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Morphological characterisation and evaluation of cacao (Theobroma cacao L.) in Trinidad to facilitate utilisation of Trinitario cacao globally

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Abstract

Cacao (Theobroma cacao L.) accessions conserved at the International Cocoa Genebank Trinidad (ICGT) are routinely characterised and evaluated in terms of traits of taxonomic and economic interest. The resulting data are crucial for selecting suitable candidates for future germplasm utilisation and breeding. In this study, the distribution of traits of taxonomic and economic interest was examined among Trinitario accession groups, represented by 260 accessions, and compared to what pertains for the 1900 genotypes characterised at the ICGT. Among the 1900 accessions studied, the Pod Index, an indicator of yield potential, ranged from 13.9 to 92.8. Twenty-three percent of the accessions with superior yield potential (Pod Index of 21 or lower) were ‘Trinitarios’, including the best. Despite a significantly negative correlation (r = − 0.162, P < 0.0001) between seed mass and seed number of the accessions studied, several Trinitarios combined large seed number (44 or more) with large seed (cotyledon) mass (1.2 g or more). The Trinitarios selected in Trinidad were observed to be phenotypically closely related. Trinitarios with high yield potential, large seed size and other favourable traits were identified. They are potentially useful sources of genes for introgression into Trinitario planting material in fine or flavour cocoa producing countries, which provide premium cocoa to an ever expanding global niche market. The resulting economic and social benefits of improvement in Trinitario cacao planting material should be significant.

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Notes

  1. Cacao’ refers to the tree and its parts, and ‘cocoa’ to the dried beans and products of manufacture.

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Acknowledgements

We acknowledge the Government of the Republic of Trinidad and Tobago and Cocoa Research Association, UK for financial support of this research. The Director of the Cocoa Research Centre, Prof. P. Umaharan, former Heads of the Cocoa Research Unit, Drs. D.R. Butler and A.J. Kennedy, and the late Prof. J.A. Spence are recognised for administrative support. The statistical advice of Dr. I. Bekele is gratefully acknowledged as well as useful discussions with Drs. E.S. Johnson, J. Engels, Albertus Eskes, C. Lanaud and C. Cilas. J. Bhola, Dr. W. Mollineau, V. Badall, A. Richardson-Drakes, N. Persad, S. Samnarine, C. Jagroop and other individuals are gratefully acknowledged for technical assistance at various times during the period of study. The helpful comments of an anonymous reviewer are also gratefully acknowledged.

Funding

This study was funded by Government of the Republic of Trinidad and Tobago and the Cocoa Research Association, UK.

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  1. Cocoa Research Centre, The University of the West Indies, St. Augustine, Trinidad and Tobago

    Frances L. Bekele & Gillian G. Bidaisee

  2. Faculty of Food and Agriculture, The University of the West Indies, St. Augustine, Trinidad and Tobago

    Harjit Singh

  3. Department of Food Production, Faculty of Food and Agriculture, The University of the West Indies, St. Augustine, Trinidad and Tobago

    Duraisamy Saravanakumar

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  1. Frances L. Bekele
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Bekele, F.L., Bidaisee, G.G., Singh, H. et al. Morphological characterisation and evaluation of cacao (Theobroma cacao L.) in Trinidad to facilitate utilisation of Trinitario cacao globally. Genet Resour Crop Evol 67, 621–643 (2020). https://doi.org/10.1007/s10722-019-00793-7

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