ABSTRACT

Introduction of exotic clones into the pedigree of commercial cashew clones could constitute a viable strategy to overcome the current low early nut yield and nut weight of the crop in West Africa. The aim of this study was to assess the combining abilities of Beninese, Brazilian and Ghanaian clones for early nut yield and nut weight. Twelve F₁ hybrids were evaluated in the field for five traits such as stem diameter increment, canopy spread, nut yield, nut weight and cropping efficiency. Significant difference (p ≤ .01) was observed for most of the traits. Nut weight varied from 5.3 to 10.1 g/year, whilst nut yield ranged from 666.1 to 872.8 kg/ha/year among the top five crosses in the third to fifth year after planting. The Beninese (BE) progenies were comparable to the Ghanaian (SG) progenies for early nut yield but inferior to the Ghanaian and Brazilian (A) progenies for nut weight. Pearson correlation coefficient estimate (r = 0.74; p ≤ .01) suggest that, selecting for canopy spread in the north-south direction might improve early nut yield. GCA effects were more important than SCA effects. Narrow-sense heritability was moderate and exceeded 50% for all the traits. BE203 and SG224 showed positive GCA for early nut yield, whereas A2 and SG273 showed positive GCA for nut weight. Our study suggest that the Brazilian, Beninese and Ghanaian clones had different merits as potential parents for early nut yield and nut weight and could constitute a suitable genetic resource for improving cashew productivity.

摘要

将外来无性系引入商业腰果无性系谱系可能构成克服目前西非作物早期坚果产量和坚果重量低的可行策略。本研究的目的是评估贝宁、巴西和加纳无性系对早期坚果产量和坚果重量的组合能力。对12 个 F ₁杂种在田间进行了茎粗增加、冠层展开、坚果产量、坚果重量和种植效率等五个性状的评估。显着差异 ( p ≤ .01)观察到大多数性状。坚果重量从 5.3 到 10.1 克/年不等，而在种植后的第 3 年到第 5 年的前五名杂交中，坚果产量从 666.1 到 872.8 公斤/公顷/年不等。贝宁 (BE) 后代在早期坚果产量方面与加纳 (SG) 后代相当，但在坚果重量方面低于加纳和巴西 (A) 后代。Pearson 相关系数估计 ( r = 0.74; p ≤ .01) 表明，选择南北方向的冠层分布可能会提高早期坚果产量。GCA 效应比 SCA 效应更重要。狭义遗传力中等，所有性状均超过50%。BE203 和 SG224 对早期坚果产量的 GCA 呈阳性，而 A2 和 SG273 对坚果重量的 GCA 呈阳性。我们的研究表明，巴西、贝宁和加纳的无性系在作为早期坚果产量和坚果重量的潜在亲本方面具有不同的优点，并且可以构成提高腰果生产力的合适遗传资源。