Bambara Groundnut Research Articles

Estimates of Phenotypic and Genotypic Variance and Heritability in Eighty-Nine Bambara Groundnut [Vigna subterranea (L.) Verdcourt] Accessions Collected from Six Regions of Niger

The bambara groundnut [Vigna subterranea (L.) Verdc. (Fabaceae)] is a legume mainly cultivated by women, for the nutritional quality of these seeds. It is a so-called minor culture and the improvement of the plant and its popularization remains to be promoted. The objective of this present work is to evaluate the genetic variability of bambara groundnut accessions. The experiment was carried out according to a completely randomized block device with four replications. Twenty-two (22) characters including four (4) phenological, four (4) morphological and fourteen (14) related to yield were evaluated for accessions characterization. Descriptive analysis showed significant differences. The coefficients of variation ranged from 3.51% (maturity date) to 38.87% (shell weight). Significantly high values (CV˃20%) for 8 of the metric parameters were observed. Pod weight per plant and seed weight per plant (r=0.943), yield in kg/ha (r=0.943); seed weight per plant and yield in kg/ha (r=0.999) showed the strongest correlations. The phenotypic and genotypic coefficients of variation were high for dry biomass weight (PCV=42.23%; GCV=28.40%), shell weight (PCV=63.46%; GCV=22.46%) and 100-seed weight (PCV=25.57%; GCV=25.25%). Maturity date (95.77%) and 100-seed weight (99.84%) had high heritabilities. Broad-sense heritability and genetic gain are high for 100-seed weight (H2=99.84%; GA=52.58%). The Ascending hierarchical classification produced four groups of which group 4 is the most efficient in yield with short (20.58cm) early accessions (80.32 days). Groups 1 and 2 include, late accessions (~22cm) with respectively maturity dates (DM=85.67 days and DM=86.53 days.

Pro-vitamin A content of red palm oil emulsions formed with malted bambara groundnut, Brachystegia eurycoma (achi) and cowpea

This research determined the effect of red palm oil emulsification with malts of Brachystegia eurycoma, bambara groundnut and cowpea on the pro-vitamin A content of the emulsions. Bambara groundnut, B. eurycoma (“achi”) and cowpea seeds were processed by malting for 96 hours and oven dried at 50 oC before milling into flour. The malted flours were used to form emulsions with red palm oil. Pro-vitamin A contents of the emulsions were determined using standard methods and the results were as follows: B. eurycoma was in the range of 33.30 – 400.00 IU; bambara groundnut (66.67 – 333.33 IU) and cowpea (66.70 – 233.33). Emulsion stability tests indicated that the 72 and 96 hour malts gave stable emulsions after 3 hours. The emulsions obtained with the control, 72 and 96 hour malt were analyzed for anti-nutrient contents. Tannin ranged from 0.01 – 0.10 mg/100 g for achi, 0.03- 0.12 mg/100 g for bambara groundnut and 0.02 – 0.05 mg/100 g for cowpea malts, phytate was in the range of 0.03 – 1.09 mg/100 g for achi, 1.04 – 4.26 mg/100 g for bambara groundnut and 0.40 – 2.80 mg/100 g for cowpea. Malting of the achi seeds may have reduced the components that bind pro-vitamin A in the unmalted samples. Hence, malted achi is recommended for food fortification of plant based complementary foods to increase their pro-vitamin A content.

Market Integration of Small-Scale Farms: Exploring the Bambara Groundnut Markets in Nigeria

The extent of uncertainty caused by price inefficiency and instability with reference to Bambara groundnut has made the subsector a dicey one. Markets that are not integrated may convey inaccurate price signals that might distort producers’ marketing decisions and contribute to inefficient product movement. The study analyzed the market integration of Bambara groundnut in South-east, Nigeria. The study population comprised all Bambara groundnut marketers in South-east, Nigeria. Out of the five states in South-east, Nigeria, two States will be purposively selected as the study area to establish the movement of prices between the two states to establish a fair comparison of prices between the producing zone and consumption zone. The choice of the two states was based on the predominance of Bambara groundnut marketers. A two-stage sampling technique was adopted in selecting 221 respondents that were interviewed for the study. Data for this study was poised from primary sources using a well-structured questionnaire, oral interviews and direct observations of Bambara groundnut marketers and was analyzed using descriptive and inferential statistics.- The results of the VECM showed that Enugu urban retail prices had a short-run influence of -0.057 although not signicant and a long-run significant influence of -0.2391 on Abia urban retail prices. The results of the VECM estimates for both short-run and long-run relationships indicated that the Enugu rural price of Bambara groundnut had short-run influences of -0.034023 and 0.0032032 with a long-run influence of -0.203230 on Abia rural price. The study recommended that to improve pricing effectiveness and market integration, it is necessary to encourage Bambara groundnut market price information in South-east Nigeria. The flow of information regarding Bambara groundnut prices, demand, and supply will improve both market integration and pricing effacing. The government should create regulations for information services. How to Cite: Agbo Josephine Nkechi, Okpukpara Benjamin C., Ude Kingsley David, Udemba Klinsmann Uche., 2023. "Market Integration of Small-Scale Farms: Exploring the Bambara Groundnut Markets in Nigeria." Journal of Agriculture and Crops, vol. 10, pp. 11-19.

