Horton D. M., Feleke Y., Pasquet Rémy, Javadi F., Melville K. A., Delgado-Salinas A., Thulin M., Mithen R. F., Gepts P., Egan A. N. (2024). Phylogenetic systematics of Vigna sensu stricto in the context of Physostigma and allies. American Journal of Botany, [Early access], p. [20 p.]. ISSN 0002-9122.
Titre du document
Phylogenetic systematics of Vigna sensu stricto in the context of Physostigma and allies
Année de publication
2024
Auteurs
Horton D. M., Feleke Y., Pasquet Rémy, Javadi F., Melville K. A., Delgado-Salinas A., Thulin M., Mithen R. F., Gepts P., Egan A. N.
Source
American Journal of Botany, 2024,
[Early access], p. [20 p.] ISSN 0002-9122
Premise: Vigna includes economically vital crops and wild species. Molecular systematic studies of Vigna species resulted in generic segregates of many New World (NW) species. However, limited Old World (OW) sampling left questions regarding inter- and intraspecific relationships in Vigna s.s. Methods: African species, including the putative sister genus Physostigma, were comprehensively sampled within the context of NW relatives. Maximum likelihood and Bayesian inference analyses of the chloroplast matK-trnK and nuclear ribosomal ITS/5.8 S (ITS) DNA regions were undertaken to resolve OW Vigna taxonomic questions. Divergence dates were estimated using BEAST to date key nodes in the phylogeny. Results: Analyses of matK and ITS data supported five clades of Vigna s.s.: subg. Lasiospron, a reduced subg. Vigna, subg. Haydonia, subg. Ceratotropis, an enlarged subg. Plectrotropis, and a clade including V. kirkii and V. stenophylla. Genome size estimates of 601 Mb for V. kirkii are near the overall mean of the genus, whereas V. stenophylla had a larger genome (810 Mb), similar to some Vigna subg. Ceratotropis or Plectrotropis species. Conclusions: Former subg. Vigna is reduced to yellow- and blue-flowered species and subg. Plectrotropis is enlarged to mostly all white-, pink-, and purple-flowered species. The age of the split between NW and OW Vigna lineages is similar to 6-7 Myr. Genome size estimates cannot rule out a polyploid or hybrid origin for V. stenophylla, potentially involving extinct lineage ancestors of Vigna subg. Ceratotropis or Plectrotropis, as indicated by network and phylogenetic analyses. Taxonomic revisions are suggested based on these results.
Plan de classement
Sciences du monde végétal [076]
Description Géographique
MONDE
Localisation
Fonds IRD [F B010091189]
Identifiant IRD
fdi:010091189
