Solanum species of the Leptostemonum clade were mapped, and predictions made on the distribution and possible habitats using a set of environmental variables. The variables were temperature, rainfall, slope, soil and land use/cover. During field surveys, location presence data (geocoded with Germin S90 GPS) was collected. Additional data were obtained from herbarium specimens kept at Makerere University Herbarium and others obtained from the Global Biodiversity Information Facility. Distribution maps were generated in ArcMap software. Using MaxEnt software (version 3.3.3), spatial distribution models were generated. Model evaluation was based on the generated Area Under Curve (AUC) of both the testing and training gain data. The Jackknife test was used to assess the importance of each environmental variable in predicting species occurrence. Eighteen species were analyzed out of the 20 known to occur in the country. Solanum chrysotrichum was recorded as a new species to Uganda, thus, a new total of 21 species known for the country. Presence of S. forskalii in Uganda was confirmed. Most of the species occur in disturbed habitats in the land use/cover areas defined as croplands, tree cover and grasslands. The highest species richness was recorded in south western Uganda with a total of 11 species. Karamoja had unique diversity with species restricted to the region and these included S. forskalii, S. lanzae, S. coagulans and S. hastifolium. The environmental parameters selected for the study when used in combination had a good fit in predicting the occurrence of species as revealed by the high AUC values. Temperature and rainfall were the most useful variables in predicting occurrence of Solanum species. Karamoja region and south western Uganda are hotspots for conservation of the spiny Solanum. Periodic field surveys should be carried out to assess the effect of climate change and anthropogenic disturbance on the occurrence of the species.

Uganda lies within the drier end of the natural distribution range of Coffea canephora and contains unexplored genetic material that could be drought-adapted and useful for developing climate-resilient varieties. Using experimental treatments, (i) ample and (ii) restricted-water, response of 148 genotypes were studied comprising wild, feral and cultivated C. canephora. Biomass allocation, standing leaf area and leaf area growth data were collected. Linear mixed effect models and PCA were used to analyse effect of drought on genotypes from different: (i) cultivation status, (ii) genetic groups and (iii) locations. We assessed the relationship between drought tolerance for relative growth rate in leaf area (RGRA), total number of leaves (TNL), total leaf area (TL) and total leaf dry weight (TLDW) of genotypes at final harvest. Restricted-water reduced RGRA across genetic groups (3.2 – 32.5%) and locations (7.1 – 36.7%) but not cultivation status. For TNL, TL and TLDW, genotypes that performed well in ample-water performed worse under restricted-water, indicating growth-tolerance trade-off. Drought tolerance in RGRA and TNL were negatively correlated with wetness index suggesting some degree of adaptation to local climate. Findings indicate a growth-tolerance trade-off within this tropical tree species and drought tolerance of Uganda’s C. canephora is somewhat associated with local climate.