Evaluation and Multivariate Analysis of Cowpea [Vigna unguiculata (L.) Walp] Germplasm for Selected Nutrients—Mining for Nutri-Dense Accessions

Abstract

A total of 120 highly diverse cowpea [Vigna unguiculata (L.) Walp] genotypes, including indigenous and exotic lines, were evaluated for different biochemical traits using AOAC official methods of analysis and other standard methods. The results exhibited wide variability in the content of proteins (ranging from 19.4 to 27.9%), starch (from 27.5 to 42.7 g 100 g−1), amylose (from 9.65 to 21.7 g 100 g−1), TDF (from 13.7 to 21.1 g 100 g−1), and TSS (from 1.30 to 8.73 g 100 g−1). The concentration of anti-nutritional compounds like phenols and phytic acid ranged from 0.026 to 0.832 g 100 g−1 and 0.690 to 1.88 g 100 g−1, respectively. The correlation coefficient between the traits was calculated to understand the inter-trait relationship. Multivariate analysis (PCA and HCA) was performed to identify the major traits contributing to variability and group accessions with a similar profile. The first three principal components, i.e., PC1, PC2, and PC3, contributed to 62.7% of the variation, where maximum loadings were from starch, followed by protein, phytic acid, and dietary fiber. HCA formed six distinct clusters at a squared Euclidean distance of 5. Accessions in cluster I had high TDF and low TSS content, while cluster II was characterized by low amylose content. Accessions in cluster III had high starch, low protein, and phytic acid, whereas accessions in cluster IV contained high TSS, phenol, and low phytic acid. Cluster V was characterized by high protein, phytic acid, TSS, and phenol content and low starch content, and cluster VI had a high amount of amylose and low phenol content. Some nutri-dense accessions were identified from the above-mentioned clusters, such as EC170579 and EC201086 with high protein (>27%), TSS, amylose, and TDF content. These compositions are promising to provide practical support for developing high-value food and feed varieties using effective breeding strategies with a higher economic value.

Development and optimization of NIRS prediction models for simultaneous multi-trait assessment in diverse cowpea germplasm

“…Four hundred seventy-five accessions of cowpea consisting of indigenous and exotic collections were taken from MTS of National Gene Bank at ICAR-NBPGR, New Delhi, India, having high variability in seed morphology. Using Augmented Block Design accessions were grown in Issapur experimental farm, New Delhi, India, following standard agronomic practices (29). Matured and dried seeds were collected, and extraneous material was removed.…”

Mining nutri-dense accessions from rice landraces of Assam, India

“…The linear correlation between starch, amylose, total dietary fiber, protein, oil, phenols, and phytate was done using a Pearson correlation matrix and plotted using the Jamovi statistical package. The data was also subjected to PCA using Jamovi to identify superior traits responsible for the variation among them [ 35 ] .…”

Cowpea Constraints and Breeding in Europe

“…Recently, in Europe the consumption of high protein vegetables, such as cowpea, is intensively promoted [ 10 ]. Cowpea is characterized by high seed protein content even higher than 30% [ 343 , 344 ] and low-fat content as well as a significant concentration of carbohydrates [ 3 , 345 ].…”

“…Padhi et al [ 345 ], evaluating 120 cowpea genotypes, found remarkable variability among them regarding their proximate composition. Proximate and nutrient composition of cowpea fresh pods and seeds have been found to be strongly affected by environment [ 15 ] and genotype [ 346 , 347 , 348 ], while a genotype x environment interaction is also usually present [ 10 , 174 , 349 ].…”

“…Strong correlations among seed crude protein and Fe and Zn contents [ 354 ] and between K and Mg as well as between Ca and Mg [ 56 ] indicate the possibility of breeding for increased concentrations of some nutrient components simultaneously. However, cowpea contains various amounts of several antinutritional factors such as alkaloids, flavonoids, saponins, tannins [ 355 ], phenols and phytic acid [ 345 ] in seeds, and oxalates, phytates and nitrates in leaves, reducing its nutritional value [ 356 ]. Statistically significant differences were observed among European cowpea cultivars regarding their antinutritional factors [ 357 ].…”