Intra-plant variation in seed weight and seed protein content of cowpea

Abstract

Seed size and protein content are the major breeding objectives for cowpeas (Vigna unguiculata). However, intra-plant variation in these traits causes heterogeneous seed quality and seed depreciation. To determine the causes and severity of intra-plant variation in cowpea single seed weight and protein content, seeds from individual plants were analyzed in relation to their positional effects. Associations between positional variables and seed traits were revealed by additive Bayesian network analysis, and the graphical models were compared for different accessions. Intra-plant variation in single seed weight and protein content were large compared to the variations in genetic resources, and these variations are thought to be related to the source/sink ratio within a plant. In accessions with longer flowering periods, the later-flowering peduncles on the upper nodes produced comparatively larger seeds due to a greater availability of assimilated carbon from leaves that maintain their greenness. While, in accessions with shorter flowering periods, the earlier-flowering peduncles on the lower nodes produced relatively larger seeds because less carbon is available at the later filling periods due to rapid senescence. For all accessions, protein content was higher in seeds derived from later-flowering peduncles and in pods with lower seed numbers. The nitrogen source/sink ratio may be higher in the later filling period because of a smaller number of filling seeds and a higher availability of nitrogen remobilized from senescing leaves and stems. ARTICLE HISTORY

Seed to seed variation of proteins of the yellow pea (Pisum sativum L.)

“…Confirming their study, our results show that this high variability also exists among the individual seeds of the same variety grown at the same location and time. Furthermore, in cowpeas, is has been shown that intra-plant variations in single seed weight and protein content might be associated biased carbon and nitrogen source/sink ratios caused by non-uniform flowering [ 19 ], which may help account for variability reported in the present study.…”

A High Plant Density and the Split Application of Chemical Fertilizer Increased the Grain and Protein Content of Cowpea (Vigna unguiculata) in Burkina Faso, West Africa

“…However, high-protein cowpea is yet to be released. Grain proteins are considered a polygenic trait influenced by environmental and management factors [13]. The main genetic loci identified for protein content and seed size are highly heritable; therefore, these traits can be improved in cowpea (with other favourable agronomic traits) through breeding [14,15].…”

“…In cowpea, the single-seed weight and grain crude protein content range from 0.13 to 0.30 g and 23% to 33%, respectively [16]. Within the same plant, the single-seed weight and protein content can vary by up to 0.1 g and 10%, respectively [13]. Therefore, breeding programs that could simultaneously address genotypic averages and reduce intra-plant heterogeneity are required.…”

Diversity of Cowpea [Vigna unguiculata (L.) Walp] Landraces in Mozambique: New Opportunities for Crop Improvement and Future Breeding Programs

“…Maringué also showed the highest number of days to flowering and to mature pods together with Nhamatanda (NHA), Sede Nova (SED), and Tambara (TAM); Figure 1). While seed weight is a yield indicator [40,41], late-flowering correlates with higher protein contents due to the higher availability of nitrogen remobilized from senescing leaves and stems [42]. Regarding the qualitative traits, the color of seeds, eye color, and flower color also presented significant differences between landraces.…”