Characterization of the Sexual Self- and Cross-Compatibility in Genotypes of Cacao

Cacaois a tree crop of high economic importance and the subject of several studiesaiming the genetic improvement of the species with the incorporation ofcharacteristics that are agronomically important to create superior genotypes.In this context, this study aimed to characterize 22 genotypes of cacao forsexual compatibility, which is a trait that is strongly associated with yield.Additionally, we identify genotypes incompatible with clone TSH-1188 throughcontrolled intercrosses, due to the great importance of this clone in cocoa breeding. Fifteen genotypeswere characterized as self-incompatible and other seven as self-compatible,considering the retention index (20%) of self-pollinated flowers. Nine genotypeswere characterized for the first time: CCN-16, COCA-3310, COCA-3370/5, EB-1017,IMC-119, IMC-97, LCTEEN-37A, NA-45, and UF-612. Cacao genotypes showed flowerretention index ranging from0.0% to 55.1% after 15 days of self-pollinations. The number of retainedflowers varied after self-pollination ofcacao genotypes at 1, 5 and 15 days after pollination. CCN-51, Catongo, CCN-10and P-4B, were the genotypes with minor losses of flowers after 15 days ofpollination, while IMC-119 and TSH-516 had 100% of loss of flowers between 1 and 5 days after pollination. Moreover, the flower retention index 15 daysafter cross-pollination with TSH-1188 ranged from 0.0% to 87.5% among thetested genotypes. The results of cross-pollinations identified two genotypesthat are incompatibles, EB-1017 and IMC-119. This result is important forfuture allelic studies of incompatibility in cacao, because it might indicate that these genotypes share the sameself-incompatibility allele(s). We conclude, therefore, that this studyenable the characterization of thisworking collection of cocoa germplasm for sexual compatibility and thisinformation is important for subsequent crosses between cacao genotypes.