Isolation and characterization of microsatellite loci in the red mangrove Rhizophora mangle (Rhizophoraceae) and its related species

Fourteen microsatellite markers were isolated from the red mangrove Rhizophora mangle (Rhizophoraceae), a widely distributed mangrove plant in the New World and West Africa. The range of expected heterozygosity of these markers was 0.000–0.672 in the two populations of R. mangle. Cross-species testing was examined for five other species of Rhizophora, and Kandelia candel and Bruguiera gymnorrhiza. All 14 markers could be amplified in R. samoensis, thirteen in R. racemosa, and six markers in all other species of Rhizophora. Our findings greatly increase the utility of these markers.     

Spatial and Temporal Distribution of Northern Waterthrushes Among Nonbreeding Habitats in Southwestern Puerto Rico1

We surveyed nonbreeding Northern Waterthrushes (Seiurus noveboracensis) in several coastal habitats in southwestern Puerto Rico, West Indies. Waterthrush abundance was highest (mean = 2.2/point) in well‐developed mangrove habitats characterized by large trees and standing water, and lowest (mean = 0.1/point) in dry coastal scrub and savannah. Within the latter habitats, waterthrushes were more common in moist microhabitats such as temporary ponds and dry washes. Abundance in most habitats declined between October and January, probably a result of the presence of transients during the October surveys, Between January and March, abundance in mature red mangrove (Rhizophora mangle) forests increased dramatically, suggesting that this habitat provides a refuge for birds at the end of the dry season and prior to northward migration. In conjunction with other data demonstrating the use of coastal red mangroves as nocturnal roosting sites, these results suggest that mangroves are the most important nonbreeding habitat for this species. Conservation of this globally threatened habitat may thus be important for the long‐term stability of waterthrush populations.     

History of Late Holocene vegetation at Quintana Roo,Caribbean coast of Mexico

A pollen record of a Late Holocene sediment core from the Mexican Caribbean coast (Quintana Roo) shows the development and changes of a mangrove system. Humid conditions seem to have persisted for the period approximately 2500–1500 ¹⁴C yr BP (pollen zone I), and mangrove Rhizophora mangle dominated with a good representation of elements from the nearby semi-evergreen tropical forest. During the period approximately 1500–1200 ¹⁴C yr BP (pollen zone II) the mangrove Conocarpus erecta dominated. R. mangle almost disappeared and other taxa appeared, suggesting drier climatic conditions and generally more open vegetation. This dry period coincided with the period of the Maya cultural decline. The following period (pollen zone III, approximately 1200–1000 ¹⁴C yr BP) was characterized by the recovery of R. mangle, indicating more humid conditions than in the preceding pollen zone. Pollen zone IV (approximately 1000 ¹⁴C yr BP till present) suggests a drier period reoccuring with C. erecta; this marks the transition to present day conditions.     

REEXAMINATION OF PORE WATER SULFIDE CONCENTRATIONS AND REDOX POTENTIALS NEAR THE AERIAL ROOTS OF RHIZOPHORA MANGLE AND AVICENNIA GERMINANS

Soil redox potentials and pore water sulfide concentrations on a mangrove island in the Belizean barrier reef system were significantly correlated with the presence of the aerial roots of mangrove trees. Sulfide concentrations were three to five times lower near the prop roots of Rhizophora mangle (red mangrove) and the pneumatophores of Avicennia germinans (black mangrove) than in adjacent (≤ 1 meter away) unvegetated sediment. Soil redox potentials were also significantly higher near the aerial roots. A comparison of the two species revealed that sulfide concentrations in the rhizosphere of R. mangle were as low as that of A. germinans. However, sulfide concentrations in areas occupied by the black mangrove were variable and a function of pneumatophore density. The occurrence of an oxidized rhizosphere around the roots of both species suggests that the adult trees are equally capable of exploiting reduced sediments as long as their respective pathways for root aeration are functional.     

