The diallel cross constitutes an informative genetic design for choosing genitors and crosses in breeding programmes since it provides estimates of general (GCA) and specific (SCA) combining abilities. Because the breeding programme for Urochloa humidicola ([Rendle] Morrone & Zuloaga; syn. Brachiaria humidicola [Rendle] Schweick) at Embrapa Beef Cattle is recent, these estimates are still unknown. Thus, the aim of this study was to obtain the estimates of GCA and SCA from the partial diallel cross design between sexual and apomictic parents. The crosses involved nine sexual and ten apomictic parents. Seventy‐one full‐sib progenies were obtained and evaluated in an incomplete block design, using all parents and the cv. BRS Tupi as a check. The agronomic and forage quality traits were evaluated using seven harvests. Statistical analysis was performed using the mixed model approach. Significant variations were associated with GCA among sexual parents for biomass yield and forage quality traits. However, this cannot be observed for apomictic parents for GCA. The SCA effect was not significant for the assessed traits. These results showed the predominance of additive effects. Sexual parents SEX3 and SEX4 presented the highest potential for contributing favourable alleles in hybrid combinations. The absence of GCA among apomictic parents and SCA suggests the need to increase genetic variability for the generation of breeding populations of U. humidicola.

中文翻译：

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乌拉圭乌拉ic无亲和无性父母之间的结合能力

由于能够提供一般（GCA）和特定（SCA）结合能力的估计值，因此，dialeel杂交构成了用于选择繁殖者的遗传信息设计，可用于选择种系和杂交。因为用于育种程序尾稃草属humidicola（[Rendle]莫罗＆苏洛阿加;顺臂形humidicola[Rendle] Schweick）最近是Embrapa牛的，但这些估计数仍然未知。因此，本研究的目的是从性亲和无融合生殖亲本之间的部分拨号杂交设计中获得GCA和SCA的估计值。十字架涉及九个性爱父母和十个无融合生殖父母。使用所有亲本和cv，获得了71个全同胞后代，并在不完整的区组设计中进行了评估。BRS Tupi作为支票。农艺和牧草品质性状使用七个收获期进行评估。使用混合模型方法进行统计分析。性亲本之间GCA的显着差异与生物量产量和牧草品质性状有关。但是，对于GCA的无融合生殖亲本不能观察到。对于评估的性状，SCA效应并不显着。这些结果表明了加性效应的优势。性亲本SEX3和SEX4在杂种组合中贡献有利等位基因的潜力最高。无融合生殖亲本和SCA中缺乏GCA，这表明有必要增加遗传变异性，以培育成年繁殖种群。U. humidicola。