Paternity analysis of cacao trees selected for resistance to witches' broom in plantations of Bahia, Brazil. In: Agrotrópica v. 11 p. 83-88, 1999.

Abstract

ldentification of the potential parents of disease resistant plants selected in plantations is vcry important to use them more efficientl y in a brceding programo This is the first time markers were used in cacao aiming to determine the origin of trees selected in farm s. In this study the patemity of 39 cacao trees selected for resistance to witches' broom disease in plantations of Bahia. Brazil. was established, using three enzyme systems as markers (MDH, DIA, IDH). Out of the 39 trees, the most likely source of resistance was uniquely delermined for 26. Sca-12 is the most likely parent of 10 selections (VB-3, 18,21. 83, 129, 137,139.148.165. and 181), Sca-6 of S selections (VB-4, 16, 19.37,117,119.141 , and 143), IMC-67 of5 selections (VB-13, 22.24,26, and 127), and Pa-150 of 3 seJections (VB-20, 74, and 118). For 9 selections it was not possible to distinguish between two potential parents; hut the two parents carne from the same population (UF-168 vS. UF-667, Pa-30 vs. Pa-121, Sca-6 vs. Sca12). Only 4 selections. whose genotypes for the locus DIA or IDH was not possible to be scored, multip1e potential parents were assigned. Therefore, even with as few as three loci, isozymes are quite efficient in establishing paternity of selections in plantations.