Landscape genetic structure of <Emphasis Type="Italic">Olea europaea</Emphasis> subsp. <Emphasis Type="Italic">cuspidata</Emphasis> in Ethiopian highland forest fragments

Understanding patterns of genetic diversity at the landscape scale will enhance conservation and management of natural populations. Here we analyzed the genetic diversity, population connectivity, and spatial genetic structure among subpopulations and age groups of Olea europaea subsp. cuspidata, a cornerstone species of the Afromontane highlands. The study was conducted at the landscape level within a radius of approximately 4 km, as well as on a fine scale (intensive study plot) of less than 300 m radius. In total 542 samples from four natural subpopulations in northwestern Ethiopia were analyzed using ten nuclear microsatellite markers. Inbreeding was higher in smaller populations. No genetic difference was detected among cohorts of different tree sizes in the intensive studied plot. Average population differentiation was low but significant (F _ST ?=?0.016). Landscape genetic analysis inferred two groups: the most distant subpopulation WE located less than 4 kms from the other three subpopulations formed a separate group. Sixty-four percent of the total migrants were shared among the three latter subpopulations, which are spatially clustered. Immigrants were non-randomly distributed inside of the intensive study plot. Significant spatial genetic structure (SGS) was found both at the landscape scale and in the intensive study plot, and adults showed stronger SGS than young trees. An indirect estimate of 220 m as mean gene dispersal distance was obtained. We conclude that even under fragmentation migration is not disrupted in wild olive trees and that large protected populations at church forests are very important to conserve genetic resources. However, the higher level of inbreeding and evidence for population bottlenecks in the small populations, as well as the persisting heavy pressure on most remaining populations, warrants quick action to maintain genetic diversity of wild olive in the Ethiopian highlands.     

Microsatellite analysis to estimate realized dispersal distance in <Emphasis Type="Italic">Phragmites</Emphasis><Emphasis Type="Italic">australis</Emphasis>

An understanding of the mean and maximum dispersal distances of target species and subsequent scaling of management efforts to dispersal distance can be key in slowing, containing, or eradicating invasive species. However, dispersal distance is often difficult to measure. Patterns of genetic relatedness can be interpreted to understand realized genetic dispersal distances, which can then be applied to management. We analyzed patterns of microsatellite relatedness using Mantel correlograms and used them to estimate realized dispersal distance for the invasive wetland grass, Phragmites australis. We found that genetic relatedness declined quickly with increasing distance, decreasing to the level of the mean subestuary genetic relatedness by 100 m and to nearly zero by 500 m. We interpret this to indicate that most dispersal is <100 m and very little dispersal extends beyond 500 m. This suggests that management of P. australis may need to consider dispersal from stands up to 500 m from an area that is being managed, perhaps at the scale of whole subestuaries. Results of this study demonstrate that analysis of dispersal patterns can be used to develop landscape-scale approaches to the management of invasive species.     

Pollen ultrastructure in <Emphasis Type="Italic">Aristolochia manshuriensis</Emphasis> and <Emphasis Type="Italic">A. contorta</Emphasis> (Aristolochiaceae)

Pollen ultrastructure has been studied in two relict and rare species of the genus Aristolochia, A. contorta Bunge and A. manshuriensis Kom. (Aristolochiaceae). Both species have inaperturate, spheroidal, sometimes distally monocolpate or distally bicolpate pollen grains. The equatorial and polar axes of pollen grain in A. manshuriensis are 48.5 and 44.0 μm, respectively. The percentage of defective pollen grains in A. manshuriensis is 3.4%. The fossulate, perforated exine is up to 2.3 μm in thickness; the sexine and the nexine are almost equal in thickness. In A. contorta, the equatorial axis of pollen grain is 36.6 μm: the defectiveness percentage, 24.5%. The exine is verrucate, up to 0.3 μm in thickness, while the sexine is two to three times thicker than the nexine. The pollen germination experiments have shown that pollen of A. manshuriensis, in contrast to A. contorta, can germinate in 10–20% sucrose at 22°С. These data and the high percentage of pollen defectiveness in A. contorta indicate that the androecium function in this species is reduced. The reduction of the androecium function is evidenced by a small amount of pollen grains in anthers or empty anthers and a high percentage of defective pollen grains.     

