陆地棉机采性状对皮棉产量的遗传贡献分析

摘要

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(CRD=10％),其次是节间长度的贡献(CRD=8％),而霜前花率对皮棉产量有较大的抑制作用(CRD=-25％)；霜前花率对皮棉产量的加加上位贡献率最大(CRAA=86％),其次是第一果枝节位(CRAA=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(CRDE=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.%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 Fi and F2 hybrids, at two locations, using a genetic model with additive, dominant, additive x 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 x additive epistatic restraining effect on lint yield in certain environments. Different parents had different dominance and additive x 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 differ-ent 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 x 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 x additive epistatic effect of lint yield in different crosses.