Phylogenetic relationships and natural hybridization among the North American woody bamboos (Poaceae: Bambusoideae:Arundinaria)

Abstract

In spite of the ecological and economic importance of temperate bamboos, relatively little is known about their population biology or evolutionary history. Recently, hybridization has emerged as a potential source of diversity in this group, as well as an underlying cause of taxonomic problems. As part of a broader phylogenetic study of the temperate bamboos, we report the results of an analysis of the North American Arundinaria gigantea species complex, including estimates of genetic variation and molecular evidence of natural hybridization among A. gigantea, A. tecta, and A. appalachiana. The study involved a comparative analysis of amplified fragment length polymorphisms (AFLPs) and chloroplast DNA sequences representing diversity within and among all three species plus individuals with intermediate or unusual morphological characteristics (putative hybrids). Molecular results support the recognition of three species previously defined on the basis of morphology, anatomy, and ecology, with most of the molecular variance accounted for by among-species variation. Molecular evidence also demonstrates that A. tecta and A. appalachiana are sister species, forming a clade that is significantly divergent from A. gigantea. The role of hybridization in the phylogenetic history of Arundinaria is discussed along with implications for the evolution and taxonomy of the temperate woody bamboos.

High-Throughput Sequencing of Six Bamboo Chloroplast Genomes: Phylogenetic Implications for Temperate Woody Bamboos (Poaceae: Bambusoideae)

“…B. emeiensis was sister to B. oldhamii in Bambuseae and this relationship was consistent with a recent phylogenetic tree based on five cp DNA fragments [43], while it differs from phylogenetic studies which included nuclear DNA sequences in analyses [44], [45]. Triplett and Clark [46] suggested that reticulate evolution may be more significant in temperate woody bamboos than previously suspected. Natural hybridization has been reported in tropical woody bamboos as well [47].…”

Independent allopolyploidization events preceded speciation in the temperate and tropical woody bamboos

“…We also investigated several species of putative hybrid origin in the temperate clade. Sasaella , Semiarundinaria , and the monotypic genus Hibanobambusa encompass a set of morphologically intermediate species that have been alternatively interpreted as members of distinct genera or else as intergeneric hybrids (Takahashi et al ., ; Triplett & Clark, ; Triplett et al ., ). Our data strongly support a hybrid origin for each of the sampled taxa, and also indicate that different species in a particular genus (e.g.…”

The chloroplast genome of the hexaploid Spartina maritima (Poaceae, Chloridoideae): Comparative analyses and molecular dating

“…3). The age of 5-6 my found here and in Burke et al (2014) for the split between Ferrocalamus and Phyllostachys is puzzling because this divergence is supposed to be older than the split between Chimonobambusa and Phyllostachys (Triplett et al, 2010), which was estimated as 10 mya (Christin et al, 2008;Vicentini et al, 2008). In Pooideae, Brachypodium diverged from Triticum 42-50 mya, compared to 30-33 mya in Prasad et al (2011) and 34-44 mya in Christin et al (2014); Triticum diverged from Agrostis 37-44 mya and from Hordeum 14-21 mya compared to 31-39 and 14-16 mya in Christin et al (2014), and Agrostis diverged from including the phytoliths, but also older than the ages we estimated using the same calibration, whereas without including the phytoliths, they found ages younger than ours and even younger than those reported by Christin et al (2014).…”