Blood protein variation of a new population of gelada baboons (Theoropithecus gelada), in the Southern Rift Valley, Arsi Region, Ethiopia

Blood protein polymorphism of gelada baboon (Theropithecus gelada) to the south of the Rift Valley, Arsi Region, were examined for 36 genetic loci using three electrophoresis techniques for 48 blood samples from three localities, and compared with the northern geladas. New variant alleles and genetic markers of Hb-α, PA-2, and TBPA loci were detected. The distribution patterns of the variant alleles of Hb-α, PA-2, TBPA, Pi, Gc, PGM-II, and TBPA loci were localized in the geographic regions of south and north gelada populations, respectively. Genetic variability of southern geladas was estimated as P_poly=0.083 and , which was comparable to northern geladas. A remarkably high genetic differentiation between the two geographic populations was shown byNei's genetic distance=0.071 and G_ST value=0.420. Our results of genetic analysis suggest that the southern and northern gelada populations have been separated for several hundred thousand years, and gene flow between the two geographic populations is severely restricted. The southern gelada baboon may be regarded as a distinct subspecies.     

Genetic consequences of postglacial range expansion in two codistributed rodents (genus Dipodomys) depend on ecology and genetic locus

How does range expansion affect genetic diversity in species with different ecologies, and do different types of genetic markers lead to different conclusions? We addressed these questions by assessing the genetic consequences of postglacial range expansion using mitochondrial DNA (mtDNA) and nuclear restriction site‐associated DNA (RAD) sequencing in two congeneric and codistributed rodents with different ecological characteristics: the desert kangaroo rat (Dipodomys deserti), a sand specialist, and the Merriam's kangaroo rat (Dipodomys merriami), a substrate generalist. For each species, we compared genetic variation between populations that retained stable distributions throughout glacial periods and those inferred to have expanded since the last glacial maximum. Our results suggest that expanded populations of both species experienced a loss of private mtDNA haplotypes and differentiation among populations, as well as a loss of nuclear single‐nucleotide polymorphism (SNP) private alleles and polymorphic loci. However, only D. deserti experienced a loss of nucleotide diversity (both mtDNA and nuclear) and nuclear heterozygosity. For all indices of diversity and differentiation that showed reduced values in the expanded areas, D. deserti populations experienced a greater degree of loss than did D. merriami populations. Additionally, patterns of loss in genetic diversity in expanded populations were substantially less extreme (by two orders of magnitude in some cases) for nuclear SNPs in both species compared to that observed for mitochondrial data. Our results demonstrate that ecological characteristics may play a role in determining genetic variation associated with range expansions, yet mtDNA diversity loss is not necessarily accompanied by a matched magnitude of loss in nuclear diversity.     

Population genetics of Wolbachia‐infected,parthenogenetic and uninfected,sexual populations of Tetrastichus coeruleus (Hymenoptera: Eulophidae)

Wolbachia are endosymbiotic bacteria known to manipulate the reproduction of their hosts. These manipulations are expected to have consequences on the population genetics of the host, such as heterozygosity levels, genetic diversity and gene flow. The parasitoid wasp Tetrastichus coeruleus has populations that are infected with parthenogenesis‐inducing Wolbachia and populations that are not infected. We studied the population genetics of T. coeruleus between and within Wolbachia‐infected and uninfected populations, using nuclear microsatellites and mitochondrial DNA. We expected reduced genetic diversity in both DNA types in infected populations. However, migration and gene flow could introduce new DNA variants into populations. We therefore paid special attention to individuals with unexpected (genetic) characteristics. Based on nuclear and mitochondrial DNA, two genetic clusters were evident: a thelytokous cluster containing all Wolbachia‐infected, parthenogenetic populations and an arrhenotokous cluster containing all uninfected, sexual populations. Nuclear and mitochondrial DNA did not exhibit concordant patterns of variation, although there was reduced genetic diversity in infected populations for both DNA types. Within the thelytokous cluster, there was nuclear DNA variation, but no mitochondrial DNA variation. This nuclear DNA variation may be explained by occasional sex between infected females and males, by horizontal transmission of Wolbachia, and/or by novel mutations. Several females from thelytokous populations were uninfected and/or heterozygous for microsatellite loci. These unexpected characteristics may be explained by migration, by inefficient transmission of Wolbachia, by horizontal transmission of Wolbachia, and/or by novel mutations. However, migration has not prevented the build‐up of considerable genetic differentiation between thelytokous and arrhenotokous populations.     

