[Science news] - High levels of genetic diversity in wild populations of Robusta coffee in Yangambi (DR Congo)
Gene flow in tropical forest understorey species can be strongly affected by forest degradation, potentially resulting in genetic erosion and changes in the genetic structure of populations. In tropical Africa however, these processes are still poorly studied. Robusta coffee (Coffea canephora) is an economically important species occurring in the understorey of tropical rainforests of Central and West Africa and was used as a model to study the effects of degradation and regeneration of tropical forests.
A team of researchers from Meise Botanic Garden, KU Leuven, ILVO and the University of Kisangani studied the genetic diversity and structure in wild Robusta coffee (Coffea canephora) populations in Yangambi and their relation with forest disturbance. Over 250 Robusta coffee plants were sampled in old disturbed and undisturbed forest plots and in forests that had regenerated over the last decades.
Genotyping of these more than 250 Robusta trees revealed a high genetic diversity in the Yangambi area, while evidence of genetic erosion linked to forest disturbance was lacking. The current genetic structure of the populations was mainly driven by geographic location. We furthermore found that the coffee populations in recent forest patches originated from neighbouring populations and were subject to founder effects.
This study highlights the fact that wild Robusta coffee populations still harbour high levels of genetic diversity in the Yangambi area and can be seen as a starting point for future extensive monitoring to unravel the response of these populations to ongoing forest degradation.
Depecker, J., Verleysen, L., Asimonyio, J.A. et al. Genetic diversity and structure in wild Robusta coffee (Coffea canephora A. Froehner) populations in Yangambi (DR Congo) and their relation to forest disturbance. Heredity (2023). https://doi.org/10.1038/s41437-022-00588-0
Pictures : © CIFOR/Alex Fassio