很少人知道，百姓餐桌上经常“露面”的白菜、甘蓝、芥菜和油菜等，在蔬菜专业研究领域都属于芸薹属。长期以来，这些蔬菜的“祖先”到底是谁？对于研究芸薹属植物起源与进化的科学家来说一直是个难解之谜。记者日前从中国农业科学院获悉，该院蔬菜花卉研究所王晓武研究员带领的科研团队对芸薹属物种基因组进化的研究获得了重要成果，相关研究论文近日在国际学术期刊《植物细胞》上在线发表，同时发表的还有《植物细胞》主编对该论文的推荐文章《重建白菜祖先基因组》。
该研究在完成白菜基因组测序的基础上，首次明确了芸薹属及其近缘物种具有七条染色体的共同祖先基因组，阐明了芸薹属基因组进化的关键环节。在此基础上，重新构建了白菜的三个亚基因组，并精确定义了十字花科模式基因组的7个重组区块，解决了白菜、甘蓝、油菜、萝卜等重要作物多年未解的染色体进化难题。
业内专家表示，明确芸薹属及其近缘物种共同祖先的基因组，不仅对阐明芸薹属作物的进化过程具有重要意义，而且对芸薹属基因功能研究将产生重大影响。王晓武研究员带领的科研团队多年从事芸薹属物种的研究，主导了白菜基因组的测序工作。（生物谷Bioon.com）
生物谷推荐英文摘要：
The plant cell doi:10.1105/tpc.113.110486
Deciphering the Diploid Ancestral Genome of the Mesohexaploid Brassica rapa
Feng Cheng, Terezie Mandáková, Jian Wua, Qi Xie, Martin A. Lysak, and Xiaowu Wang
The genus Brassica includes several important agricultural and horticultural crops. Their current genome structures were shaped by whole-genome triplication followed by extensive diploidization. The availability of several crucifer genome sequences, especially that of Chinese cabbage (Brassica rapa), enables study of the evolution of the mesohexaploid Brassica genomes from their diploid progenitors. We reconstructed three ancestral subgenomes of B. rapa (n = 10) by comparing its whole-genome sequence to ancestral and extant Brassicaceae genomes. All three B. rapa paleogenomes apparently consisted of seven chromosomes, similar to the ancestral translocation Proto-Calepineae Karyotype (tPCK; n = 7), which is the evolutionarily younger variant of the Proto-Calepineae Karyotype (n = 7). Based on comparative analysis of genome sequences or linkage maps of Brassica oleracea, Brassica nigra, radish (Raphanus sativus), and other closely related species, we propose a two-step merging of three tPCK-like genomes to form the hexaploid ancestor of the tribe Brassiceae with 42 chromosomes. Subsequent diversification of the Brassiceae was marked by extensive genome reshuffling and chromosome number reduction mediated by translocation events and followed by loss and/or inactivation of centromeres. Furthermore, via interspecies genome comparison, we refined intervals for seven of the genomic blocks of the Ancestral Crucifer Karyotype (n = 8), thus revising the key reference genome for evolutionary genomics of crucifers.
