Ongoing projects


1- Multigenomic evolution of temperate grasses (Pooideae, Poaceae). Biogeography and phylogeography of key pooid species (FestucaBrachypodiumAnthoxanthum-HierochloeBromus) in the Old World (CGL2009-12955-C02-01 project)
 


funded by the Spanish Ministry of Science and Innovation (2010-2012)
 
Researchers:
University of Zaragoza (Spain): P. Catalan (PI), L. Inda, E. Perez-Collazos, A. Diaz, M. Minaya, D. López
University of Coruña (Spain): E. Sahuquillo, M. Pimentel
University of Leon (Spain): C. Acedo, F. Llamas, A. Alonso
 
Summary:
We have extended our phylogenetic analyses to representatives of Pooideae using a large number of nuclear (GBSS, b-amylase, pgiC1, pgiC2, ITS, ETS), mitochondrial (rps3), and plastid (ndhF, matK, rbcL, trnH-psbA, trnTL, trnLF) genes. We want to obtain a solid Pooideae tree-of-life that would allow us to: i)  infer relationships among taxa; ii) estimate the evolutionary rates of lineages, genes and genomes; iii) evaluate potential adaptive selection operating on non-synonymous positions of genes, and iv) test correlations between evolutionary rates and different biological and ecological features. We are investigating intringuing, recently discovered cases of horizontal gene transfer (HGT) of both mitochondrial genes and pseudogenes and nuclear functional genes among Festuca and other non-related subfamilial lineages. We want to assess: i) the frequency of these phenomena across the Pooideae, ii) their impact on phylogenetic reconstruction, iii) their importance on the evolutionary processes of these grasses, and iv) the putative mechanisms that have caused them. Our research on the origins and nature of polyploidy in the pooids have been expanded through comparative analysis of biparentally inherited single copy and multiple copy nuclear alleles and  maternally inherited non-recombinant plastid sequences.
 
Biogeography and phylogeography of key pooid species: We are conducting a broad comparative biogeographical study of four key pooid genera (FestucaBrachypodiumAnthoxanthum-Hierochloë and Bromus) in the Mediterranean region (Europe, Africa, W Asia), the centre of diversity of these grasses. Our analyses aimed at inferring well constructed historical distribution scenarios on the origins, speciation events and colonization patterns of their main lineages. Divergence times have been calculated and alternative dispersal hypotheses have been tested through statistical methods based on both deterministic and probabilistic models.  The recovered patterns are going to be contrasted with paleogeographical data and used to construct predictive models within a common biogeographical frame. Exhaustive phylogeographical studies are being conducted with selected restrictive groups (Festuca sects. Lojaconoa-SubbulbosaeFestuca gr. “afrofestuca”, Brachypodium distachyonAnthoxanthum sect. Eu-AnthoxanthumBromus gr. alopecurus-lanceolatus) through large genome sequencing and retrospective methods based on coalescence. The objectives are to recover the past history of their populations, to test hypotheses of dispersal vs isolation and to answer the questions about their continental and transcontinental migrations (E-W Mediterranean, out of Africa-into Africa, S-N Europe, NW Africa-S Iberia-N Iberia) within different ancient and recent spatial and climatic scenarios.