Vol. 11, Issue 8 (2022)

Author(s):
Unnati Vaghela, Mayur Kumar Sonagara, Girish Faldu and Pratik Satasiya

Abstract:
The present experiment was carried out in line × tester fashion during 2018-19 to study heterosis, combining ability and gene action in American cotton for fiber quality and biochemical parameters. Twelve diverse parents, four lines (female) and eight testers (male) were crossed to produce 32 F1 hybrids. A total of 45 (including check) genotypes were evaluated for fiber quality and biochemical parameters to determine the mode of gene action, extent of heterosis, and combining abilities that assisted in formulating an effective breeding strategy for cotton for industrial use. In case of fiber quality parameters, the maximum value of standard heterosis in desired direction was 3.52% (GSHV 199 × SIMA 5) for fiber length and -6.82% (GSHV 199 × SIMA 5, GISV 319 × CPD 1602) for fiber fineness. Whereas, biochemical parameters, the maximum value of standard heterosis in desired direction for oil content was 4.83% (GSHV 199 × PBH 42), for gossypol content -71.33% (GSHV 199 × SIMA 5 and GISV 298 × SIMA 5) and for phenol content 60.71% (GISV 298 × BGDS 1033). As a result, different hybrids demonstrated varying fiber quality and biochemical superiority based on requirements for industrial use. GSHV 199 was found good general combiner for four characters viz., fiber length, fiber strength, fiber fineness and gossypol content and developing hybrids for textile and oil industries products. For fiber fineness, oil percentage, gossypol content and phenol content additive and dominance components were found significant in controlling the traits whereas, the predominance of the additive type of genetic variance found in the inheritance of fiber length, fiber strength and maturity co-efficient. That suggested the simultaneous exploitation of additive gene actions by adopting selective intermating and recurrent selection, which would accumulate more of additive genetic variability whereas, non-additive gene effect can be exploited by heterosis breeding or biparental mating followed by few cycles of recurrent selection.