Molecular Population Genetics Group, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.
PLoS One. 2011;6(8):e23632. doi: 10.1371/journal.pone.0023632. Epub 2011 Aug 25.
Jatropha curcas is a potential plant species for biodiesel production. However, its seed yield is too low for profitable production of biodiesel. To improve the productivity, genetic improvement through breeding is essential. A linkage map is an important component in molecular breeding. We established a first-generation linkage map using a mapping panel containing two backcross populations with 93 progeny. We mapped 506 markers (216 microsatellites and 290 SNPs from ESTs) onto 11 linkage groups. The total length of the map was 1440.9 cM with an average marker space of 2.8 cM. Blasting of 222 Jatropha ESTs containing polymorphic SSR or SNP markers against EST-databases revealed that 91.0%, 86.5% and 79.2% of Jatropha ESTs were homologous to counterparts in castor bean, poplar and Arabidopsis respectively. Mapping 192 orthologous markers to the assembled whole genome sequence of Arabidopsis thaliana identified 38 syntenic blocks and revealed that small linkage blocks were well conserved, but often shuffled. The first generation linkage map and the data of comparative mapping could lay a solid foundation for QTL mapping of agronomic traits, marker-assisted breeding and cloning genes responsible for phenotypic variation.
麻疯树是生产生物柴油的有潜力的植物物种。然而，其种子产量太低，无法实现生物柴油的盈利生产。为了提高生产力，通过育种进行遗传改良是必不可少的。连锁图谱是分子育种的重要组成部分。我们使用包含两个回交群体的 93 个后代的作图面板，建立了第一代连锁图谱。我们将 506 个标记（216 个微卫星和 290 个来自 EST 的 SNPs）映射到 11 个连锁群上。图谱全长 1440.9 cM，平均标记间距为 2.8 cM。对含有多态性 SSR 或 SNP 标记的 222 个麻疯树 EST 进行 EST 数据库比对表明，91.0%、86.5%和 79.2%的麻疯树 EST 分别与蓖麻、杨树和拟南芥的对应物同源。将 192 个直系同源标记映射到拟南芥全基因组序列的组装上，鉴定出 38 个共线性块，表明小的连锁块得到了很好的保守，但经常发生重排。第一代连锁图谱和比较作图数据为农艺性状的 QTL 作图、标记辅助育种和克隆表型变异相关基因奠定了坚实的基础。
