Preliminary Study on the Solanum nigrum L. (Solanaceae) Complex in the Democratic Republic of the Congo

Black nightshade, or the Solanum nigrum complex, includes a number of species that botanists consider problematic due to their morphological resemblance and the high rate of hybridization. As part of the revision of the family Solanaceae for the Flora central Africa,we realized a molecular study of the Solanum nigrum complex in the western part of the Democratic Republic of Congo. A total of 21 samples of this complex were collected and identified using the recent revision by [11]. The DNA of each specimen was extracted and then amplified by PCR for 4 molecular markers: the two nuclear regions waxy and ITS, and the two chloroplastics markers trnL-F and trnH-psbA. Additional sequences of specimens reliably identified were obtained from GenBank. The combined molecular data set allowed for the identification of two distinct groups. The first we conclude that in the western part of D.R. Congo, two species of the Solanum nigrum complex occur, both showing high morphological variability, while the true Solanum nigrum is absent from that region. The two species are Solanum americanum Mill. and Solanum scabrum Mill. The results confirm the taxonomic decisions of [11]. The generally low resolution in the analyses did not allow to visualize a geographical signal in the variation.

Characterization of the Chemical and Phytochemical Profiles during Fruit Development and Ripening in Selected Cultivars of African Nightshade (Solanum Nigrum Complex) Edible Berries

Solanum nigrum complex is a green, indigenous leafy vegetable that grows in many parts of the world and its utilization can deliver more nutrients and phytochemicals into the diet. Even though it can help in alleviating the burden of hidden hunger, only the leafy part is utilized whereas the plant has edible berries. This study sought to address the problem of underutilization by looking at the benefits that can be derived from the berries. Four varieties of the plant were harvested through four stages; green, colour break, ripe and at senescence. Chemical analyses of the berries were done to determine the content and changes in macro and micro-nutrients and the phytochemical content of the berries as they ripened. Analysis of Variance (ANOVA) was used to determine the significant difference between nutrient and phytochemical composition of the different S. nigrum varieties at different ripening stages. The results show that fibre, ash and protein increased at senescence while carbohydrates decreased. Magnesium was the most abundant mineral. As berries ripened, oxalates, total phenols, flavonoids and phytates decreased while Vitamin C, tannins and total carotenoids increased. Conclusively, the berries in this study have comparable nutritional value with other commonly consumed fruits and could, therefore, be incorporated into the family pot.