Inheritance Pattern of Fiber Related Traits under Normal and Hypoxia Conditions in Cotton (Gossypium Hirsutum L.)

An 8 × 8 diallel crossing system was employed in F₁ generation of cotton to study the inheritance pattern of fiber related traits like micronaire, strength and maturity under normal and hypoxia conditions. Analysis of variance revealed significant variation (P < 0.01) for all the traits under both environments. The regression coefficient b deviated significantly from zero but not from unity for all studies traits allowed further analysis of the data. The additive component (D) was significant for all the traits and more than the values of dominance components H₁ and H₂ in case of fiber strength under both conditions and for fiber uniformity under normal conditions thus showing the preponderance of additive genetic effects. For micronaire non-additive effects were predominant under both environments. Estimates of narrow sense heritability for micronaire were 38.6% under normal and 49.5% for hypoxia, 79 and 80% for fiber strength and for fiber uniformity the estimates were 79% under normal conditions and 63% under hypoxia conditions. Predominance of additive genetic effects, high heritability along with partial dominance for fiber strength under both conditions and for fiber uniformity under normal conditions is indicative of early generation selection but for micronaire under both conditions selection may be practiced in later generations.