Cocoa Research Centre, Sir Frank Stockdale Bldg., The University of the West Indies, St. Augustine, 330912, Trinidad, Trinidad and Tobago.
The Ministry of Agriculture, Land and Fisheries, the Government of the Commonwealth of Dominica.
Genome. 2020 Dec;63(12):583-595. doi: 10.1139/gen-2019-0214. Epub 2020 Aug 27.
Cacao ( L.), an introduced tree crop in Dominica, is important for foreign exchange earnings from fine or flavour cocoa. The genetic structure of farmed cacao in Dominica was examined to identify varieties for conservation, breeding, and propagation to improve their cocoa industry. Cacao trees (156) from 73 sites over seven geographical regions were genotyped at 192 single nucleotide polymorphism (SNP) markers. Identity, regional differentiation, phylogenetic, multi-variate, ancestry, and core collection analyses were performed. Farmed cacao germplasm had moderate gene diversity ( = 0.320 ± 0.005) from generally unique trees, but cocoa growing regions were genetically similar. Synonymous matching (16.3%) showed that some clonal material was supplied to farmers. Cacao trees were mainly mixed from Amelonado, Criollo, Iquitos, Contamana, and Marañon ancestries, with predominantly Amelonado-Criollo hybrids. Criollo ancestry, linked to fine or flavour cocoa, was found at more than 30% in 28 unique trees. Forty-five trees, containing the SNP diversity of cacao in Dominica, are recommended as a core germplasm collection. This study identifies promising trees for improving cocoa quality; provides genetic evidence that community, regional, or country-wide pooling would not compromise the exclusive fine or flavour cocoa industry; and discusses other implications towards improving the Dominican cocoa industry.
在多米尼克，可可（Theobroma cacao）是一种外来的经济树种，因其优质或风味可可而赚取外汇。为了保护、培育和繁殖可可品种，提高其可可产业，我们对多米尼克的人工种植可可的遗传结构进行了研究。从 7 个地理区域的 73 个地点选取了 156 棵可可树，对其进行 192 个单核苷酸多态性（SNP）标记的基因分型。我们进行了身份鉴定、区域分化、系统发育、多元分析、祖先分析和核心收集分析。人工种植的可可种质具有中等的基因多样性（ = 0.320 ± 0.005），通常来自独特的个体，但可可种植区在遗传上是相似的。同义匹配（16.3%）表明，一些克隆材料是供应给农民的。可可树主要是由 Amelonado、Criollo、Iquitos、Contamana 和 Marañon 祖先混合而成，主要是 Amelonado-Criollo 杂种。与优质或风味可可相关的 Criollo 祖先在 28 棵独特的可可树上的比例超过 30%。我们推荐 45 棵含有多米尼克可可 SNP 多样性的可可树作为核心种质收集。本研究确定了一些有潜力的可可树，可以用来提高可可的质量；提供了遗传证据表明，社区、地区或全国范围内的混合不会损害多米尼克的优质或风味可可产业；并讨论了其他提高多米尼克可可产业的影响。
