IMPROVING EGYPTIAN COTTON USING F2 Triallel CROSSES
Abstract: The aim of this investigation is to determine combining ability estimates for yield, yield components traits and some fiber properties in cotton. The genetic materials used in the present study included five cotton lines and their 30 F2 three-way crosses. All these lines belong to the species Gossypium barbadense L. In 2010 growing season, these genotypes were evaluated in a field trial experiment at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate. The following traits were estimated: seed cotton yield/plant, lint yield/plant, boll weight, lint percentage, fiber strength, fiber fineness and upper half mean. The results showed that the performances of most the F2 three-way crosses were as good as or better than their both grand parents or/and their third parent. The mean squares of genotypes were highly significant for all studied traits. From the analyses of F2 triallel crosses, the parental lines Giza 86 (P1) and Suvin (P3) were the best combiners as a grand parent and/or parent for all studied traits except fiber fineness property. On the other hand, the variety Giza 89 (P5) was the best combiner as a grand parent for fiber fineness (F.F.) property. Therefore, these parental genotypes could be utilized in a breeding program to improve these traits through selection in the segregating generations. The results also investigated that the crosses (P1 x P3) x P4 , (P1 x P5) x P2, (P2 x P5) x P4, (P3 x P5) x P4 and (P3 x P4) x P2 would be the best for all studied yield traits and upper half mean (UHM) property. Meanwhile, (P1 x P2) x P4, (P1 x P5) x P4 and (P2 x P3) x P4 appeared to be the best promising crosses for breeding toward all studied yield traits potentiality. In addition, the combinations (P1 x P4) x P5 and (P3 x P4) x P5 appeared to be the best promising for all studied yield traits, fiber strength (F.S.) and upper half mean (UHM) properties.Furthermore, the combination (P2 xP4) x P1 appeared to be the best promising for seed cotton yield/plant (S.C.Y./P.), lint yield per plant (L.Y./P.) and fiber fineness (F.F.) property. Most of these combinations had involved at least one of the best general combiners for yield.This indicates that predications of superior crosses based on the general combining ability effects of the parents which would be generally valid and the contribution of non-allelic interaction in the inheritance of these traits.These findings may explain the superiority of the three-way crosses over their parental lines for these traits.
Concerning epistatic variances, additive by additive genetic variances (?2AA), it showed positive values for all studied traits except for (F.F) property. While, additive by dominance genetic variances (?2AD) played the major role in controlling the inheritance of the studied characters of the triallel crosses. Therefore, recurrent selection might be useful in improving the studied characters of the triallel crosses in the breeding programs. The results also cleared that the calculated values of heritability in narrow sense ranged from 39.43% to 55.19% for seed cotton yield/plant (S.C.Y./P.) and fiber fineness (F.S.), respectively.
Publication year 2013
Pages 943 - 956
Organization Name
Project
Author(s) from ARC
Publication Type Journal
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