不同生态环境下短季棉早熟及相关性状的混合遗传

分别在河南新乡和新疆石河子2个生态环境下,对短季棉早熟及相关性状进行了主基因-多基因混合遗传分析。结果表明,除花铃期和衣分外,其它性状在2个环境中均检测到主基因。2个环境生育期的最适模型相同且主基因与多基因分量趋势一致,果枝始节、铃重虽最适模型相同,但主基因与多基因分量趋势相反,苗期、蕾期、花铃期、衣分、果枝始节高度2个环境最适模型不同。生育期在不同生态环境早代选择有效,果枝始节高度和果枝始节可作为鉴定早熟性的可靠形态指标。2个环境生育期、蕾期和果枝始节高度均以主基因遗传为主,其它性状均分别以主基因遗传为主或以多基因遗传为主,针对各性状的遗传模式提出了具体的育种策略。

Mixed Inheritance of Earliness and its Related Traits of Short-season Cotton under Different Ecological Environments

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 Ⅰ) and Northwest Inland Region (Shihezi, Xinjiang, Environment Ⅱ), 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 controlledby 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.