Farmer-perceived phenotypic variation and preferences reveal potential for multi-traits selection in the desert date Balanites aegyptiaca (L.) Delile in Benin

Due to their historical interactions with plants, farmers have gained knowledge of natural variations in plant traits that can be useful for the domestication and sustainable management of genetic resources. This study focused on Balanites aegyptiaca (L.) Delile, a neglected and underutilized wild fruit tree species in Benin. The objectives of the study were to assess farmers' (1) perceived phenotypic variations in fruit, seed, leaflet, thorn, and stem bark, (2) desirable and undesirable traits, and (3) on-farm management of the species. Using semi-structured interviews (461) in 14 communities spanning the species distribution area, data were collected on perceived phenotypic variation, criteria of classification, desirable and undesirable traits, and on-farm management practices of the species. Descriptive statistics and principal component analysis were used for the data analysis in R software. Results revealed 10 criteria to differentiate morphological types of the species, the most cited criteria being thorns length (100%), stem bark color (91.1%), leaf shape (70%), fruit size (54.2%), and fruit pulp taste (45.8%). Preferred characteristics were large fruits (50.4%), sweet fruits (42.8%), elongated leaf (70%), yellowish stem bark (88.9%), long thorn (64.5%) and fruiting trees (100%) and depended on age, geographical location, and gender. Interestingly, reasons supporting these preferences reveal potential for multi-traits selection. The most encountered farmer management practices were tree sparing on-farm (18.5%), and protection against grazing (10.2%) and fire (10.4%). However, the extent of these practices does not guarantee sustainable management of the species. Our findings provide interesting insights for further domestication initiatives. However, further research is needed to understand the interrelated relationship between genotypes and environmental factors in shaping the observed morphological variations.