Protein Content and Seed Trait Analysis in a Subset of the USDA, ARS, PGRCU Cowpea [Vigna unguiculata (L.) Walp.] Core Collection

Cowpea (Vigna unguiculata (L.) Walp is used as a vegetable and feedcrop worldwide, but knowledge is limited regarding the variability and correlations for protein and seed traits within a cowpea core collection. We analyzed protein content and seed trait data from the cowpea core collection representing 111 accessions. The accession PI 354729 produced the significantly highest protein content of 25.527%. Eight Indian cowpea accessions produced significantly high protein content averaging 24.423%. Protein content was significantly correlated with seed pattern (r2 = 0.274***), seed texture (r2 = 0.346***), seed coat color (r2 = 0.136*) and seed pattern significantly correlated with seed texture (r2 = 0.197**). However, protein content showed a significant negative correlation (r2 =-0.333***) with 100 seed weight. One hundred seed weight (gm) showed significantly negative correlations with seed pattern (r2 = -0.191**) and seed texture (r2 = -0.265***). Seed coat color showed a significant negative correlation with seed pattern (r2 = -0.14). Based on these results, potential cowpea cultivars could be developed with improved protein content and morphological seed traits.