Nucleotide variation screening in regions of the chloroplast genome useful for phylogeographic and phylogenetic approaches in cacti species

• Grant number: 11/23499-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: December 31, 2012
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Evandro Marsola de Moraes
• Grantee: Viviane Cristina Dias
• Host Institution: Centro de Ciências e Tecnologias para a Sustentabilidade (CCTS). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

In eastern and central-western Brazil cacti species show a markedly disjunct distribution, occurring in enclaves of xerophitic vegetation within cerrado domain. Such a geographic pattern is also observed for many other taxonomic groups and has been interpreted as evidence of a more widely distributed xerophytic vegetation in the past, which would have suffered fragmentation due to paleoclimatic changes. The cacti species belonging to PILOSOCEREUS AURISETUS exhibit this geographic pattern of distribution and have been adopted as a model group to test the hypothesis of historical changes of xerophytic vegetation enclaves within cerrado. Although phylogeographic studies have the potential to reveal such changes, in plants these studies are limited by the availability of molecular markers with adequate rate of evolution. This study aims to identify molecular markers in chloroplast genome (cpDNA) useful for phylogeographic and phylogenetic studies in the P. AURISETUS species group. The nucleotide variation will be screened in four intergenic spacers (trnQ(UUG)-5'rps16, petL-psbE, 3'trnV(UAC)-ndhC e psbD-trnT(GGU)), one intron (trnK-matK), and in a gene segment (matK). These regions were identified in the literature as potentially informative for studies at low taxonomic levels, including cactus. This study encompasses the amplification, sequencing and estimation of nucleotide variation in these segments of cpDNA in a sample of individuals belonging to different species and populations of P. AURISETUS species group.(AU)