PMID- 15829509 OWN - NLM STAT- MEDLINE DCOM- 20050817 LR - 20181113 IS - 0305-7364 (Print) IS - 1095-8290 (Electronic) IS - 0305-7364 (Linking) VI - 96 IP - 1 DP - 2005 Jul TI - Ancestry of American polyploid Hordeum species with the I genome inferred from 5S and 18S-25S rDNA. PG - 23-33 AB - BACKGROUND AND AIMS: The genus Hordeum exists at three ploidy levels (2x, 4x and 6x) and presents excellent material for investigating the patterns of polyploid evolution in plants. Here the aim was to clarify the ancestry of American polyploid species with the I genome. * METHODS: Chromosomal locations of 5S and 18S-25S ribosomal RNA genes were determined by fluorescence in situ hybridization (FISH). In both polyploid and diploid species, variation in 18S-25S rDNA repeated sequences was analysed by the RFLP technique. * KEY RESULTS: Six American tetraploid species were divided into two types that differed in the number of rDNA sites and RFLP profiles. Four hexaploid species were similar in number and location of both types of rDNA sites, but the RFLP profiles of 18S-25S rDNA revealed one species, H. arizonicum, with a different ancestry. * CONCLUSIONS: Five American perennial tetraploid species appear to be alloploids having the genomes of an Asian diploid H. roshevitzii and an American diploid species. The North American annual tetraploid H. depressum is probably a segmental alloploid combining the two closely related genomes of American diploid species. A hexaploid species, H. arizonicum, involves a diploid species, H. pusillum, in its ancestry; both species share the annual growth habit and are distributed in North America. Polymorphisms of rDNA sites detected by FISH and RFLP analyses provide useful information to infer the phylogenetic relationships of I-genome Hordeum species because of their highly conserved nature during polyploid evolution. FAU - Taketa, Shin AU - Taketa S AD - Faculty of Agriculture, Kagawa University, Ikenobe, Miki, Kagawa 761-0795, Japan. staketa@ag.kagawa-u.ac.jp FAU - Ando, Hirotaka AU - Ando H FAU - Takeda, Kazuyoshi AU - Takeda K FAU - Ichii, Masahiko AU - Ichii M FAU - von Bothmer, Roland AU - von Bothmer R LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20050413 PL - England TA - Ann Bot JT - Annals of botany JID - 0372347 RN - 0 (DNA, Ribosomal) RN - 0 (RNA, Plant) RN - 0 (RNA, Ribosomal) SB - IM MH - Americas MH - Biological Evolution MH - Chromosomes, Plant MH - DNA, Ribosomal MH - Genome, Plant MH - Hordeum/*genetics MH - Karyotyping MH - Polymorphism, Restriction Fragment Length MH - *Polyploidy MH - RNA, Plant/*genetics MH - RNA, Ribosomal/*genetics PMC - PMC4246806 EDAT- 2005/04/15 09:00 MHDA- 2005/08/18 09:00 PMCR- 2006/07/01 CRDT- 2005/04/15 09:00 PHST- 2005/04/15 09:00 [pubmed] PHST- 2005/08/18 09:00 [medline] PHST- 2005/04/15 09:00 [entrez] PHST- 2006/07/01 00:00 [pmc-release] AID - mci147 [pii] AID - 10.1093/aob/mci147 [doi] PST - ppublish SO - Ann Bot. 2005 Jul;96(1):23-33. doi: 10.1093/aob/mci147. Epub 2005 Apr 13.