The diversity of African leafy vegetables: agromorphological characterization of subsets of AVRDC's germplasm collection

Traditional African leafy vegetables are important components of daily diets for the majority of the population in sub-Saharan Africa. Some crops, like amaranth, contribute considerably to the daily intake of iron and vitamin A of people living in rural households in Africa. African leafy vegetables can be grown under harsh climatic conditions with low external inputs. Important crops/species include, but are not limited to, amaranth (Amaranthus cruentus, A. dubius, A. hybridus, A. blitum), African nightshade (Solanum scabrum, S. villosum), and spider plant (Cleome gynandra). Traditional leafy vegetables typically contain high but variable levels of essential nutrients. For instance, for amaranth, African nightshade and spider plant, the protein content ranged from 3.2 to 4.4 g, beta-carotene from 2.7 to 5.8 mg, iron from 2.2 to 3.8 mg, calcium from 158 to 582 mg, and zinc from 0.5 to 1.5 mg 100 g(-1) of fresh weight. At AVRDC Eastern and Southern Africa in Tanzania, 140 accessions of amaranth, 128 of African nightshade and 93 of spider plant are conserved in a seed repository. This study assessed the level of genetic diversity of a subset of this germplasm collection. A total of 25 amaranth, 14 African nightshade and 20 spider plant accessions were characterized using a standard set of morphological descriptors. Days to flowering, leaf length and leaf width, total biomass, and plant height were the most useful parameters for discrimination purposes. Accessions with potential for germplasm development were identified. The importance of linking conservation and utilization is highlighted.