Caracterización fenotípica y reproductiva de genotipos promisorios de Theobroma cacao

Abstract

Cocoa is a species native to the tropical forests of South America, considered one of the world's most important agricultural crops. This study aimed to determine phenotypic variability, establish the self-compatibility and intercompatibility index, and calculate the reproductive efficiency index in promising cocoa genotypes, emphasizing the importance of characterization in tree selection. Thirty trees from 7 families of intraspecific hybrids were evaluated. Phenotypic characterization utilized Engels' descriptors. Reproductive systems were assessed through controlled pollinations, and reproductive efficiency was determined by examining fruit formation after natural and controlled pollination. Cocoa trees exhibited variability in qualitative leaf characteristics at the base, apex, and color, as well as leaf size, with a length/width ratio ranging from 2.4 to 3.6. Flowers displayed color variability related to anthocyanin presence, except for the staminode, which was red in all individuals. Fruit variability was noted in shape, apex, basal construction, and surface roughness. Size-related characteristics such as fruit weight (260 to 727 g), shell weight (209 to 568 g), and seed number (29 to 46) also varied. Maturity after manual pollination ranged from 10% to 80%, and natural pollination resulted in fruit formation between 3% and 38%. The reproductive efficiency index for evaluated genotypes ranged from 0.02 to 1.9. In conclusion, significant genetic variability exists in leaf, flower, and fruit characteristics among the evaluated cocoa trees. These genotypes are both self-compatible and inter-compatible, demonstrating diverse reproductive efficiency indices.