Systematics of Pithophoraceae Wittrock (Cladophorales, Chlorophyta) from Brazil with emphasis on Southeast and South regions

• Grant number: 23/01877-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2023
• End date: October 31, 2026
• Field of knowledge: Biological Sciences - Botany - Plant Taxonomy
• Principal Investigator: Orlando Necchi Junior
• Grantee: Marina Ramos Auricchio
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

The current circumscription of the family Pithophoraceae (Cladophorales) after recent changes in systematics based on molecular and morphological evidence comprises 41 species distributed in 12 genera with little diversity of filamentous green algae. Currently, the known diversity of Pithophoraceae in Brazil is represented by five species belonging to three genera (Aegagropilopsis sterocladia, Arnoldiella chelonum, Arnoldiella elbakyaneae, Arnoldiella emedii and Pithophora roettleri). In addition to these records, samples referred to as Cladophora glomerata for the northwest region of the São Paulo State were recently analyzed based on molecular data and proved to be Aegagropilopsis clavuligera, thus representing a new addition to the reported data. Species of the family have been sparsely sampled in the country, so that the phylogenetic relationships of the Brazilian species are still unknown and, so far, no work has presented phylogenetic information on any species of Pithophoraceae. In this way, the study of the phylogenetic relationships of the species becomes relevant for a better understanding of the historical relationships between lineages within the group and implications for the taxonomic status of the group. The general objective of this work is to know the phylogenetic relationships of the Pithophoraceae species in Brazil, with emphasis on populations from the Southeast and South regions, positioning them in relation to the other representatives of the group. For this, morphological characterization of the specimens will be carried out, as well as analysis of two molecular markers - nuclear genes that encode the large (LSU rDNA) and small (SSU rDNA) ribosomal subunits. In this way, it is expected to elaborate a taxonomic review of the species that occur in the South and Southeast regions of Brazil and the generated sequences will be analyzed and compared with the sequences of the other species from other regions of the world already available in GenBank, allowing to infer their phylogenetic relationships. Thus, dubious or poorly known clades may be better resolved, and may allow the registration of new species for Brazil and, possibly, for science. The robust hypotheses will be tested throughout the project: 1) the diversity of the Pithophoraceae family in Brazil is much greater than what is currently known and additional genera and species, including probable new species, are expected to be found, and; 2) information on phylogenetic relationships arising from Brazilian species should cause changes in the current systematics of the group, especially for less studied genera, as is the case of Basicladia. Therefore, expanding knowledge in the taxonomic and phylogenetic area implies greater availability of information on biodiversity, directly contributing as basic science to several other areas, including conservation projects. (AU)