| Abstract: | Backgroundwater shortage is the greatest significant reason controlling crop yield that harmfully affects fruit production, boll shedding, lint yield and fiber properties quality in cotton plants. Objectives: this study was carried out at Sakha Agricultural Research Station, Kafr El-Sheikh, Agric. Res. Center, Egypt, during 2014 and 2015 growing seasons. A study was undertaken in cotton (G. barbadense L.) to detect the magnitude of genetic divergence among parental cotton genotypes and their F1s cross combinations and to select most suitable combinations for tolerant water deficient. Results and conclusion: the data showed that the first eight main principal components with eigen value more than one are extracted from the complicated components, the total cumulative variance of these eight factors amount for about 85.28% of the total multivariate variance. Suggesting that these PCA scores might be used to summarize the original variables in any further analysis of the data. The female parent 10,229 formed wide cluster having wide divergent distance from the other groups. On the same trend, the extra-long varieties Giza 96 and Giza 45 formed unique groups, cluster number 8 and cluster 1 nearly related. Cluster number 7 and cluster 4 which consisted of two genotypes for each characterized by susstable to water deficit conditions. The cross combinations Giza 77 x Dandra, Giza 77 x Pima S6, Giza 96 x Australy and Minufy x Dandra grouped at the same cluster, however the cross combinations Giza 86 x Dandra and Giza 68 × 10,229 classified into two different clusters. The data revealed that the inter cluster distance was higher than the intra cluster, indicating wide genetic divergent among the studied genotypes. Principal components analysis is useful in identifying and most influential characters affecting genetic variation of population. |
