Near-infrared reflectance spectroscopy reveals wide variation in major components of sesame seeds from Africa and Asia

Sesame is an important oilseed crop in Africa and Asia, owing to its high nutritional quality seed and market value. Variation in sesame seed components including oil, oleic acid,linoleic acid, and protein was investigated by near-infrared reflectance spectrometry in 139 samples collected from different countries. Oil and protein contents were between 40.8%and 60.3%(mean 53.0%) and 15.5% to 25.5%(mean 20.4%), respectively. Linoleic acid,ranging from 31.8% to 52.4%(mean 46%) was more abundant than oleic acid(31.8%–50.6%,mean 38.1%). Light-seeded samples displayed higher nutritional quality, as they were richer in oil, protein, and linoleic acid than dark seeds. Samples from Africa had higher oil and linoleic acid contents, while Asian samples had higher oleic content. The analysis revealed West African sesame cultivars containing especially high levels of seed components, which may command high market values. Two clusters of sesame samples grouped by seed composition were obtained, including one cluster with high oil and oleic acid content and the other with high protein and linoleic acid content. This study revealed that sesame samples from Africa and Asia harbor high variation for major seed components and also provided background information for breeding high-nutrition varieties according to the demands of sesame seed markets.

Development of new cowpea(Vigna unguiculata)mutant genotypes,analysis of their agromorphological variation,genetic diversity and population structure

Cowpea is one of the most important legume grains in the sub-Saharan region of Africa used for human consumption and animal feed,but its production is hampered by biotic and abiotic constraints raising the need to broaden its genetic basis.For this purpose,seeds of two cowpea varieties Melakh and Yacine were irradiated with 300 and 340 Gy of gamma-ray,respectively.The developed mutant populations were agromorphologically characterized from M5 to M7,while the genetic diversity of the latter was evaluated using 13 ISSR markers.Based on the agromorphological characterization,variation of flower color,pod length,seed coat color,and seed weight with 78.01,68.29,94.48,and 57.58%heritability,respectively,were recorded in the mutant lines.PCA analyses allowed to identify the elite mutants based on their agromorphological traits,while Pearson’s correlation results revealed a positive correlation between yield and yield component traits.Three subpopulations were identified through STRUCTURE analyses,but the assignment of the individuals in each group was improved using DAPC(Discriminant Analysis of Principal Components)analysis.Analysis of Molecular Variance revealed that the majority(85%)of the variance rather existed within groups than among(15%)groups.Finally,our study allowed us to select new promising mutant genotypes that could be tested for multi-locational trials to evaluate their agronomic performance.