Post-pollination hybridization barriers in <Emphasis Type="Italic">Nicotiana</Emphasis> section <Emphasis Type="Italic">Alatae</Emphasis>

Nicotiana section Alatae contains eight species with variable flower sizes and morphologies. Section members readily hybridize in the glasshouse, but no hybrids have been observed in natural sympatric and parapatric populations. To investigate interspecific crossing relationships with respect to mechanisms preventing hybridization, all members of section Alatae were intercrossed in a complete diallel. We found positive correlation between the pistil length of the pollen donor and interspecific seed set relative to the conspecific cross. Pollen tube growth rate and pollen donor pistil length were positively correlated as well. Furthermore, pollen from short-pistil members of section Alatae could only grow a maximum distance proportional to, but greater than, their own pistil lengths. Our results show that pollen tube growth capacity (i.e., rate and distance), provides a hybridization barrier in long-pistil species × short-pistil species crosses. We also found another hybridization barrier not specifically related to pollen tube growth capacity in short-pistil species × long-pistil species. Taken together, these barriers can generally be described by a ‘pistil-length mismatch’ rule; in section Alatae, pollen has the most success fertilizing ovules from species with pistil lengths similar to their own. This rule could contribute to hybridization barriers in Section Alatae because the species display dramatically different pistil lengths. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Dispersal Patterns in <Emphasis Type="Italic">Tarsius spectrum</Emphasis>

One of the most widely accepted explanations for the difference in the sex bias between mammals and birds is that male-biased dispersal in mammals is due to the preponderance of polygynous mating systems exhibited by this class, whereas birds are predominantly monogamous. Spectral tarsiers (Tarsius spectrum) are unusual in that they exhibit variation in its mating system. Although the majority of spectral tarsier groups are monogamous, ca. 15% are polygynous. If mating system influences dispersal, then I predicted that the polygynous groups would exhibit male biased dispersal whereas I predicted that the dispersal patterns of the monogamous groups would be analogous to that exhibited by birds, specifically female biased. Alternatively, I hypothesized that ecological variation may influence dispersal habits in this species. Specifically, I predicted that polygynous groups would exhibit greater habitat quality than monogamous groups. The 2 hypotheses are not mutually exclusive. On the basis of 14 individuals birdbanded between 1994 and 1999, I determined that individuals of both sexes were equally likely to disperse (males, n = 5; females, n = 9). Males dispersed twice as far as females did. The mean dispersal distance for males was 660 m, and for females it was 266 m. Females (77%) were more likely to form a territory adjacent to the parental territory than were males (20%). Individuals exhibited relatively high amounts of site fidelity (86%) that were related to physical characteristics of the sleeping site. Adults that dispersed a second time (n = 4) initially resided in trees that were shorter and had a smaller diameter-at-breast height than the trees of individuals that exhibited site fidelity. The results of my study partly support the parental mating system hypothesis and also support the habitat quality hypothesis.     

Landscape determinants of genetic differentiation,inbreeding and genetic drift in the hazel dormouse (<Emphasis Type="Italic">Muscardinus avellanarius</Emphasis>)

The dispersal process is crucial in determining the fate of populations over time, but habitat fragmentation limits or prevents it. Landscape genetic is an effective tool to assess the degree to which dispersal still occurs in fragmented landscapes. The purpose of this study was to investigate the landscape determinants of genetic differentiation in the hazel dormouse (Muscardinus avellanarius), a forest-dependent species of conservation concern. By comparing subpopulations in a continuous (SLR) and a fragmented (VTH) population, we (i) searched for the presence of Isolation-by-Resistance (IBR); (ii) estimated migration rates; (iii) evaluated the degree of inbreeding and genetic drift, and searched for their landscape determinants. We found an IBR effect in VTH, which heavily hindered the dispersal process. The overall number of migrants among VTH subpopulations was very low (1 per generation, compared to 15 in SLR), although a between-patch displacement of about 4 km along a well-structured hedgerow probably occurred. The inbreeding (F?>?0.2 in most subpopulations) and the genetic drift (four out five subpopulations showed private alleles on several loci, with relatively high frequencies) are of particular concern in VTH. However, they were found to be limited in large patches or in patches connected by hedgerows with a high number of neighbouring patches. As a conservation strategy in the VTH landscape, characterized by small patches, we suggest that the dispersal process among subpopulations is enhanced to sustain a functional metapopulation. For this purpose, an effective ecological network should be created by enhancing the continuity and the internal features of hedgerows.     

