June 4, 2009
Source:
PLOS
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0005795
An Integrated Genetic and
Cytogenetic Map of the Cucumber Genome
Yi Ren, Zhonghua Zhang, Jinhua Liu, Jack E. Staub, Yonghua
Han, Zhouchao Cheng, Xuefeng Li, Jingyuan Lu, Han Miao, Houxiang
Kang, Bingyan Xie, Xingfang Gu, Xiaowu Wang, Yongchen Du, Weiwei
Jin, Sanwen Huang
Abstract
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.
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0005795 |
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