Genetic impacts of fiber sugar content on fiber characters in Sea Island cotton, Gossypium barbadense L.

A genetic model with additive effect, dominant effect, additive x additive effect, and their interaction with environment effect (GE) was employed to analyze the 2-year data of F-1 and F-2 hybrids from 5 x 4 diallel cross, whose parents were Sea Island cotton with different fruit branch types. Unconditional and conditional genetic variances were analyzed to demonstrate genetic impacts of fiber sugar content on fiber characters. Results of unconditional genetic variances showed that dominance x environment interaction effect and additive x additive epistatic effects mainly controlled the genetic variation of fiber sugar content, and environment influenced the inheritance of fiber sugar content. Fiber uniformity, fiber elongation, and fiber micronaire were mainly controlled by dominance x environment effects. Fiber strength was mainly controlled by the interaction of additive x additive epistatic effects and the environment. Analysis of correlation coefficients indicated that the varieties or hybrids with high-fiber sugar content had short fiber, low-fiber uniformity, strength, and fineness, which indicated the close co-variation between fiber quality traits and fiber sugar content. Relatively better fiber quality traits could be obtained effectively through selecting parents with low-fiber sugar. Fiber sugar content of different parents had different genetic effect on fiber quality traits.