J Syst Evol

• Research Article •    

A phylogenetic framework to study desirable traits in the wild relatives of Theobroma cacao (Malvaceae)

Ana M. Bossa‐Castro1*, Matheus Colli‐Silva2,3, José R. Pirani2, Barbara A. Whitlock4, Laura T. Morales Mancera1, Natalia Contreras‐Ortiz5,6, Martha L. Cepeda‐Hernández7,8, Federica Di Palma9,10, Martha Vives1, and James E. Richardson5,11,12,13   

  1. 1 Departamento de Ciencias Biológicas, Facultad de Ciencias, Universidad de los Andes, Carrera 1 18A‐12, Bogotá, Colombia;
    2 Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo 05508‐090, São Paulo, Brazil;
    3 Royal Botanic Gardens, Kew, Richmond, Surrey, UK;
    4 Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146, USA;
    5 Tropical Diversity Section, Royal Botanic Garden Edinburgh, Edinburgh EH3 5NZ, United Kingdom;
    6 Department of Molecular Plant Science, University of Edinburgh, Old College, South Bridge, Edinburgh EH8 9YL, UK;
    7 Facultad de Ciencias, Universidad de los Andes, Carrera 1 18A‐12, Bogotá, Colombia;
    8 Corporación Corpogen, Carrera 4 20‐41, Bogotá, Colombia;
    9 School of Biological Sciences, University of East Anglia, Norwich NR4 7TU, UK;
    10 Genome British Columbia, 575 W 8th Ave 400, Vancouver BC V5Z 0C4, Canada;
    11 School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland;
    12 Environmental Research Institute, University College Cork, Ellen Hutchins Building, Lee Road, Cork T23 XE10, Ireland;
    13 Departamento de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Calle 12C, 6‐25, Bogotá, Colombia
    *Author for correspondence. E‐mail: ana.bossa@alumni.colostate.edu
  • Received:2023-09-26 Accepted:2023-11-27 Online:2024-02-18

Abstract: Crop wild relatives (CWRs) of cultivated species may provide a source of genetic variation that can contribute to improving product quantity and quality. To adequately use these potential resources, it is useful to understand how CWRs are related to the cultivated species and to each other to determine how key crop traits have evolved and discover potentially usable genetic information. The chocolate industry is expanding and yet is under threat from a variety of causes, including pathogens and climate change. Theobroma cacao L. (Malvaceae), the source of chocolate, is a representative of the tribe Theobromateae that consists of four genera and c. 40 species that began to diversify over 25 million years ago. The great diversity within the tribe suggests that its representatives could exhibit advantageous agronomic traits. In this study, we present the most taxonomically comprehensive phylogeny of Theobromateae to date. DNA sequence data from WRKY genes were assembled into a matrix that included 56 morphological characters and analyzed using a Bayesian approach. The inclusion of a morphological data set increased resolution and support for some branches of the phylogenetic tree. The evolutionary trajectory of selected morphological characters was reconstructed onto the phylogeny. This phylogeny provides a framework for the study of morphological and physiological trait evolution, which can facilitate the search for agronomically relevant traits.

Key words: cacao, crop wild relatives, Herrania, Malvaceae, morphological and molecular characters, phylogeny, Theobroma, trait evolution