10月20日，《自然—遗传学》杂志在线发表了中国农业科学院蔬菜花卉研究所国际黄瓜变异组的研究成果，研究人员对115个黄瓜品系进行了深度重测序，并构建了包含360多万个位点的全基因组遗传变异图谱。该研究为全面了解黄瓜这一重要蔬菜作物的进化及多样性提供了新思路，并为全基因组设计育种打下了基础。
黄瓜源自喜马拉雅山脉南麓，本是印度境内土生土长的植物，如今已成为品种多样、在世界范围内普遍种植的蔬菜。在科研上黄瓜常被用来作为研究植物性别决定、维管束形成的重要模式系统。自2009年蔬菜花卉研究所发表黄瓜全基因组序列图之后，科研人员对黄瓜展开了更深入的探索。
研究人员发现黄瓜基因组中有100多个区域受到了驯化选择，包含2000多个基因。其中7个区域包括了控制叶片和果实大小的基因，果实失去苦味的关键基因已经明确地定位在染色体5上一个包含67个基因的区域里，为下一步克隆这一重要蔬菜驯化基因打下了基础。(生物谷Bioon.com)
生物谷推荐的英文摘要
Nature Genetics doi:10.1038/ng.2801
A genomic variation map provides insights into the genetic basis of cucumber domestication and diversity
Jianjian Qi,Xin Liu,Di Shen,Han Miao,Bingyan Xie,Xixiang Li,Peng Zeng,Shenhao Wang,Yi Shang, Xingfang Gu,Yongchen Du,Ying Li,Tao Lin,Jinhong Yuan, Xueyong Yang,Jinfeng Chen,Huiming Chen,Xingyao Xiong,Ke Huang,Zhangjun Fei,Linyong Mao,Li Tian, Thomas Stadler,Susanne S Renner,Sophien Kamoun
Most fruits in our daily diet are the products of domestication and breeding. Here we report a map of genome variation for a major fruit that encompasses ~3.6 million variants, generated by deep resequencing of 115 cucumber lines sampled from 3,342 accessions worldwide. Comparative analysis suggests that fruit crops underwent narrower bottlenecks during domestication than grain crops. We identified 112 putative domestication sweeps; 1 of these regions contains a gene involved in the loss of bitterness in fruits, an essential domestication trait of cucumber. We also investigated the genomic basis of divergence among the cultivated populations and discovered a natural genetic variant in a β-carotene hydroxylase gene that could be used to breed cucumbers with enhanced nutritional value. The genomic history of cucumber evolution uncovered here provides the basis for future genomics-enabled breeding.
