多室油菜在高产育种中具有很大应用潜力。甘蓝型油菜中由于缺乏这种资源，限制了该性状的分子机理研究与育种应用；而传统的遗传修饰技术同时改造多位点的能力有限，很难在该多倍体作物中用于创建多室突变体。因此，在前期研究中申请人建立了油菜中的CRISPR/Cas9技术体系，并成功对多室候选基因CLV3的所有同源拷贝进行了编辑。在此基础上，本研究拟在甘蓝型油菜中开展以下工作：1、系统创建CLV途径中多个重要多室候选基因的单基因突变体（包括单个特异拷贝、多个同源拷贝的突变体），鉴定出其中的多室基因，明确各基因的不同拷贝在多室形成过程中的功能及相互关系；2、通过杂交聚合产生多基因突变体，从调控途径上研究不同多室基因间的相互关系；3、将创建的多室基因资源转育到优良油菜品种中，初步评价其应用潜力。通过上述工作，实现甘蓝型油菜多室种质资源创新、解析该性状形成的分子调控机制，为油菜的分子设计育种提供新材料和方法。

Multilocular rapeseed has great potential for the development of high-yield crops. In Brassica napus, the molecular basis of the important trait is poorly understood because of lacking multilocular germplasm resources, which also retards its application in practical breeding. Because of the limited capability of simultaneous modification multiple loci, the traditional technologies of genetic modification are difficult to create multilocular germplasms in this polyploid crop. Therefore, we established the CRISPR/Cas9 genome editing system in rapeseed in previous study, and successfully generated transgenic rapeseed plants that carry mutations in all three alleles of an important multilocular candidate gene CLV3 in Brassica napus. In the present project, we will conduct the following works in Brassica napus: 1) to systematically create single-targeted gene mutants (including plants mutated in a specific allele or several homoeoalleles) for several important candidate genes in the CLV pathway, and identify their functions in the development of multilocular silique, and then determine the functions and relationships of different copies of each multilocular gene; 2) to pyramid multiple mutated genes/loci by crossing of different multilocular single mutants, and conduct pathway-level studies on the genetic regulation of different multilocular genes; 3) to introduce the new generated multilocular alleles into elite rapeseed cultivar, and assess their potential in breeding application preliminarily. These works will help to realize innovation of multilocular germplasm resources in Brassica napus, and provide important information and insights into the molecular mechanism of multilocular silique development, as well as new allelic variants and efficient tool for molecular design breeding in rapeseed.