甘蓝型油菜结角高度与荚层厚度的全基因组关联分析

角果是油菜重要的光合作用和种子存储器官，对油菜产量具有重要贡献。本研究以412份具有代表性的甘蓝型油菜品种(系)为材料，利用芸薹属60K Illumina Infinium SNP芯片对其基因型分析，并对油菜结角高度和角果层厚度进行全基因组关联分析。结果共检测到16个显著关联的SNP，其中重庆环境下分别检测到2个和4个SNP与结角高度和结角层厚度显著关联，单个SNP解释的表型变异为5.61%~5.69%和5.94%~6.31%。云南环境下分别检测到5个和1个显著关联的SNP，单个标记解释的表型变异为12.66%~13.97%和22.43%。对2个环境的结角高度差和结角层厚度差共检测到3个和1个与性状显著相关的SNP，它们对表型变异的解释率分别为17.33%~20.32%和29.05%。其中，环境间结角厚度差的关联SNP与重庆环境结角层厚度的1个显著关联SNP位于同一LD区间。各显著关联标记LD区段的多个基因调节植物细胞组织发生、花分生组织发育、角果数目和多器官发育，如NSN1、TPST和SAC1等，它们可能通过上述功能影响油菜花序或角果的生长发育，导致结角高度或结角层厚度差异。本研究发掘的这些位点和候选基因可作为影响油菜结角高度和角果层厚度的重要候选区域和基因，为揭示油菜结角性状的遗传基础和分子机制，提高油菜单位面积产量奠定了基础。

Genome-Wide Association Analysis of Height of Podding and Thickness of Pod Canopy in Brassica napus

Layer of pod canopy is an important photosynthetic and seed storage part in rapeseed, providing important contribution to yield. In this study, 412 representative Brassica napus varieties (or lines) were genotyped using the Brassica 60 K Illumina Infinium SNP array by genome-wide association analysis of the height of podding (HP) and thickness of pod canopy (TPC). A total of 16 significant SNPs were identified, including two and four SNPs associated with HP and TPC in Chongqing, each of them explained 5.61%–5.69% and 5.94%–6.31% of phenotypic variation, respectively. Five and one significant SNPs accounting for 12.66%–13.97% and 22.43% of the phenotypic variation for HP and TPC in Yunnan, respectively, were also detected. Three and one significant SNPs associated with the difference of HP and TPC between two environments were detected, explaining 17.33%–20.32% and 29.05% of phenotypic variation, respectively. The latter SNP marker was located in the same linkage disequilibrium (LD) interval with one of significant SNPs related to TPC in Chongqing. Functional annotation of genes within the LD intervals containing significant markers showed that several genes involved in regulation of cell organization and biogenesis, floral meristem development, number of silique, and multicellular organismal development existed, such as NSN1, TPST, and SAC1, which might result in the variation of HP and TPC through affecting the growth and development of flower or silique in B. napus. These loci and genes could be regarded as important candidate regions and genes for HP and TPC of B. napus. The results lay the foundation for revealing the genetic basis and molecular mechanism for podding traits, and improving the yield per unit area of B. napus.