由中国国家玉米改良中心、威斯康星大学以及中国农业部联合组成的研究团队已绘制完成黄瓜基因组的综合遗传学和细胞遗传学图谱，这对于育种家培育更好的葫芦科作物而言是十分重要的资源。该图谱包括分布在7个连锁群的995个简单重复序列（SSR）标记，总长为573厘摩。这995个SSRs中，有49%、26%和22%是分别属于甜瓜、西瓜和南瓜。应用FISH分析已确定了各连锁群间和黄瓜染色体组的关系。
这一图谱是首个报道的葫芦科植物的基因组图谱。Yi Ren及其同事在已发表在PloS ONE的一篇论文中指出，这一图谱的有效性将推动整个基因组测序和定位克隆技术的发展，加强辅助标记选择，并为研究葫芦科植物的共性提供更佳选择。（生物谷Bioon.com）
生物谷推荐原始出处：
PLoS ONE 4(6): e5795. doi:10.1371/journal.pone.0005795
An Integrated Genetic and Cytogenetic Map of the Cucumber Genome
Yi Ren1#, Zhonghua Zhang1#, Jinhua Liu2#, Jack E. Staub3, Yonghua Han2, Zhouchao Cheng1, Xuefeng Li1, Jingyuan Lu2, Han Miao1, Houxiang Kang1, Bingyan Xie1, Xingfang Gu1, Xiaowu Wang1, Yongchen Du1, Weiwei Jin2*, Sanwen Huang1*
1 Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Sino-Dutch Joint Lab of Horticultural Genomics, Opening Lab of Genetic Improvement of Agricultural Crops of Ministry of Agriculture, Beijing, China, 2 National Maize Improvement Center of China, Key Laboratory of Crop Genetic Improvement and Genome of Ministry of Agriculture, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China, 3 USDA, ARS, Vegetable Crops Research Unit, Department of Horticulture, University of Wisconsin, Madison, Wisconsin, United States of America
The Cucurbitaceae includes important crops such as cucumber, melon, watermelon, squash and pumpkin. However, few genetic and genomic resources are available for plant improvement. Some cucurbit species such as cucumber have a narrow genetic base, which impedes construction of saturated molecular linkage maps. We report herein the development of highly polymorphic simple sequence repeat (SSR) markers originated from whole genome shotgun sequencing and the subsequent construction of a high-density genetic linkage map. This map includes 995 SSRs in seven linkage groups which spans in total 573 cM, and defines ~680 recombination breakpoints with an average of 0.58 cM between two markers. These linkage groups were then assigned to seven corresponding chromosomes using fluorescent in situ hybridization (FISH). FISH assays also revealed a chromosomal inversion between Cucumis subspecies [C. sativus var. sativus L. and var. hardwickii (R.) Alef], which resulted in marker clustering on the genetic map. A quarter of the mapped markers showed relatively high polymorphism levels among 11 inbred lines of cucumber. Among the 995 markers, 49%, 26% and 22% were conserved in melon, watermelon and pumpkin, respectively. This map will facilitate whole genome sequencing, positional cloning, and molecular breeding in cucumber, and enable the integration of knowledge of gene and trait in cucurbits.
