title: High-resolution organellar genome analysis of Triticum and Aegilops sheds new light on cytoplasm evolution in wheat.
abstract: We have utilised polymorphic chloroplast microsatellites to analyse cytoplasmic relationships between accessions in the genera Triticum and Aegilops. Sequencing of PCR products revealed point mutations and insertions/deletions in addition to the standard repeat length expansion/contraction which most likely represent ancient synapomorphies. Phylogenetic analyses revealed three distinct groups of accessions. One of these contained all the non- Aegilops speltoides S-type cytoplasm species, another comprised almost exclusively A, C, D, M, N, T and U cytoplasm-type accessions and the third contained the polyploid Triticum species and all the Ae. speltoides accessions, further confirming that Ae. speltoides or a closely related but now extinct species was the original B-genome donor of cultivated polyploid wheat. Successive decreases in levels of genetic diversity due to domestication were also observed. Finally, we highlight the importance of elucidating longer-term evolutionary processes operating at microsatellite repeat loci.
authors.affiliation: School of Biology and Biochemistry, The Queen's University of Belfast, 97 Lisburn Road, BT9 7BL, Belfast, Northern Ireland. J.Provan@qub.ac.uk
authors.forename: J
authors.initials: J
authors.lastname: Provan
authors.forename: P
authors.initials: P
authors.lastname: Wolters
authors.forename: K H
authors.initials: KH
authors.lastname: Caldwell
authors.forename: W
authors.initials: W
authors.lastname: Powell
mesh_terms: D001483:Base Sequence; D016000:Cluster Analysis; D017931:DNA Primers; D018742:DNA, Chloroplast / Q000235:genetics*; D019143:Evolution, Molecular; D018895:Microsatellite Repeats / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D006109:Poaceae / Q000235:genetics*; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics*
chemical_list: D017931:DNA Primers; D018742:DNA, Chloroplast