Performance and Stability of Doubled Haploid Lines of Upland Cotton Derived via Semigamy1

Abstract

Doubled haploid lines of cotton (Gossypium hirsutum L.) derived via semigamy and colchicine doubling from diverse parental strains were evaluated for yield in several year‐location environments in Mississippi in 1980 and 1981. Experiments were conducted to determine agronomic performance and fiber properties of 15 doubled haploid lines. Selected doubled haploids, their parental strains, and commercial cultivars were evaluated in 1980 for allelochemic compounds alleged to confer resistance to the tobacco budworm, Heliothis virescens (F.). Stability parameters were determined for seed cotton yield and allelochemics using linear regression analyses to estimate regression coefficients (b values) and coefficients of determination (r2 values). A genotype was considered environmentally stable when a unit change in genotype performance corresponded to a unit change in environmental index. The hypothesis, Ho: β = 1.0, or no significant difference between the performance of a cotton line and the mean performance of all lines over environments was tested for each strain. Agronomic and fiber traits were improved for some doubled haploids but were inferior for other traits compared with their respective parental strains. Generally, doubled haploid lines were as environmentally stable for yield performance as parental strains. This was also true for within‐season variability of allelochemic compounds. Heterogeneity of a strain or cultivar was not an apparent prerequisite for environmental buffering effects. Cumulative expression of genetic traits may play a more important role in maintaining environmental stability than relative heterozygosity.