Phylogenetic analysis of Jarava (Poaceae, Pooideae, Stipeae) and related genera: testing the value of the awn indumentum in the circumscription of Jarava

Abstract

Jarava, a genus of the tribe Stipeae with 31 American species, is considered polyphyletic. In previous phylogenetic analyses, despite a few species of Jarava were used, they were included in the Major American Clade (MAC) together with species of Achnatherum, Amelichloa and Nassella. The main goal of this study is to test the monophyly of Jarava and to estimate relationships of Jarava species and allied genera. Eighty-nine species of Stipeae (17 species of Jarava) were included in the analyses of trnH-psbA and ITS regions from plastid and nuclear genomes, respectively. Morphological characters were optimized on one of the shortest trees derived from the combined analysis. Jarava splits into different lineages. Jarava ichu, the type species of the genus, and other eight species of Jarava were grouped into subclade B; another four species were associated with Achnatherum in subclade A. Both subclades A and B were included into the MAC. Three species: Jarava neaei, J. psylantha, and J. subplumosa, were grouped with Pappostipa in subclade C. The close relationship between Jarava and Pappostipa appears as a novelty and they should be considered within this genus or recognized as a new genus sister to Pappostipa. The awn indumentum (hair length and position of long hairs, either in part or the entire awn) and the subacute or acute callus are useful to recognize the group (subclade C). Geographical distribution of Jarava from subclade C overlaps completely with that of Pappostipa. The shared geographical distribution is in accordance with major groupings in our phylogenetic topology.

Grasses through space and time: An overview of the biogeographical and macroevolutionary history of Poaceae

“…Elias) Barkworth, 5 spp., North America); Jarava Ruiz & Pav. (30 spp., Central & South America; Sclovich et al, 2015); Lorenzochloa Reeder & C. Reeder (8 spp., South America, including Anatherostipa s.s., leaving four spp. unplaced; Romaschenko, 2021, pers.…”

Phylogenetic implications of nuclear rRNA IGS variation in Stipa L. (Poaceae)

“…The ITS sequences were also shown to be useful for assessing evolutionary relationships among closely related grass species for example within the genera of Bromus 22 , Miscanthus 23 , Hordeum 24 , Elymus 25 , Setaria 26 and Festuca-Lolium complex 27 . However, the literature data have shown that phylogenetic trees derived from ITS sequences were unresolved within clades comprising Stipa 3 , 28 . The branch of ITS-based cladogram published by Hamasha et al .…”

Plastid super-barcodes as a tool for species discrimination in feather grasses (Poaceae: Stipa)

“…a few nuclear markers and several plastid markers were applied. Among nuclear loci usefulness of internal transcribed spacers (ITS) was tested both as a complete ITS 15 , 17 , 20 and separately as ITS1 and ITS2 19 , 21 . Moreover, external transcribed spacer (ETS) was applied in one study 19 .…”