Cowpea (Vigna unguiculata L. Walp) is a multipurpose crop widely cultivated in tropical and subtropical regions around the world. Characterizing cowpea phenotypes in germplasm collections is a crucial step to ensure future breeding efforts in the species. In this study, we estimated variance components and calculated genetic parameters for eight traits in 292 accessions from the University of California Riverside cowpea mini-core collection, along with three lines released by the USDA, and seven cultivars. Broad-sense heritability (H²) ranged from .21 to .83 for all accessions evaluated in Year 1, and from .16 to .83 for traits evaluated in 100 accessions during Year 2. Genotype × year correlations ranged from .45 to .99, illustrating consistency in phenotypic performance for some traits. Positive trait correlations were estimated for plant height and days to flowering, biomass at flowering (R1), and biomass at pod maturity (R6). Biomass at R1 and R6 were highly positively correlated. The USDA line US-1137 showed high biomass production and can be used as forage and cover crop, whereas US-1136, US 1138, and the cultivar Iron Clay showed superior traits as dual-purpose (grain and/or fodder). Several accessions from the mini-core outperformed cultivars and represent valuable genetic resources that can contribute to cowpea improvement. Moreover, these results showed that multiyear and/or multienvironment studies are needed to reliable select improved germplasm for agronomic traits. This study will provide cowpea breeders and geneticists with valuable phenotypic data to start new breeding efforts, and/or opportunities for gene discovery for key phenological and agronomic traits.

中文翻译：

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UC-Riverside 豇豆 (Vigna unguiculata L. Walp) 迷你核心系列中物候和农艺性状的表型多样性

豇豆（Vigna unguiculata L. Walp ）是一种多用途作物，在世界各地的热带和亚热带地区广泛种植。在种质收集中表征豇豆表型是确保该物种未来育种工作的关键步骤。在这项研究中，我们估计了来自加州大学河滨分校豇豆迷你核心系列的 292 个种质中的 8 个性状的方差分量并计算了遗传参数，以及美国农业部发布的 3 个品系和 7 个品种。广义遗传力 ( H ²) 在第 1 年评估的所有种质的范围为 0.21 到 0.83，第 2 年期间评估的 100 个种质的性状为 0.16 到 0.83。基因型 × 年份的相关性范围为 0.45 到 0.99，说明表型表现的一致性对于某些特征。估计了植物高度和开花天数、开花时生物量 (R1) 和豆荚成熟时生物量 (R6) 的正性状相关性。R1 和 R6 处的生物量呈高度正相关。USDA 品系 US-1137 显示出高生物量产量，可用作饲料和覆盖作物，而 US-1136、US-1138 和栽培品种铁粘土显示出优异的两用性状（谷物和/或饲料）。来自迷你核心的几个种质表现优于品种，代表了有助于豇豆改良的宝贵遗传资源。而且，这些结果表明，需要多年和/或多环境研究来可靠地选择具有农艺性状的改良种质。这项研究将为豇豆育种者和遗传学家提供宝贵的表型数据，以开始新的育种工作，和/或发现关键物候和农艺性状的基因的机会。