Genetic diversity and environmental associations of wild wheat,Triticum dicoccoides,in Israel

Summary Allozyme variation in the tetraploid wild progenitor of wheat, Triticum dicoccoides, was studied for the proteins encoded by about 50 gene loci in 457 individuals representing 12 populations from Israel. Six spikelet morphological traits were measured in the same populations. The results indicate that: (a) 16 loci (= 32%) were monomorphic in all 12 populations, 15 loci (= 30%) were locally polymorphic, and 19 loci (= 38%) were regionally polymorphic. All polymorphic loci (but one) displayed high levels of polymorphism ( 10%). In Israel, the proportion of polymorphic loci per population, P, in wild wheat averaged 0.25 (range, 0.16–0.38), and the genetic diversity index, H_e averaged 0.07, (range, 0.03 – 0.12). (b) Altogether there were 110 alleles at the 50 putative loci tested (c) Genetic differentiation of populations included regional and local patterns: (i) The coefficients of genetic distance between populations were high (mean D = 0.10 range, 0.02 – 0.25), and indicated sharp genetic differentiation over short distances, (ii) Common ( 10%) but sporadic and localized alleles were frequent (76%), and (iii) Rare alleles were few (only 5 alleles). (d) The patterns of allozyme and spikelet variation in the wild gene pool were significantly correlated with, and partly predictable by, water factors, including those of precipitation, evaporation, and relative humidity as well as of soil type, (e) All six spikelet characters showed statistically significant variation among localities and (f) Allozymic variation was correlated with spikelet variation.These results suggest in T. dicoccoides: (i) the operation of natural selection in population genetic structure, (ii) local adaptive genetic differentiation caused by diversifying selection through climate and soil, and (iii) the guidelines for sampling these resources for use in wheat breeding programs.     

Population genetics of Japanese monkeys: III. Ancestry and differentiation of local populations

Genetic variability in local populations of the Japanese macaque (Macaca fuscata) was quantified by the proportion of polymorphic loci (P_poly) and the average heterozygosity per individual ( ) from the starch- and polyacrylamide-gel electrophoreses of blood proteins controlled by 32 independent genetic loci. P_poly averaged 13.6% and 2.1%, the values being at lower level compared with other mammalian species. Geographical distribution of the genetic variations was not uniform in the whole species but its local differentiation was remarkable. Genetic variability tended to be lower in the southern localities, especially in the southernmost island of Yaku, than in the central and northern localities. The genetic distance and the principal component analyses showed that the most divergent local populations were the population in the Shimokita peninsula at the northernmost distribution area of the species and the populations on the Yaku island at the southernmost. The most contributory loci to the genetic divergence were the PGM-II, Gc, and Hb-β, the variant allele at the first locus being concentrated in the Yaku island, in the Shimokita peninsula, and in the easternmost Boso peninsula, and the variant allele at the latter two loci having high frequencies in the Shimokita and the Izu peninsulas. The Hennigian cladistic analysis, for which the Chinese rhesus macaque (M. mulatta) was used as the outgroup, revealed that the number of presence of derived (apomorphic) alleles was conspicuously smaller in southern islet populations than in central and northern populations, whereas any areal tendency was not recognized in the number of loss of ancestral (plesiomorphic) alleles. The observed distribution pattern that the plesiomorphic variant allele at the PGM-II locus concentrated only in the peripheral (southernmost, northernmost, and easternmost) ranges of the species, would indicate, as a possibility, the occurrence of two or more waves of immigration of ancestors of the present-day Japanese macaque from the Asian continent.     