Field evaluation of single and interaction effects of nematode, fungus and bacterium on nodulation and pathological parameters of Bambara groundnut (Vigna subterrenea (l.) Verdc.) in field condition

The aim of the present study was to determine the effects of single and mixed infections of nematode (Meloidogyne javanica), fungus (Fusarium oxysporum) and bacterium (Xanthomonas axonopodis) on nodulation and pathological parameters of Bambara groundnut (Vigna subterrenea (L.) Verdc.) in field condition. Nematode infested field was used while other pathogens were obtained from diseased plants. The Randomized Complete Block Design (RCBD) was adopted in a 5 × 9 × 5 factorial design (5 blocks, 9 treatments and 5 replicates per treatments) resulting in 225 experimental units. In each experimental unit, three seeds were sown to a depth of 5cm and thinned to one plant per planting hole after germination at day 7. Treatments were inoculated into test plant following standard methods. As a result, the control treatment recorded the highest number of nodules (64.0 ± 6.91), followed by bacterium (45.2 ± 5.11) while N + F + B had the lowest number of root nodules (23.4 ± 2.42). Simultaneous treatment (N + F + B) gave the highest percentage reduction in nodulation (63.44%), followed by treatment N + F7 (56.25%). Fungus treatment recorded the highest mean wilted plants (3.8 + 0.20) followed by N + F7 treatment (3.40 + 0.40). Gall formation in the nematode treatment increased proportionately by 56.33% as the highest recorded, followed by treatment N + F7 with 50.0%. Treatment N + F7 had the highest reproduction factor (Rf) value of 9.30 followed by nematode (8.30), N + B7 (7.40), N + F + B (6.80) and N + F14 (6.50). Zero (0) Rf value was recorded in fungus, bacterium and control treatments. The observed differences in nodulation and pathological parameters among the treatments are significant (P < 0.05). The data provided in this work is important in the control of the three pathogens affecting the productivity of Bambara nut. Formulation of a single protectant should be designed to have potent effects on the three pathogens to achieve effective protection and good production of Bambara nut.

Bambara groundnut ameliorates kidney histology in female mice with protein deficiency

BACKGROUND Protein deficiency (PD) can lead to kidney damage. Consuming plant-based proteins may improve this condition. Bambara groundnut (Vigna subterranea)has an essential amino acid score of 80%, which is higher than other legumes; thus, it is potent in overcoming malnutrition. This study aimed to determine the effect of Bambara groundnut supplementation on kidney histology in adult female mice with PD.
 METHODS The study was conducted for 2 months in randomly selected female mice. These mice were grouped into the control, PD, and PD supplemented with Bambara groundnuts at 100, 200, and 300 g/kg of feed. 1 day after the last treatment, the kidneys of the mice were collected and processed histologically using the paraffin method (stained with hematoxylin and eosin and Masson’s trichrome). Parameters for observation included histopathological scoring (glomerular and interstitial space fibrosis and tubular damage), kidney histomorphometry, and organ index. Semi-quantitative data were analyzed using the Kruskal–Wallis test, while quantitative data were analyzed using one-way ANOVA (followed by Tukey’s test) and nested t-test. Statistical analysis was performed using SPSS software version 20 (IBM Corp., USA) (p≤0.05).
 RESULTS PD caused cell sloughing (moderate level) and dilatation (severe level) of the kidney tubules. It also reduced glomerular diameter and area by approximately 17.66% and 29%, respectively. PD and Bambara groundnut administration had no significant effects on the glomerular number, cortex and medulla thickness, distal and proximal tubule diameter, and kidney organ index (p>0.05).
 CONCLUSIONS Bambara groundnut (V. subterranea) administration prevented damage to the kidney’s histological structure of protein-deficient mice.

