Associations among Lint Yield, Yield Components, and Fiber Properties in an Introgressed Population of Cotton

Broadening the genetic base is essential for genetic improvement of lint yield and fiber quality in upland cotton (Gossypium hirsutum L.). An exotic germplasm population derived from multiple crosses between G. barbadense L. and G. hirsutum was obtained from USDA-ARS at Las Cruces, NM. Experiments were designed to evaluate this germplasm for genotypic variation in lint yield and fiber quality. Two hundred germplasm lines and five cultivars were planted at two locations in 2006 and one location in 2007. Significant (P <= 0.001) genotypic variation for yield and fiber quality was identified. In path coefficient analysis, bolls per square meter had the largest direct effect on lint yield, while boll weight and lint percentage had secondary direct effects on yield. Lint yield was negatively associated with fiber quality. Lint per seed was favorably correlated with lint percentage, elongation, span lengths, and fineness. Based on stepwise analysis, 50% length, short fiber content, fineness, maturity ratio, and 2.5% length contributed to strength, in decreasing order of significance. Short fiber content was negatively correlated with fineness (r = -0.41). These results indicate that this germplasm is a useful genetic resource for genetic improvement of lint yield, fiber quality, and analysis of interrelationships between lint yield and fiber quality.