Sahelian smallholder farmers depend on many trees and shrubs, primarily indigenous species, for a range of essential products and environmental services that improve their livelihoods. Ziziphus mauritiana Lam. is one of the priority fruit trees for smallholder farms in the region. A tree domestication programme for Z. mauritiana has been initiated in Burkina Faso, Mali, Niger, and Senegal. In this paper, we discuss the importance of Z. mauritiana for smallholder farmers; we briefly present recent studies on genetic variation and controlled pollination of Z. mauritiana; and we describe a recently launched breeding programme to improve productivity and drought adaptation in the West African Sahel. The goal of the breeding programme is to produce and propagate germplasm that combines the heavy-fruiting characteristics of Asian germplasm with the pest and drought tolerance of local germplasm.

The success of terrestrial carbon sequestration projects for rural development in sub-Saharan Africa lies in the (i) involvement of local populations in the selection of woody species, which represent the biological assets they use to meet their daily needs, and (ii) information about the potential of these species to store carbon. Although the latter is a key prerequisite, there is very little information available. To help fill this gap, the present study was undertaken in four pilot villages (Kou, Dao, Vrassan and Cassou) in Ziro Province, south-central Burkina Faso. The objective was to determine carbon storage potential for top-priority woody species preferred by local smallholders. We used (i) participatory rural appraisal consisting of group discussions and key informant interviews to identify priority species and functions, and (ii) landscape assessment of carbon stocks in the preferred woody species. Results revealed over 79 priority tree and shrub species grouped into six functions, of which medicine, food and income emerge as the most important ones for the communities. For these functions, smallholders overwhelmingly listed Vitellaria paradoxa , Parkia biglobosa , Afzelia africana , Adansonia digitata , Detarium microcarpum , and Lannea microcarpa among the most important tree species. Among the preferred woody species in Cassou and Kou, the highest quantity of carbon was stored by V. paradoxa (1,460.6 ±271.0 kg C ha ⁻¹ to 2,798.1±521.0 kg C ha ⁻¹ ) and the lowest by Grewia bicolor (1.6±1.3 kg C ha ⁻¹ ). The potential carbon stored by the preferred tree communities was estimated at 5,766.2 Mg C ha ⁻¹ (95% CI: 5,258.2; 6,274.2 Mg C ha ⁻¹ ) in Kou and 6,664.0 Mg C ha ⁻¹ (95% CI: 5,810.2; 7,517.8 Mg C ha ⁻¹ ) in Cassou. The findings of this study will help design data-based development of biocarbon projects, which are rare in the West African Sahel despite being considered as one of the most impactful climate change resilient strategies.

Manglietia conifera Dandy is a fast-growing tree species that has been introduced to China from Vietnam, which has great potential for commercial planting. However, plantation development is hindered by a lack of seed material, due to low natural seed-set in locally grown trees. Thus, we investigated the morphological characteristics of male and female flower organs, and conducted controlled pollination to understand the breeding systems of the species. The individual flower of M. conifera is bisexual, and the stamen group is polymerized at the base of the receptacle. Pollen is symmetrically distributed on both sides. Controlled pollination suggests that apomixis does not occur in M. conifera. Results from the flower structure, pollen–ovule ratio, outcrossing index, and controlled pollination indicated that the breeding system in M. conifera was outcrossing (partially self-compatible, pollinators required), and self-incompatibility occurred in a later stage of embryonic development. Moreover, the self-incompatibility phenomenon was revealed by the abnormal germination of pollen on the stigma. This paper provides a basis for controlled pollination programs of M. conifera.