Long-Term Growth and Succession in Restored and Natural Mangrove Forests in Southwestern Florida

We compared colonization, growth and succession from 1989 to 2000 in a restored mangrove site and in gap and closed canopy sites in a natural mangrove forest. The restored site was created in 1982 and planted with Rhizophora mangle (≈2 m⁻²) propagules. By 1989, Laguncularia racemosa, with densities up to 12.9 tree m⁻², was a dominant in all plots, although densities were greater at edge plots relative to inner plots, and near open water (west plots) relative to further inland (east plots), and in tall mangrove plots relative to scrub plots. Rhizophora mangle (1989 tree densities about 2 m⁻²) was a codominant in inner and scrub plots, while Avicennia germinans had the lowest densities (<1 tree m⁻²) in all plots. From 1989 to 2000 L. racemosa experienced reduced recruitment and apparent density-dependent mortality of canopy individuals in plots with high initial densities. Scrub plots experienced high rates of colonization by R. mangle and L. racemosa, rapid growth in height of all species (1989–1996), followed by a dieoff of L. racemosa in later years (1997–2000) as the canopy came to resemble that of tall mangrove plots. Colonization and growth rates were lower in gap and closed canopy regions of the natural forest relative to rates in the restored site. After 11 years, densities of L. racemosa were 10–20× lower and R. mangle slightly less in the gap relative to densities in tall mangrove plots in the restored site at the same age. Although the restored stand had converged with the natural forest by 2000 in terms of some factors such as species richness, vegetation cover, litterfall, and light penetration, trees were still much smaller and stem densities much higher. Full development of mature structure and ecological function will likely require decades more development.     

Association between pore water sulfide concentrations and the distribution of mangroves

At Humingbird Cay, Exuma, Bahamas, distributions of bothRhizophora mangle (red mangrove) andAvicennia germinans (black mangrove) are closely correlated with amounts of hydrogen sulfide (H₂S) in the soil.R. mangle is primarily distributed within large areas of low to moderate H₂S concentrations (mean= 40 mg/l). H₂S levels underA. germinans are lower (mean = 22 mg/l), but the area immediately beyond their root zone often has extremely high sulfide concentrations (mean= 120 mg/l). These results suggest that past attempts to explain mangrove distribution in terms of monotonic soil gradients, the dispersal characteristics of propagules, and interspecific competition are incomplete, and that it will be necessary to examine the link between soil sulfur chemistry and mangrove distribution more fully.     

Small Gap Creation in Belizean Mangrove Forests by a Wood–Boring Insect1

We investigated the role of wood-boring insects in the creation of light gaps within mangrove forests. We compared the frequency of gaps caused by wood borers to other gap-forming processes and characterized the physical attributes of light gaps in mangrove forests on small islands in Belize. Methods of quantifying light gaps included aerial photography, ground surveys, and experimental plots. Small light gaps (≤12 m²) were very common in Rhizophom mangle fringe, comprising almost 22 percent of these forests. Rhizophora mangle gaps were smaller than gaps in Avicennia germinans forests. In R. mangle forests, gaps were caused by branch death, and in A. germinans forests, gaps were caused primarily by downed trees. More than 91 percent of the gap-forming branches and boles in the R. mangle fringe were killed by a wood-boring cerambycid beetle, Elaphidion mimeticum, indicating that it is the major cause of small-scale disturbances in these forests. No trees or branches in the A. germinans forest were attacked by this beetle. In R. mangle forests, small gaps had significantly higher light levels and soil temperatures than areas under the closed canopy; however, soil conditions for sulfide concentrations, porewater salinity, and redox potentials were similar in small gaps and under the closed canopy. Survival of R. mangle, A. germinans, and Laguncularia racemosa seedlings was also higher inside these small gaps, indicating their importance in regeneration of mangrove forests. Feeding by wood borers is thus an important type of indirect herbivory in mangrove forests, with a critical role in ecological processes such as gap dynamics.     

Root biomechanics in Rhizophora mangle: anatomy,morphology and ecology of mangrove’s flying buttresses

