Phylogenetic structure of the grass subfamily Pooideae based on comparison of plastid matK gene–3′trnK exon and nuclear ITS sequences

Abstract

The grass subfamily Pooideae was studied using DNA sequence information from the chloroplast (cp) matK gene–3′trnK exon and the nuclear ribosomal (nr) ITS1–5.8S gene–ITS2 in a sample of 67 taxa covering all of its tribes. Branches with strong bootstrap support are consistently resolved in both datasets, whereas discrepancy is confined to low‐support or unsupported nodes in one of the datasets. The results do not reveal a significant role of past hybridisation, plastid lineage sorting or reticulation in the evolutionary diversification of the major lineages of the subfamily. The combined analysis of the plastid and nuclear datasets results in a largely well‐supported pattern of divergence for the major lineages of the subfamily. Some re‐alignments of tribes and subtribes are proposed and discussed with reference to relevant morphological and structural characters. We propose the recognition of broader tribes Nardeae with subtribes Nardinae and Lygeinae, Meliceae with subtribes Brylkiniinae and Melicinae, Stipeae with subtribes Ampelodesminae and Stipinae, and Triticeae with subtribes Littledaleinae, Brominae and Hordeinae. For the tribe complex of Aveneae and Poeae, the clear‐cut split into two major clades and further resolution into some high‐support lineages depicted by cpDNA is not contradicted by nuclear ITS and their taxonomic treatment as separate tribes or a single tribe remains an unanswered question.

Evolution of the beta-amylase gene in the temperate grasses: Non-purifying selection, recombination, semiparalogy, homeology and phylogenetic signal

“…1) and MP tree ( Fig. 1; bootstrap support values) from the combined data set were highly congruent to each other and with those obtained for the grasses by previous authors (Bouchenak-Khelladi et al, 2008;Schneider et al, 2009;Blaner et al, 2015;Soreng et al, 2015). The MP statistics of the Poaceae cpDNA-ITS tree are shown in Table S2.…”

“…GPWG, 2001GPWG, , 2012Sanchez-Ken et al, 2007;Bouchenak-Khelladi et al, 2008;Schneider et al, 2009;Blaner et al, 2015;Soreng et al, 2015). The PACCMAD clade was split into two strongly supported sister lineages, Centothecoi deae-Panicoideae and Danthonioideae-Chloridoideae (e.g., Soreng and Davis, 1998;Bouchenak-Khelladi et al, 2008, and references therein).…”

“…Previous evolutionary studies of the Poaceae (e.g., GPWG, 2001GPWG, , 2012Davis and Soreng, 2007;Bouchenak-Khelladi et al, 2008;Schneider et al, 2009) have provided valuable insights into the evolutionary structure of grass genomes and their phylogeny. However, major phylogenetic relationships remain to be solved, especially at the tribal and generic levels.…”

Abscission of leaf laminas – An unnoticed factor in tussock grass formation

“…This might have a phylogenetic component, because grasses in general show strong differences in the anatomy of their vegetative organs. Danthoniastrum and Macrochloa are nowadays considered part of the grass subfamily Pooideae, though under different tribes (Phaenospermateae and Stipeae, respectively; Schneider et al, 2009) whereas Aristida turned out widely distant from Stipeae and is part of the separate subfamily Aristidoideae (GPWG, 2001). It must be expected therefore, that other tussock grasses with different phylogenetic relationship will even show further mechanisms and different structural features to abscise leaf blades.…”

Molecular characterisation and interpretation of genetic diversity within globally distributed germplasm collections of tall fescue (Festuca arundinacea Schreb.) and meadow fescue (F. pratensis Huds.)

“…The cpDNA matK gene was ampliWed, puriWed and sequenced from each accession as described previously (Hand et al 2010), except that the primer PO-matK860F (Schneider et al 2009) was used for sequencing of each amplicon. Further sequencing based on use of the S5-1F ampliWcation primer was then performed to discriminate between accessions initially identiWed as either F. mairei, octoploid tall fescue or decaploid tall fescue.…”