[Science news] - Genetic diversity of Robusta coffee in the Democratic Republic of the Congo

Our staple coffee, known as Robusta, descends from wild Coffea canephora. The Congo Basin has a century-long history of Robusta coffee cultivation, and is likely to be where many of the cultivated varieties were bred. However, very little is known about the genetic composition of C. canephora here. 

Researchers from Meise Botanic Garden and colleagues from the University of Kisangani and the Institut National des Etudes et Recherches Agronomique (INERA) studied the genetic diversity of wild and cultivated C. canephora shrubs in north-eastern Democratic Republic of the Congo. 

We collected leaves from wild and backyard-grown C. canephora shrubs in the Tshopo and Ituri provinces, and from the collection at INERA Yangambi, a historical research station and coffee breeding centre. Back at Meise Botanic Garden, we extracted DNA from the leaves, for genetic analysis.

We found that wild Robusta coffee shrubs in the region’s forests are genetically different from the cultivated shrubs in local backyards and those in the INERA Yangambi Coffee Collection. Most C. canephora in local backyards originated from INERA breeding programs, while a few were obtained directly from surrounding forests. Very little local wild genetic diversity is preserved at INERA Yangambi, so enriching the coffee collection with local wild shrubs would increase the genetic resources for breeding and would support ex situ conservation.