Distribution, phylogeographic structure and genetic variation in Brazilian freshwater red algae (Batrachospermales - Rhodophyta)

Abstract

The project proposes the study of populations of species of Rhodophyta , the Batrachospermales order, based on currently available information (morphological and molecular) and new analysis proposed here. The following hypotheses will be tested: 1) the population genetic structure should reveal distinct pattern between species, which is related to historical biogeographic connections of each species; 2) the number of haplotypes within a single population is small (typically 1 or 2), on the other hand, a much higher number of haplotypes (typically more than 5) in the group of all populations for each species; 3) the genetic similarity between populations will be progressively smaller the farther away from each other, with greater genetic divergence inter than intrapopulational for all the markers used ; 4) genetic divergence trends for each of the markers tested will be congruent . To test them , the following activities are proposed : 1) to evaluate the genetic variability patterns of populations of several species of Batrachospermales order (Rhodophyta) in Brazil by analyzing molecular markers of nuclear and mitochondrial genomes and also check for this correlation variation with those environmental data obtained ; 2) to determine the diversity levels of the nuclear internal transcriber spacer (ITS), intergenic spacer between the cytochrome oxidase subunit 2 and cytochrome oxidase subunit 3 genes with the flanking gene regions and the cox 1barcoding region (which encodes the I subunit cytochrome c oxidase 1); 3) estimate the intra and inter genetic variability of these three molecular markers ; 4) check for each species investigated the existence of genetic divergence levels between the strains detected. (AU)