National Engineering Research Center for Vegetables, Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China.
Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
BMC Biol. 2021 May 5;19(1):93. doi: 10.1186/s12915-021-01031-2.
Brassica oleracea includes several morphologically diverse, economically important vegetable crops, such as the cauliflower and cabbage. However, genetic variants, especially large structural variants (SVs), that underlie the extreme morphological diversity of B. oleracea remain largely unexplored.
Here we present high-quality chromosome-scale genome assemblies for two B. oleracea morphotypes, cauliflower and cabbage. Direct comparison of these two assemblies identifies ~ 120 K high-confidence SVs. Population analysis of 271 B. oleracea accessions using these SVs clearly separates different morphotypes, suggesting the association of SVs with B. oleracea intraspecific divergence. Genes affected by SVs selected between cauliflower and cabbage are enriched with functions related to response to stress and stimulus and meristem and flower development. Furthermore, genes affected by selected SVs and involved in the switch from vegetative to generative growth that defines curd initiation, inflorescence meristem proliferation for curd formation, maintenance and enlargement, are identified, providing insights into the regulatory network of curd development.
This study reveals the important roles of SVs in diversification of different morphotypes of B. oleracea, and the newly assembled genomes and the SVs provide rich resources for future research and breeding.
芸薹属包括几种形态差异很大、经济价值很高的蔬菜作物，如花椰菜和白菜。然而，遗传变异，特别是大型结构变异（SVs），是芸薹属极端形态多样性的基础，但这些变异在很大程度上仍未被探索。
本研究提供了两种芸薹属形态型，花椰菜和白菜的高质量染色体水平基因组组装。这两个组装的直接比较确定了约 120 K 个高可信度的 SVs。使用这些 SVs 对 271 个芸薹属样本进行的群体分析清楚地将不同形态型分开，表明 SVs 与芸薹属种内分化有关。在花椰菜和白菜之间选择的受 SVs 影响的基因富集了与应激和刺激反应、分生组织和花发育相关的功能。此外，还确定了受选择 SVs 影响并参与定义结球起始的营养生长到生殖生长的转换、花球分生组织增殖、花球维持和扩大的基因，为花球发育的调控网络提供了新的见解。
本研究揭示了 SVs 在芸薹属不同形态型多样化中的重要作用，新组装的基因组和 SVs 为未来的研究和育种提供了丰富的资源。
