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作者	单位
杨兴圣，梁子英，李华，沈玮囡，李美霞，奚亚军，王竹林，刘曙东	(西北农林科技大学农学院，陕西杨凌 712100)

摘要点击次数: 1973

全文下载次数: 1217

中文摘要:

为给小麦遗传育种中籽粒性状改良提供参考，以小麦大粒品系0911-46为母本与小粒品系42杂交产生P₁、P₂ 、F₁ 、BC₁ 、BC₂ 和F₂共4个世代6个群体，应用主基因+多基因混合遗传模型多世代联合分析方法分析了小麦粒重、粒长、粒宽、粒厚的遗传特点。结果表明，千粒重、粒宽、粒厚都符合2对加性-显性-上位性主基因+加性-显性-上位性多基因遗传模型。2对粒重主基因都具有正向加性效应，可以增加粒重，但其互作效应有正有负且互相抵消，对粒重影响不大。粒宽和粒厚的显性效应为正向作用，有利于增加籽粒体积。粒长符合加性-显性-上位性多基因模型，无主基因。千粒重主基因+多基因遗传率在BC₁、BC₂、F₂三个分离世代分别为88.02%、78.53%、87.82%；粒长多基因遗传率在3个分离世代分别为71.95%、61.64%、62.93%；粒宽主基因+多基因遗传率在3个分离世代分别为43.90%、32.69%和68.47%；粒厚主基因+多基因遗传率在3个世代分别为50.01%、42.86%和68.63%。所有籽粒性状中以粒重的遗传力最高。

英文摘要:

Wheat kernel characters, including grain weight, grain length, grain width and grain thickness, are associated with yield tightly. 0911-46, the female parent, which had bigger grain size and grain weight, was crossed with “Line 42”, which was relatively smaller in each trait, and produced six pedigrees of 4 generations (P₁, P₂, F₁, BC₁, BC₂ and F₂). The methods of multiple generations of conjoint analysis of major gene plus polygenes mixed inheritance model were used for genetic analysis of grain weight, grain length, grain width and grain thickness, so as to understand the genetic regularity of grain trait in common wheat. In this study, IECM (interated expectation and conditional maximization) was used to evaluate the related parameters in mixed distribution and then the compatibility was tested through the judgment of AIC (Akaike's information criterion) values. Meanwhile, optimal genetic model was chosen during this analytic process and least square method was used to evaluate the genetic parameters of wheat grain traits. Through variance analysis, grain weight, grain length, grain width and thickness showed significant quantitative properties. Phenotypic analysis showed that the grain weight was controlled by major genes and minor genes at the same time. The grain length was controlled by multiple genes. The grain width was controlled by major genes and minor genes simultaneously. The grain thickness was controlled by more than one pair of major genes as well as several minor genes (modifier genes).The results of genetic models demonstrated that the grain weight, grain width and grain thickness conformed to the genetic model of two additive-dominant-epistatic major genes plus additive-dominant-epistatic polygenes. Two major genes of grain weight had positive additive effects that could increase grain weight. Both positive and negative interaction effect was found between the two major genes. Because of the similar effect value, the interaction effect was canceled each other out, so little effect was found on grain weight. The dominant effect of grain width and grain thickness was positive, which was helpful for increasing grain volume. Grain length conformed to the gene model of additive-dominant-epistemic and had no major gene. The genetic heritability of major gene plus polygene for grain weight in the three segregating generations (BC₁, BC₂ and F₂) was 88.02%, 78.53% and 87.82%, respectively. The polygenic genetic heritability of grain length in the three segregating generations was 71.95%, 61.64% and 62.93%, respectively. The inheritance rate of major gene plus polygene for grain width in the three segregating generations was 43.9%, 32.69% and 68.47%, respectively. The inheritance rate of major gene plus polygene for grain thickness in the three segregating generations was 50.01%, 42.86% and 68.63%, respectively. Among all grain characters, the heritability of thousand kernels weight was the highest, which indicated that thousand kernels weight was a stable character, and less affected by the environment, and might be chosen and improved effectively in filial generation.

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