高产小麦主要性状的遗传模型分析

Genetic Model Analysis and Parameter Estimate on Main Characters of High-yield Wheat

选用 1 9个高产小麦品种 ,形成 1 0 9+1 9增广 NCII设计 ,对 1 8个数量性状进行遗传研究。结果表明 ,一节高比、二节高比符合加性效应模型 ,三节高比和退化小穗数符合加性—显性效应模型 ,株粒重、株穗数、单穗重、单株生物产量、千粒重、穗粒数、有效小穗数、穗长、株高、穗颈长、穗下一节长、穗下二节长、穗下三节长、颈高比等 1 4个性状不符合加性—显性效应模型 ,还存在其它效应。对三节高比和退化小穗数二性状的遗传参数估计结果表明 :二性状雌、雄亲的遗传变异主要是加性效应 ,平均显性度为程度不同的部分显性 ;二性状增、减效等位基因频率在雌亲组中和雄亲组中 ,平均来说都不相等 ;二性状在雄亲组中显性等位基因占优势 ,在雌亲组中显、隐性等位基因频率大致相等 ,穗下三节高比的提高和退化小穗数的减少是由显性基因控制的 ,且均为部分显性。

In this paper,10×9+19 augmented NCII design was adopted, 19 high yield common wheat varieties collected from several districts were selected for the genetic model analysis and genetic parameter estimate. The results of genetic model analysis showed that, the ratio of first internode length under spike to plant height (FL/PH) and the ratio of second internode length under spike to plant height (SL/PH) fitted additive effect model (in augmented NCⅡdesign),and the ratio of third internode length under spike to plant height (TL/PH) and deteriorated spiklet number fitted additive dominance effect model. The other 14 traits didn′t fit additive dominance effect model. The genetic regression equations of covariance (Wr) on variance (Vr) over arrays were given. To TL/PH and deteriorated spikelet number, the results of the estimate of genetic parmeters showed that:(1)The two characters were mainly controlled by additive genes in both female and male parents, and their average degree of dominance was partial dominance at certain degree. (2)The frequency of increasing and decreasing effect allel of the two traits was unequal, both in female and male parents. (3)In male parents the dominant allels of the two characters dominated, but, in female parents the dominant allel frequency was approximately equal to that of the recessive allel. (4)The increase of TL/PH and the decrease of deteriorated spikelet number were controlled by dominant genes, which were prtially dominant.