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United States Department of Agriculture

Agricultural Research Service

Research Project: Genetic Improvement of Cacao Through Genomics-Assisted Breeding

Location: Subtropical Horticulture Research

Title: The genetic identity of Theobroma cacao L. CCN-51

Authors
item Boza, Edward
item Amores, Freddy -
item Gutierrez, Osman
item Tondo, Cecile
item Schnell, Raymond -
item Motamayor, Juan Carlos -

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2013
Publication Date: January 11, 2013
Citation: Boza, E.J., Amores, F.M., Gutierrez, O.A., Tondo, C.L., Schnell, R.J., Motamayor, J. 2013. The genetic identity of Theobroma cacao L. CCN-51. Meeting Abstract. Int'l Plant & Animal Genome Conference, San Diego, CA, January 12-16, 2013.

Technical Abstract: Cacao (Theobroma cacao L.) is an important cash crop for several growing regions of the world especially for small cacao farmers. In the Americas the cacao production is ~13.0% globally. Ecuador is among the higher producers in South America and its cacao beans are well known for fine flavors, aroma, and fat content. The reported pedigree of CCN-51 is complex and commonly regarded as Nacional type. The variety was developed by Homero Castro in Ecuador using a single selected hybrid plant from a cross of ICS-95 x IMC-67 and crossing it with Canelos. Seventy single simple repeat loci were used to dissect the genetic identity of CCN-51; in which 80% (56) were heterozygous and 20% (14) were homozygous. Suggesting CCN-51 is too heterozygous to be a Nacional clone. No specific Nacional alleles were found. Comparison for agronomic characteristics between CCN-51 and several Nacional clones indicated significant differences in cacao bean dry weight, yield potential, productive efficiency, healthy pods, and witches' broom disease reaction. Additionally, physical, chemical, and organoleptic characteristics suggest that CCN-51 is different from those of Nacional lineage. Based on population structure analysis, the predominant ancestries for CCN-51 are Iquitos (45.4%), Criollo (22.2%), and Amelonado (21.5%). Less proportion of their genome was accounted for Contamana (3.9%), Purús (2.5%), Marañon (1.8%) and Nacional (1.1%) admixtures. Moreover, bootstraps values on phylogenetic analysis using neighbor joining and unweighted pair group method with arithmetic mean (UPGMA) trees and parentage analysis strongly support the relatedness of CCN-51 with the aforementioned ancestries. CCN-51 constitutes a valuable genetic resource that is currently used not only in its country of origin but also in many other different national breeding and selection program worldwide.

Last Modified: 9/2/2014
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