Genomic characterisation of (Valls & C.E. Simpson, 2005) (Leguminosae): multiple origin of species with x = 9.

The genus Linnaeus, 1753 comprises four species with = 9, three belong to the section Arachis: (Krapov. W.C. Greg. & Valls, 1994), (Krapov. W.C. Greg. & Valls, 1994) and (Krapov. W.C. Greg. & Valls, 1994) and only one belongs to the section Erectoides: (Valls & C.E. Simpson, 2005). Recently, the = 9 species of section Arachis have been assigned to G genome, the latest described so far. The genomic relationship of with these species is controversial. In the present work, we carried out a karyotypic characterisation of to evaluate its genomic structure and analyse the origin of all = 9 species. showed a karyotype formula of 14m+4st, one pair of A chromosomes, satellited chromosomes type 8, one pair of 45S rDNA sites in the SAT chromosomes, one pair of 5S rDNA sites and pericentromeric C-DAPI+ bands in all chromosomes. Karyotype structure indicates that does not share the same genome type with the other three = 9 species and neither with the remaining Erectoides species. Taking into account the geographic distribution, morphological and cytogenetic features, the origin of species with = 9 of the genus cannot be unique; instead, they originated at least twice in the evolutionary history of the genus.