ABSTRACT
The Ansanto Valley's Mefite, one of the Earth's largest non-volcanic CO2 gas emissions, is distinguished by its cold natural carbon dioxide springs. These emissions originate from the intricate tectonics and geodynamics of the southern Apennines in Italy. Known for over two millennia for its lethal concentration of CO2 and other harmful gases, the Mefite has a reputation for being toxic and dangerous. Despite its historical significance and unique geological features, there is a lack of information on the microbial diversity associated with the Mefite's gas emissions. This study presents an integrated exploration of the microbial diversity in the mud soil, using high-throughput sequencing of 16S rRNA (Prokaryotes) and ITS2 (Fungi), alongside a geochemical site characterisation. Our findings reveal that the Mefite's unique environment imposes a significant bottleneck on microbial diversity, favouring a select few microbial groups such as Actinobacteria and Firmicutes for Prokaryotes, and Basidiomycota for Fungi.
Subject(s)
Carbon Dioxide , Microbiota , Carbon Dioxide/analysis , RNA, Ribosomal, 16S/genetics , Bacteria/genetics , Soil , Microbiota/geneticsABSTRACT
The delimitation of Limonium taxa is highly complicated due to hybridization, polyploidy, and apomixis. Many "microspecies" were described and aggregated into groups, most of which are still poorly known from both molecular and morphological points of view. The aim of this study is to investigate four endemic species from the Tyrrhenian coast of central Italy and the Ponziane Archipelago belonging to the L. multiforme group (L. amynclaeum, L. circaei, L. pandatariae, and L. pontium) by means of molecular and morphometric analyses. Molecular data by sequencing ITS and three plastid markers and morphometric data highlight new information about the taxonomy of these taxa so as to reduce them into a single specific entity. In fact, the better taxonomic choice is to consider the populations studied as part of a single species, i.e., Limonium pontium. Three subspecies are recognized, i.e., subsp. pontium [= L. circaei = L. amynclaeum; from Circeo to Gianola localities (excluding Terracina) and from islands Ponza, Palmarola, Zannone, and Santo Stefano], subsp. pandatariae comb. et stat. nov. (from island of Ventotene), and subsp. terracinense subsp. nov. (from Terracina).
ABSTRACT
Genista etnensis is a remarkable and well-known tree endemic to Sicily, Sardinia, and Corsica (Mediterranean Basin). Nevertheless, its morphological variability and its native status throughout its range need to be further investigated. In this study, we aim to clarify some aspects of this infraspecific variability by molecular means. Sequences of one nuclear and five plastid markers were analyzed under maximum parsimony by using TCS software. Plastid data were also time-calibrated under a Bayesian Inference framework. Plastid data revealed strong isolation between the populations from the Cyrno-Sardinian biogeographical province, which are also the most diverse and presumably the most archaic, and those from Sicily and Southern Italy (in this latter area, the species is naturalized). The calibration analysis indicates that the last common ancestor between G. etnensis and its sister group G. fasselata dates back to the middle Pliocene or slightly later, when sclerophyllous Mediterranean vegetation spread, whereas G. etnensis itself might have originated in the middle Pleistocene. The current, rather unusual distribution of G. etnensis could be explained by long-range seed dispersal from the western part of the range or by anthropogenic introduction into Sicily, with extinctions of transported haplotypes in the region of origin. Interestingly, the Vesuvius population, introduced from Sicily in recent times and locally naturalized, shows private genotypes, and was richer in both genotypes and haplotypes than the Sicilian ones.
