Breeding Potentials of Noncultivated Cottons. III. Inheritance of Date of First Flower1

Abstract

Date of first flower was analyzed in parental, F1 F2, and backcross generations of two cultivars and three Texas race stocks of cotton (Gossypium hirsutum L.). The cultivar ‘Deltapine 16’ (DPL) differed from Texas 203 (T‐203) by an additive component and from Texas 40Y (T‐40Y) by an additive and an epistatic component. T‐203 and T‐40Y were similar phenotypically but showed slight genetic differences from one another in flowering response. Both differed from the third race stock, Texas 711 (T‐711), by at least two genetic factors. DPL‐16 differed from T‐711 by more factors for flowering response than T‐203 or T‐40Y. The other cultivar, ‘Stoneville 7A’ (St 7A), seemed closely related phenotypically to DPL‐16. However, the hybrid combination between the two revealed significant additive, dominance, and epistatic effects. St 7A differed genetically from T‐40Y but not from T‐203 for date of first flower. St 7A, like DPL‐16, was quite different from T‐711. Favorable F1‐midparent heterosis was exhibited by two of the 10 hybrid combinations, DPL‐16 ✕ T‐711 and St 7A ✕ T‐711.