Breeding system,gene dispersal and small-scale spatial genetic structure of a threatened food tree species, <Emphasis Type="Italic">Pentadesma butyracea</Emphasis> (Clusiaceae) in Benin

Pentadesma butyracea Sabine, a rain forest food tree species, plays a vital role in the socio-economic livelihood of some West African rural communities due to its various products. However, its scattered populations are threatened in Benin. Defining appropriate conservation strategies requires a good knowledge of mating patterns and their consequences for population genetics. The outcrossing rate, levels of correlated paternity and fine-scale spatial genetic structure of adults and maternal sibships were estimated for one small population and three large populations in Benin using microsatellite markers. Similar outcrossing rates (88–95%) were found in all populations, showing that P. butyracea is mainly an outbreeding species. We found no evidence of inbreeding depression from a decay of inbreeding with age. The spatial genetic structure within the large populations (Sp statistic?=?0.003–0.038) was consistent with isolation-by-distance expectations, showing that gene dispersal is spatially limited. Limited pollen dispersal is highlighted by the decay of the degree of correlated paternity between sibships with spatial distance. The mean pollen dispersal distance was estimated between 50 m and 450 m, but up to 21% pollen may migrate from external sources. The smallest population displayed slightly higher correlated paternity than the large populations (r _p ?=?0.37 vs. r _p ?=?0.17–0.30). In conclusion, our results suggest that small populations may show a reduction in sire numbers in seed, while the fragmented populations, large and small, are connected through gene flow. There is little inbreeding and no evidence of inbreeding depression.     

Effects of ozone in <Emphasis Type="Italic">Plantago lanceolata</Emphasis> and <Emphasis Type="Italic">Salix atrocinerea</Emphasis> pollen

Pollen can be modified by the increasing environmental pollution which can lead to a rising trend in pollen-induced respiratory allergies. The aim of this work was to study the fertility, protein profile and allergenicity of Plantago lanceolata and Salix atrocinerea pollen after exposure to ozone. The pollen collected directly from the anthers of both species was exposed to O₃ in an environmental chamber, for 6 h at different concentrations. After exposing the pollen, viability tests and in vitro germination were performed. Total protein content was determined by the Bradford method, the polypeptides were separated by SDS-PAGE and the antigenic properties were analyzed by immunological techniques using patients’ sera. The concentrations of O₃ tested affected the pollen fertility and the total protein content, but the protein profiles did not show any differences. Furthermore, the immunological tests revealed an increase in IgE binding reactivity when pollen was exposed to the pollutant.     

Distribution and habitats of <Emphasis Type="Italic">Phengaris</Emphasis> (<Emphasis Type="Italic">Maculinea</Emphasis>) butterflies and population ecology of <Emphasis Type="Italic">Phengaris</Emphasis><Emphasis Type="Italic">teleius</Emphasis> in China

Many species of the butterfly genus Phengaris are regarded as endangered in many parts of their distribution. Several species are also widely distributed across northern China. Due to land use change and overgrazing, their habitats are declining and many patches have been lost. This paper investigates the distribution and habitats of the Chinese Phengaris species (of the subgenus Maculinea). Shrub-grassland near forests seem the most frequent habitat for Phengaris, while flat open grasslands are mostly over-grazed and thus survival for Phengaris butterflies there seems difficult. Throughout Europe, P. teleius is an endangered species, while there is still no information on its status in China. To improve the knowledge on the population ecology of P. teleius, its population structure, adult behaviour and movement were studied through mark–release–recapture methods in the Qinling Mountains of Taibai County. Eight grassland patches which were potentially suitable were found in the area in 2013. In total, 480 individuals (274 females) were marked, resulting in an overall recapture rate of 16 %. The average daily population size was 44 butterflies (±23 SD) during the adult flight period. Sixty-seven percent of the females and 38 % of the males moved less than 50 m, and 17 % of recaptured females and 38 % of males moved more than 200 m. The mean movement distance was 107 ± 177 m for males and 182 ± 122 m for females. The majority of the recaptures (86 %) were made within the patches, only a few individuals (14 %) moved between patches. Due to human disturbance and destruction, all of the eight potentially suitable patches are becoming smaller and increasingly isolated, thus these populations of P. teleius may face an increasing risk of extinction, which may well be a tip of the iceberg of habitat loss and fragmentation of P. teleius in Taibai County and possibly beyond. Hence we hope our initial study of P. teleius could have positive impacts on the conservation of Phengaris butterflies in China.     