Molecular signatures of divergence and selection in closely related pine taxa

Efforts to detect loci under selection in plants have mostly focussed on single species. However, assuming that intraspecific divergence may lead to speciation, comparisons of genetic variation within and among recently diverged taxa can help to locate such genes. In this study, coalescent and outlier detection methods were used to assess nucleotide polymorphism and divergence at 79 nuclear gene fragments (1212 SNPs) in 16 populations (153 individuals) of the closely related, but phenotypically and ecologically distinct, pine taxa Pinus mugo, P. uliginosa and P. uncinata across their European distributions. Simultaneously, mitochondrial DNA markers, which are maternally inherited in pines and distributed by seeds at short geographic distance, were used to assess genetic relationships of the focal populations and taxa. The majority of nuclear loci showed homogenous patterns of variation between the taxa due to a high number of shared SNPs and haplotypes, similar levels of polymorphism, and low net divergence. However, against this common genetic background and an overall low population structure within taxa at mitochondrial markers, we identified several genes showing signatures of selection, accompanied by significant intra- and interspecific divergence. Our results indicate that loci involved in species divergence may be involved in intraspecific local adaptation.     

Population genetics of bisexual and unisexual populations of the scaly-winged bark louse Echmepteryx hageni (Insecta: Psocoptera)

The scaly-winged bark louse, Echmepteryx hageni, exhibits a unique pattern of co-existence of apparently differnt reproductive modes. Unisexuality is widespread in eastern North America, while sexual populations are restricted to isolated rock out-croppings in southern Illinois and eastern Kentucky. Three of the four nuclear loci examined show greater genetic diversity in the unisexual form compared to the sexual form of E. hageni, in accordance with the pattern previously shown in mitochondrial genetic data. Neutrality tests of the nuclear loci indicate a consistent signal of demographic expansion in asexual populations, but not in sexual populations. There was evidence of inbreeding in the isolated sexual populations at three of the nuclear loci, and one locus had signs of gene specific balancing selection. However, there is no significant genetic differentiation between bisexual and unisexual populations, possibly due to the greater effective population size of nuclear loci relative to mitochondrial loci. The mitochondrial differentiation of E. hageni populations in the northwestern part of their range (Minnesota and Wisconsin) was also not reflected in the nuclear data. We present three hypotheses that may explain the disparity in observed nuclear and mitochondrial genetic diversity between the reproductive forms of E. hageni.     

Genetic diversity and differentiation of Siberian spruce populations at nuclear microsatellite loci

The results of the study of 21 populations of Siberian spruce (Picea obovata Ledeb.) from different parts of the species natural range by microsatellite (SSR) analysis of nuclear DNA are presented. Using nine loci developed for Picea abies (L.) Karst. and Picea glauca (Moench) Voss and detecting variation in Picea obovata, the parameters of intra- and interpopulation genetic diversity, as well as the degree of population differentiation, were determined. It was demonstrated that the population of Siberian spruce in the study was characterized by a relatively high average level of intrapopulation variability (H_o = 0.408; H_e = 0.423) and low interpopulation differentiation (F_st = 0.048, P = 0.001) at this class of DNA markers. The genetic distance between populations ranged from 0.009 to 0.167, averaging 0.039. The isolated Magadan population, located in the extreme Northeast of Russia at a considerable distance from the main species range and characterized by the lowest genetic diversity among the studied populations, was maximally differentiated from the rest of the spruce populations. In addition, the steppe Ubukun population from Buryatia and the population from the Bogd Khan Uul Biosphere Reserve, Mongolia, were considerably different in the genetic structure from most populations of Siberian spruce, although to a lesser extent than the Magadan population. These findings are consistent with the results of previous studies of this species carried out using allozyme and microsatellite loci of chloroplast DNA and point to the prospects of using nuclear microsatellites as DNA markers to analyze the population genetic structure of Siberian spruce.     

