Fatokun C A, Menancio-Hautea D I, Danesh D, Young N D
Department of Plant Pathology, University of Minnesota, St. Paul 55108.
Genetics. 1992 Nov;132(3):841-6. doi: 10.1093/genetics/132.3.841.
A well saturated genomic map is a necessity for a breeding program based on marker assisted selection. To this end, we are developing genomic maps for cowpea (Vigna unguiculata 2N = 22) and mung bean (Vigna radiata 2N = 22) based on restriction fragment length polymorphism (RFLP) markers. Using these maps, we have located major quantitative trait loci (QTLs) for seed weight in both species. Two unlinked genomic regions in cowpea contained QTLs accounting for 52.7% of the variation for seed weight. In mung bean there were four unlinked genomic regions accounting for 49.7% of the variation for seed weight. In both cowpea and mung bean the genomic region with the greatest effect on seed weight spanned the same RFLP markers in the same linkage order. This suggests that the QTLs in this genomic region have remained conserved through evolution. This inference is supported by the observation that a significant interaction (i.e., epistasis) was detected between the QTL(s) in the conserved region and an unlinked RFLP marker locus in both species.
对于基于标记辅助选择的育种计划而言，一张饱和度高的基因组图谱是必不可少的。为此，我们正在基于限制性片段长度多态性（RFLP）标记，开发豇豆（Vigna unguiculata 2N = 22）和绿豆（Vigna radiata 2N = 22）的基因组图谱。利用这些图谱，我们已经定位了这两个物种中控制种子重量的主要数量性状位点（QTL）。豇豆中有两个不连锁的基因组区域包含的QTL解释了种子重量变异的52.7%。绿豆中有四个不连锁的基因组区域解释了种子重量变异的49.7%。在豇豆和绿豆中，对种子重量影响最大的基因组区域以相同的连锁顺序跨越相同的RFLP标记。这表明该基因组区域中的QTL在进化过程中保持了保守性。在这两个物种中，保守区域的QTL与一个不连锁的RFLP标记位点之间均检测到显著的互作（即上位性），这一观察结果支持了上述推断。
