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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Perennial Crops Laboratory » Research » Publications at this Location » Publication #348083

Research Project: Genetic Diversity Assessment of Cacao and Other Tropical Tree Crop Genetic Resources

Location: Sustainable Perennial Crops Laboratory

Title: Genetic Diversity and Genetic Structure of Wild Cacao Collected in the Oriente using Single Nucleotide Polymorphisms

Author
item MOTILAL, LAMBERT - University Of The West Indies
item Zhang, Dapeng
item Mischke, Barbara
item Meinhardt, Lyndel
item UMAHARAN, PATHMANATHAN - University Of The West Indies

Submitted to: Proceedings of the International Symposium on Cocoa Research
Publication Type: Proceedings
Publication Acceptance Date: 5/15/2018
Publication Date: 7/5/2018
Citation: Motilal, L., Zhang, D., Mischke, B.S., Meinhardt, L.W., Umaharan, P. 2018. Genetic Diversity and Genetic Structure of Wild Cacao Collected in the Oriente using Single Nucleotide Polymorphisms. Proceedings of the International Symposium on Cocoa Research. November 13-17, 2018, Lima, Peru. 12:1-8.

Interpretive Summary: Increasing yields is a prominent feature of all crop breeding programs including the economically important cacao (Theobroma cacao L.). As a tropical rainforest tree crop, the time (up to 7 years) and expense needed to select for improved varieties limits the cacao improvement process. Findings ways to make the selection at an early seedling stages would greatly reduce costs. In this study candidate, molecular microsatellite markers were identified for five fruit and three seed parameters and were validated for marker assisted selection. These markers are now being recommended to the international cacao community for use in cacao breeding programs. This information will be used by researchers, extension staff, germplasm curators and plant breeders to improve cacao.

Technical Abstract: Increasing yield is a prominent feature of crop breeding programmes including the economically important cacao (Theobroma cacao L.). As a tropical tree crop, the time and acreage needed for selection of improved varieties are limiting factors. Selection at an early seedling stage in a marker assisted selection programme is desirable. Candidate molecular microsatellite markers were identified under an association mapping approach for five fruit (fruit mass, husk mass, fruit length, fruit girth and fruit volume) and three seed (length, width and size of fresh peeled seeds) traits. Eleven microsatellite markers (mTcCIR 19, 30, 40, 43, 57, 60, 126, 157, 184, 225 and 275) were consistently obtained under general and mixed linear models and explained between 5.82 – 12.87% of the observed variation. Markers mTcCIR60, mTcCIR126 and mTcCIR184 were tagged to various traits and were most significantly associated with the reproductive traits. The adoption of these markers is recommended to the international cacao community.