Drought-tolerant indigenous crops decline in the face of climate change: A political agroecology account from south-eastern Senegal

In south-eastern Senegal, Bassari farmers have historically cultivated and consumed a wide diversity of varieties of sorghum, fonio, and Bambara groundnut, most of which thrive in poor soils, are nutritious, and withstand drought. These crops are now on the verge of disappearance from the fields of the Bassari despite their potential fit in the predicted drier climate in the area. To understand why, we explore the intertwining between the local dynamics of crop diversity and socio-economic changes at local, national, and regional scales. We draw upon the critical reading of secondary sources and field data, analyzed through the lens of political agroecology. The abandonment of traditional Bassari crops can be explained by government and international policies that interact with cultural trends and household-level factors. Colonial and post-colonial agricultural policies and research priorities have promoted the expansion of exotic crops with market value or high yield potential (e.g., peanut, cotton, rice, horticultural crops), failing to value indigenous crop diversity. These policies, together with market forces and historical legacies, have intersected with outmigration, dietary changes, decreases in community social capital, and gender-dynamics, favouring the switch from drought-tolerant traditional crops to more water-demanding exotic crops. We then consider what the interplay between social dynamics and crop diversity means under climate change. Our results suggest that current trends in crop diversity might threaten climate resilience in the long-term. Drawing on political agroecology, we discuss potential avenues to support the capacity of Bassari farmers to practice agriculture in a drier climate. We argue that in order to increase the climate resilience of smallholder farmers it is necessary not only to consider the cross-scale processes and multiple dimensions of power that affect crop diversity but also to reconsider research and policy priorities in favour of drought-tolerant indigenous crops.

Energy and nutrient composition of bambara groundnut (Vigna substarranea) enriched pap

Background: Complementary foods produced from cereals alone are usually deficient in some essential nutrients. Combining cereals and legumes to produce complementary foods has been shown to enhance their nutrient composition.
 Objective: The study aims to evaluate the energy and nutrient composition of Vigna subterranea-enriched pap.
 Methods: Maize grains, bambara groundnut, and granulated sugar were purchased at Ubani market in Umuahia, Abia State. The flours were produced using standard methods; blend formulation was based on protein content. The proximate compositions of the products were evaluated using AOAC methods. Minerals were determined using wet-acid digestion. The energy value of each nutrient was obtained by multiplying the nutrient value by its Atwater factor (4, 4, and 9 for protein, carbohydrate, and lipid, respectively). Energy density was calculated by dividing the total energy value by 100. The data generated were analyzed using Statistical Product for Service Solution version 20. Means were separated and compared with the Duncan multiple range test and Analysis of Variance. Significance was accepted at p < 0.05.
 Results: Protein values ranged between 2.21% and 6.70%, with protein content in bambara groundnut-enriched maize pap samples significantly (p < 0.05) higher than the protein content of 100% maize pap (2.21%). Fat (1.00%–1.47%) and crude fiber (0.60%–1.83%), fat energy value (9.0–13.23 kcal/100g), protein energy value (15.20–26.8 kcal/100g), and total energy densities (177.28–186.91 kcal/100g) were also significantly higher in bambara groundnut-enriched maize pap. All the analyzed minerals increased with an increase in the quantity of the supplement.
 Conclusion: Protein, calcium, iron, zinc, and nutrient density increased with an increase in bambara groundnut flour. Supplementing pap with 40% bambara groundnut was observed to meet over 100% of the protein Recommended Daily Intake (RDI) for children aged 6–12 months old.

Morphometric diversity of some Nigerian accessions of Bambara groundnut (Vigna subterranea)

