【作者】 陈伟；

【导师】 周永明；

【作者基本信息】 华中农业大学 ， 作物生物技术， 2009， 硕士

【摘要】 油菜是世界重要的植物油脂来源。油菜种子各种脂肪酸的相对含量很大程度上决定了菜籽油的营养价值和经济价值。在低芥酸的基础上进一步提高油酸的含量和降低亚麻酸的含量,是油菜品质育种的重要内容。本研究旨在通过标记辅助选择（MAS）加快回交转育甘蓝型油菜高油酸、低亚麻酸优良品系的进程,获得具有高油酸、低亚麻酸目的性状且遗传背景回复为轮回亲本程度高的优良品系。本研究利用三个回交组合,针对油菜种子高油酸、低亚麻酸含量进行分子标记辅助选择。利用基因池筛选与油酸、亚麻酸含量相关的分子标记;运用气相色谱仪对油酸、亚麻酸含量进行表型鉴定;主要结果如下:1.与甘蓝型油菜种子油酸、亚麻酸含量相关的标记筛选在组合甲A177×甲A254中,利用集团分离分析法,筛选出与油酸含量相关的SSR分子标记SSR373、BRGMS630;与亚麻酸含量相关的分子标记BM135、SSR698、BM44-2、SSR128-3。对目的性状进行QTL扫描,得到一个与油酸含量相关的主效QTL。该QTL LOD值为66.1,贡献率为85.61%。其中标记BRGMS630距QTL峰值位置4.4cM,SSR373距QTL峰值位置15.01cM。两标记分别位于主效QTL的两侧。2.前景标记的功能验证利用组合甲A177×甲A254的DH分离群体,针对油酸含量性状,对标记SSR373、BRGMS630进行前景选择效果验证。结果SSR373的错选率为24.73%,BRGMS630的错选率为10.22%。而两标记一起使用错选率为5.88%。3.最终优良入选单株的获得利用分子标记与气相色谱仪表型选择相结合的手段对分离单株进行前景选择,再用分子标记进行背景选择。最终在组合甲A177×甲A254 BC₃F₂代获得优良单株08CW183。08CW183油酸含量达到73.95%,遗传背景回复率达到了94.12%。更多还原

【Abstract】 Brassica napus is a very important source of plant edible oil. The nutritional and economic value of rapeseed oil is largely determined by its relative contents of fatty acids in the seed. Therefore, it has become an important aspect of quality breeding in rapeseed to further increase oleic acid content and decrease linolenic acid content. In this study, the course of backcross breeding was accelerated to obtain the fin lines with high oleic acid and low linolenic acid through marker-assisted selection（MAS）. And the genetic background of fine lines got a high recovery of recurrent parent.In this study, we used marker-assisted selection for high-oleic, low linolenic acid content rapeseed in three backcross combinations. Molecular markers related to oleic and linolenic acid content were developed by bulk segregation analysis. Gas chromatography was used for the phenotype identification of oleic and linolenic acid content. The main results are as follows.1. Screening of markers related to oleic and linolenic acidIn the combination of甲A177×甲A254, we detected SSR markers SSR373 and BRGMS630 which were related to oleic acid content according to bulked segregation analysis. In the same way,wo identified SSR markers of BM135、SSR698、BM44-2、SSR128-3 which were related to linolenic acid content. We used the markers to scan correlative QTLs, and got a major QTL related to oleic acid content with the max LOD of 66.1, accounting for 85.61% of the total variance. Genetic distance between the marker BRGMS630 and the max QTL position was 4.4cM, and the genetic distance between the marker SSR373 and the max QTL position was 15.04cM. The two marker were located at both sides of the main-effect QTL.2. Functional verification of the foreground markersWe used DH lines of甲A177×甲A254 to validate the effect of foreground selection by marker SSR373 and BRGMS630. The ratio of false selection of SSR373 was 24.73%, and the ratio of false selection of BRGMS630 was 10.22%.While, we used the SSR373 and BRGMS630 together, the ratio was 5.88%. 3. Selection of genotypes with target characters and highest percentage of background from recurrent parentThe foreground selection was carried out by MAS and gas chromatography. And then, we used SSR and AFLP markers to give background selection of the whole genome. Finally, we got the fine individual 08CW183 in the BC₃F₂ of甲A177×甲A254. The oleic acid content of 08CW183 is 73.95%, and its recovering ratio of genetic background was 94.12%.更多还原