An analysis of the relationships of the wild peanut species in the taxonomic section 1 Arachis using high2 density single nucleotide polymorphisms – a resource for botanical classification, crop improvement 3 and germplasm management

LEAL-BERTIOLI, S. C. M; DE BLAS, F. J; CHAVARRO, M. C; SIMPSON, CH. E; VALLS, J. F. M; TALLURY, S. P; MORETZOHN, M. C; CUSTODIO, A. R; STALKER, H. T; SEIJO, J. G; BERTIOLI, D. J

AMERICAN JOURNAL OF BOTANY

BOTANICAL SOC AMER INC

Lugar: St. Louis; Año: 2024

0002-9122

Premise of the study: Wild species are strategic sources of valuable traits to be introduced into crops through hybridization. For peanut, the 33 wild species in the section Arachis are particularly important because of their sexual compatibility with the domesticated species, Arachis hypogaea. Although numerous wild accessions are carefully preserved in seed banks, their morphological similarities pose challenges to routine classification. Methods: Using a high-density array, we genotyped 272 accessions encompassing all diploid species in the Arachis section. Detailed relationships between accessions and species were revealed through phylogenetic analyses and interpreted using the expertise of germplasm collectors and curators.Key results: Two main groups were identified: one with A genome species and the other with B, D, F, G, and K genomes. Species groupings generally showed clear boundaries. Structure within groups was informative, for instance, revealing the history of the proto-domesticate A. stenosperma. However, some groupings suggested multiple sibling species. Others were polyphyletic, indicating the need for taxonomic revision. Annual species were better defined than perennial ones, revealing limitations in applying classical and phylogenetic species concepts to the genus Arachis. We suggest new species assignments for several accessions.Conclusions: Curated by germplasm collectors and curators, this analysis of species relationships lays the foundation for future species descriptions, classification of unknown accessions, and germplasm use for peanut improvement. It supports the conservation and curation of current germplasm, both critical tasks considering the threats to the genus posed by habitat loss, and the current restrictions on new collections and germplasm transfer.