大豆脂肪及脂肪酸组分含量的遗传分析

INHERITANCE OF FAT AND FATTY ACID COMPOSITION CONTENTS IN SOYBEAN

以Essex×ZDD2315的P1、P2、F1、BC1F3为材料,用主基因+多基因混合遗传模型,分析大豆脂肪及脂肪酸组分含量的遗传机制及相关关系。结果表明,大豆脂肪含量受2对加性互补主基因+多基因控制,主基因遗传率为16.23%,多基因遗传率为53.49%;棕榈酸、硬脂酸和亚油酸均为3对主基因+多基因遗传模型,其中均有2对主基因效应为等加性,主基因遗传率分别为71.63%,91.51%和91.59%,棕榈酸多基因遗传率为14.78%,硬脂酸和亚油酸未估计出多基因遗传率;油酸为3对加性主基因遗传模型,其中2对主基因效应为等加性,主基因遗传率为74.66%;亚麻酸为2对等加性主基因+多基因遗传模型,主基因遗传率为41.98%,多基因遗传率为24.17%。相关分析结果,棕榈酸、亚麻酸与脂肪呈极显著负相关(-0.272、-0.325);油酸与亚油酸亚麻酸呈极显著负相关(-0.833、-0.604);亚油酸和亚麻酸呈极显著正相关(0.287);棕榈酸与油酸亚油酸呈极显著和显著负相关(-0.255和-0.211);硬脂酸与亚油酸呈极显著负相关(-0.310)。因此,脂肪及脂肪酸组分含量的遗传涉及到主效基因和多基因,脂肪及亚麻酸含量的主基因遗传率较低,其它性状主基因遗传率均在70%以上,改善脂肪含量要注重多基因的积累,改善脂肪酸组分可着重在主基因的利用,提高脂肪含量与改善脂肪酸组分无突出矛盾。

Genetic improvement of fat and fatty acid composition content of soybean seed is interesting to both farmers and processors. The objective of this study was aimed at revealing the genetic mechanism of fat and fatty acid composition content in soybean. Genetic analysis were performed under major gene ＋ polygene mixed inheritance model in the P1 ,P2 ,F1 ,and BC1F3 of the cross Esse× ZDD2315. The results showed that fat content and linolenic acid content of the cross were controlled by two major genes plus polygenes,with the major gene heritability of 16.23%, and 41, 98 %, respectively,and polygene heritability of 53.49 %, and 24.17 %, respectively. Three major genes and polygenes contributed to the inheritance of palmitic,linoleic and stearic acids contents,with the major gene heritability of 71.63%, 91.59%, and 91.51%, respectively, and polygene heritability of 14. 78% in palmitic acid, but no polygenes detected in linoleic and stearic acids. The inheritance of oleic acid content was controlled by three major additive genes,with the heritability of 74.66 %. The conclusions were as follows：the inheritance of fat and fatty acid composition content in soybean involved with both major genes and polygenes; while for other fatty acids mainly due to major genes with their heritability of more than 70% ,the major gene heritability of fat and linolenic acid contents were smaller. In the improvement of fat content,accumulating polygenes should be emphasized, while utilization of major genes is preferred for fatty acid improvement. There will be no serious contradictions in the improvement of both fat content and fat quality traits.