Incipient speciation in Calceolaria polyrhiza complex (Calceolariaceae): cytogenetic analysis supports molecular and morphological data

MERMOUD, S.; COSACOV, A.; SÉRSIC, A.; ACOSTA, M. C.

PLANT BIOSYSTEMS

TAYLOR & FRANCIS LTD

Año: 2021 p. 1 - 13

1126-3504

Calceolaria polyrhiza is a perennial herb distributed in southern South America. The species ishighly polymorphic and includes four described morphotypes that were previously considereddifferent species. We performed a detailed study of the karyotype of each morphotype consideringat least two localities for each one, with the aim of contributing to the taxonomic delimitationof the Calceolaria polyrhiza complex. In addition, a principal component analysis and a mappingof chromosome traits onto a phylogeny of nuclear DNA sequences were performed. This detailedkaryotypic study has revealed specific markers, which have allowed to characterize eachmorphotype. ?Prichardii? morphotype was consistently polyploid. ?Mendocina? and ?Lanceolata?morphotypes had the highest total heterochromatin amount, with two pairs of chromosomescarrying NORs. ?Mendocina? samples showed the most asymmetrical karyotypes. ?Polyrhiza?morphotype had the most symmetrical karyotypes of the four morphotypes and the simplestfluorescent chromosome banding pattern. Thus, the four morphotypes could be characterized bychromosomal data and, together with the phylogenetic analysis of molecular data, could beconsidered taxonomic units in the process of diversification.