Genetic and QTL Analysis for Hilum-Eye Types in Cowpea (Vigna Unguiculata L. Walp)

Cowpea is an important food legume widely grown in the semi-arid tropics and serves as a main source of dietary protein, minerals, and vitamins. However, varieties differ from region to region based on the consumer’s preference for seed types determined by seed size, seed coat texture, seed color, and hilum-eye types. The genetics of seed size, seed color, and seed coat texture have been well documented, but the hilum-eye types have not been studied well because they represent seven different types with complex interactions. We studied the genetic segregation for hilum-eye types and determined the number of genes involved in a recombinant inbred line (RIL) population derived from a cross between a small eye parent ‘GEC’ and a Watson eye parent ‘IT98K-476-8’. The results demonstrated a three-gene model, W (Watson), S (small), and R (large), for cowpea seed hilum-eye type pattern and the interaction of these three genes, W, S, and R, resulted in five phenotypes, viz. self, Watson, small, large, and ring hilum-eye types. Moreover, we also mapped the RILs for hilum-eye types, identified three quantitative trait loci (QTLs), and aligned to the cowpea reference genome as QTL qHilum7.1, qHilum9.1, and qHilum10.1, corresponding to these three genes, Ring type (R), Watson type (W), and Small type (S) hilum-eye type patterns, respectively. Therefore, there was a complete agreement between the genetic analysis and QTL mapping for the number of genes controlling the hilum types in cowpea.

Effect of Cowpea Seed Beetle (Callosobruchus maculatus) Infestation on Selected Landraces of Bambara Groundnut During Storage

The study was carried out to assess the effect of Callosobruchus maculatus infestation on selected Bambara groundnut (Vigna subterranean) landraces in Gombe during storage to determine the Landrace (s) that are less susceptible to infestation caused by C. maculatus during storage. The trial was done in the Botany laboratory of Gombe State University, Gombe. Seeds were collected from five different Landraces, 40 grams each of healthy and C. maculatus infestation free seeds were infested with two males and three females. Completely Randomized Design (CRD) with three replicates was used to assess the effects of C. maculatus infestation on the selected landraces of Bambara groundnut during storage. The results of the analysis of variance displayed significant differences (p≤ 0.05) among the parameters studied. It indicated that the Mottled and Cream landraces are relatively less susceptible and witness lower damage from the bruchids attack 14.6 (36%) and 17 (46%), whereas Red and Black landraces are more susceptible 24 (61 %) and 22 (57 %) (recorded higher damage from the C. maculatus in terms of percentage weight loss recorded). These results showed the existence of variation among the different Bambara groundnut landraces used due to the infestation of C. maculatus. It can be observed from this study that the use of infestation free landraces at storage time may perhaps be a worthwhile and auspicious factor for integrated pest management especially on bruchids in Bambara groundnuts. additionally, Mottle and Cream landraces might be employed as sources of resistance genes for the subsequent plant improvement program.

Influence of Varieties and Integrated Nutrient Management Practices on Growth and Yield of Seed in Cowpea (Vigna unguiculata L.)

Background: Cowpea is one of the most important leguminous vegetable crops. It has a unique ability of biological nitrogen fixation and mobilization of insoluble soil nutrient and bringing qualitative changes in soil. The basic concept of integrated nutrient management system is to maintain of plant nutrients supply to achieve a good level of crop production by optimizing the benefits from all possible sources of plant nutrients in an integrated manner, appropriate to each farming system. Considering these aspects, a field experiment was conducted to boost up productivity of cowpea seed. Methods: A field experiment was carried out during Rabi season, 2015-16 at Research Field of the Department of Vegetable Science, College of Horticulture, Mandsaur (Madhya Pradesh). The experiment was arranged in factorial randomized block design with twenty treatment combinations comprising four cowpea varieties, viz. V1-Pusa Sukomal, V2-Kashi Unnati, V3-Kashi Kanchan and V4-Kashi Shyamal and five integrated nutrient management (INM) practices, viz. N1-Vermicompost 2.5t + Rhizobium (10g/kg seeds) + PSB (10 g/kg seeds) + N (0 kg) + P2O5 (90 kg) + K2O (70 kg)/ha; N2 -Vermicompost 2.5t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (15kg) + P2O5 (90kg) + K2O (70 kg)/ha; N3 -Vermicompost 2.5t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (20 kg) + P2O5 (90 kg) + K2O (70 kg)/ha; N4 -Vermicompost 2.5 t + Rhizobium (10 g/kg of seeds) +PSB (10 g/kg seeds) + N (25 kg) + P2O5 (90 kg) + K2O (70 kg)/ha and N5-Vermicompost 2.5 t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (30 kg) + P2O5 (90 kg) + K2O (70 kg)/ha. Result: In present experiment the cowpea variety V1-Pusa Sukomal recorded superior performance for growth attributes, yield and yield attributes and quality attributes. This variety had taken minimum days to first flowering, days to 50% flowering and days to harvesting. Among the nutrient levels, application of Vermicompost 2.5 t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (30 kg) + P2O5 (90 kg) + K2O (70 kg)/ha resulted in the highest growth parameters, yield and yield parameters of cowpea seed.

