温光敏雄性不育小麦BNS育性的遗传效应分析

Genetic Analysis on Male Sterility of Thermo-Photo-Sensitive Male Sterile Line BNS in Wheat

【目的】探究新型生态型雄性不育系BNS的遗传特点,为不育系的转育与改良提出理论指导,并为BNS败育机制的进一步研究奠定基础。【方法】利用7个品种(系)与BNS的正反交组合,判断BNS雄性不育的胞质效应,并利用植物数量性状主基因+多基因混合遗传模型,连续3年对BNS/山农055525 F1、F2的育性表现进行分析,判别其最佳模型,并估计遗传参数。【结果】BNS雄性不育性主要受核基因的控制,部分品种(系)表现胞质效应。BNS/山农055525 F2育性呈现连续分布状态,具有明显的多峰或偏态现象,遗传符合E_1,即2对加性-显性-上位性主基因+加性-显性多基因模型。主基因遗传率为72.5%—79.7%,多基因遗传率为4%—11.6%,环境方差占表型方差的比例为8.8%—23.6%。BNS雄性不育基因的表达受温度因子的影响较大,F2自交结实率及遗传参数因年度间的温度不同而异。【结论】BNS的雄性不育性受2对主基因和多基因的共同控制,并初步发现存在一定的胞质效应。2对主基因对育性的遗传影响较大,其加性效应远远大于显性效应。因此,在不育系的转育与改良过程中可以进行早代选择,以提高育种效率。

[Objective] The objective of this research is to explore the genetic characteristics of new eco-genetic male sterile line BNS, to provide a theoretical guidance for breeding of wheat, and to lay a foundation for the further study on abortion mechanism of BNS. [Method] Reciprocal combinations between BNS and eight varieties （ lines ） were constructed to evaluate the cytoplasmic effects in BNS male sterility. Fertilities of F1 and F2 generations from cross of BNS/Shannong 055525 were analyzed in successive three years to obtain the optimal mode by applying the major gene plus polygene model of quantitive traits, and genetic parameters were also estimated. [Result] The fertility of BNS was controlled chiefly by nuclear genes, but cytoplasmic effects existed in some varieties （lines）. The fertility ofF2 populations showed a continuous distribution, and had obvious multi peak or skew phenomenon. The fittest genetic models was E_l, and that is the mode of two additive-dominant-epistasis major genes plus additive - dominant and additive-dominant gene. The major gene heritability was 72.5%-79.7%, and the major gene heritability was 4%-11.6%. The proportion of environmental variance was 8.8%-23.6% in phenotype variance. Male sterile gene expression in BNS was mainly regulated by the temperature, which leading to the changes ofF2 seed setting rates and genetic parameters. [Conclusion] The male fertility in BNS was controlled by two major genes plus polygene, and a certain amount of cytoplasmic effects was preliminarilyfound. The two major gene have more effects on the fertility, and their additive effect are much more than their dominant effects. The male sterile lines transformed or improved from BNS might be selected in early generations to enhance the efficiency of breeding.