Extremely low nucleotide polymorphism in Pinus krempfii Lecomte,a unique flat needle pine endemic to Vietnam

Pinus krempfii Lecomte is a morphologically and ecologically unique pine, endemic to Vietnam. It is regarded as vulnerable species with distribution limited to just two provinces: Khanh Hoa and Lam Dong. Although a few phylogenetic studies have included this species, almost nothing is known about its genetic features. In particular, there are no studies addressing the levels and patterns of genetic variation in natural populations of P. krempfii. In this study, we sampled 57 individuals from six natural populations of P. krempfii and analyzed their sequence variation in ten nuclear gene regions (approximately 9 kb) and 14 mitochondrial (mt) DNA regions (approximately 10 kb). We also analyzed variation at seven chloroplast (cp) microsatellite (SSR) loci. We found very low haplotype and nucleotide diversity at nuclear loci compared with other pine species. Furthermore, all investigated populations were monomorphic across all mitochondrial DNA (mtDNA) regions included in our study, which are polymorphic in other pine species. Population differentiation at nuclear loci was low (5.2%) but significant. However, structure analysis of nuclear loci did not detect genetically differentiated groups of populations. Approximate Bayesian computation (ABC) using nuclear sequence data and mismatch distribution analysis for cpSSR loci suggested recent expansion of the species. The implications of these findings for the management and conservation of P. krempfii genetic resources were discussed.     

Genetic diversity of wild emmer wheat in Israel and Turkey

Summary Allozyme variation in the tetraploid wild emmer wheat, Triticum dicoccoides, the progenitor of all cultivated wheats, was studied for the proteins encoded by 42 gene loci in 1815 plants representing 37 populations - 33 from Israel and 4 from Turkey - sampled in 33 localities from 1979 to 1987. The results showed that: (a) 6 loci (14%) were monomorphic in all populations, 15 loci (36%) were locally polymorphic, and 21 loci (50%) were regionally polymorphic. These results are similar to those obtained earlier on 12 Israeli populations. All polymorphic loci (except 4) displayed high local levels of polymorphism (>/ 10%). (b) The mean number of alleles per locus, A, was 1.252 (range: 1.050–1.634); the proportion of polymorphic loci per population averaged 0.220 (range: 0.050–0.415); genic diversity, He, averaged 0.059 (range: 0.002–0.119). (c) Altogether there were 119 alleles at the 42 putative loci tested, 114 of these in Israel, (d) Genetic differentiation was primarily regional and local, not clinal; 70% of the variant alleles were common (>/ 10%) and not widespread, but rather localized or sporadic, displaying an archipelago population genetics and ecology structure. The coefficients of genetic distance between populations were high and averaged D = 0.134; range: 0.018–0.297, an indication of sharp genetic differentiation over short distances, (e) Discriminant analyses differentiated Israeli from Turkish populations, and within Israel, between central and 3 marginal regions, as well as between different soil-type populations, (f) Allozymic variation comprised 40% within and 60% between populations, (g) Gametic phase disequilibria were abundant, their number being positively correlated (r_s = 0.60, P<0.01) with the humidity, (h) Multilocus organization was substantive, also positively correlated with humidity, (i) Allozyme diversity, overall and at single loci, was significantly correlated with, and partly predictable by, climatic and edaphic factors, (j) The distrubition of the significant positive and negative values and the absence of autocorrelations in the correlogram revealed no similar geographic patterns across loci, eliminating migration as a prime factor of population genetic differentiation. These results suggest: (I) during the evolutionary history of wild emmer, diversifying natural selection, through climatic and edaphic factors, was a major agent of genetic structure and differentiation at both the single and multilocus levels; (II) wild emmer harbors large amounts of genetic diversity exploitable as genetic markers in sampling and abundant genetic resources utilizable for wheat improvement.     

