ASSESSMENT OF GENETIC DIVERSITY AND STABILITY FOR YIELD TRAITS OF SOME EGYPTIAN LONG-STAPLE COTTON ENOTYPES

The present study aimed to evaluate some Egyptian cotton genotypes using stability statistical analysis and genetic diversity for seed and lint cotton yield, boll weight, lint percentage, seed index, lint index and earliness index. Nineteen cotton genotypes were evaluated with two promising crosses i.e. Giza 89 x Pima 56 and Giza 89 x Giza 86 and three Egyptian varieties i.e. Giza 89, Giza 86 and Giza 85, used as a check, were grown in a randomize complete blocks design with three replications at five locations. The studied baits showed highly significant mean squares for, genotypes, environment and genotype x environment interaction. Nine genotypes no. 1,2,3,4,6,15,16,17,19 and the promising cross
Giza 89 x Giza 86 exhibited high average level of stability and
surpassed other genotypes in the mean performance of seed and lint cotton yield. The genotypes no. 4, 9 and 18 behaved in the same way for boll weight, the genotypes no. 5, 10 and 18 and Giza 86 behaved in the same way for lint % and the genotypes no. 1, 4, 5, 6, 8, 9 and 17 for seed index. Also the genotypes no. 1, 3, 6 and 10 behaved the same way for lint index and the genotype no.6, 16 for earliness index. As for the genetic diversity, the results showed that the genotypes no. 1 and 16 revealed the lower genetic distance while the genotypes no. 13 and 14 showed the highly genetic distance. Also the results indicated that variety Giza 85 could be replaced by the promising cross Giza 89 x Pima S6. While variety Giza 89 could be replaced by Giza 89 ^x Giza 86. The breeder should select the superior genotypes to produce commercial variety or used in the breeding program.