Genetic diversity among farm and germplasm bank accessions of cacao in Bahia, Brazil

Abstract

The objective of this work was to assess genetic diversity of farm cacao accessions, previously selected as productive and resistant to witch broom in Bahia, Brazil, and to study their interrelationship with reference genotypes on germplasm bank. DNA samples from 120 cacao accessions, collected on 17 farms in seven counties in Southern Bahia, were amplified by RAPD technique (random amplified polymorphic DNA). The coefficients of genetic dissimilarity, calculated from the RAPD bands by Jaccard method, allowed to show by cluster analysis that most farm selections (89.2%) grouped with accessions from germplasm bank considered representatives of the cacao genetic diversity (hybrids, Trinitarian, Scavina, Amazon and common cacao). The other selections were distributed in seven distinct groups. There is high genetic diversity among farm selections, and some of them may have originated from other progenitors not included in this analysis. These materials present potential for clone selection with higher diversity for new crossings or direct use by agriculturists.