Variación genética en especies de cícadas estrechamente relacionadas en Ceratozamia (Zamiaceae: Cycadales) mediante el uso de RAPDs

Abstract

The Ceratozamia norstogii complex from Southern Mexico is made up of four closely related taxa and occurs in similar habitats (Quercus forest). All have linear-lanceolate leaflets with great similarity between them, especially in juvenile stages, but differentiate with age. There has been debate regarding delimitation of species due to character loss in herbarium specimens. The aim of this study was to determine the genetic variation, and to measure genetic similarity between the four taxa. We studied populations in Cintalapa (Chiapas) for C. alvarezii and C. norstogii; the Sierra Atravesada (Oaxaca) for C. chimalapensis, and Villa Flores (Chiapas) for C. mirandae. One population for each taxon was sampled (only one population is known for C. alvarezii) 11-15 randomly chosen adult individuals were sampled. Twenty-eight primers were tested of which five were polymorphic using the RAPD’S technique. The data were analyzed using Bayesian methods. Results revealed low genetic diversity, and a differentiation was found between species, suggesting a recent divergence. A previous morphological and anatomical study on the complex has found the taxa to be distinct. However, the results of this study have shown that the C. norstogii species complex is in a divergence process, probably through genetic drift and founder effects.

A novelty in Ceratozamia (Zamiaceae, Cycadales) from the Sierra Madre del Sur, Mexico: biogeographic and morphological patterns, DNA barcoding and phenology

“…In particular, there are some populations in Oaxaca and Chiapas that still await closer inspection. In the present work, 31 species have been recognized for the genus (Stevenson et al 1986;Nicolalde-Morejón et al 2014;Vovides et al 2016;Pérez-Farrera et al 2017;Martínez-Domínguez et al 2017, 2018a, with C. becerrae and C. microstrobila treated as synonyms of C. zoquorum and C. latifolia, respectively (Stevenson et al 1986;Martínez-Domínguez et al 2017, 2018a.…”

Ceratozamia schiblii (Zamiaceae): A New Cycad Species from the Eastern Mountains of Oaxaca, Mexico

“…Indeed, some 26 cycad species in Mexico have been described in the last 20 years. Most Mexican species are endemic to the southern states of Oaxaca, Chiapas, and Veracruz, a region recognized as one of the main hotspots of cycad diversity in the New World [1][2][3]. The majority of cycad species are considered threatened [4], so an increased understanding of the species richness and diversity within this region will contribute to their conservation.…”