Evaluation of Bambara Groundnut (Vigna subterranea (L.) Verdc) Accessions for Growth, Phytochemical, and Proximate-Related Traits for Improvement Program

Abstract

Bambara groundnut (Vigna subterranea (L.) Verdc.) is an underutilized crop of high economic importance for alleviating food security. However, morpho-phytochemical variability, which exists among different accessions of V. subterranea of different origins, is sketchy in the literature. Identifying these variations is relevant for evolving strategies necessary for further breeding program to improve its utilization. Therefore, variations in agrobotanical and bioactive compounds among Bambara groundnut accessions were evaluated. Two field trials were conducted during the 2019 and 2020 planting seasons at the Teaching and Research Farm of the University of Ibadan, Nigeria. Thirty Bambara groundnut accessions were assessed for variations in number of primary branches (NPBs), number of leaves (NLs), plant height (PH), plant canopy width (PCW), plant canopy length (PCL), and biomass. The trial was arranged in a randomized complete block design (n = 3). Some accessions in distinct clusters were selected for phytochemical and proximate components assessment using standard procedures. Data were analyzed using descriptive statistics and analysis of variance (ANOVA) at p<0.05. The highest NPB was 18.33 recorded in TVSu-315, whereas TVSu-1578 had the highest NL (40.00). TVSu-1874 was taller (13.66 cm), with wider PCW of 18.51 cm and PCL of 18.95 cm. The 30 accessions were clustered into five distinct groups. The concentration of alkaloid (20.6 mg/100 g) in TVSu-1432 was significantly higher than the concentration in other accessions. In addition, TVSu-253 had the highest concentration (0.3 mg/100 g) of tannin, which was significantly higher than that of the other accessions. Flavonoid (0.03 mg/100 g) and saponin (2.6 mg/100 g) were highest in TVSu-2032. TVSu-1578 had higher ash content (14.0%) than other accessions, whereas TVSu-2032 had the highest crude fiber of 4.9%. TVSu-1432 had the highest crude protein (38.2%), ether extract (6.0%), and dry matter (91.1%) relative to other accessions. High coefficients of variation (CV) were recorded in petiole length and dry matter components. Petiole length and dry matter discriminated the 30 Bambara groundnut accessions. TVSu-1432 was superior with respect to proximate composition, whereas TVSu-2032 had superior phytochemical constituents.