Both cowpea and yard-long bean belong to Vigna unguiculata ssp. unguiculata but have diverged through human induced evolution in sub-Saharan Africa and Asia, respectively. To map the quantitative trait loci (QTLs) for yield associated traits and derive new lines that may combine the attributes of both types, we developed a F2:3 mapping population derived from a cross between cowpea line TVu2185 and yard-long bean line TVu6642. Using DArT markers, a total of 30 QTLs accounting for 1.8–13.0% phenotypic variation was detected for pod and seed traits. Some novel major QTLs for peduncle number per plant (qPeN2.2), pod length (qPoL3), seed breadth (qSB4), length (qSL7.2) and thickness (qST9) identified on chromosomes 2, 3, 4, 7 and 9, respectively, are particularly interesting and need to be validated. Moreover, we confirmed previously reported QTLs for pod length (qPoL8) and 100-seed weight (qSW8) on chromosome 8 and for seed number per pod (qSN9.2) on chromosome 9 suggesting usefulness for marker-assisted-selection purpose. Notably, some QTLs for these traits were clustered especially on chromosomes 5, 7, 8, 9 and 10 indicating the presence of the same QTL or linked loci in these regions. Moreover, the involvement of epistasis was observed for trait expressions, but compared with the main effect QTLs, the phenotypic effects of epistatic-QTLs detected were much less. The present QTL analysis may provide a useful tool for breeders to formulate efficient breeding strategy for introgression of the desirable alleles for yield related traits in cowpea using molecular markers.

中文翻译：

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基于 DArT 标记的豇豆和长豆 (Vigna unguiculata (L.) Walp.) 杂交产量相关性状的遗传剖析

豇豆和豇豆都属于豇豆。unguiculata，但分别在撒哈拉以南非洲和亚洲通过人类诱导的进化而分化。为了绘制产量相关性状的数量性状基因座 (QTL) 并获得可能结合两种类型属性的新品系，我们开发了一个 F2:3 作图群体，该群体源自豇豆品系 TVu2185 和一码长豆品系 TVu6642 之间的杂交。使用 DArT 标记，共检测到 30 个 QTL，占豆荚和种子性状的 1.8-13.0% 表型变异。在 2、3、4、7 和 9 号染色体上鉴定的每株花序梗数 (qPeN2.2)、豆荚长度 (qPoL3)、种子宽度 (qSB4)、长度 (qSL7.2) 和厚度 (qST9) 的一些新的主要 QTL分别是特别有趣和需要验证的。而且，我们确认了先前报道的第 8 号染色体上豆荚长度 (qPoL8) 和 100 粒种子重量 (qSW8) 以及第 9 号染色体上每个豆荚种子数 (qSN9.2) 的 QTL，表明可用于标记辅助选择目的。值得注意的是，这些性状的一些 QTL 特别聚集在 5、7、8、9 和 10 号染色体上，表明这些区域中存在相同的 QTL 或连锁基因座。此外，在性状表达中观察到上位性的参与，但与主效应QTL相比，检测到的上位QTL的表型效应要小得多。目前的 QTL 分析可以为育种者提供有用的工具，以制定有效的育种策略，使用分子标记为豇豆产量相关性状的理想等位基因渗入。