陆地棉机采性状对皮棉产量的遗传贡献分析

 采用加性-显性-加加上位性及其与环境互作的遗传模型（ADAA模型），对8个陆地棉亲本（其中有6个机采棉品种）及其F₁和F₂的28个组合5个机采性状和单株皮棉产量的新疆阿拉尔和石河子2试点资料，进行了贡献分析。结果表明，5个机采性状对皮棉产量表型值的贡献变化范围为－20%～－14%；在显性贡献中，第一果枝高度对皮棉产量的贡献率最大（CR_D=10%），其次是节间长度的贡献（CR_D=8%），而霜前花率对皮棉产量有较大的抑制作用（CR_D=－25%）;霜前花率对皮棉产量的加加上位贡献率最大（CR_AA=86%），其次是第一果枝节位（CR_AA=24%）。霜前花率在特殊的环境中对皮棉产量表现为很大的显性正向贡献（CR_DE=78%）和加加上位效应抑制作用。不同亲本5个机采性状对其皮棉产量的显性和加加上位效应贡献不同。5个机采性状对不同组合皮棉产量显性效应的贡献较小，霜前花率对皮棉产量的显性效应的贡献在2个地点的表现往往和单株皮棉产量在不同地点表现显性效应的性质（正或负）相一致，并且在5个机采性状中对皮棉产量的显性贡献是最大的。加加上位效应在皮棉产量的遗传中起着很重要的作用，而在8个亲本及其后代各组合的5个机采性状中，霜前花率可作为选择皮棉产量加加上位效应的主选性状。在不同的环境中，皮棉产量加加上位效应的主选机采性状随组合有所不同。

Analysis of Genetic Contribution of Mechanical Harvesting Traits to Lint Yield in Upland Cotton

We investigated the effects of the genetic contribution of mechanical harvesting traits to lint yield in upland cotton(Gossypum hirsutum L.),in Alar and Shihezi,Xinjiang,China.We analyzed the data for lint yield per plant,five mechanical harvesting traits for eight parents and F1 and F2 hybrids,at two locations,using a genetic model with additive,dominant,additive×additive epistatic effects(the ADAA model).There were phenotypic contributions to lint yield from five mechanical harvesting traits(contribution ratios ranged from-20% to-14%).The height of first fruit branch had the greatest contribution to lint yield(CRD=10%),followed by internode length(CRD=8%),while there was greater restraining effect from yield percentage at pre-frost to dominance effect of lint yield(CRD=-25%).The largest ADAA effect on lint yield from yield percentage at pre-frost was 86%,followed by internode length of the first branch(CRAA=24%).Yield percentage at pre-frost had very high positive dominance contribution ratios(CRDE=78%) and an additive×additive epistatic restraining effect on lint yield in certain environments.Different parents had different dominance and additive×additive epistatic contributions depending on the particular mechanical harvest trait.The five mechanical harvesting traits had little contribution to lint yield,and yield percentage at pre-frost had different contributions(positive or negative) at two locations.There also existed a larger contribution to lint yield than the other four mechanical harvesting traits.The additive×additive epistatic effect was very important for lint yield,while yield percentage at pre-frost was mainly a selection trait for them.In special environments,there were different mechanical harvesting selection traits for the additive×additive epistatic effect of lint yield in different crosses.