Premium
Postglacial north–south expansion of populations of Rhizophora mangle (Rhizophoraceae) along the Brazilian coast revealed by microsatellite analysis
Author(s) -
Pil Maria W.,
Boeger Maria R. T.,
Muschner Valéria C.,
Pie Marcio R.,
Ostrensky Antonio,
Boeger Walter A.
Publication year - 2011
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.1000392
Subject(s) - rhizophora mangle , mangrove , biology , rhizophoraceae , ecology , gene flow , genetic structure , population , genetic variability , genetic variation , genotype , demography , biochemistry , sociology , gene
• Premise of the study: Red mangrove ( Rhizophora mangle ) dominates tropical tidal areas along both sides of the Atlantic, yet little is known about its degree of population differentiation over large geographical scales. Information on the genetic variability of mangrove species along the Brazilian coast is important not only for understanding the recent gene flow dynamic between populations, but also to evaluate models of evolutionary diversification and develop effective strategies for conservation. We investigated the genetic variability of the red mangrove along the Brazilian coast. • Methods: Eight microsatellite loci were used to genotype 145 individuals across 10 populations spanning more than 4500 km of coast line. We estimated the genetic variability and structure of the populations and the historical gene flow between them. • Key results: The level of genetic variability was low, with only 27 different alleles being detected and allele richness between 1.25 and 2.75. On the other hand, there was substantial population differentiation (R st = 0.48; P < 0.001), especially between the northern and southern populations. The populations from Pará and Maranhão had significantly greater genetic variability than did the remaining locations. • Conclusions: This difference might reflect the older age of the northern mangroves, which likely remained stable during the Quaternary glaciations. The lowest variability observed in the southern populations of the red mangrove most likely reflects their recent age, associated with allelic reduction, resulting from the consecutive founder events that followed subsequent colonization of estuaries during the gradual warming by the end of the last glacial period.