AbstractThis study evaluated the morphological diversity of some Nigerian accessions of Bambara groundnut. Field experiments were conducted in Nigeria in two locations and the phenotypic variation of Bambara groundnut accessions evaluated in 3 years (2017–2020) using a randomized complete block design. Twenty-eight quantitative and 10 qualitative traits were observed. Twenty-three out of the 28 quantitative morphological traits showed significant differences. TVSu-589 (28.85) and TVSu-670 (28.57) had the highest plant height; TVSu-572 (121.52), TVSu-271 (113.10) and TVSu-336 (104.15) had the highest 100-seed weight. Genetic variations were also observed in seed colour, terminal leaflet shape, petiole colour and eye pattern. Principal component analysis showed PC1 constituting 23.36% and PC2 constituting 15.76% of the total variation, while the first eight principal components with eigenvalues ≥1 revealed 77.28% of the total variation. Cluster analysis grouped the accessions into four groups. Based on yield data in this study, accessions TVSu-594, TVSu-350, TVSu-336, TVSu-1242, TVSu-129, TVSu-14, TVSu-179, TVSu-2100, TVSu-261 and TVSu-589 were the best for yield and are recommended for further evaluation to improve yield. This study showed that a wide range of diversity exists in Bambara groundnut of Nigerian origin that could be useful for further utilization of genetic resources and improvement.

Phenolic compound and total antioxidant contents of seed extracts from 5 varieties of Vigna subterranea from Chad

Vigna Subterranea is a plant whose seeds are widely consumed in Chad. Five seed varieties from the Chadian Institute of Agronomic Research for Development (CIARD) in, Chad. Total polyphenol and total anthocyanin contents were assessed by the Folin-Ciocalteu and pH-differential methods respectively. Total antioxidant levels were determined by DPPH and ABTS. The total polyphenol contents obtained were 11.647 mg GAE/g for B12 seed extract, 8.234 mg GAE/g for B16 seed extract, 0.98450 mg GAE/g for B9 seed extract, 1.625 mg GAE/g for B7 seed extract and 0.230 mg GAE/g for B3 seed extract. The total anthocyanin content of these extracts were 0.0100 mg/g, 0.0098 mg/g, 0.0063 mg/g, 0.0026 mg/g and 0.0013 mg/g for B16, B7, B12, B9 and B3 respectively for the five varieties. Results for antioxidant potency showed that the B12 seed extract contains most total antioxidants. Followed by seed extracts from varieties B16, B7 and B9 varieties. Seed extract from variety B3 contains less antioxidants.

Optimization of Extrusion Cooking on the Characteristics of Ready-to-Eat Breakfast Cereal Made from Bambara Groundnut Based Composite Flour

ABSTRACT Optimization of extrusion cooking effects on the proximate composition, anti-nutritional factors, mass flow rate, and torque, among other responses of Bambara groundnut-based flour blends, was the objective of this research. Bambara groundnut, pearl millet, malted sorghum, and banana flours were blended in the ratio of 50:20:20:10, respectively. Box–Behnken design of response surface methodology (RSM) was applied. Extrusion cooking reduced crude protein (20.01–17.19%), reduced the activities of oxalates, saponins, and trypsin inhibitors by 88.31%, 87.30%, and 82.35%, respectively, and increased carbohydrate content (57.48–68.82%). Barrel temperature had a strong increasing correlation (R2 = 0.9033) with mass flow rate, while net torque increased (78.15–81.26%) with decreasing screw speed (350–300 rpm). The RSM was successfully used to design, process, and develop prediction model equations for the manufacture of the Bambara groundnut-based breakfast cereal. Therefore, up to 50% Bambara groundnut is acceptable for a nutritionally improved breakfast cereal using extrusion cooking.

Nutritive and Antinutritive Values of Fermented Guinea Corn (Sorghum bicolor L.) Fortified with Bambara Groundnut (Vigna subterranea L.) Flour

The fermented guinea corn (Sorghum bicolor L) is a processed “ogi baba” and a popular starchy porridge in the west coasts of Africa. Although it is consumed by both young and old as a breakfast cereal, its main use is as weaning food for infants. In this study, the nutritive values of “ogi baba” from a composite mixture of guinea corn and bambara groundnut (Vigna subterranea L) were evaluated using standard processing techniques. Sorghum flour was substituted with bambara flour at ratios of 90:10, 80:20, 70:30 and 60:40 guinea corn:bambara groundnut; with 100% sorghum–ogi and 100% bambara groundnut flours as controls. The results showed that the contents of ash, crude fat, crude protein and crude fibre were enhanced with increased bambara groundnut flour substitution. All the nutritive minerals such as Na, K, Ca, Mg and P also recorded increased concentrations in the fortified samples. Harmful metals such as cadmium and lead were not at detectable range of atomic absorption spectrophotometer. The total essential amino acids ranged from 28.74–37.14 g/100g crude protein or from 43.70–44.26% of the TAA while 60:40 substitution ratio has the best essential amino acid score values amongst the fortified samples based on the provisional FAO/WHO standards. There were decrease in the values of saponins, phytate, oxalate and alkaloids in the fortified samples compared with the controls. The results of sugars showed that there was gradual increase in the total sugar concentration with increased bambara groundnut flour substitution from 1.54 g/100g (90:10 ratio) reaching 2.41 g/100g (60:40 ratio).

