To evaluate combing ability in cotton, twenty-eight hybrids were produced by half-diallel crossings between eight different parents. The results of combining ability studies' analysis of variance showed that the expression of seed cotton yield/plant (g) and its contributing traits was influenced by both additive and non-additive gene actions. The ratio of gca/sca for the pooled locations shows that all the traits, with the exception of day to 50% flowering and day to first picking at Surat and Bharuch, and plant height (cm) at Surat, were determined by non-additive gene action. This suggests that selection and hybridization would be an effective way to achieve desired improvements in seed cotton yield/plant and related traits, such as bolls/plant, boll weight, etc. The results of the GCA effect indicated that GN Cot 26 (5.54) and GBHV 200 (3.11) at Navsari, GN Cot 26 (4.70) and GSHV 242 (3.18) at Surat, and GBHV 200 (4.14) at Bharuch were the best combiners for seed cotton yield/plant among the eight parents. When combined over locations, GN Cot 26 (3.81) and GBHV 200 (2.43) performed well as general combiners

Combing ability, GCA, SCA, Half diallel, Seed Cotton Yield

Studies on combining ability help to identify the best parents and provide genetic information on the inheritance pattern of traits. Among the eight parents, at Navsari, GN Cot 26 (5.54) and GBHV 200 (3.11); at Surat, GN Cot 26 (4.70) and GSHV 242 (3.18) while at Bharuch, GBHV 200 (4.14) identified as best combiners for this trait. Pooled over locations, GN Cot 26 (3.81) and GBHV 200 (2.43) manifested as good general combiners while GN Cot 22 (-4.35) was the worst combiner among the 8 parents for this trait. An analysis for the specific combining ability effect revealed that top three hybrids with significant and desirable(positive) SCA effect at Navsari centre were GSHV 242 X GBHV 253 (11.83) followed by GBHV 200 X GISV 361 (8.60) and G Cot 16 X GN Cot 26 (7.61). At Surat location, GBHV 200 X GISV 361 (23.26), GSHV 242 X GBHV 253 (21.28) and GN Cot 26 X GISV 361 (13.30) were the best three hybrids while at Bharuch, GSHV 242 X GBHV 253 (18.93) followed by G Cot 16 X GN Cot 26 (18.04) and GBHV 200 X GISV 361 (12.12) were top most hybrids with significant and desirable (positive) SCA effect. Pooled over i.e., Navsari (L1), Surat (L2) and Bharuch (L3) centres; top three hybrids with significant and desirable (positive) SCA effect, across all the three centres (i.e. pooled over three centres) were GSHV 242 X GBHV 253 (17.35), GBHV 200 X GISV 361 (14.66) and G Cot 16 X GN Cot 26 (11.64)

Rakesh S. Ganvit, Kamleshkumar N. Chaudhari, Rajesh J. Panchal, Hardik R. Patel and Ashita Patel (2024). Combining Ability and Gene Action Studies for Yield and its Component Traits Over Different Environments in Cotton (G. hirsutum L.). Biological Forum – An International Journal, 16(4): 154-165.