Estimation of genetic merit of diallel hybrids of sweet pepper by mixed models

ABSTRACT: The use of mixed models for evaluating diallel crosses is a highly timely option to the reliable prediction of progeny genetic values. In the sweet pepper crop, hybrids are commercially explored on a large scale, mainly because of their characteristics of economic importance. This study aimed to assess the potential of hybrids obtained from a partial diallel among five sweet pepper lines developed for the hydroponic cultivation system and two simple hybrids, by applying mixed models. It was performed crosses in the partial diallel scheme among the (L1B, L6, L7, L18, and L19) lines and the simple hybrids ‘Valdor’ and ‘Atlantis’. Plants were cultivated in hydroponic system with substrate and irrigated three times a day using nutrient solution. On the basis of mixed models, the following traits were assessed: mean fruit diameter (FD), mean fruit length (FL), mean fruit number per plant (FNP), mean fruit mass (FM), early yield (EYIELD), and mean fruit mass per plant (FMP). The L6 line was the one that showed the highest estimate of general combination capacity for FMP, FM, and EYIELD, proving to be promising for recommendation. The hybrid that provided the best specific combining ability for FD, FM, FMP, and EYIELD was L6 x ‘Valdor’. Triple hybrids were efficient to maximize yield for the traits of interest by the use of the mixed model.

摘要：采用混合模型（mixed models）开展双列杂交（diallel crosses）评估，是可靠预测后代遗传值的极具时效性的技术方案。在甜椒作物中，杂交品种因其具备重要经济性状，已实现大规模商业化推广应用。本研究旨在通过混合模型，评估5个适配水培栽培系统的甜椒自交系与2个单交种之间的部分双列杂交所得杂交种的潜力。试验按照部分双列杂交方案，对（L1B、L6、L7、L18和L19）自交系与单交种'Valdor'和'Atlantis'进行杂交。试验植株采用基质水培系统栽培，每日以营养液灌溉三次。基于混合模型，对以下性状进行评估：平均果实直径（FD）、平均果实长度（FL）、单株平均结果数（FNP）、平均单果质量（FM）、早期产量（EYIELD）以及单株平均果实总产量（FMP）。自交系L6在FMP、FM和EYIELD上表现出最高的一般配合力（general combining ability）估算值，证明其具备推广应用前景。在FD、FM、FMP和EYIELD上表现出最优特殊配合力（specific combining ability）的杂交组合为L6 × 'Valdor'。借助混合模型分析，三交种可有效实现目标性状的产量最大化。