Spatial genetic structure and restricted gene flow in a functionally dioecious fig, <Emphasis Type="Italic">Ficus pumila</Emphasis> L. var. <Emphasis Type="Italic">pumila</Emphasis> (Moraceae)

The mutualism between fig plants and fig wasps has been recognized as one of the most specialized systems of symbiosis. Figs are pollinated by their highly specific pollinating fig wasps, and the pollinating fig wasps are raised within the syconia of figs. Recent studies indicated a difference between monoecious and dioecious figs in the dispersal range of pollinating wasps, which has potential consequences for gene flow. In this study, we detected the gene-flow pattern of the dioecious climbing fig, Ficus pumila L. var. pumila, at both local and regional scales. At the local scale, spatial autocorrelation analysis indicated strong genetic structure at short distances, a pattern of limited gene flow. This result was also supported by a high inbreeding coefficient (F _IS = 0.287) and significant substructuring (F _ST = 0.060; P < 0.001). Further analysis indicated that the effective gene dispersal range was 1,211 m, and the relative contribution of seed dispersal was smaller than that of pollen dispersal. The inferred effective range of pollen dispersal ranged from 989 to 1,712 m, while the effective seed dispersal range was less than 989 m. Lack of long-distance dispersal agents may explain the limited seed dispersal. The high density of receptive fig trees was the most likely explanation for limited pollen dispersal, and the position of syconia and relatively low wind speed beneath the canopy may contribute to this phenomenon. At the regional scale, significant negative correlations (kinship coefficient F _ij ranging from −0.038 to −0.071) existed in all comparisons between the studied population and other populations, and the assignment test grouped almost all individuals of the studied population into a distinct cluster. Asynchronous flowering on the regional scale, which provides a barrier for the pollinating wasps to fly from the studied population to the other populations, is probably responsible for the limited gene flow on the regional scale.     

Effects of logging rotation in a lowland dipterocarp forest on mating system and gene flow in <Emphasis Type="Italic">Shorea parvifolia</Emphasis>

Selective logging is one of several silvicultural practices used in sustainable forest management in the lowland dipterocarp forest in Indonesia. Selecting only trees with diameters >50 cm for logging can reduce the density of reproductive trees, thereby affecting pollen dispersal and influencing the mating system among remaining trees. We evaluated the effect of logging rotations on the mating system, gene flow and genetic diversity in populations of Shorea parvifolia in primary forest, and in first and second rotation forest. Our results revealed that multiple (or at least two) selective logging events with a 30-year logging rotation had a significant impact on the genetic diversity of pollen clouds. However, the average pollen dispersal distance did not differ significantly among the multiple selective logging rotations. The multiple rotations reduced the outcrossing rate and the number effective of pollen donors in the logged forest. Moreover, the number of pollen donors in a plot was affected by the basal area of reproductive trees present. These results suggest that reducing the number of reproductive trees by logging with multiple rotations might increase the bi-parental inbreeding rate due to the reduction in density of reproductive trees in a selectively logged forest. We conclude that multiple rotations with a 30-year cycle of selective logging as currently practiced would reduce the density of reproductive trees, and would not be sustainable in terms of maintaining genetic diversity in tropical forests of Southeast Asia.     

Pollen dispersal patterns and population persistence in a small isolated population of <Emphasis Type="Italic">Fagus crenata</Emphasis>

The potential of long-distance pollen dispersal and the effects of small population size and population isolation on persistence of Fagus crenata populations were investigated in a small, severely isolated population (the Gofuku-ji population) and two other populations located within 7 km of this population (including 87 adult trees in total). Parentage analysis using 13 microsatellite loci showed that 94 of 100 seedlings derived from seeds collected from the Gofuku-ji population had parent pairs within this population, six had one parent within the population, and four of the six seedlings had alleles that were not detected in any of the three populations, indicating that some pollen is dispersed over distances exceeding 7 km. The estimated expected heterozygosity and effective population size were lower in the Gofuku-ji population than in previously examined large continuous populations. Therefore, levels of genetic diversity within the population may have been reduced by strong genetic drift and limitations of pollen- and seed-mediated gene flow associated with the small size and severe isolation. The contemporary mating pattern estimated at the seedling stage was biased toward outbreeding, which may be explained by possible processes: the level of inbreeding in the adult trees is increased; then, inbreeding frequently occurs but is rarely successful, while outbreeding successfully produces offspring. Additionally, high levels of significant linkage disequilibrium and higher numbers of alleles than expected under mutation–drift equilibrium from analyses of the populations’ evolutionary history suggest that the Gofuku-ji population may have experienced admixture before its severe isolation. Therefore, the persistence of the Gofuku-ji population is being adversely affected by the decrease in population size and severe isolation. Further studies of gene flow via pollen in other populations with various degrees of isolation could enhance our understanding of the effects of population isolation and long-distance pollen dispersal in F. crenata and similar species.     

