Assessment of relationships of quantitative and fiber quality traits and their variations among tetraploid cotton (G. hirsutum) cultivars

In order to correlation diversity assessment among the quantitative and fiber quality traits, five cultivars of tetraploid cotton (G. hirsutum) cultivars were evaluated at Varamin region in 2009. In this study the populations of the cultivar lines were planted near together and 100 lines randomly were selected at the end of the season followed by measuring seed cotton yield and quantitative and fiber quality traits of each plant. The correlations among the traits, stepwise regression analysis of lint percent as dependent variable and other traits as independent variables calculated for cultivars, separately, as well as all them together. Further, cluster analysis using Ward method was used to classify the cultivars in view of all traits and correlations. The results showed that, there is a high variation among cultivars regarding correlation among the traits. The correlation between fiber length and fiber fineness was negative among all cultivars and only it was significant with Sealand and Avangard cultivars. There was not any significant correlation between seed cotton yield and fiber quality traits among cultivars. The variation also existed among cultivars in term of the traits which entered the multiple regression models and affected the fiber percent. Cultivars classification based on correlation among the traits was in agreement with that based on measured traits. The results suggest that the existing variation among cultivars may be useful for further cotton improvement programs.