【目的】研究白菜型油菜的自交亲和性、角果及种子相关性状的QTL定位,为白菜型油菜自交亲和品种、优良自交系的选育及其产量和品质的遗传改良提供依据。【方法】以自交亲和性较差的菜薹L58和自交亲和性较好的白菜型油菜R-O-18构建的包含117个株系的RIL群体为试验材料,利用已构建的包括372个In Del标记的分子遗传图谱,采用区间作图法(IM)对花期亲和指数、结角率、角果长度、角果喙长度、角果长宽比、角果喙长度/角果长度、每角果种子数、千粒重及种子颜色9个性状分别进行QTL分析。【结果】RIL群体在自交亲和性、角果及种子相关的9个性状上表现为连续变异,并且变异幅度较大,均呈正态分布或偏正态分布,具有典型的数量性状遗传特点。花期亲和指数与结角率、角果长度、角果喙长度、角果长宽比、每角果种子数、千粒重均存在极显著的正相关,其中花期亲和指数与每角果种子数间的相关系数最大,达到0.8487。与其他几个性状的相关性大小依次为:千粒重〉结角率〉角果喙长度〉角果长度〉角果长宽比。每角果种子数及千粒重均与结角率、角果长度、角果喙长度、角果长宽比呈现极显著正相关,而每角果种子数与千粒重之间也存在极显著的正相关(0.6477)。结角率、角果长度、角果喙长度与角果长宽比之间呈现显著正相关;而角果喙长/角果长除了与角果长呈负相关,角果喙长度存在极显著正相关性外,与其他性状均不相关。共检测到12个QTL位点,其中6个QTL位于A09连锁群,10个QTL解释大于10%的表型变异。2个控制花期亲和指数的QTL均位于A09连锁群上,分别可解释13.1%和16.7%的表型变异;6个角果相关性状的QTL,分别位于A06、A09和A10连锁群上,单个QTL可解释13.4%—17.7%的表型变异;4个种子相关性状的QTL,分别位于A02、A05、A06和A09连锁群上,可解释7.9%—42.
[ Objective ] Brassica rapa is an important oil crop in the world. Higher seed yield with good quality is one of the important agronomic traits. Due to the self-incompatibility characteristic of most B. rapa, it is difficult to purify breeding materials and realize maximum yield of this plant, since the seed yield of this crop is influenced by the silique related traits, such as the number of pods, number of seed per silique. Besides, the seed quality is closely related to seed color. The aim of this research is providing an important genetic basis for breeding self-compatibility varieties or inbred lines of B. rapa and genetic modification of yield with quality in this crop. [ Method] The Recombinant Inbred Lines (RILs) population derived from the cross between genotypes R-O-18 with welt self-compatibility and L58 with weak self-compatibility consisting of 117 lines was used to conduct QTL analysis. Based on previous linkage map generated by 372 InDel markers, the Interval Mapping (IM) method was used to survey a total of nine traits as follows: compatible index of flowering time (CIFT), pods rate (PR), silique length (SL), silique beak length (SBL), silique length/silique width (SL/SW), silique beak length/silique length (SBL/SL), number of seed per silique (NSPS), thousand seed weight (TSW) and seed color (SC). [Result] RILs population in the 9 self-compatibility, siliques and seeds-related traits showed continuous variation and variation margin, showed normal or partial normal distribution, with typical quantitative genetic characteristics. CIFT showed an extremely significant positive correlation with PR, SL, SBL, SL/SW, NSPS, and TSW, where the correlation coefficient between CIFT and NSPS was the largest, reaching 0.8487; and several other traits in order of size (high to low): TSW, PR, SBL, SL, and SL/SW. NSPS and TSW presents a very significant positive correlation with PR, SL, SBL, SL/SW, NSPS also had a significant positive correlation with TSW (0.6