Comparative study on baobab fruit morphological variation between western and south-eastern Africa: opportunities for domestication

The baobab tree (Adansonia digitata L.) is one of the key species for domestication in the semi-arid regions of Africa. In order to help select superior materials for cultivation, fruit morphological variation focussing on pulp content was studied in two physically isolated genetically different baobab populations: Mali and Malawi (West and south-eastern Africa, respectively). In each country eight study sites were selected following a climatic gradient, and their fruit characteristics were measured. Fruit morphology was correlated with climatic and soil data. Significant differences in fruit characteristics between countries and study sites within one country were observed. In general, fruits from Mali tended to be more elongated and their seeds were lighter than those from Malawi. Some sites had significantly high fruit weight and pulp percentage. The general trend (in both countries) was the hotter the environment the lower the pulp percentage, the more spherical the fruits and the smaller the seeds. Moreover, the wetter the environment, the higher the pulp percentage. Results from this study suggest that both genetics and the environment play roles in baobab fruit morphology. Although further research is needed to confirm whether baobabs producing desirable fruits keep producing the same fruits when grown in another environment, it seems that there is room for selecting high quality planting materials.