Project description:Fungal diversity present in soil of King George Island, Antarctica assessed by environmental DNA metabarcoding through high throughput sequencing
Project description:Abstract Deschampsia antarctica Desv. can be found in diverse Antarctic habitats which may vary considerably in terms of environmental conditions and soil properties. As a result, the species is characterized by wide ecotypic variation in terms of both morphological and anatomical traits. The species is a unique example of an organism that can successfully colonize inhospitable regions due to its phenomenal ability to adapt to both the local mosaic of microhabitats and to general climatic fluctuations. For this reason, D. antarctica has been widely investigated in studies analyzing morphophysiological and biochemical responses to various abiotic stresses (frost, drought, salinity, increased UV radiation). However, there is little evidence to indicate whether the observed polymorphism is accompanied by the corresponding genetic variation. In the present study, retrotransposon?based iPBS markers were used to trace the genetic variation of D. antarctica collected in nine sites of the Arctowski oasis on King George Island (Western Antarctic). The genotyping of 165 individuals from nine populations with seven iPBS primers revealed 125 amplification products, 15 of which (12%) were polymorphic, with an average of 5.6% polymorphic fragments per population. Only one of the polymorphic fragments, observed in population 6, was represented as a private band. The analyzed specimens were characterized by low genetic diversity (uHe = 0.021, I = 0.030) and high population differentiation (FST = 0.4874). An analysis of Fu's FS statistics and mismatch distribution in most populations (excluding population 2, 6 and 9) revealed demographic/spatial expansion, whereas significant traces of reduction in effective population size were found in three populations (1, 3 and 5). The iPBS markers revealed genetic polymorphism of D. antarctica, which could be attributed to the mobilization of random transposable elements, unique features of reproductive biology, and/or geographic location of the examined populations. Deschampsia antarctica is among the two angiosperms considered as a native for the Antarctic. The retrotransposon?based iPBS markers applied in the study revealed low genetic variation of the species accompanied by surprisingly high population differentiation.
Project description:The observational data described here was collected between 28 February 2011 and 30 November 2015. The data analysis and interpretation were published in the article "Surface radiation balance and weather conditions on a non-glaciated coastal area in the Antarctic region" [1]. An instrumented tower located on the non-glaciated coastal area of the of the Brazilian Antarctic Comandante Ferraz Station, at King George Island, Antarctic Peninsula was used. It was collected data of air temperature and relative humidity, wind speed and direction, barometric pressure, incident and reflected shortwave radiation, longwave radiation emitted by atmosphere and by surface, and net radiation with a sampling frequency of 0.1 Hz. The data was stored as 5-min averages and automatically transmitted to the Air-Sea Interaction Laboratory, at the University of São Paulo, Brazil. The dataset is hosted in the Mendeley repository.
Project description:Glacial retreat is one of the most conspicuous signs of warming in Antarctic regions. Glacier soils harbor an active microbial community of decomposers, and under the continuous retraction of glaciers, the soil starts to present a gradient of physical, chemical, and biological factors reflecting regional changes over time. Little is known about the biological nature of fungi in Antarctic glacier soils. In this sense, this work aimed at studying the behavior of fungal community structure from samples of glacier soil collected after glacial retreat (Collins Glacier). A total of 309 fungi distributed in 19 genera were obtained from eleven soil samples. Representatives of the genera Pseudogymnoascus (Ascomycota) and Mortierella (Mortierellomycota) were the most abundant isolates in all samples. The data revealed the presence of filamentous fungi belonging to the phylum Basidiomycota, rarely found in Antarctica. Analysis of the generalized linear models revealed that the distance from the glacier as well as phosphorus and clay were able to modify the distribution of fungal species. Environmental variations proved to have influenced the genera Pseudogymnoascus and Pseudeutorium.