Background and Aims Rhizophora species of mangroves have a conspicuous system of stilt-like roots (rhizophores) that grow from the main stem and resemble flying buttresses. As such, the development of rhizophores can be predicted to be important for the effective transmission of dynamic loads from the top of the tree to the ground, especially where the substrate is unstable, as is often the case in the habitats where Rhizophora species typically grow. This study tests the hypothesis that rhizophore architecture in R. mangle co-varies with their proximity to the main stem, and with stem size and crown position.Methods The allometry and wood mechanical properties of R. mangle (red mangrove) trees growing in a mangrove basin forest within a coastal lagoon in Mexico were compared with those of coexisting, non-buttressed mangrove trees of Avicennia germinans. The anatomy of rhizophores was related to mechanical stress due to crown orientation (static load) and to prevailing winds (dynamic load) at the study site.Key Results Rhizophores buttressed between 10 and 33 % of tree height. There were significant and direct scaling relationships between the number, height and length of rhizophores vs. basal area, tree height and crown area. Wood mechanical resistance was significantly higher in the buttressed R. mangle (modulus of elasticity, MOE = 18·1 ± 2 GPa) than in A. germinans (MOE = 12·1 ± 0·5 GPa). Slenderness ratios (total height/stem diameter) were higher in R. mangle, but there were no interspecies differences in critical buckling height. When in proximity to the main stem, rhizophores had a lower length/height ratio, higher eccentricity and higher xylem/bark and pith proportions. However, there were no directional trends with regard to prevailing winds or tree leaning.Conclusions In comparison with A. germinans, a tree species with wide girth and flare at the base, R. mangle supports a thinner stem of higher mechanical resistance that is stabilized by rhizophores resembling flying buttresses. This provides a unique strategy to increase tree slenderness and height in the typically unstable substrate on which the trees grow, at a site that is subject to frequent storms.     

Primary Herbivory by Wood-Boring Insects along an Architectural Gradient of Rhizophora mangle

We investigated the distribution of primary xylovores in Rhizophora mangle (red mangrove) first-order branches, i.e., “twigs”, along an architectural gradient on Belizean mangrove cays. Greater structural diversity in R. mangle architecture, xylovore availability, occurrence of natural enemies, and habitat do not result in variable xylovore species richness. Despite large differences in architectural complexity, tall, fringe, dwarf, and sapling trees host the same set of primary wig borers. However, tall trees support greater diversity and abundance of twig inquilines than other tree forms. Primary twig borers have a key role in structuring these mangrove communities because their galleries and pupal chambers provide habitats for numerous species of secondary xylovores and inquilines. We also measured the amount of leaf area removed from R. mangle's canopy by wood- and leaf-feeding herbivores. Vigorously growing tall and sapling trees sustain greater losses because of twig borers than dwarf trees. However, xylovory in fringe trees was not different from any of the other categories. Cumulative herbivory was greatest in the tall trees. In most cases, leaf-area loss as an indirect or collateral result of primary xylovory equaled or exceeded leaf-area loss as a direct result of folivory.     

Does Mangrove Leaf Chemistry Help Explain Crab Herbivory Patterns?

We examined feeding by the mangrove tree crab Aratus pisonii in Tampa Bay, Florida, in relation to the percent dry weight of carbohydrate, protein, phenolics, condensed tannins, ash, carbon, nitrogen, carbonmitrogen ratio, water content, and sclerophylly for leaves of the red mangrove Rhizophora mangle. Comparisons of leaf chemistry were made among leaves that experienced variable levels of crab damage. Because R. mangle is the crab's preferred food source based on damage patterns in the field, comparisons of R. mangle leaf chemistry were made in relation to that of the black mangrove Avicennia germinans and the white mangrove Laguncularia racemosa. We observed a negative relationship between level of leaf damage and percent dry weight of nitrogen, carbohydrates, condensed tannins, and sclerophylly. In contrast, a positive relationship was found between leaf damage and the carbon:nitrogen ratio. The chemical constituents that provided the best explanation for differences in damage among the three mangrove species include condensed tannins, nitrogen, carbon:nitrogen ratio, carbohydrates, phenolics, water content, and ash. The results from this study suggest that chemistry only partially explains food preference by A. pisonii. It appears that A. pisonii feeding behavior and preference may be influenced by a more complex series of factors and interactions, which may include reproduction by, predation on, and interspecific competition with A. pisonii.     

Nutrient relations of dwarf <Emphasis Type="Italic">Rhizophora mangle</Emphasis> L. mangroves on peat in eastern Puerto Rico

