National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.
Ann Bot. 2010 Dec;106(6):927-44. doi: 10.1093/aob/mcq188. Epub 2010 Sep 29.
The Asian genus Vigna, to which four cultivated species (rice bean, azuki bean, mung bean and black gram) belong, is suitable for comparative genomics. The aims were to construct a genetic linkage map of rice bean, to identify the genomic regions associated with domestication in rice bean, and to compare these regions with those in azuki bean.
A genetic linkage map was constructed by using simple sequence repeat and amplified fragment length polymorphism markers in the BC(1)F(1) population derived from a cross between cultivated and wild rice bean. Using this map, 31 domestication-related traits were dissected into quantitative trait loci (QTLs). The genetic linkage map and QTLs of rice bean were compared with those of azuki bean.
A total of 326 markers converged into 11 linkage groups (LGs), corresponding to the haploid number of rice bean chromosomes. The domestication-related traits in rice bean associated with a few major QTLs distributed as clusters on LGs 2, 4 and 7. A high level of co-linearity in marker order between the rice bean and azuki bean linkage maps was observed. Major QTLs in rice bean were found on LG4, whereas major QTLs in azuki bean were found on LG9.
This is the first report of a genetic linkage map and QTLs for domestication-related traits in rice bean. The inheritance of domestication-related traits was so simple that a few major QTLs explained the phenotypic variation between cultivated and wild rice bean. The high level of genomic synteny between rice bean and azuki bean facilitates QTL comparison between species. These results provide a genetic foundation for improvement of rice bean; interchange of major QTLs between rice bean and azuki bean might be useful for broadening the genetic variation of both species.
亚洲豇豆属包含四个栽培种（饭豆、红豆、绿豆和黑眼豆），适合进行比较基因组学研究。本研究旨在构建饭豆的遗传连锁图谱，鉴定与饭豆驯化相关的基因组区域，并与红豆进行比较。
利用栽培种和野生饭豆杂交产生的 BC(1)F(1)群体中的简单序列重复和扩增片段长度多态性标记构建遗传连锁图谱。利用该图谱对 31 个驯化相关性状进行了数量性状位点（QTL）分析。比较了饭豆的遗传连锁图谱和 QTL 与红豆的情况。
共检测到 326 个标记，可归为 11 个连锁群（LG），与饭豆的单倍体染色体数相对应。饭豆的驯化相关性状与少数主要 QTL 有关，这些 QTL 分布在 LG2、4 和 7 上。饭豆和红豆的遗传连锁图谱上的标记顺序高度一致。在饭豆中，主要 QTL 位于 LG4 上，而在红豆中，主要 QTL 位于 LG9 上。
这是首次报道饭豆驯化相关性状的遗传连锁图谱和 QTL。驯化相关性状的遗传非常简单，少数主要 QTL 可以解释栽培种和野生种之间的表型变异。饭豆和红豆之间具有高度的基因组同线性，有利于在物种间进行 QTL 比较。这些结果为饭豆的改良提供了遗传基础；在饭豆和红豆之间交换主要 QTL 可能有助于拓宽两个物种的遗传变异。
