Speed breeding of cacao may be facilitated by a genome-wide association study in Trinidad

What is it about?

This study centered on a subset of 421 cacao accessions from the International Cocoa Genebank Trinidad. A genome-wide association study (GWAS) was done to unravel marker-trait associations (MTAs) between SNP (molecular) markers and phenotypic traits. Seventeen significant MTAs of interest, including six yield-related traits, were identified. Highly significant yield-related MTAs were observed on chromosomes 5, 7 and 1 and some MTAs of relevance to yield improvement were located on chromosome 4. The detection of associations between certain traits and multiple SNPs suggests polygenic control of these traits. Candidate genes, which encode embryo and seed development, protein synthesis, carbohydrate transport and lipid biosynthesis and transport, were identified in the flanking regions of significantly associated SNPs and in linkage disequilibrium with them. Testing of a genomic selection approach revealed good predictive value for seed number, seed length, seed width, seed length to width ratio, cotyledon mass and ovule number. The identification of MTAs involving yield-related traits with good predictive value could expedite the process of genetic improvement of cacao through genomic selection.

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Photo by Quang Nguyen Vinh on Unsplash

Photo by Quang Nguyen Vinh on Unsplash

Why is it important?

Traditional cacao breeding is very time and labor intensive. Breeding with genomics can significantly accelerate progress in obtaining elite cultivars to enhance cacao production.

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