Dwarf mangroves on peat substrate growing in eastern Puerto Rico (Los Machos, Ceiba State Forest) were analyzed for element concentration, leaf sap osmolality, and isotopic signatures of C and N in leaves and substrate. Mangrove communities behind the fringe presented poor structural development with maximum height below 1.5 m, lacked a main stem, and produced horizontal stems from which rhizophores developed. This growth form departs from other dwarf mangrove sites in Belize, Panama, and Florida. The dwarf mangroves were not stressed by salinity but by the low P availability reflected in low P concentrations in adult and senescent leaves. Low P availability was associated with reduced remobilization of N and accumulation of K in senescent leaves, contrasting with the behavior of this cation in terrestrial plants. Remobilization of N and P before leaf abscission on a weight basis indicated complete resorption of these nutrients. On an area basis, resorption was complete for P but not for N. Sulfur accumulated markedly with leaf age, reaching values up to 400%, compared with relatively modest accumulation of Na (40%) in the same leaves. This suggests a more effective rejection of Na than sulfate at the root level. Dwarf mangrove leaves had more positive δ¹³C values, which were not related to salinity, but possibly to drought during the dry season due to reduced flooding, and/or reduced hydraulic conductance under P limitation. Negative leaf δ¹⁵N values were associated with low leaf P concentrations. Comparison with other R. mangle communities showed that P concentration in adult leaves below 13 mmol kg⁻¹ is associated with negative δ¹⁵N values, whereas leaves with P concentrations above 30 mmol kg⁻¹ in non-polluted environments had positive δ¹⁵N values.     

Effect of environment and gibberellins on the early growth and development of the red mangrove, Rhizophora mangle L.

Seedlings of the red mangrove, Rhizophora mangle L., were subjected to a variety of salinity, light, and plant growth regulator treatments to examine the influence of these factors on early development. Stem, leaf, and root growth were significantly enhanced in both low salinity seawater and under reduced intensities of solar radiation. Semi-quantitative analyses of GAs by enzyme-linked immunoabsorbant assays (ELISA) suggest that under these conditions the early 3/13 hydroxylation GA₁ biosynthetic pathway is predominant in R. mangle. Concentrations of GA₁ and GA₁₉-like substances were highest in propagules exhibiting enhanced development. Attempts to identify the endogenous GAs by GC-MS were unsuccessful, most likely due to undetermined impurities present in mangroves. Exogenous applications of GA₃ to R. mangle were moderately successful in alleviating shoot growth inhibitions observed at higher salinities and light levels. The role of gibberellins is discussed in terms of metabolic responses to the external environment and possible impacts upon the distribution of this species.     

Sun-shade adaptability of the red mangrove,Rhizophora mangle (Rhizophoraceae): Changes through ontogeny at several levels of biological organization

Rhizophora mangle L., the predominant neotropical mangrove species, occupies a gradient from low intertidal swamp margins with high insolation, to shaded sites at highest high water. Across a light gradient, R. mangle shows properties of both “light-demanding” and “shade-tolerant” species, and defies designation according to existing successional paradigms for rain forest trees. The mode and magnitude of its adaptability to light also change through ontogeny as it grows into the canopy. We characterized and compared phenotypic flexibility of R. mangle seedlings, saplings, and tree modules across changing light environments, from the level of leaf anatomy and photosynthesis, through stem and whole-plant architecture. We also examined growth and mortality differences among sun and shade populations of seedlings over 3 yr. Sun and shade seedling populations diverged in terms of four of six leaf anatomy traits (relative thickness of tissue layers and stomatal density), as well as leaf size and shape, specific leaf area (SLA), leaf internode distances, disparity in blade–petiole angles, canopy spread: height ratios, standing leaf numbers, summer (July) photosynthetic light curve shapes, and growth rates. Saplings showed significant sun/shade differences in fewer characters: leaf thickness, SLA, leaf overlap, disparity in bladepetiole angles, standing leaf numbers, stem volume and branching angle (first-order branches only), and summer photosynthesis. In trees, leaf anatomy was insensitive to light environment, but leaf length, width, and SLA, disparities in bladepetiole angles, and summer maximal photosynthetic rates varied among sun and shade leaf populations. Seedling and sapling photosynthetic rates were significantly depressed in winter (December), while photosynthetic rates in tree leaves did not differ in winter and summer. Seasonal and ontogenetic changes in response to light environment are apparent at several levels of biological organization in R. mangle, within constraints of its architectural baiiplan. Such variation has implications for models of stand carbon gain, and suggest that response flexibility may change with plant age.     

