Molecular genetic diversity in a core of cocoa (Theobroma cacao L.) clones with potential for selection of disease resistance, plant height and fruit production

Abstract

This study aimed to assess the genetic variability in groups of 11 clones of Theobroma cacao L., from different geographical regions, based on microsatellite markers, with the interest to characterize germplasm for breeding. The products of the amplification of these materials with 15 simple sequence repeat (SSR) markers were separated into ABI377 sequencer. The genotype encoded data were analyzed by means of Roger’s genetic distances, which was employed in the main coordinate’s analysis. The high heterozygosity observed in this group of clones (Ho = 0.7276) and genetic distances between pairs of clones (average 0.75) show that there is a high diversity among these clones. In cluster analysis, the cluster of Trinitario clones and hybrids was separated from the others according to their genealogy, while Forasteros were classified into different groups. The variability among these clones makes them important materials for parent selection in order to obtain hybrid progenies.

Key words: Theobroma cacao, genetic diversity, simple sequence repeat (SSR), germplasm, breeding.