title: Phylogenetic relationships of the monogenomic species of the wheat tribe, Triticeae (Poaceae), inferred from nuclear rDNA (internal transcribed spacer) sequences.
abstract: Phylogenetic relationships of 30 diploid species of Triticeae (Poaceae) representing 19 genomes were estimated from the sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The ITS sequence phylogeny indicated that: (i) each genome group of species is monophyletic, concordant with cytogenetic evidence; (ii) Hordeum (I) and Critesion (H) are basal; (iii) Australopyrum (W) is closely related to Agropyron (P); (iv) Peridictyon (G), Heteranthelium (Q), and Dasypyrum (V) are closely related to Pseudoroegneria (S); (v) most of the annuals, Triticum s.l. (A, B, D), Crithopsis (K), Taeniatherum (T), Eremopyrum (F), Henrardia (O), Secale (R), and two perennials, Thinopyrum (J) and Lophopyrum (E), all of Mediterranean origin, are a monophyletic group. However, phylogenetic trees based on morphology group these Mediteranean species with various perennial lineages of the Arctic-temperate region. The molecular data and biogeography of the tribe suggest that the Mediterranean lineage is derived from the Arctic-temperate lineage and that the two lineages have evolved in parallel. Extensive morphological parallelism apparently obscures the true genealogical history of the tribe when only morphology is considered.
authors.affiliation: United States Department of Agriculture, Utah State University, Logan 84322-6300, USA.
authors.forename: C
authors.initials: C
authors.lastname: Hsiao
authors.forename: N J
authors.initials: NJ
authors.lastname: Chatterton
authors.forename: K H
authors.initials: KH
authors.lastname: Asay
authors.forename: K B
authors.initials: KB
authors.lastname: Jensen
mesh_terms: D000352:Africa, Northern; D001110:Arctic Regions; D001483:Base Sequence; D002980:Climate; D018744:DNA, Plant / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics*; D004171:Diploidy; D002523:Edible Grain / Q000145:classification / Q000235:genetics; D005060:Europe; D008877:Middle East; D008969:Molecular Sequence Data; D010802:Phylogeny; D006109:Poaceae / Q000145:classification / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014158:Transcription, Genetic; D014908:Triticum / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D004275:DNA, Ribosomal