Countrywide

Introduction: Understanding the genome-wide variation pattern in crop germplasm is required in profiling breeding products and defining conservation units. Yet, such knowledge was missing for the large germplasm collection of Methods: Using 1,114 high-quality SNPs, this study: i) investigated the spatial variation of the genetic structure of 305 accessions sampled along the South-North ecological gradient of Benin, ii) derived a core collection from the batch of accessions and iii) gauged the extent of (mal)adaptation of this core set. Results and discussion: Overall, we detected a moderate diversity with a total gene diversity of 0.28 and an expected heterozygosity estimate of 0.27. The spatial variation of the genomic diversity painted an increasing trend following the South-North ecological gradient, giving rise to four optimal genetic groups based on STRUCTURE analysis while the neighbour-joining analysis revealed three clusters. The ShinyCore algorithm application yielded a core set of 54 accessions that echoed a good geographical representativeness and encompassed a level of diversity comparable to that of the whole collection. Nearly 88% of this core set accessions were characterized by a low genomic offset score, which suggests a strong adaptation potential to future climate. This SNP-based core collection represents a unique and viable working asset for accelerated traits-discovery, in the species and should play a pivotal role in international collaborative initiatives dedicated to promoting