CAT and MDH improve the germination and alleviate the oxidative stress of cryopreserved <Emphasis Type="Italic">Paeonia</Emphasis> and <Emphasis Type="Italic">Magnolia</Emphasis> pollen

Researches have reported that reactive oxygen species (ROS)-induced oxidative stress plays an important role in cell cryodamage during cryopreservation. In the current study, pollen from Magnolia denudata and Paeonia lactiflora ‘Zi Feng Chao Yang’ was cryopreserved and incubated with exogenous catalase (CAT) and malate dehydrogenase (MDH) immediately after thawing. The effect of CAT and MDH on the germination of cryopreserved pollen was measured. Based on that, the ROS level, lipid peroxidation and antioxidants activities in fresh pollen, cryopreserved pollen added with or without CAT or MDH were determined to investigate their relationship with oxidative stress. Pollen from Magnolia and Paeonia showed a significant loss of germination, but marked increase of ROS and malondialdehyde (MDA) production after cryostorage. Antioxidant profiles in them were also enhanced. CAT and MDH addition increased the post-LN pollen germination of Magnolia and Paeonia significantly. Their germination rate achieved the highest with 100 IU ml^?1 MDH and 400 IU ml^?1 CAT application, respectively. Compared to their untreated controls, ROS and MDA accumulation reduced significantly in cryopreserved Magnolia pollen treated with 100 IU ml^?1 MDH, while superoxide dismutase (SOD) activity improved markedly. In the case of Paeonia, significantly lower level of ROS and MDA, but higher activity of CAT and SOD were observed in cryopreserved pollen treated with 400 IU ml^?1 CAT. In conclusion, pollen deterioration after cryopreservation is associated with ROS-induced oxidative stress. Exogenous CAT and MDH can reduce the oxidative damage through the activity stimulation of antioxidant enzymes, and play a protective role in the pollen during cryopreservation.     

Distribution,ecology, and conservation of Hermes copper (Lycaenidae: <Emphasis Type="Italic">Lycaena</Emphasis> [<Emphasis Type="Italic">Hermelycaena</Emphasis>] <Emphasis Type="Italic">hermes</Emphasis>)

Hermes copper butterfly (Lycaena [Hermelycaena] hermes) is a rare species inhabiting the coastal sage scrub adjacent to San Diego, CA USA. Conservation groups and wildlife agencies recognize this species is threatened by habitat loss due to urbanization and recent wildfires extirpating local populations. To assess the status of the Hermes copper, we summarize the literature concerning taxonomy, distribution, and ecology, as well as present original distributional and ecological data. Adults were sampled by presence/absence surveys, Pollard Walks, and mark-release-recapture. The current distribution is reduced from historic ranges, specifically in extreme southern and northern San Diego County. Recent wildfires in 2003 and 2007 led to the extirpation of many populations, with only one post-fire recolonization documented. Adult emergence dates ranged from mid-May to early June, while densities varied from five to nine-fold among years based on peak abundance and mark-release-recapture estimates, respectively. We observed significantly more males; most were territorial and exhibit a relatively sedentary behavior. The median dispersal range was 25.8 and 11.3 m, and the median minimum distance traveled was 34.4 and 17.6 m at Rancho Jamul Ecological Reserve and Hollenbeck Canyon Wildlife Area, respectively. The longest recorded movement by an individual was 1,132.0 m. Post-fire habitat recovery and the ability to move across the landscape are essential for the Hermes copper to persist in an increasingly dynamic and fragmented coastal sage scrub habitat. Therefore, we need to develop a better understanding of habitat requirements and connectivity of populations for the long-term management and conservation of this species.     

