Format: ORAL

Mara Fernanda Moreno-Aguilar1, Juan Viruel2,Aminael Snchez-Rodrguez3, Itziar Arnelas3, Juan Camilo Ospina4, Gloria Martnez-Segarra5, Diana Caldern3, Juan Antonio Devesa5, Pilar Cataln1,6

1 Departamento de Ciencias Agrarias y del Medio Natural. Escuela Politécnica Superior de Huesca. Universidad de Zaragoza. C/ Ctra. Cuarte Km 1. E-22071 Huesca. Spain. mmoreno@uniza.es. 2 Royal Botanic Gardens, Kew. Richmond. United Kingdom. 3 Departamento de Ciencias Biológicas y Agropecuarias, Universidad Técnica Particular de Loja, San Cayetano Alto s/n. CP 11-01-608 Loja. Ecuador. 4 Facultad de Ciencias Agrarias. Universidad Nacional de Jujuy. Av. Bolivia 1239, San Salvador de Jujuy. Y4600 Jujuy. Argentina. 5 Departamento de Botánica, Ecología y Fisiología Vegetal, Universidad de Córdoba, Campus de Rabanales. E-14014 Córdoba. Spain. 6 Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada al CSIC, E-50059 Zaragoza. Spain.

Resolving the phylogeny of recently evolved groups that have experienced recurrent introgressions and polyploidizations throughout their history is challenging. Evolutionary reconstruction based on a large set of biparentally inherited single-copy nuclear genes is considered a suitable approachto recover relationships that might otherwise be obscured by nuclear ribosomal genes in concerted evolution or biased by maternally inherited plastomes. Here we present the first single-copy gene phylogeny of the ecologically and economically important grass subtribe Loliinae (Festucaand related genera) using 241 nuclear coding loci captured from the Angisoperm353 probe set and a large sample of 137 representative taxa of Loliinae, covering all of its 22 evolutionary lineages. We have further completed genome-skimming sampling of other nuclear (35S rDNA gene) and organellar (plastome) sequences to elucidate the reticulate history of the Loliinae from multiple and complementary genome sources. Concatenated maximum likelihood and multispecies coalescent trees of single-copy genes showed well-supported relationships that were generally consistent across analyses and with previous taxonomic and phylogenetic findings but also revealed high levels of gene discordance.Hybridization and topological incongruence tests between the nuclear and plastome-based trees confirmed the rampant introgression experienced by Loliinae at deep and shallow nodes, detecting hybridization in four broad-leaved (Subulatae-Hawaiian, Schenodorus, Tropical-South African, Mexico-Central-South American) and five highly-diversified fine-leaved (American II, Exaratae-Loretia, Aulaxyper, Afroalpine, American-Neozeylandic)Loliinae lineages. The levels of intragenomic discordance could have been magnified by the prevalence of allopolyploids in the Loliinae and methodological bias in the selection of orthologs; however, our nuclear and plastome trees have revealed key hybrid origins in these grasses.