甘蓝型油菜籽粒含油量、蛋白质、纤维素及半纤维素含量QTL分析

QTL Mapping for Oil,Protein,Cellulose,and Hemicellulose Contents in Seeds of Brassica napus L.

以甘蓝型黄籽油菜GH06和甘蓝型黑籽油菜P174为亲本,通过单粒法连续自交8代构建重组自交系群体,应用SSR标记绘制31个连锁群(LGs)的遗传连锁图谱,图谱总长1437.1cM,相邻标记间的平均距离为3.89cM。对4个不同环境下RIL8群体中每个株系籽粒含油量、蛋白质、纤维素和半纤维素含量进行了近红外检测。性状相关性分析表明,含油量与其他3个性状均表现负相关,蛋白质含量与纤维素和半纤维素分别表现负相关和正相关。结合构建的遗传图谱,采用复合区间作图法分析4个性状QTL,共检测到26个QTL,分布在N2、N3、N8、N9、N11、N13、N16和N17连锁群上,其中8个含油量QTL可解释表型变异的4.96%～21.83%;6个蛋白含量QTL,可解释表型变异的3.12%～14.28%;4个纤维素含量QTL,可解释表型变异的4.60%～17.29%;8个半纤维素含量QTL,可解释表型变异率的6.66%～16.68%。在N8上,发现有含油量QTL与半纤维素含量QTL重叠的区段。在N9上,发现有纤维素含量QTL与半纤维素含量QTL重叠的区段,上述2个区段重叠QTL加性效应方向相反。本研究认为油菜种子含油量、蛋白质、纤维素和半纤维素属于典型的数量性状,受环境影响较大,与这些QTL紧密相关的分子标记可为下一步分子标记辅助育种提供一定技术支撑。

The objective of this study was to detect quantitative trait loci （QTLs） associated with oil, protein, cellulose and hemi- cellulose contents in rapeseed. The mapping population contained 176 recombinant inbred lines （RILs, Fs）, which was developed from the cross between yellow seeded female parent GH06 and black seeded male parent P174. A linkage map was constructed using 369 simple sequence repeat （SSR） markers, which was composed of 31 linkage groups with the total length of 1437.1 cM and the average distance of 3.89 cM between adjacent markers. We measured four quality traits of seeds in four environments. According to correlation analysis, oil content was negatively correlated with other three traits, whereas, protein content was nega- tively correlated with cellulose content but positively correlated with hemicellulose content. Using composite interval mapping （CIM） method, a total of 26 QTLs distributed on linkage groups N2, N3, N8, N9, N 11, N 13, N 16, and N 17 were detected for the four seed quality traits. Eight QTLs were associated with oil content, and the contribution of a single locus for phenotypic varia- tion ranged from 5.0% to 21.8%. Six QTLs were detected for protein content, which explained 3.1%-14.3% of the phenotypic variation. Four and eight QTLs were detected for cellulose and hemicellulose contents, with phenotypic contributions of4.6%-17.3% and 6.7%-16.7%, respectively. Furthermore, overlapping regions were observed in linkage group N8 between QTLs for oil content and hemicellulose content and in linkage group N9 between QTLs for cellulose content and hemicellulose content. These results suggest that oil, protein, cellulose and bemicellulose contents are typical quantitative traits controlled by many mi- nor-effect genes with significant influence of environment. Molecular markers linked to these QTLs might be useful in molecular marker-assisted breeding.