| dc.description.abstract | Bambara groundnut (BGN) (Vigna subterranea (L.) Verdc.) is a drought-resilient, nutrient-rich
legume indigenous to Africa. Despite its nutritional and agronomic potential, BGN remains
underutilized in Kenya’s Lake Victoria Basin (LVB), where diverse landraces are grown but lack
comprehensive characterization. Knowledge gaps in morphological traits, yield potential, and
protein diversity hinder effective classification, breeding, and utilization, especially due to
overlapping physical characteristics and varying farmer preferences. Moreover, low yields across
zones, largely due to recycling of non-adapted germplasm, highlight the need for zone-specific
yield assessments and genetic diversity studies. This study aimed to evaluate the genetic
diversity of BGN in the LVB using morphological traits, yield performance, and protein
profiling. Specifically, it focused on identifying morphological characteristics of selected
landraces across different agro-ecological zones and greenhouse conditions, determining yield
variation, and assessing protein composition in high-yielding accessions. Six landraces (K1, K2,
B1, B4, M2 and M4) were cultivated at three KALRO research sites (Alupe, Kibos, Oyani) and
under controlled greenhouse conditions at Maseno University. A randomized complete block
design with three replications was used. Morphological characterization followed the Vigna
subterranea descriptor list, yield was assessed using standard agronomic metrics, and protein
profiling was conducted via Bradford assay and SDS-PAGE. The study revealed high phenotypic
diversity, especially in pod color, leaflet shape, and seed testa patterns. Shannon-Weiner indices
indicated significant morphological diversity (H' > 1.6), with terminal leaflet shape and seed eye
pattern showing the highest diversity (H' = 2.071). Quantitative traits such as plant height, pod
number, and seed weight exhibited significant variation within and between zones (P ≤ 0.05),
largely influenced by soil moisture availability. Accessions B1, M4, and M2 showed consistently
high pod numbers. Cluster and principal component analyses differentiated landraces based on
terminal leaflet area, seed weight, and pod number. Biplot analysis further identified B1 as a
likely progenitor. Yield analysis revealed B4 (2.7 t/ha), M2 (3.3 t/ha), and M4 (1.6 t/ha) as the
highest yielders at Alupe, Kibos, and Oyani, respectively. In greenhouse trials, B1 recorded the
highest yield under irrigation (3.8 t/ha), while K1 excelled under drought (1.2 t/ha). Traits like
flower number, pod number, and leaflet area correlated positively with yield (r ≥ 0.50). Among
the top performers, M2 had the highest total protein content (0.123 mg/mL), with albumins being
the most abundant protein fraction. SDS-PAGE revealed seven shared protein bands across
landraces, with M2 uniquely expressing a 180 kDa band, suggesting potential as a molecular
marker. In conclusion, the study demonstrated significant morphological and molecular diversity
among BGN landraces in the LVB, identified high-yielding accessions, and discovered a unique
protein marker in M2. These findings support the targeted selection and breeding of adaptable,
high-yielding BGN varieties. The study recommends focusing on M2 and B1 in future breeding
efforts and integrating protein markers into classification and improvement programs for
underutilized BGN in Kenya. | en_US |