<Emphasis Type="Italic">Metschnikowia</Emphasis> mating genomics

Genes involved in mating type determination and recognition were examined in Metschnikowia and related species, to gather insights on factors affecting mating compatibility patterns among haplontic, heterothallic yeast species of the genus. We confirmed the universality of the special mating locus organisation found in Clavispora lusitaniae across and exclusive to the family Metschnikowiaceae (i.e., Metschnikowia and Clavispora). Timing of the divergence between idiomorphs was confirmed to coincide with the origin of the larger (CUG-ser) clade comprising the Debaryomycetaceae and the Metschnikowiaceae, exclusive of Cephaloascus fragrans. The sequence of the a mating pheromone is highly conserved within the large-spored Metschnikowia species, including Metschnikowia orientalis and Metschnikowia hawaiiana, but not Metschnikowia drosophilae or Metschnikowia torresii, which have a pattern of their own, as do other clades in the genus. In contrast, variation in α pheromones shows a more continuous, although imperfect correlation with phylogenetic distance as well as with in vivo mating compatibility.     

Fine-scale spatial genetic structure in the frankincense tree <Emphasis Type="Italic">Boswellia papyrifera</Emphasis> (Del.) Hochst. and implications for conservation

The fine-scale genetic structure and how it varies between generations depends on the spatial scale of gene dispersal and other fundamental aspects of species’ biology, such as the mating system. Such knowledge is crucial for the design of genetic conservation strategies. This is particularly relevant for species that are increasingly fragmented such as Boswellia papyrifera. This species occurs in dry tropical forests from Ethiopia, Eritrea and Sudan and is an important source of frankincense, a highly valued aromatic resin obtained from the bark of the tree. This study assessed the genetic diversity and fine-scale spatial genetic structure (FSGS) of two cohorts (adults and seedlings) from two populations (Guba-Arenja and Kurmuk) in Western Ethiopia and inferred intra-population gene dispersal in the species, using microsatellite markers. The expected heterozygosity (H _E) was 0.664–0.724. The spatial analyses based on kinship coefficient (F _ij) revealed a significant positive genetic correlation up to a distance of 130 m. Spatial genetic structure was relatively weak (Sp = 0.002–0.014) indicating that gene dispersal is extensive within the populations. Based on the FSGS patterns found, we estimate indirectly gene dispersal distances of 103 and 124 m for the two populations studied. The high heterozygosity, the low fixation index and the low Sp values found in this study are consistent with outcrossing as the (predominant) mating system in B. papyrifera. We suggest that seed collection for ex situ conservation and reforestation programmes of B. papyrifera should use trees separated by distances of at least 100 m but preferably 150 m to limit genetic relatedness among seeds from different trees.     

Palynological analysis of five selected <Emphasis Type="Italic">Onosma</Emphasis> taxa

Pollen size and exine structure of the following five Onosma L. species from Slovakia and Italy were studied by light and scanning electron microscopy: Onosma echioides, O. tornensis, O. visianii, O. arenaria, and O. pseudoarenaria. Among the taxa studied, O. echioides has the smallest pollen grains in average (10.5–17.5 × 8.0–14.5 μm), and O. pseudoarenaria the largest grains in average (15.3–20.5 × 12.3–16.3 μm). Pollen grains of all 5 species are small sized, 3-syncolporate, subprolate, heteropolar, with ovate equatorial outlines and circular to rounded triangular polar outlines; the tectum is microechinate. A positive correlation is found between pollen size and chromosome number. The value of pollen characters for taxonomic purposes and the position of the taxa studied within the genus Onosma are discussed.     

Understanding the effects of isolation on seed and pollen flow,spatial genetic structure and effective population size of the dioecious tropical tree species <Emphasis Type="Italic">Myracrodruon urundeuva</Emphasis>