Mangrove ecosystem changes during the Holocene at Spanish Lookout Cay, Belize

Mangroves are halophytic plants living at the land–sea interface and are therefore natural trackers of sea-level. Multiple proxies of a continuous (8 m) mangrove peat core (BT-79) from Spanish Lookout Cay, Belize illustrate mangrove ecosystem changes during the Holocene. Radiocarbon measurements show this site was colonized by mangroves ~ 8000 cal. yrs BP, with a significant decrease in the peat accumulation rate from ~ 6000 to 1000 cal. yrs BP. Stratigraphic characteristics of this peat core such as bulk density, magnetic susceptibility, and loss on ignition show relative uniformity, inferring an uninterrupted mangrove ecosystem during a majority of the Holocene. This is supported by pollen data from BT-79 that show that the site has been consistently dominated by Rhizophora mangle (red mangrove), with Avicennia germinans (black mangrove) and Laguncularia racemosa (white mangrove) present as well. Subfossil R. mangle leaves are used for stable nitrogen, carbon, and oxygen isotope (δ¹⁵N, δ¹³C, and δ¹⁸O) analyses. δ¹⁵N and δ¹³C values provide a proxy of this plant's past physiology and stand structure showing that dwarf (δ¹⁵N < − 3‰) and tall (δ¹³C < − 27‰) R. mangle stands were previously present at the site, which are a result of nutrient limitations that we equate with seawater inundation. δ¹⁸O values show differences in source water of R. mangle, with higher values attributed to the source water being composed of a greater proportion of seawater relative to precipitation. A decrease in inundation at the site is shown by lower δ¹⁸O values (< 19‰) from ~ 7000 to ~ 1000 cal. yrs BP that covary with the decreased sedimentation rate. Existing Caribbean sea-level data do not show evidence of a decrease in the rate of relative sea-level rise or fluctuations that we take to be the major causes of environmental changes at site BT-79.     

Genetic structure of the red mangrove (<Emphasis Type="Italic">Rhizophora mangle</Emphasis> L.) on the Colombian Pacific detected by microsatellite molecular markers

Rhizophora mangle, one of the five species of the genus Rhizophora, is found widely distributed along the American and West African coasts. This species is one of the principal constituents of the mangrove ecosystem in Colombia and is also found within the most important economic activities for the communities that inhabit the littoral. In order to assess the degree of genetic diversity of R. mangle in five populations of the Colombian Pacific, nuclear microsatellite molecular markers were used. In 92 individuals sampled, it was found that 100% of the loci were polymorphic , and no private alleles were detected. The population structure of R. mangle in the Colombian Pacific, was highly significant (P < 0.001); however, the greatest differentiation was detected at the within-population level (94.62%). For the populations of La Plata, Virudó and Charambirá, the tendency toward panmixia could be the cause of the low differentiation among these three locations. Within populations, the genetic diversity revealed a deviation from Hardy–Weinberg equilibrium with high significance in Virudó and Tumaco, where it appears the intense anthropogenic activity has exercised strong pressure on the red mangrove, resulting in the possible fragmentation of the local landscape and therefore an increase in the rate of endogamy within these populations. Despite this situation, our study―one of the first developed in genetics of the red mangrove in Colombia―did not show evidence of recent bottleneck effects or deterioration in its genetic composition, which could be exploited to propose management and restoration programs for the zones where the forests of this species are degraded. Handling editor: K. Martens     

Mangrove litter dynamics in La Mancha Lagoon,Veracruz, Mexico

In the mangrove surrounding the coastal lagoon of La Mancha, Veracruz, Mexico, we studied litter fall, litter standing crop, and turnover rates in four different mangrove settings, based on the ecological classification of Lugo and Snedaker (1974). We studied those three prominent ecological processes at the basin, fringe and riverine mangrove settings, being the last one a relict riverine stand. The aim was to describe and compare litter dynamics among mangrove types in a lagoon with an ephemeral inlet, as a way of understanding functional heterogeneity within this coastal ecosystem. The daily average values of litter fall were different (P < 0.01) among mangrove site basin I, formed by Avicennia germinans and Rhizophora mangle (2.35 g/m²/day); basin II, formed by Laguncularia racemosa, Avicennia germinans, and Rhizophora mangle (2.93 g/m²/day); fringe with Rhizophora mangle (2.13 g/m²/day); and relic riverine, also with R. mangle (4.70 g/m²/day). The amount of litter standing crop was different among sites (P < 0.001), and also between the dry and rainy season, for each mangrove type (P < 0.001). Turnover ratios were higher in basin I and basin II sites (6.34 and 7.44 times per year) than in relic riverine and fringe mangroves (1.49 and 2.39 times per year). Interstitial salinity and sediment nutrients varied among mangrove types and could influence litter production. Since this lagoon has an ephemeral inlet, continuous inundation throughout 7–8 months per year has an important effect on litter dynamics.     

