Estimation of heterosis, gene action, heritability and genetic advance in Egyptian cotton ( Gossypium barbadense L.) [electronic resource].

Includes references.

Six generations P1, P2, F1, F2, BC1 and BC2 carried out at the Experimental Farm, Faculty of Agriculture, Minofiya University at Shebin EI-Kom during the three successive seasons 2009, 2010 and 2011 to evaluate genetic variance and detecting epistatic variation in two crosses i.e. Giza 92 x Giza 45 (cross I) and Giza 90 x Giza 80 (cross II). The means of the six generations recorded for days to first flower, plant height, number of fruiting branches per plant, number of open bolls per plant, boll weight, lint percentage, seed index, seed cotton yield, lint yield and lint index, were subjected to six parameters method to detect epistasis and estimates of m, a, d, aa, ad and dd parameters. Results showed that the genetic variance within F2 populations were found to be significant for all traits in the two crosses investigated. The results revealed that the epistatic gene effect cannot be ignored when establish a new br(jeding programe to improve cotton populations for economic traits. The inheritance of all studied traits was controlled by additive and non-additive genetic effects. Consequently, it could be concluded that selection procedures based on the accumulation of additive effects would be successful in improving all traits studied. However, to maximize selection advance, procedures which are known to be effective in shifting gene frequency when both additive and non-additive genetic variances are involved would be preferred. Heterobeltiosis was found to be significantly positive for number of open bolls per plant, boll weight, seed index, lint yield per plant and lint index in the two crosses, and plant height, number of fruiting branches and seed cotton yield per plant in cross fl. Inbreeding depression values estimated here were found to be highly significant and positive for boll weight, seed index and lint index in each of cross I and cross II, number of fruiting branches in cross I and plant height, number of open bolls per plant and lint yield per plant in cross II.

Summary in Arabic.

1