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Titolo:
Patterns of allozyme variation in diploid and tetraploid Centaurea jacea at different spatial scales
Autore:
Hardy, OJ; Vekemans, X;
Titolo Testata:
EVOLUTION
fascicolo: 5, volume: 55, anno: 2001,
pagine: 943 - 954
SICI:
0014-3820(200105)55:5<943:POAVID>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
GENE FLOW; CONTACT ZONE; POPULATION-STRUCTURE; DYNAMIC NATURE; F-STATISTICS; PLANTS; EVOLUTION; DISTANCE; MECHANISMS; POLYPLOIDY;
Keywords:
autopolyploidy; Centaurea; genetic structure; hybridization; isolation by distance; polyploid complex; spatial autocorrelation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
57
Recensione:
Indirizzi per estratti:
Indirizzo: Hardy, OJ Free Univ Brussels, Lab Genet & Ecol Vegetales, 1850 Chaussee Wavre, B-1160 Brussels, Belgium Free Univ Brussels 1850 Chaussee Wavre Brussels Belgium B-1160
Citazione:
O.J. Hardy e X. Vekemans, "Patterns of allozyme variation in diploid and tetraploid Centaurea jacea at different spatial scales", EVOLUTION, 55(5), 2001, pp. 943-954

Abstract

The extent and spatial patterns of genetic variation at allozyme markers were investigated within and between diploid and autotetraploid knapweeds (Centaurea jacea L. sensu late, Asteraceae) at contrasted geographic scales: (1) among populations sampled from a diploid-tetraploid contact zone in thenortheastern part of the Belgian Ardennes, and (2) within mixed populations from that zone where diploids and tetraploids coexist. Our data were alsocompared with a published dataset by Sommer (1990) describing allozyme variation in separate diploid and tetraploid knapweeds populations collected throughout Europe. Genetic diversity was higher in tetraploids. In the Belgian Ardennes and within the mixed populations, both cytotypes had similar levels of spatial genetic structure, they were genetically differentiated, and their distributions of allele frequencies were not spatially correlated. In contrast, at the European scale, diploids and tetraploids did not show differentiated gene pools and presented a strong correlation between their patterns of spatial genetic variation. Numerical simulations showed that thestriking difference in patterns observed at small and large geographic scales could be accounted for by a combination of (1) isolation by distance within cytotypes; and (2) partial reproductive barriers between cytotypes and/or recurrent formation of tetraploids. We suggest that this may explain the difficulty of the taxonomic treatment of knapweeds and of polyploid complexes in general.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/12/20 alle ore 13:12:20