Challenges in the Sustainable Economy of Northern Ghana– Impacts of Soybean Trade on Bambara Groundnut: A Case Study

The global seed trade has reached and conquered Northern Ghana, squeezing out local suppliers. Considering ongoing population growth, rapidly urbanizing communities, changing diets, and vast quantities of imported food products, the endeavours of enterprises that try to reduce the local food production deficit should be more appreciated. Rice, maize, and soybeans are three types of grain that dominate the global seed trade. Furthermore, the natural conditions and vegetation of the sub-tropical region are close to optimal. While rice and maize have been cultivated for a long time, soybeans are a new crop in the semi-arid climate zone of the Guinea-Savannah.The motivations and ambitions are clear: pushing improved soybean seeds into the traditional farming system of Northern Ghana to meet the zero hunger sustainable development goal while widening the market for western seed producers. In the Ghanaian context, microfinance is built on making customers dependent on services. On the bone hand, it is a tool to extend farm sizes through mechanization, fertilizers, and modern cultivation technologies to increase yield; on the other hand, microfinance could cause financial difficulties within society and farmer associations, and it has negative effects on unsupported and unfinanced activities such as cultivating indigenous crops.

Torrefaction of Bambara Groundnut Shell: experimental optimization and prediction of the energy conversion efficiency using statistical and machine learning approaches

Optimising input variables is a necessity for efficient waste-to-energy conversion. Using a tubular furnace as the torrefaction medium, this study investigated the effects of four process parameters (viz., temperature, retention time, moisture contents and particle size) on the Higher Heating Value (HHV) and Energy Yield (EY) of Bambara Groundnut Shell (BBGS). An optimal HHV of 21.78 MJ/kg was obtained at a particle size of 1 mm, temperature of 260°C, retention time of 23 min and moisture content of 10%. The input–output relationships of the BBGS torrefaction process were modelled and validated using Response Surface Methodology (RSM) and Bayesian information criterion (BIC)-pruned stepwise regression (SR), resulting in a regression model that balances interpretability and strong prediction performance.

Variability assessment of Bambara groundnut (Vigna subterranea (L) Verdc) landraces based on the qualitative trait seed coat colour

In many parts of Sub-Saharan Africa, female subsistence farmers rely on the production of underutilized crops such as Bambara groundnut (Vigna subterranea (L.) Verdc) for both sustenance and generating income. Bambara groundnut is, however, grown at a low rate especially in South Africa. Although it has the potential to yield high amounts of seed and can grow under adverse weather conditions, amongst offering other benefits, it remains underutilized and under-researched. To date there are no improved varieties. Farmers therefore rely on indigenous knowledge systems to select varieties based on their preferences, thereby unconsciously contributing to genetic erosion of the crop. Improved varieties are important for adaptability under environmental stochasticity. This study was conducted to determine whether seed coat colour can be used as a basis for selecting Bambara groundnut landraces with favourable agronomic traits for breeding programs and development of genetically enhanced varieties. A completely randomized design with ten replications was used to assess whether landraces classified based on seed coat colour are both morphologically and genetically similar. Significant differences (P<0.05) in the yield parameters, number of pods per plant, and growth habit were observed. This suggests that some genotypes yield more seed than others. Anatomical assessment of the leaf revealed that there are genotypes with high trichome density and two types of trichomes on the same plant. These characteristics make those plants more resilient to disease pressure than others. There is, however, little evidence that these findings are related to the seed coat colour. Attributing one character i.e. seed coat colour to genetic diversity is therefore reductive and should not be undertaken.