Antibacterial Peptides Produced by Alcalase from Cowpea Seed Proteins

Cowpea seed protein hydrolysates (CPH) were output from cowpea seeds applying alcalase® from Bacillus licheniformis. CPH with an elevated level of hydrolysis was fractionated by size exclusion chromatography (SEC). Both CPH and SEC-portions showed to contain antimicrobial peptides (AMPs) as they inhibited both Gram-positive bacteria, such as Listeria monocytogenes LMG10470 (L. monocytogenes), Listeria innocua. LMG11387 (L. innocua), Staphylococcus aureus ATCC25923 (S.aureus), and Streptococcus pyogenes ATCC19615 (St.pyogenes), and Gram-negative bacteria, such as Klebsiella pnemoniae ATCC43816 (K. pnemoniae), Pseudomonas aeroginosa ATCC26853 (P. aeroginosa), Escherichia coli ATCC25468) (E.coli) and Salmonella typhimurium ATCC14028 (S. typhimurium).The data exhibited that both CPH and size exclusion chromatography-fraction 1 (SEC-F1) showed high antibacterial efficiency versus almost all the assessed bacteria. The MIC of the AMPs within SEC-F1 and CPHs were (25 µg/mL) against P. aeruginosa, E.coli and St. pyogenes. However, higher MICsof approximately 100–150 µg/mL showed for both CPHs and SEC-F1 against both S. aureus and L. innocua; it was 50 µg/mL of CPH against S.aureus. The Electro-spray-ionization-mass-spectrometry (ESI-MS) of fraction (1) revealed 10 dipeptides with a molecular masses arranged from 184 Da to 364 Da and one Penta peptide with a molecular mass of approximately 659 Da inthe case of positive ions. While the negative ions showed 4 dipeptides with the molecular masses that arranged from 330 Da to 373 Da. Transmission electron microscope (TEM) demonstrated that the SEC-F1 induced changes in the bacterial cells affected. Thus, the results suggested that the hydrolysis of cowpea seed proteins by Alcalase is an uncomplicated appliance to intensify its antibacterial efficiency.

Inheritance of Pod Length and Other Yield Components in Two Cowpea and Yard-Long Bean Crosses

This study determined the gene effects involved in the inheritance of pod length and other yield-related traits and relationships among traits in crosses between two cowpea lines (TVu 2280 and TVu 2027) and a yard-long bean (TVu 6642) line with long pods. Plants of six generations (P1, P2, F1, F2, BC1P1, and BC1P2) derived from TVu 2280 × TVu 6642 and TVu 2027 × TVu 6642 were evaluated under field conditions. Data collected on 14 yield components of each cross were used for generation mean analysis. Gene effects and their magnitudes varied with the crosses; digenic epistatic gene effects were detected for 10 traits in TVu 2280 × TVu 6642 and 11 traits in TVu 2280 × TVu 6642. Only additive gene effect was significant for pod length in TVu 2280 × TVu 6642 while additive, dominant, and two of the three digenic epistatic gene effects were significant in TVu 2027 × TVu 6642. Models that incorporated only significant additive, dominant, and digenic epistasis were adequate for all 14 traits in TVu 2280 × TVu 6642 and eight of the 12 traits in TVu 2027 × TVu 6642 for which model-fitting was possible. Across segregating generation of the two crosses, pod length (PodLNT) was significantly (p < 0.001) correlated with three major yield components viz. pod weight (0.84, 0.77), number of seeds per pod (0.41, 0.30) and seed weight per pod (0.61, 0.29). Significant correlation of PodLNT with seed yield per plant was moderate and significant (p < 0.01–0.001) in the BC1P1 of the two crosses (0.31 and 0.41). An improvement in cowpea seed yield is feasible through selection for long pods in segregating generations involving crosses with yard-long bean.

Health Benefits and Industrial Applications of Functional Cowpea Seed Proteins

Cowpea (Vigna unguiculata) is among the pulse’s species of greatest economic and social importance. This legume is strategic for the food security and health of millions of people in the world. Cowpea is rich in nutraceuticals compounds such as dietary fibre, antioxidants and polyunsaturated fatty acids and polyphenols, whose health benefits and use in the food industry have been extensively studied. However, research on the identification of functional proteins from cowpea, their metabolic functions and applications in the food, health and other industries are still scarce. In this chapter, a critical review of the most recent and important research about functional cowpea proteins. We objective was identify and systematize information about the nature and functions of these proteins, as well as their use and applications in food, health and other industries. Cowpea seed proteins are highly versatile and offer direct health benefits such as reducing the incidence of cardiovascular disease and some types of cancer. The proteins of cowpea are also used in material science for the development of new technologies such as development of special fabrics for protection against ultraviolet rays and microencapsulation of ascorbic acid.

EFFECT OF COWPEA SEED PROCESSING ON INTESTINAL MICROFLORAL POPULATION OF RATS

Five cowpea varieties were subjected to autoclaving, cooking, germination and soaking. Soaked samples gave the highest intestinal microfloral population with autoclaved and cooked cowpea seeds having intermediate microbial count values aithough cooking was more effective than autoclaving in reducing microbial population. Germinated samples gave very little microbial population. Intestinal microfloral population was positively correlated (r=0.85; P<0.001) to oligosaccharide concentrations, in the raw cowpea varieties, good nuniber of the antinutritional factors worked complementarily depending on the processing method with the oligosaccharides and thus hai significant effects in promoting microhial growth. Varietal and processing methoris greatly influenced microbial population (P<0.001).