Browsing by Author "Goncalo A. de Souza Filho"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Development and characterization of novel tetra-,tri- and di-nucleotide microsatellite markers in cacao (Theobroma cacao L.)
    (Springer Science+Business Media B.V., 2007) Iona S. Araujo; Messias G. Pereira; Aline C. Intorne; Uilson Vanderlei Lopes; Goncalo A. de Souza Filho
    The cacao plant, Theobroma cacao L., produces white seeds (beans) that form the major ingredient of processed chocolate. A great deal of research effort has been expended to the development of new genetically modified cacao plants with improved productivity and resistance and beans of good industrial quality. The availability of suitable genetic markers is an important aspect of the efficient selection and breeding of this perennial species. We describe the development of 123 microsatellite loci of cacao. An optimized protocol was used to construct and screen a microsatellite-enriched genomic library from which we isolated 64 di-nucleotide, 45 trinucleotide and 14 tetra-nucleotide microsatellite loci. The primers were tested on samples from five different T. cacao accessions, one accession from T. grandiflorum and one accession from Herranea sp. Among the 123 loci, 54 were polymorphic, 61 were monomorphic and eight did not present an amplifi- cation product. These new markers will be useful in future studies by increasing the accuracy of genotypic assessments in diverse cocoa tree populations as well as in other species of the Theobroma genus.
  • Thumbnail Image
    Item
    Mapping of Quantitative Trait Loci for Butter Content and Hardness in Cocoa Beans (Theobroma cacao L.)
    (2009) Goncalo A. de Souza Filho; Iona S. Araujo; Messias G. Pereira; Fabio G. Faleiro; Vagner T. de Queiroz; Claudia T. Guimaraes; Everaldo G. de Barros; Maurilio A. Moreira; Jose L. Pires; Regina C.R. Machado; Uilson Vanderlei Lopes; Raymond Schenell
    Cocoa butter is an important raw material for the chocolate, pharmaceutical, and cosmetic industries. The butter content and quality in cocoa beans are genetically controlled characteristics, and affect its commercial value and industrial applicability. In the present work, an F2 population derived from the cross between the ICS-1 and Scavina-6 cocoa clones was used for molecular mapping. A linkage map was constructed based on amplified fragment length polymorphism, random amplified polymorphic DNA, and simple sequence repeat markers, resulting in a total of 273 markers, distributed in 14 linkage groups (LGs). Phenotyping of butter content was performed after ether extraction and butter hardness was determined by sweeping differential calorimetry. One quantitative trait locus (QTL) associated to butter content was mapped at linkage group 9 (LG9) and two QTLs for butter hardness were identified at linkage groups 9 and 7 (LG9 and LG7). The two QTLs mapped at the LG9 explained 51.0% and 28.8% of the phenotypic variation for butter content and hardness, respectively. These QTLs were concentrated in the same map region, suggesting a close genetic linkage or pleiotropic effect. The QTLs identified may be useful in further marker-assisted selection breeding programs aimed at cocoa butter quality improvement.