PMID- 18285356
OWN - NLM
STAT- MEDLINE
DCOM- 20080801
LR  - 20211020
IS  - 1095-8290 (Electronic)
IS  - 0305-7364 (Print)
IS  - 0305-7364 (Linking)
VI  - 101
IP  - 7
DP  - 2008 May
TI  - Karyotype diversification and evolution in diploid and polyploid South American 
      Hypochaeris (Asteraceae) inferred from rDNA localization and genetic fingerprint 
      data.
PG  - 909-18
LID - 10.1093/aob/mcn023 [doi]
AB  - BACKGROUND AND AIMS: Changes in chromosome structure and number play an important 
      role in plant evolution. A system well-suited to studying different modes of 
      chromosome evolution is the genus Hypochaeris (Asteraceae) with its centre of 
      species' diversity in South America. All South American species uniformly have a 
      chromosome base number of x = 4 combined with variation in rDNA number and 
      distribution, and a high frequency of polyploidy. The aim of this paper is to 
      assess directions and mechanisms of karyotype evolution in South American species 
      by interpreting both newly obtained and previous data concerning rDNA 
      localization in a phylogenetic context. METHODS: Eleven Hypochaeris species from 
      18 populations were studied using fluorescence in situ hybridization (FISH) with 
      35S and 5S rDNA probes. A phylogenetic framework was established from 
      neighbour-net analysis of amplified fragment length polymorphism (AFLP) 
      fingerprint data. KEY RESULTS: A single 5S rDNA locus is invariably found on the 
      short arm of chromosome 2. Using 35S rDNA loci, based on number (one or two) and 
      localization (interstitial on the long arm of chromosome 2, but sometimes 
      lacking, and terminal or interstitial on the short arm of chromosome 3, only very 
      rarely lacking), seven karyotype groups can be distinguished; five of these 
      include polyploids. Karyotype groups with more than one species do not form 
      monophyletic groups. CONCLUSIONS: Early evolution of Hypochaeris in South America 
      was characterized by considerable karyotype differentiation resulting from 
      independent derivations from an ancestral karyotype. There was marked 
      diversification with respect to the position and evolution of the 35S rDNA locus 
      on chromosome 3, probably involving inversions and/or transpositions, and on 
      chromosome 2 (rarely 3) concerning inactivation and loss. Among these different 
      karyotype assemblages, the apargioides group and its derivatives constitute by 
      far the majority of species.
FAU - Weiss-Schneeweiss, Hanna
AU  - Weiss-Schneeweiss H
AD  - Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 
      14, A-1030 Vienna, Austria. hanna.schneeweiss@univie.ac.at
FAU - Tremetsberger, Karin
AU  - Tremetsberger K
FAU - Schneeweiss, Gerald M
AU  - Schneeweiss GM
FAU - Parker, John S
AU  - Parker JS
FAU - Stuessy, Tod F
AU  - Stuessy TF
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080219
PL  - England
TA  - Ann Bot
JT  - Annals of botany
JID - 0372347
RN  - 0 (DNA, Plant)
RN  - 0 (DNA, Ribosomal)
SB  - IM
MH  - Asteraceae/classification/*genetics
MH  - Chromosomes, Plant/genetics
MH  - DNA, Plant/genetics
MH  - DNA, Ribosomal/*genetics
MH  - *Diploidy
MH  - *Evolution, Molecular
MH  - Genetic Variation
MH  - In Situ Hybridization, Fluorescence
MH  - Karyotyping
MH  - Phylogeny
MH  - *Polyploidy
MH  - South America
PMC - PMC2710225
EDAT- 2008/02/21 09:00
MHDA- 2008/08/02 09:00
PMCR- 2009/05/01
CRDT- 2008/02/21 09:00
PHST- 2008/02/21 09:00 [pubmed]
PHST- 2008/08/02 09:00 [medline]
PHST- 2008/02/21 09:00 [entrez]
PHST- 2009/05/01 00:00 [pmc-release]
AID - mcn023 [pii]
AID - 10.1093/aob/mcn023 [doi]
PST - ppublish
SO  - Ann Bot. 2008 May;101(7):909-18. doi: 10.1093/aob/mcn023. Epub 2008 Feb 19.