PRODUCTION AND QUALITY EVALUATION OF ENRICHED BREAD FROM FLOUR BLENDS OF WHOLE WHEAT, BAMBARA NUT, SOYBEANS AND CASHEW NUT SEED

Bread is a staple food prepared from dough of flour and water, usually by baking. Throughout recorded history, bread has been very popular around the world. It is one of humanity’s oldest foods, having been of great importance since the dawn of Agriculture. The major ingredient in bread production is wheat flour which is very expensive. The study was conducted to produce enriched bread from composite flour blend of whole wheat, soybeans, bambara nut and cashew nut seed. Four samples were produced of varying ratio mixes and then subjected to proximate, microbiological and sensory evaluation analysis. The result from the proximate analysis indicated that the nutritional value of the product increased significantly with the incorporation of flour composite. Sample A was rated highest for moisture (26%), sample B (16%) ash, sample C (18.5%) protein, (15.8%) fat respectively. Also sample C was the most accepted in terms of sensory qualities indicating improved bread quality. The result for micro biological qualities of the product indicated that the product is fit for human consumption. An enriched and nutritious adequate bread can be produced by substituting whole wheat flour with other flour composite. The study therefore based on its findings recommended that the product should be subjected for mineral and vitamin analysis to determine the micro nutrient content of the product and also its anti- nutritional composition.

Towards inoculant development for Bambara groundnut (Vigna subterranean (L.) Verdc) pulse crop production in Namibia.

The globally expanding population, together with climate change, poses a risk to the availability of food for humankind. Bambara groundnut (BGN) (Vigna subterranea (L.) Verdc) is a neglected, relatively drought-tolerant native legume of Sub-Saharan Africa that has the potential to become a successful food crop because of its nutritional quality and climate-smart features. Nitrogen fixation from root nodule symbiosis with climate-adapted rhizobial symbionts can contribute nitrogen and organic material in nutrient-poor soil and improve yields. However, high soil temperature and drought often reduce the abundance of native rhizobia in such soil. Therefore, the formulation of climate-smart biofertilizers has the potential to improve the farming of BGN at a low cost in a sustainable manner. The effect of seven Bradyrhizobium spp. strains native to Namibia, including B. vignae and B. subterraneum, were tested on three Namibian BGN varieties (red, brown, cream) in greenhouse pot experiments in Namibia, using soil from the target region of Kavango. Each variety was treated with a mixed inoculant consisting of seven preselected strains ("MK") as well as with one promising single inoculant strain. The results revealed that in all three varieties, the two inoculants (mixed or single) outperformed the non-inoculated cultivars in terms of shoot dry weight by up to 70%; the mixed inoculant treatment performed significantly better (p < 0.05) in all cases compared to the single inoculant used. To test whether the inoculant strains were established in root nodules, they were identified by sequence analysis. In many cases, the indigenous strains of Kavango soil outcompeted the inoculant strains of the mix for nodule occupancy, depending on the BGN variety. As a further preselection, each of the individual strains of the mix was used to inoculate the three varieties under sterile conditions in a phytotron. The agronomic trait and root nodulation response of the host plant inoculations strongly differed with the BGN variety. Even competitiveness in nodule occupancy without involving any indigenous strains from soil differed and depended strictly on the variety. Severe differences in symbiont-plant interactions appear to occur in BGN depending on the plant variety, demanding for coupling of breeding efforts with selecting efficient inoculant strains.

Development and Mineral Properties of Energy Bars Made from Composite Flour of Cassava, Bambara Groundnut and Cashew Kernel Using Response Surface Methodology

Development and Mineral Properties of Energy Bars Made from Composite Flour of Cassava, Bambara Groundnut and Cashew Kernel Using Response Surface Methodology

Changes in Seed Quality during Seed Development and Maturation of Bambara Nut (Vigna subterranea (L.) Verdc.) Landraces

This study aimed at determining changes in the seed quality of bambara nut (BN) landraces during seed development and maturation so as to more precisely time seed harvest for better seed quality. Three bambara nut landraces, AbiBam001, LocalBam, and TVSU544, were sown in two field experimental sites in northern Uganda in October 2020 and 2021. Seeds were harvested at 83, 93, 103, 113, and 123 days after sowing (DAS) in the first experiment and at 123, 130, and 138 DAS in the second. Seeds were subjected to quality tests of seed dry weight, final germination percentage (FGP), germination velocity index (GVI), and seedling dry weight (SDW). All landraces showed significant differences P &lt; 0.05 in seed weight and seedling dry weight at progressive developmental stages in the first experiment. All parameters showed no differences P &gt; 0.05 in the second experiment except for the seed weight of AbiBam001 and the FGP of TVSU544. Both TVSU544 and LocalBam attained mass maturity (highest seed weight) at approximately 113 DAS, while AbiBam001 reached mass maturity at about 130 DAS. Seeds of the highest quality were obtained at 103 DAS for TVSU544 and at 113 DAS for both LocalBam and AbiBam001. For both AbiBam001 and TVSU544, the highest quality seeds occur before mass maturity, while for LocalBam, at about mass maturity. Seed harvest should be timed at 103−113, 113−123, and 120−130 DAS for TVSU544, LocalBam, and AbiBam001, respectively. The assessment of seed development before 83 DAS and maturation after 138 DAS in the main growing season will synchronize growing conditions with farmers’ practices and crucially provide a complete picture of the developmental patterns of the landraces.

