ASSOCIATION OF FIBER QUALITY PARAMETERS AND WITHIN-BOLL YIELD COMPONENTS IN UPLAND COTTON

Lint yield and fiber quality in upland cotton, Gossypium hirsutum L., are interrelated through a series of individual components such as fib er length and the number of fibers produced on each seed Numerous stud ies have reported the relationships among various components of yield and yield per unit land area, but none have reported on the relationsh ips among the most basic within-boll yield components and fiber qualit y parameters. The objectives of this study were (i) to determine the a ssociation of fiber quality parameters with basic within-boll yield co mponents for six diverse cotton genotypes and (ii) to determine if rep ulsion phase linkage explained the high negative correlations reported among fiber quality parameters and List yield. The second objective w as investigated by comparing the associations of fiber length, strengt h, and micronaire with within-boll yield components among selected F-1 populations developed by mating parents with similar direction of gen eral combining ability (GCA) for fiber quality and within-bell lint yi eld components with selected F-1 populations derived by mating parents with dissimilar direction of GCA. Parents and F1S were grown at Colle ge Station, TX, in 1989 and 1992. Fiber quality parameters were determ ined by high volume instrumentation. Within-bull lint yield components were determined by direct measurement or through calculations. Fiber strength and length were negatively associated with the most basic wit hin-bell lint yield components. Repulsion phase linkage appears to pla y a role in the negative association of fiber quality and within-boll lint yield but pleiotropic effects could not be ruled out.