ÃÞ »¨ ѧ ±¨ Cotton Science 2010£¬22£¨4£©£º304-311
Mixed Inheritance of Earliness and its Related Traits of Short-season Cotton under Different Ecological Environments Abstract: Major gene-polygene mixed inheritance model was generated to analyze the genetics of earliness and its related traits of short-season cotton by using six generations including earliness variety Baimian 2 (P2) and genetic standard line TM-1 (P1) in upland cotton (Gossypium hirsutum L.), and their F1, B1, B2, and F2 grown in the Yellow River Valley Region (Xinxiang, Henan, Environment ¢ñ ) and Northwest Inland Region (Shihezi, Xinjiang, Environment ¢ò ), respectively. The results indicated that major genes were always detected under two environments in all traits except flower and boll period as well as lint percentage. Under two environments, optimum genetic models of growth period were identical, and the tendencies of their major gene heritability proportion were also consistent as well as that of polygene. Although optimum genetic models of fruit branch beginning site and boll weight under two environments were identical, the tendencies of their major gene heritability proportion were opposite as well as that of polygene. Optimum genetic models of seedling period, bud period, flower and boll period, lint percentage and height of fruit branch beginning site were all different under two environments. Under two environments, total heritability tendencies of growth period, seedling period, bud period, height of fruit branch beginning site and fruit branch beginning site were more stable than other traits, in which total heritability of growth period was always the highest of all, indicating selection was efficient in early generations under different ecological environments, height of fruit branch beginning site and fruit branch beginning site might be considered as credible morphological indices to identify earliness of short-season cotton. Under two environments, growth period, bud period and height of fruit branch beginning site were all mainly controlled by major gene; seedling period, flower and boll period, fruit branch beginning site and lint percentage were all mainly controlled by major gene and polygene, respectively; boll weight was mainly controlled by polygene and major gene, respectively. To improve breeding efficiency, single cross recombination or simple backcross should be adopted for the traits mainly controlled by major gene, while polymerization backcross or recurrent selection to cumulate positive alleles should be adopted for the traits mainly controlled by polygene.
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