Deciphering the Theobroma cacao self-incompatibility system: from genomics to diagnostic markers for self-compatibility
Year: 2017
Type: article
Abstract: Cocoa self-compatibility is an important yield factor and has been described as being controlled by a late gameto-sporophytic system expressed only at the level of the embryo sac. It results in gametic non-fusion and involves several loci. In this work, we identified two loci, located on chromosomes 1 and 4 (CH1 and CH4), involved in cocoa self-incompatibility by two different processes. Both loci are responsible for gametic selection, but only one (the CH4 locus) is involved in the main fruit drop. The CH1 locus acts prior to the gamete fusion step and independently of the CH4 locus. Using fine-mapping and genome-wide association studies, we focused analyses on restricted regions and identified candidate genes. Some of them showed a differential expression between incompatible and compatible reactions. Immunolocalization experiments provided evidence of CH1 candidate genes expressed in ovule and style tissues. Highly polymorphic simple sequence repeat (SSR) diagnostic markers were designed in the CH4 region that had been identified by fine-mapping. They are characterized by a strong linkage disequilibrium with incompatibility alleles, thus allowing the development of efficient diagnostic markers predicting self-compatibility and fruit setting according to the presence of specific alleles or genotypes. SSR alleles specific to self-compatible Amelonado and Criollo varieties were also identified, thus allowing screening for self-compatible plants in cocoa populations.
Source: Journal of Experimental Botany
DOI: 10.1093/jxb/erx293
Authors: Claire Lanaud, Olivier Fouet, Thierry Legavre, Uilson Lopes, Olivier Sounigo, Marie Claire Eyango, Benoit Mermaz, Marcos Ramos Da Silva, Rey Gaston Loor Solorzano, Xavier Argout, Gabor Gyapay, Herman Ebai Ebaiarrey, Kelly Colonges, Christine Sanier, Ronan Rivallan, Géraldine Mastin, Nicholas Cryer, Michel Boccara, Jean-Luc Verdeil, Ives Bruno Efombagn Mousseni, Karina Peres Gramacho, Didier Clément
Institutions: Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Amélioration Génétique et Adaptation des Plantes méditerranéennes et tropicales, Comissão Executiva do Plano da Lavoura Cacaueira - Ceplac, Institut de Recherche Agricole pour le Développement, Instituto Nacional de Investigaciones Agropecuarias, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Genoscope, Mondelēz International (United Kingdom)
Language: English
Topic: Plant Reproductive Biology
Subfield: Molecular Biology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: hybrid
Estimated APC paid: $4,341
OpenAlex ID: W2764005772