title: Genome analysis of Thinopyrum intermedium and Thinopyrum ponticum using genomic in situ hybridization.
abstract: Genomic in situ hybridization (GISH) using genomic DNA probes from Thinopyrum elongatum (Host) D.R. Dewey (genome E, 2n = 14), Thinopyrum bessarabicum (Savul. & Rayss) A. Löve (genome J, 2n = 14), and Pseudoroegneria strigosa (M. Bieb.) A. Löve (genome S, 2n = 14), was used to examine the genomic constitution of Thinopyrum intermedium (Host) Barkworth & D.R. Dewey (2n = 6x = 42) and Thinopyrum ponticum (Podp.) Barkworth & D.R. Dewey (2n = 10x = 70). Evidence from GISH indicated that hexaploid Th, intermedium contained the J, Js, and S genomes, in which the J genome was related to the E genome of Th. elongatum and the J genome of Th. bessarabicum. The S genome was homologous to the S genome of Ps. strigosa, while the Js genome referred to modified J- or E-type chromosomes distinguished by the presence of S genome specific sequences close to the centromere. Decaploid Th. ponticum had only the two basic genomes J and Js. The Js genome present in Th. intermedium and Th. ponticum was homologous with E or J genomes, but was quite distinct at centromeric regions, which can strongly hybridize with the S genome DNA probe. Based on GISH results, the genomic formula of Th. intermedium was redesignated JJsS and that of Th. ponticum was redesignated JJJJsJs. The finding of a close relationship among S, J, and Js genomes provides valuable markers for molecular cytogenetic analyses using S genome DNA probes to monitor the transfer of useful traits from Th. intermedium and Th. ponticum to wheat.
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, AB, Canada. Chenqi@em.agr.ca
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.forename: R L
authors.initials: RL
authors.lastname: Conner
authors.forename: A
authors.initials: A
authors.lastname: Laroche
authors.forename: J B
authors.initials: JB
authors.lastname: Thomas
mesh_terms: D002503:Centromere / Q000235:genetics; D015342:DNA Probes; D002523:Edible Grain / Q000235:genetics*; D018745:Genome, Plant; D005843:Geography; D017403:In Situ Hybridization / Q000379:methods; D007621:Karyotyping; D018517:Plant Roots
chemical_list: D015342:DNA Probes