| Abstrakt: |
The hybrid vigor in Gossypium hirsutumL. ✕ G. barbadenseL. F1hybrids is usually associated with late maturity and excessive vegetative growth relative to reproductive development. These undesirable traits tend to limit the range of hybrid adaptability to areas with long growing seasons. Experiments reported herein demonstrate that an early semidwarf G. hirsutumline of Yugoslavian, Kekchi, and Acala (YKA) origin produced highly desirable agronomic types of hybrids in crosses with three G. barbadenselines. These F1hybrids were shorter‐statured and as early and productive as the bestyielding locally adapted commercial variety, ‘Acala 1517‐70.’ The YKA parent transmitted dominant factors for early, prolific fruiting to its progeny. The tendency for heavy fruiting early in the season apparently reduced the rate of vegetative growth so that hybrids were relatively short‐statured at maturity. The interspecific hybrids required a longer period for boll maturation than did Acala 1517‐70. Because the hybrids had fiber 4 to 6 mm longer than the check, it was reasoned that the longer boll period was associated with fiber length and that further advances in earliness might be gained from crossing very short‐fibered lines of G. barbadense✕ YKA to produce short‐fibered hybrids. Other properties of the hybrids were discussed, and subsequent steps to be taken in the improvement of interspecific hybrids were outlined. |
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