Association mapping in bambara groundnut [Vigna subterranea (L.) Verdc.] reveals loci associated with agro-morphological traits

BackgroundGenome-wide association studies (GWAS) are important for the acceleration of crop improvement through knowledge of marker-trait association (MTA). This report used DArT SNP markers to successfully perform GWAS on agro-morphological traits using 270 bambara groundnut [Vigna subterranea (L.) Verdc.] landraces sourced from diverse origins. The study aimed to identify marker traits association for nine agronomic traits using GWAS and their candidate genes. The experiment was conducted at two different locations laid out in alpha lattice design. The cowpea [Vigna unguiculata (L.) Walp.] reference genome (i.e. legume genome most closely related to bambara groundnut) assisted in the identification of candidate genes.ResultsThe analyses showed that linkage disequilibrium was found to decay rapidly with an average genetic distance of 148 kb. The broadsense heritability was relatively high and ranged from 48.39% (terminal leaf length) to 79.39% (number of pods per plant). The GWAS identified a total of 27 significant marker-trait associations (MTAs) for the nine studied traits explaining 5.27% to 24.86% of phenotypic variations. Among studied traits, the highest number of MTAs was obtained from seed coat colour (6) followed by days to flowering (5), while the least is days to maturity (1), explaining 5.76% to 11.03%, 14.5% to 19.49%, and 11.66% phenotypic variations, respectively. Also, a total of 17 candidate genes were identified, varying in number for different traits; seed coat colour (6), days to flowering (3), terminal leaf length (2), terminal leaf width (2), number of seed per pod (2), pod width (1) and days to maturity (1).ConclusionThese results revealed the prospect of GWAS in identification of SNP variations associated with agronomic traits in bambara groundnut. Also, its present new opportunity to explore GWAS and marker assisted strategies in breeding of bambara groundnut for acceleration of the crop improvement.

Assessment of Yield Stability of Bambara Groundnut (Vigna subterranea (L.) Verdc.) Using Genotype and Genotype–Environment Interaction Biplot Analysis

Biplot analysis has emerged as a crucial statistical method in plant breeding and agricultural research. The objective of this research was to identify the best-performing genotype(s) for the environments in three distinct regions of Nigeria while also examining the characteristics and magnitude of genotype–environment interaction (GEI) effects on the yield of Bambara groundnut (BGN). The study was conducted in Ibadan, Ikenne, and Mokwa, utilizing a sample of 30 accessions. The yield of BGN was found to be significantly affected by accessions, environment, and their interaction through a combined analysis of variance, with a p-value &lt; 0.001. Biplots were utilized to demonstrate the pattern of interaction components, specifically the genotype’s main effect and genotype–environment interaction (GEI). The initial two principal components elucidated the complete variance of the GGE model, encompassing both genetic and genotype-by-environment interaction effects (PC1 = 87.81%, PC2 = 12.19%). The accessions that exhibited superior performance in each respective environment, as determined by the “which-won-where” polygon, were identified as TVSu-2223, TVSu-2236, TVSu-2240, and TVSu-2249 in Mokwa; TVSu-2214 in Ikenne; and TVSu-2188 in Ibadan. The accessions TVSu-2207 and TVSu-2199 exhibited stability in all environments, whereas the accessions TVSu-2226, TVSu-2249, TVSu-2209, TVSu-2184, TVSu-2204, and TVSu-2236 demonstrated adaptability. In addition, the accessions TVSu-2240 and TVSu-2283 were stable and adaptable in all environments. The accessions that were chosen have been suggested as suitable parental lines for breeding programs aimed at enhancing grain yield in the agro-ecological zones that were evaluated. This study’s findings identify BGN accessions with adaptability and stability across selected environments in Nigeria, suggesting specific accessions that can serve as suitable parental lines in breeding programs to enhance grain yield, thereby holding promise for improving food security.