F₂ hybrid cultivars continue to occupy a portion of the cotton (Gossypium hirsutum L.) production areas in the United States and other countries. This study was conducted to determine the genetic relationship between traits and heritabilities of characteristics in F₂ hybrid population. Sixty-four F₂ hybrids resulted from crosses of 4 commercial cultivars and 16 pest-resistant germplasm lines were evaluated for 5 fiber and 4 yielding traits in four environments at Mississippi State, MS. An additive-dominance model was employed for these traits with different genetic background in different environments. MINQUE(1) method was used for estimating genetic variance and covariance components and predicting the genetic correlation.

Results indicated that dominant variance was the major portion of the phenotypic variances for lint yield, lint percentage and boll size. A smaller proportion due to additive variance for fiber traits and the significance on additive x environment variance components suggested that lack of substantial genetic variability for fiber traits within these F₂ hybrids. However, relatively high values of narrow-sense heritabilities for lint yield and yield component indicated that a sufficient proportion of additive genetic variance might be available in F₂ hybrids for effective selection. The estimates of the genetic and phenotypic coefficients of correlation for the pairs of characters, for the most part, seem to be of comparable magnitude. Fiber strength was positive-addictively correlated with boll weight, and the paired dominant correlations between these traits with elongation and 2.5% span length were also significant positive. Based on the analysis of heritability and genetic correlation, the indirect selection for yield improvement only by lint percentage were expected to be as effective as by lint yield itself for these F(2 )populations; however, indirect selection for yield improvement by other traits, such as boll number, fiber elongation and micronaire, would be 66%, 79% and 89% less effective than selection for lint yield itself, respectively.