Genetic variation of Avicennia marina (Forsk.) Vierh. (Avicenniaceae) in Vietnam revealed by microsatellite and AFLP markers

Abstract

Genetic variation of Avicennia marina in the costal area of Vietnam was examined using microsatellite and AFLP markers. By using five microsatellite loci a total of 21 alleles were detected. The average number of alleles per locus per population ranged from 1.667 to 3.000. The observed heterozygosity varied from 0.180 to 0.263, with an average of 0.210 indicating relatively low level of genetic variation comparing to the previous studies on A. marina in the worldwide range. The expected heterozygosity was larger than the observed heterozygosity leading to positive inbreeding coefficients in all the six populations. Highly significant departures from Hardy-Weinberg Equilibrium were detected in four populations. AFLP analysis revealed a total of 386 loci, of which 232 (60.1%) were polymorphic. In congruent with microsatellite markers relatively low levels of genetic variation were detected at both gene and nucleotide levels ( H = 0.086; π = 0.0054). Reduced level of genetic variation was found in the central population, and in the southern populations. Both microsatellite and AFLP markers revealed large genetic differentiation ( F ST = 0.262 and 0.338, respectively) indicating strong genetic structure among regional populations.Pairwise genetic distance by AFLP showed two populations in the north and the other two in the south are closely related each other.

Genetic differentiation and diversity of Adansonia digitata L (baobab) in Malawi using microsatellite markers

“…According to Giang et al (2003) microsatellites as a co-dominant genetic marker enables detection of both homozygotes and heterozygotes that improves the insufficiency of AFLP and could be used for examining mating system. As few as five or six microsatellite loci can answer many conservation genetic questions (Glaubitz and Moran 2000).…”

Levels and patterns of DNA variation in two sympatric mangrove species, Rhizophora apiculata and R. mucronata from Thailand

“…The levels of polymorphism of cpDNA regions in C. tagal were unexpectedly high: however, it is not clear whether those cpDNA regions are also highly variable in other mangrove species. Although genetic markers such as AFLP (e.g., Giang et al, 2003), microsatellites (e.g., Maguire et al, 2000), cpDNA (e.g., Chiang et al, 2001) and mitochondrial DNA (e.g., Chiang et al, 2001) were developed for surveys of genetic structure, phylogeography and molecular phylogeny of some mangrove species, the amount and pattern of genetic variation of functional nuclear genes in mangrove species are largely unknown. Investigation of such regions is necessary for understanding of evolutionary forces shaping genetic structure and distribution of extant populations, finding genetic factors responsible for adaptation, and providing guidelines for conservation of mangrove forests.…”

Genetic recolonization of mangrove: genetic diversity still increasing in the Mekong Delta 30 years after Agent Orange

“…Recent assessments have revised upwards the impact of Agent Orange on human health in Vietnam (Butler 2003); the results presented here suggest a similarly pervasive effects on the ecosystem. An encouraging result, however, is the suggested ability of Avicennia alba to recolonize from external sources despite low propagule dispersal in normal conditions (Duke et al 1998, Clarke & Kerrigan 2002; this is supported by strong genetic structure at the local scale in congeneric species (Giang et al 2003, Kado et al 2004, Arnaud-Haond et al 2006. This may indicate the existence of density-dependent migration success in this mangrove species, suggesting that estimates of population genetic structure or effective migration obtained in undisturbed conditions may not provide accurate predictions of recolonization potential after local extinction.…”