Reproductive phenology and physiological traits in the red mangrove hybrid complex (Rhizophora mangle and R. racemosa) across a natural gradient of nutrients and salinity

Factors modulating introgressive hybridization between the red mangrove species Rhizophora mangle and R. racemosa in spatially defined sites are poorly understood. To investigate this, we evaluated the reproductive phenology and the nutrient and physiological traits in those two species and their F₁ hybrids genotyped with microsatellite data across a natural hybrid zone from the Pacific coast of Panama. We found no evidence that reproductive phenology represents a barrier to gene flow, because R. mangle and the F₁ hybrids produced flowers and propagules throughout the annual cycle, while R. racemosa flowered only in the dry season. Soil nutrient concentrations decreased landward, while soil salinity varied only slightly. Foliar nutrients and δ¹⁵N signatures varied according to the soil nutrient gradient, but only foliar phosphorus and carbon varied among species. In contrast, two structural variables (height and trunk diameter) and leaf variables related to salinity tolerance (Na, Cl:Na, K:Na, cation:anion) and water-use efficiency (i.e., δ¹³C) differed among species, suggesting higher salinity tolerance for R. mangle and F₁ hybrids compared with R. racemosa. We conclude that parental species and F₁ hybrids differ in salinity tolerance and water-use efficiency, which could be associated with adaptive evolution of the red mangrove hybrid complex.     

DIFFERENTIAL OXIDATION OF MANGROVE SUBSTRATE BY AVICENNIA GERMINANS AND RHIZOPHORA MANGLE

Both Avicennia germinans (black mangrove) and Rhizophora mangle (red mangrove) are commonly found in anaerobic substrate. Black mangrove roots create oxidized rhizospheres substantially larger than those described for other plant species. When air cannot enter the root system through the pneumatophores, the rhizospheres become as reduced as nearby un vegetated soil. The presence of red mangrove, in contrast, appears to have no effect on the oxidation state of surrounding anaerobic soils. It is likely that these data help to explain the distributions of both species in intertidal associations.     

Evaluation of triterpenols and sterols as organic matter biomarkers in a mangrove ecosystem in northern Brazil

Mangrove leaves, sediment, and excrementfrom the mangrove crab Ucidescordatus from the coastal areas of theBragança peninsula in North Brazil wereanalysed to determine suitable biomarkersfor mangrove-derived organic matter. Leavesof Rhizophora mangle (red mangrove),the dominant species in the area, werecharacterised by high amounts of-amyrin, germanicol, taraxerol, andlupeol. Avicennia germinans (blackmangrove) mainly contained betulin, lupeol,and -sitosterol, whereas significantquantities of -sitosterol and lupeolwere typical of Laguncularia racemosa(white mangrove), the locally leastabundant species. Except for betulin, theexcrement of U. cordatus containedall of the above substances, but moststrongly reflected the triterpenolsignature of R. mangle leaves, thepredominant diet of this crab. Surfacesediments from various mangrove locationshad relatively uniform compositions thatpossibly reflect tidal mixing. Sedimentextracts were dominated by taraxerol andcontained smaller amounts of-amyrin, germanicol, and lupeol.Only sediments in a marsh area, dominatedby Sporobolus virginicus (seashoredropseed) and Eleocharis sp. (spikerush), revealed a differentbiomarker distribution. Core samples ofsubrecent sediment (up to 4000 ¹⁴C yrBP), for which previous pollen analysisindicated vegetation dominated bymangroves, had compositions similar to thatof the surface sediment. Taraxerol was themain component in the examined mangrovesediments and may be a marker for mangrovematter in this region, although analysis ofplant material did not unequivocallysupport this. Germanicol is suggested to bea biomarker for organic matter from R.mangle in North Brazil. It was detected inolder sediments, and was not significantlyaffected by ingestion by land crabs.     

Polymorphic microsatellites in a mangrove species,Rhizophora mangle L. (Rhizophoraceae)

Twenty‐six microsatellite loci were isolated and characterized from the mangrove species Rhizophora mangle using (GT)_n and (CT)_n repeats. Eighty‐four per cent of the clones contained microsatellite sequences; the most common dinucleotides were the (GA/CT) and (CA/GT) repeats. Ten primers were selected to investigate the polymorphism among individuals of R. mangle from two natural populations of the Colombian Pacific Coast. The observed heterozygosity per locus varied from 0.20 to 0.80, the power of discrimination was 0.32–0.84 and the power of exclusion was 0.03–0.75. This set of microsatellites offers an efficient tool for population genetics studies on this species.