Molecular markers and the management of tropical trees: The case of indigenous fruits

Millions of people in the tropics benefit from the harvest, cultivation and consumption of indigenous fruit trees (IFTs). Knowledge concerning the structuring of genetic variation within these species is crucial for sustainable use and conservation, but the availability of such information has been limited. By reference to case study species that are currently the subject of active domestication initiatives, in this essay we provide guidance for the suitable application of molecular marker methods for characterising IFTs. We discuss three particular areas where molecular markers are able to provide unique insights for further promotion activities: (i) in understanding the past domestication of taxa, (ii) in determining effective population sizes; and (iii) in assessing the value of a decentralised approach for future domestication. Despite the potential utility of molecular markers, a disjunction between assessment and practical application is evident, which reflects a lack of integration of laboratory research with other species promotion activities. Greater emphasis is required on team-based research and partnerships, more work should be undertaken in agricultural landscapes, and further research on mating systems and gene flow are crucial. Our essay provides a model for molecular marker studies on other trees that are important to rural communities in the tropics.