Genetic characterization of long-tailed macaques (Macaca fascicularis) on Tabuan Island Indonesia

Protein and mitochondrial DNA variations (D-loop region PCR-RFLP) were analyzed for 7 serum and 40 clot samples collected from long-tailed macaques (Macaca fascicularis) living on Tabuan Island, Indonesia. Protein polymorphisms were examined electrophoretically for 5 and 12 kinds of protein in serum and erythrocytes, respectively. Each of the protein loci tested showed a monomorphic pattern. Polymorphisms were detected in the analysis of the D-loop-containing region of mtDNA (PCR-RFLP) using 32 restriction endonucleases. Two haplotypes, differing 1.03% in sequence divergence were observed, and both were previously undetected in other local populations. Based on genetic features and differences in pelage color as outlined inFooden's (1995) morphological analysis, the present results suggest that long-tailed macaques on Tabuan Island are a unique population. From the genetic analyses performed here, Tabuan monkeys are considered to be the same species group as those populations of Sumatra and Java (Fooden, 1995).     

Genetic diversity of the Pacific walrus (<Emphasis Type="Italic">Odobenus rosmarus divergens</Emphasis>) in the western part of the Chukchi Sea

We study 117 Pacific walrus samples from three rookeries within the western part of Chukchi Sea (Cape Vankarem, Cape Serdtse-Kamen, and Kolyuchin Island). We analyze the variability of nuclear (20 microsatellite loci) and mitochondrial DNA (three fragments). Two microsatellite loci which are described as microsatellites for the first time are used in this study: repeated sequences within introns of Coro1c and Plod2 genes. A high degree of genetic diversity is demonstrated for both nuclear and mitochondrial markers compared to Atlantic walrus. A high degree of genetic diversity is preserved within populations of Pacific walrus, despite a strong decline in the recent past. We discover the absence of significant differentiation for microsatellite loci and the presence of weak differentiation for mtDNA (mainly for a D-loop fragment). Walrus specimens that use the rookeries of the western part of Chukchi Sea are thought to belong to a single reproductive group.     

Genetic structure of Amazonian populations of Hevea brasiliensis is shaped by hydrographical network and isolation by distance

Current ex situ collections of the wild rubber tree Hevea brasiliensis were gathered more than 25 years ago mainly from populations in Southwest Amazonia. Information regarding the structure of genetic diversity among these populations is fragmented and needs refinement. Having analyzed polymorphisms at 15 microsatellites loci throughout the Hevea genome, we report on the genetic diversity of 307 clonally propagated individuals from 19 different collection points. All analyzed loci were highly polymorphic, averaging 21.7 alleles per locus, and displayed heterozygote deficiency. Differentiation among populations was analyzed on a subsample of 220 individuals from 14 populations. The overall F _ST is 0.12; although low, this value is significant and suggests moderate differentiation. Mato Grosso (Brazil) populations were genetically more distant from all other populations. A highly significant correlation between genetic and geographical distances over the whole area under study was shown by the Mantel test. The Bayesian algorithm used by STRUCTURE software allowed for the identification of three population clusters that match the boundaries of hydrographical basins of the main Amazon River tributaries. Differentiation among populations could therefore be jointly explained by both geographical location within the hydrographical Amazon network and by isolation by distance among populations belonging to distinct catchments. It is likely that some of these populations no longer exist due to severe deforestation. We provide suggestions to improve genetic resource management and sampling strategy in natural populations of H. brasiliensis.     

