The inappropriate use of cacao clones either as female or male parents in seed gardens have been suggested as some of the reasons for the low yields of cacao hybrid varieties grown in West Africa. The concept of reciprocal effects in cacao crosses has not been well studied. To investigate the impact of maternal effect on growth and yield traits, reciprocal differences and combining abilities of recommended cacao parents in Ghana were evaluated. Six clones, comprising four important seed gardens clones used across West Africa and two clones previously used as standards in international breeding projects were crossed in a 6 × 6 complete diallel mating design to produce 30 F1 progenies. These progenies were tested in the field using a random block design with four blocks and elementary plots containing 20 plants. Growth and yield traits including stem cross-sectional area in juvenile stage, jorquette height, bean weight, number of beans per pod and bean yield were monitored over a 6-year period. Mean squares of general combining ability (GCA), specific combining ability (SCA) and reciprocal effects were significant for almost all the traits except jorquette height in SCA. This indicates that additive and non-additive gene effects are important in the inheritance of the traits. The presence of reciprocal differences for all traits suggests the influence of maternal effects in controlling the traits. Manual pollinations for commercial seed production should, therefore, follow established protocol and clones recommended as female and male parents used strictly as recommended. One of the standard clones, AMAZ15/15 had significant positive GCA effect for yield, and consistently produced progenies with high SCA values. It could be added to parental clones currently used in producing cacao varieties in the seed gardens in Ghana and other West African cacao growing countries.

中文翻译：

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可可（Theobroma cacao L.）生长和产量成分的相互差异和配合力：以加纳推荐的可可品种为例

有人认为，在种子园中不恰当地使用可可无性系作为母本或父本作为西非种植的可可杂交品种产量低的部分原因。可可杂交中的互惠效应的概念尚未得到很好的研究。为了研究母体效应对生长和产量性状的影响，评估了加纳推荐的可可亲本的相互差异和配合能力。六个无性系，包括在西非使用的四个重要的种子园无性系和以前在国际育种项目中用作标准的两个无性系，以 6 × 6 完全双列交配设计杂交，产生 30 个 F1 后代。这些后代在田间使用随机区组设计进行了测试，该设计具有四个区组和包含 20 株植物的基本小区。在 6 年的时间里监测了生长和产量性状，包括幼龄期的茎横截面积、jorquette 高度、豆重、每荚豆数和豆产量。总体配合力（GCA）、特定配合力（SCA）和交互效应的均方值对SCA中除jorquette身高外的几乎所有性状均显着。这表明加性和非加性基因效应在性状遗传中很重要。所有性状的相互差异的存在表明母体效应对控制性状的影响。因此，商业种子生产的人工授粉应遵循既定的协议，并严格按照推荐使用的雌性和雄性亲本推荐的克隆。标准克隆之一 AMAZ15/15 对产量具有显着的正 GCA 效应，并持续产生具有高 SCA 值的后代。它可以添加到目前用于在加纳和其他西非可可种植国的种子园生产可可品种的亲本克隆中。