Work

Polyploids and geographic divergence blur species delimitation in the Paspalum stellatum complex (Poaceae: Paspaleae)

Year: 2024

Type: article

Abstract: Paspalum stellatum comprises a diploid and several polyploid cytotypes. The widely distributed cytotype 2n = 32 is an amphidiploid, an outcome of hybridization between diploid P. stellatum (2n = 20) and the related species Paspalum schesslii (2n = 12). Several analyses were conducted upon a set of 24 accessions of P. stellatum and representatives of three related species. Multivariate analyses of morphological data discriminated between the two potentially sexual cytotypes, 2n = 20 and 2n = 32, but the putatively apomictic higher polyploids were interspersed between them. Instead, Iner Simple Sequence Repeat (ISSR) markers separate two main groups geographically, west and east from the Brazilian-Bolivian Pantanal. Both groups include diploid (2n = 20) and tetraploid (2n = 32) cytotypes, but higher polyploids belong exclusively to the eastern group. Considering that diploids and polyploids behave as different biological entities, we propose to treat the diploid (2n = 20) cytotype as a different species, for which the name Paspalum cujabense should be rehabilitated. Meanwhile, the name P. stellatum remains for a complex including the tetraploid and all polyploid cytotypes.

Source: Conicet

Authors: Bonasora, Marisa Graciela, López, Alicia, Speranza, Pablo R., Honfi, Ana Isabel, Rua, Gabriel Hugo

Institutions: Universidad de Buenos Aires, Universidad de la República de Uruguay

Language: English

Topic: Plant Taxonomy and Phylogenetics

Subfield: Ecology, Evolution, Behavior and Systematics

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: green