Genetic and morphoecological characteristics of peled <Emphasis Type="Italic">Coregonus peled</Emphasis> acclimatized in lakes of Tuva Republic

Morphoecological and genetic characters were studied of peled Coregonus peled naturalized in lakes of Tuva Republic. For comparison (as a donor), peled was considered from Leningrad oblast to originate from “wild” peled from Lake Endyr and dispersed widely into water bodies of the former Soviet Union. The results of analysis of variations in 18 polymorphic nuclear loci, coding the proteins (allozymes), and the part of mitochondrial (mt)DNA, coding the first subunit of NADH-dehydrogenase, attest genetic and morphoecological differentiation of populations formed in Tuva lakes. Significant differences were found between them in age composition, rate of growth, and external morphology. Statistically significant differences in allele frequencies of some loci were observed between the samples of acclimatized peled, though total level of genetic differentiation between the populations was not high (F _ST = 0.028). Estimates of gene diversity by allozyme loci were maximal in the population of alpine Lake Sut-Khol, but almost minimum diversity of mtDNA was observed in this population. It is obvious that “own” genetic appearance is formed in introduced fishes in every lake with peculiar diversity in the result of interaction between relatively homogeneous donor material and specific conditions of new environment, and this interaction is especially intense at the first stages of introduction.     

Influence of drainage divides versus arid corridors on genetic structure and demography of a widespread freshwater turtle,Emydura macquarii krefftii,from Australia

The influence of Pleistocene climatic cycles on Southern Hemisphere biotas is not yet well understood. Australia's eastern coastal margin provides an ideal setting for examining the relative influence of landscape development, sea level fluctuation, and cyclic climatic aridity on the evolution of freshwater biodiversity. We examined the impact of climatic oscillations and physical biogeographic barriers on the evolutionary history of the wide‐ranging Krefft's river turtle (Emydura macquarii krefftii), using range‐wide sampling (649 individuals representing 18 locations across 11 drainages) and analysis of mitochondrial sequences (~1.3‐kb control region and ND4) and nuclear microsatellites (12 polymorphic loci). A range of phylogeographic (haplotype networks, molecular dating), demographic (neutrality tests, mismatch distributions), and population genetic analyses (pairwise F_ST, analysis of molecular variance, Bayesian clustering analysis) were implemented to differentiate between competing demographic (local persistence vs. range expansion) and biogeographic (arid corridor vs. drainage divide) scenarios. Genetic data reveal population genetic structure in Krefft's river turtles primarily reflects isolation across drainage divides. Striking north‐south regional divergence (2.2% ND4 p‐distance; c. 4.73 Ma, 95% higher posterior density (HPD) 2.08–8.16 Ma) was consistent with long‐term isolation across a major drainage divide, not an adjacent arid corridor. Ancient divergence among regional lineages implies persistence of northern Krefft's populations despite the recurrent phases of severe local aridity, but with very low contemporary genetic diversity. Stable demography and high levels of genetic diversity are inferred for southern populations, where aridity was less extreme. Range‐wide genetic structure in Krefft's river turtles reflects contemporary and historical drainage architecture, although regional differences in the extent of Plio–Pleistocene climatic aridity may be reflected in current levels of genetic diversity.     

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     

Analysis of genetic diversity in Glyptosternum maculatum (Sisoridae, Siluriformes) populations with AFLP markers

We determined the genetic diversity of geographic populations from three spawning grounds (Nyang River, Lhasa River, Shetongmon Reach of Yarlung Zangbo River) of Glyptosternum maculatum with amplified fragment length polymorphism (AFLP) markers. Five primer combinations detected 332 products, 51 of them (15.4%) were polymorphic in at least one population. The Shetongmon population was found to be the richest in genetic diversity as was indicated by the percentage of polymorphic loci and heterozygosity, followed by the Nyang population and the Lhasa population. The pair-wise genetic distance between populations were all very close, ranging from 0.0015 to 0.0042 with an average of 0.0024. The genetic distance was not proportional to the geographic distance. The analysis of molecular variance demonstrated that all variation occurred within populations. The average estimated fixation index (F _st) of three populations across all polymorphic loci was −0.0184, indicating the absence of genetic differences among the three sampled populations. The differentiation among populations was not significant, and population structure was weak. Our observations will help identify the genetic relationship among populations as the first approach to understand the genetic diversity of Glyptosternum maculatum.     

