No abstract

16Cowpea is one of the most important legume grain in the SubSaharian region of Africa used 17 for human consumption and animal feeding but its production is hampered by biotic and 18 abiotic constraints raising the need to broaden its genetic basis. For this purpose, the seeds of 19 two cowpea varieties Melakh and Yacine were respectively irradiated with 300 and 340 Gy. 20The developed mutant populations were agromorphologically characterized from M5 to M7 21 while the genetic diversity of the last were evaluated using 13 ISSR markers. Based on 22 agromorphological characterization, variation of flower color, pod length, seed coat color and 23 seed weight with respectively 78.01, 68.29, 94.48 and 57.58% heritability were recorded in 24 the mutant lines. PCA analyses allowed to identify the elite mutants based on their 25 agromorphological traits while Pearson's correlation results revealed a positive correlation 26 between yield component traits. Three subpopulations were identified through STRUCTURE 27 analyses but assignment of the individuals in each group was improved using DAPC. 28Analysis of Molecular Variance revealed that the majority (85%) of the variance rather 29 existed within group than among (15%) group. Finally, our study allowed to select new 30 promising mutant genotypes which could be tested for multi local trials to evaluate their 31 agronomic performance. 32 33 Cowpea [Vigna unguiculata (L.) Walp. 2n = 2x =22] is an important crop legume for tropical 34 and subtropical regions grown in Africa, Southern Europe, Latin America, Southeast Asia, 35 and southwestern regions of North America on 12 496 305 hectares 36