Associations of fiber quality parameters and lint yield components in six diverse cotton genotypes

Abstract

High yielding cotton, Gossypium hirsutum L., cultivars with improved fiber bundle strength are needed for today's spinning technology. This study was initiated to determine the effects of selection for improved fiber quality on within-boll yield components in six cotton genotypes. Fiber quality parameters were: upper half mean fiber length (UHM) , fiber bundle strength, micronaire, and uniformity index. Lint yield components included: seed surface area (SAS) , lint percentage (LP) , seeds per boll (SBOLL) , f ibers per seed (FS), lint yield per seed (LYS), fibers per unit seed surface area (FSA) , and lint yield per unit seed surface area (LYSA) . Parents and Fi I s from a diallel mating scheme, excluding reciprocals, were space planted in 1989 and 1992 at College Station,, Texas. Seed-cotton weight and lint weight per boll were determined from hand harvested bolls. Weight per 100 seeds (seed index) and their volumetric displacement values were determined from these boll samples, which were used to calculate individual lint yield components. Fiber strength was positively correlated with UHM and negatively correlated with LP, SBOLL, FS, FSA, LYS, and LYSA. Upper half mean length was positively associated with fiber strength, uniformity index, and SAS; and negatively associated with FSA. Micronaire was positively associated with LP and LYSA, and negatively associated with FS and FSA. General and specific combining ability values among these genotypes were significant for most of the fiber quality and yield components measured. None of the six genotypes in this study combined well for increased fiber strength and increased FSA, the most basic unit of lint yield.