Pollen movement within a continuous forest of wind-pollinated Araucaria angustifolia, inferred from paternity and TwoGener analysis

As a matter of fact, Araucaria angustifolia populations occur predominately in small and isolated stands; only a minor number of continuous natural forests of this dioecious wind-pollinated coniferous tree species remain. To implement reasonable conservation, breeding and restorations program it is necessary to have the knowledge of pollen dispersal distance and fine-scale genetic structure. In this paper, levels and dispersion distance of pollen and spatial genetic structure of A. angustifolia were investigated in a 14 ha transect in a continuous forest in Paraná State, Brazil. Analyses have been performed by the use of eight microsatellite loci, paternity and TwoGener approaches, and spatial autocorrelation analysis. In transect, 52 male and 56 female adult trees were mapped and genotyped, together with 190 seeds. In the present transect, A. angustifolia show spatial genetic structure at distances up to 75 m. Paternity analysis indicated that 54% of seeds were fertilized by pollen from trees outside the transect. The calculated average pollination distance within transect was 102 and 98 m based on the paternity analysis and TwoGener analysis, respectively. We found a significant pollen gene pool structure across seed-trees ( , P < 0.01) that corresponds to an effective number of pollen donors of 6.4 male trees or an effective pollination neighbourhood area (A _ep ) of 2.1 ha. The findings suggest long-distance pollen dispersion (>100 m) inside the continuous forest. However, the high proportion occurs in short-distance producing biparental and correlated mating as well as reducing the variance effective size.     

LOCAL GENETIC AND CLONAL STRUCTURE IN THE TROPICAL TERRESTRIAL BROMELIAD,AECHMEA MAGDALENAE

The genetic structure of populations of the clone-forming tropical terrestrial bromeliad, Aechmea magdalenae, was examined by electrophoretic analyses in nine populations occurring on and near Barro Colorado Island, Republic of Panama. For the nine populations as a whole, 33% of the loci were polymorphic and the genetic diversity was 0.121. Within populations, the mean percent of polymorphic loci was 24.1% and the mean genetic diversity was 0.084. About one-third of the total allozyme diversity resided among populations (mean G_ST = 0.356). The distribution of A. magdalenae was patchy in the study area. This, coupled with the relatively small effective population sizes and the possible founding of populations by few individuals may have contributed to the large among-population component of genetic diversity. The extent of clonal growth was inferred by examining the relationship between the proportion of rosette-pairs sharing identical multilocus genotypes and distance between pairs. This method indicates that clonal spread is local; individuals sharing multilocus genotypes most often occur within 10 m of each other.     

Congruent signals of population history but radically different patterns of genetic diversity between mitochondrial and nuclear markers in a mountain lizard

Historical factors, current population size, population connectivity and selective processes at linked loci contribute to shaping contemporary patterns of neutral genetic diversity. It is now widely acknowledged that nuclear and mitochondrial markers react differently to current demography as well as to past history, so the use of both types of markers is often advocated to gain insight on both historical and contemporary processes. We used 12 microsatellite loci genotyped in 13 populations of a mountain lizard (Iberolacerta bonnali) to test whether the historical scenario favoured by a previous mitochondrial study was also supported by nuclear markers and thereby evaluated the consequences of postglacial range movements on nuclear diversity. Congruent signals of recent history were revealed by nuclear and mitochondrial markers using an Approximate Bayesian computation approach, but contemporary patterns of mtDNA and nuclear DNA diversity were radically different. Although dispersal in this species is probably highly restricted at all spatial scales, colonization abilities have been historically good, suggesting capability for reestablishment of locally extinct populations except in fully disconnected habitats.