This study examines the levels of gene flow, the distance and the patterns of pollen and seed dispersal, the intra-population spatial genetic structure (SGS) and the effective population size of a spatially isolated Myracrodruon urundeuva population using five microsatellite loci. The study was carried out in the Paulo de Faria Ecological Station, São Paulo State, Brazil and included the sampling and mapping of 467 adult-trees and 149 juveniles. Open-pollinated seeds (514) from 29 seed-trees were also sampled and genotyped. Significant SGS was detected in both adult (S _p  = 0.0269) and juveniles trees (S _p  = 0.0246), indicating short-distance seed dispersal. Using maternity analysis, all juveniles had the mother-tree assigned within the stand. A father-tree within the stand was also assigned for 97.3% of the juveniles and 98.4% of offspring. The average pollen dispersal distance measured in juveniles \( \left( {\hat{\delta } = 1 3 8\pm 1 6 9 {\text{ m}},{\text{ mean}} \pm {\text{SD}}} \right) \) and offspring \( \left( {\hat{\delta } = 2 5 2\pm 20 4 {\text{ m}}} \right) \) were higher than the average seed dispersal distance measured in juveniles \( \left( {\hat{\delta } = 1 2 4\pm 1 50{\text{ m}}} \right) \). About 70% of the pollen from juveniles and 51% from offspring traveled less than 200 m and, 72% of the seeds traveled less than 50 m. The effective population size of the studied sample indicates that the 467 adult-trees and 145 juveniles correspond respectively to 335 and 63 individuals that are neither inbred nor relatives. The results are discussed in relation to their impact on seed collection practices and genetic conservation.     

Heteroresistance to Fluconazol in Clinical and Environmental Brazilian Strains of <Emphasis Type="Italic">Cryptococcus neoformans</Emphasis>/<Emphasis Type="Italic">C. gattii</Emphasis> Species Complex

Purpose of Study

To review the literature on heteroresistance to fluconazole (FLC) and investigate the level of heteroresistance to FLC (LHF), we analyzed 100 clinical and environmental Brazilian Cryptococcus strains.

Recent Findings

Heteroresistance is a phenomenon described as the emergence of resistant subpopulation cells within a single susceptible strain that can tolerate higher concentrations of fluconazole above the minimal inhibitory concentration (MIC) level.

Summary

We found lower FLC-MICs (0.12–64 mg/L) than LHF (8–128 mg/L). Highly heteroresistant adapted subpopulations (256 mg/L) was found in minority (9%) strains, but importantly, 33% showed low FLC-MIC (8 mg/L). We concluded for similar LHF in both species, but higher LHF in clinical strains in comparison to environmental ones. Our findings stressed that the LHF is not correlated to species and pretty is strain-dependent and alert about high heteroresistant subpopulations that hardly reverts to the original LHF even upon the removal of drug pressure.

     

Independent hybrid populations of <Emphasis Type="Italic">Formica polyctena X</Emphasis><Emphasis Type="Italic">rufa</Emphasis> wood ants (Hymenoptera: Formicidae) abound under conditions of forest fragmentation

Combined genetic and morphological data indicate frequent hybridisation between the wood ants Formica polyctena Förster 1850 and F. rufa Linnaeus 1761 in Central Europe. The genetic and morphological traits give a concordant picture of hybridisation with a strong correlation between the genotypic admixture proportions at 19 microsatellite loci and the first vectors of a principal component analysis (P < 0.001) and of a 3-class discriminant analysis (P < 0.001) of 15 quantitative morphological characters. This integrative approach enabled a grouping into F. polyctena, the hybrid and rufa. Genetic differentiation between the hybrid and F. rufa is significantly larger than between the hybrid and polyctena, indicating gene flow mainly between the latter entities. A suggested gene flow bias towards F. polyctena agrees with differential queen acceptance and mating behaviour. Both genetic and phenotypic colony parameters indicate predominance of monogyny in F. rufa but of polygyny in polyctena and the hybrid. Hybrids are intermediate between the parental species in body size, diagnostic morphological characters, monogyny frequency, size of nest population, nest diameter and infestation rate with epizootic fungi. The three entities respond differently to woodland fragmentation. Hybrids are significantly more abundant in forests with a coherent area <300 ha than in woodland above this size. Regions with high hybrid frequency in Germany—the Eastern Oberlausitz (23%) and the Baltic Sea islands Darss, Hiddensee and Rügen (28%)—are characterised by a fragmented woodland structure whereas regions with low hybrid frequency—Brandenburg and the lower Erzgebirge (3.4%)—have clearly larger and more coherent forest systems. Data from other European countries indicate habitat fragmentation to be a facilitating factor but no essential precondition for interspecific hybridisation in these ants. Hybrids are hypothesised to have selective advantage in fragmented systems because of combining the main reproductive and dispersal strategies of the parental species.