Systematics of Festuca L. sects. Eskia Willk., Pseudatropis Kriv., Amphigenes (Janka) Tzvel., Pseudoscariosa Kriv. and Scariosae Hack. based on analysis of morphological characters and DNA sequences

Abstract

A systematic revision of sections Eskia Willkomm, Pseudatropis Krivotulenko, Amphigenes (Janka) Tzvelev, Pseudoscariosa Krivotulenko and Scariosae Hackel of the genus Festuca L. (Poaceae) is presented here. Taxonomic circumscriptions of these groups and phylogenetic relationships among them and with respect to other Festuca lineages have been achieved after independent and simultaneous analyses of both morphological and molecular (ITS, trnL-F) characters. 21 representatives of these five sections of Festuca, 11 representatives of other subgenera or sections of Festuca (subgen. Festuca sects. Festuca and Aulaxyper, subgen. Schedonorus, subgen. Drymanthele, subgen. Leucopoa), and one representative each of genera Lolium, Poa, Secale, and Brachypodium were included in the survey. A phenetic study based on PCO analysis of 16 morphological characters was completed on 149 samples of representatives of the five sections under study. The phylogenetic study based on ITS and trnL-F sequences was conducted on 30 representatives of these five sections of Festuca and close allies using Brachypodium distachyon as outgroup. The total evidence principle was invoked for the simultaneous cladistic analysis based on morphological and molecular data. The multivariate PCO analysis differentiates three groups of taxa corresponding to sects. Eskia + Pseudatropis, sect. Amphigenes, and sects. Scariosae (type species) + Pseudoscariosa. Phylogenetic reconstructions based on combined analyses of ITS and trnL-F sequences indicate that representatives of sects. Eskia, Pseudatropis, and Amphigenes p.p. form a paraphyletic basal group within the `fine-leaved' Festuca whereas F. scariosa and F. pseudeskia are sister taxa of a mixed clade within the `broad-leaved' Festuca. The North African taxon Festuca mairei is shown to be a close relative of Festuca subgen. Schedonorus whereas the Canarian endemic F. agustinii belongs to Festuca sect. Aulaxyper.