent span length, uniformity ratio, micronaire, bundle strength and elongation percentage. The genotypes SVPR 3, B 1007 and MCU 5 for 2.5 per cent span length, SVPR 3, Laxmi, PHY 286 for uniformity ratio, SVPR 3 for micronaire value, Laxmi, B 1007, KC 2 and MCU 5 for bundle strength, SVPR 3, Khandwa 2 for elongation percentage would serve as good general combiners. The jassid resistant Sines DHY 286 and KC 2 were observed as good general combiners for uniformity ratio and bundle strength, respectively. The tester MCU 5 was a good general combiner for 2.5% span length and bundle strength. By hybridizing the resistant lines with MCU 5, favorable gene combinations could be accomplished for the above fibre quality traits. Further, the resistant hybrids KC 2 x MCU 7 for 2.5% span length, SVPR 3 x MCU 12 for uniformity ratio and elongation percentage, SRT1 x MCU 5 for 2.5% span length and bundle strength showed significant positive specific combining ability effects. Hence the above hybrids can be used in breeding programmes for improving the fibre quality traits coupled with jassid resistance.