Variation of karyotype and nuclear DNA content among four species of Plectranthus L’ Héritier, 1788 (Lamiaceae) from Brazil

By

Nani, Thaís
Teixeira Mesquita, Amanda
de Oliveira Bustamante, Fernanda
Barbosa, Sandro
Barbosa, João Vítor
Davide, Lisete Chamma

Type

Article

Date of Publication

2015

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

9

Series / Issue

Issue: 4

Pages

549-563

Subjects

Cytogenetics , cytotaxonomy , flow cytometry , Karyotypic evolution

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/CompCytogen.v9i4.6255

 

Abstract

Plectranthus is a genus which includes species of ornamental and medicinal potential. It faces taxonomic problems due to aggregating species previously belonging to the genus Coleus, a fact that has contributed to the existence of various synonymies. The species Plectranthus amboinicus, Plectranthus barbatus, Plectranthus grandis and Plectranthus neochilus are included in this context. Some authors consider P. barbatus and P. grandis as synonyms. The present work was carried out with the aim of comparing plants of the above-mentioned species, originating from different localities in Brazil, with regards to chromosome number and karyotypic morphology, correlated to the nuclear DNA content. There was no variation in chromosome number among plants of the same species. P. amboinicus was the only species to exhibit 2n=34, whereas the others had 2n=30. No karyotypic differences were found among the plants of each species, except for P. barbatus. The plants of the Plectranthus species revealed little coincidence between chromosome pairs. The nuclear DNA content allowed grouping P. amboinicus and P. neochilus, with the highest mean values, and P. grandis and P. barbatus with the lowest ones. Differences in DNA amount among the plants were identified only for P. barbatus. These results allow the inference that the populations of P. amboinicus and P. neochilus present coincident karyotypes among their plants, and P. grandis is probably a synonym of P. barbatus.