Résumé
The basidiomycete Moniliophthora rorer, the etiological agent of Moniliasis, reaches cacao plantations (Theobroma cacao) in Central and South Americas, but its occurrence is still not registered in Brazil . The disease causes losses of up to 90 % in the production of cocoa, has difficult to control and is close to the border with Brazil, threatening the Brazilian cacao industry. As part of a larger project of preventive breeding, this study aims to identify plants that have genes involved in the control of resistance to moniliasis , using microsatellite DNA markers associated with them. The material used in this study was collected from parents (clones) and progenies from CEPEC´s breeding program. A total of 74 genotypes were used in this study, being 34 parents used in CEPEC´s breeding program and 40 trees of the cross EET-183 x ( P-7xUF-273). DNA samples from these geotypes was obtained, from leaf tissue, by the method described by Doyle & Doyle (1993). The extracted DNA was amplified by PCR , and after amplification of the SSR loci, the reaction was applied to polyacrylamide gel stained with silver nitrate as described by CRESTE et al. al. (2001) with some modifications. The clones were scored based on the size of alleles at SSR loci previously associated with resistance to moniliasis . Based on results in the loci mtcCir 26 mtcCir 46, mtcCir mtcCir 236 and 240 , it was observed that 26 of the parents used are not suitable to be used in crosses with the source of resistance UF-273, because they had the allele associated with resistance, even though they are not resistant. On the other hand , the parents Ipiranga- 1, PS-13.19, Sca-6, CCN-10, CP-188, CP-49, Salobrinho-3 and CP -111 exhibited different alleles of the source of resistance, being , therefore, suitable to be involved in further crosses with the UF -273. The individuals of the segregating population EET -183 x (P- 7x UF- 273) , were genotyped for the purpose of obtaining individuals who showed the resistance alleles to moniliasis . Out of the 40 individuals used in the study, 16 had alleles associated to resistance. (Texte intégral)