Background: The genus Limonium Miller comprises annual and perennial halophytes that can produce sexual and/or asexual seeds (apomixis). Genetic and epigenetic (DNA methylation) variation patterns were investigated in populations of three phenotypically similar putative sexual diploid species (L. nydeggeri, L. ovalifolium, L. lanceolatum), one sexual tetraploid species (L. vulgare) and two apomict tetraploid species thought to be related (L. dodartii, L. multiflorum). The extent of morphological differentiation between these species was assessed using ten diagnostic morphometric characters.Results: A discriminant analysis using the morphometric variables reliably assigns individuals into their respective species groups. We found that only modest genetic and epigenetic differentiation was revealed between species by Methylation Sensitive Amplification Polymorphism (MSAP). However, whilst there was little separation possible between ploidy levels on the basis of genetic profiles, there was clear and pronounced interploidy discrimination on the basis of epigenetic profiles. Here we investigate the relative contribution of genetic and epigenetic factors in explaining the complex phenotypic variability seen in problematic taxonomic groups such as Limonium that operate both apomixis and sexual modes of reproduction.Conclusions: Our results suggest that epigenetic variation might be one of the drivers of the phenotypic divergence between diploid and tetraploid taxa and discuss that intergenome silencing offers a plausible mechanistic explanation for the observed phenotypic divergence between these microspecies. These results also suggest that epigenetic profiling offer an additional tool to infer ploidy level in stored specimens and that stable epigenetic change may play an important role in apomict evolution and species recognition.
|Journal||BMC Plant Biology|
|State||Published - Dec 6 2013|
Bibliographical noteFunding Information:
The authors wish to thank Ana Paula Paes (CBAA) for help in field work and Wanda Viegas (CBAA) for critical insights. We thank the Instituto da Conservação da Natureza e Biodiversidade (ICNB) for providing permissions for collecting samples. ADC (Researcher, CBAA/ISA) and ASR (SFRH/BD/ 62542/2009 grant) were supported by FUNDAÇÃO PARA A CIÊNCIA E TECNOLOGIA, FCT, Portugal). The project was funded by PEST-OE/AGR/ UI0240/2011.
- Epigenetic variation
- Genetic variation
- Ploidy diagnosis
ASJC Scopus subject areas
- Plant Science