title: Independent allopolyploidization events preceded speciation in the temperate and tropical woody bamboos.
abstract: The objectives of the current study were to investigate the origin of polyploidy in the woody bamboos and examine putative hybrid relationships in one major lineage (the temperate woody bamboos, tribe Arundinarieae). Phylogenetic analyses were based on sequence data from three nuclear loci and 38 species in 27 genera. We identify six ancestral genome donors for contemporary bamboo lineages: temperate woody bamboos (tribe Arundinarieae) contain genomes A and B, tropical woody bamboos (tribe Bambuseae) contain genomes C and D, and herbaceous bamboos (tribe Olyreae) contain genome H; some hexaploid paleotropical bamboos contain genome E in addition to C and D. Molecular data indicate that allopolyploidy arose independently in temperate (AABB) and tropical woody lineages (CCDD and CCDDEE), and speciation occurred subsequent to polyploidization. Moreover, hybridization has played a surprising and recurrent role in bamboo evolution, generating allohexaploid species in the paleotropical clade and intergeneric hybrids among the allotetraploid temperate bamboos. We suggest this complex history of reticulate evolution is at least partially responsible for the taxonomic difficulty associated with the woody bamboos. This newly-resolved phylogenetic framework reflects a major step forward in our understanding of bamboo biodiversity and has important implications for the interpretation of bamboo phylogenomics.
authors.affiliation: Department of Biology, Jacksonville State University, 700 Pelham Road N, Jacksonville, AL, 36265, USA.
authors.forename: Jimmy K
authors.initials: JK
authors.lastname: Triplett
authors.affiliation: Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, 50011-1020, USA.
authors.forename: Lynn G
authors.initials: LG
authors.lastname: Clark
authors.affiliation: Rancho Santa Ana Botanic Garden and Claremont Graduate University, 1500 N. College Ave, Claremont, CA, 91711, USA.
authors.forename: Amanda E
authors.initials: AE
authors.lastname: Fisher
authors.affiliation: Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20013-7012, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Wen
mesh_terms: D001499:Bayes Theorem; D032461:Chromosomes, Plant; D005819:Genetic Markers / Q000235:genetics; D049810:Genetic Speciation; D006824:Hybridization, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D006109:Poaceae / Q000235:genetics*; D011123:Polyploidy; D014329:Tropical Climate
chemical_list: D005819:Genetic Markers; D010940:Plant Proteins
keywords: allopolyploidy; bamboo; genome evolution; grasses; hybridization; phylogeny; polyploid speciation
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