Genetic structure and evolution of species in the mangrove genus avicennia (Avicenniaceae) in the Indo-West Pacific

Allozyme variation in species of the mangrove genus Avicennia was screened in 25 populations collected from 22 locations in the Indo-West Pacific and eastern North America using 11 loci. Several fixed gene differences supported the specific status of Avicennia alba, A. integra, A. marina, and A. rum...

Full description

Saved in:
Bibliographic Details
Published in:Evolution 1998-12, Vol.52 (6), p.1612-1626
Main Authors: Duke, N.C, Benzie, J.A.H, Goodall, J.A, Ballment, E.R
Format: Article
Language:English
Subjects:
Alleles
Allozyme
allozymes
Avicennia
Avicennia alba
Avicennia germinans
Avicennia integra
Avicennia marina
Avicennia rumphiana
Biodiversity
biogeography
Biological taxonomies
Brackish
diversity
Evolution
Evolutionary genetics
Gene flow
gene frequency
Genetic loci
Genetic variation
Genetics
Geography
mangrove
mangrove forests
Marinas
Marine
phylogeny
Population genetics
Taxa
Trees
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Allozyme variation in species of the mangrove genus Avicennia was screened in 25 populations collected from 22 locations in the Indo-West Pacific and eastern North America using 11 loci. Several fixed gene differences supported the specific status of Avicennia alba, A. integra, A. marina, and A. rumphiana from the Indo-West Pacific, and A. germinans from the Atlantic-East Pacific. The three varieties of A. marina, var. marina, var. eucalyptifolia, and var. australasica, had higher genetic similarities (Nei's I) and no fixed gene differences, confirming their conspecific status. Strong genetic structuring was observed in A. marina, with sharp changes in gene frequencies at the geographical margins of varietal distributions. The occurrence of alleles found otherwise in only one variety, in only immediately adjacent populations of another variety, provided evidence of introgession between varieties. The varieties appear to have diverged recently in the Pleistocene and are apparently not of ancient Cretaceous origin, as suggested earlier. Despite evidence of high degrees of outcrossing, gene flow among populations was relatively low (Nem≤ 1-2), except where populations were geographically continuous, questioning assumptions that these widespread mangrove species achieve high levels of long-distance dispersal.
ISSN:0014-3820
1558-5646
DOI:10.1111/j.1558-5646.1998.tb02242.x