A novel synthesis of two decades of microsatellite studies on European beech reveals decreasing genetic diversity from glacial refugia

Genetic diversity influences the evolutionary potential of forest trees under changing environmental conditions, thus indirectly the ecosystem services that forests provide. European beech (Fagus sylvatica L.) is a dominant European forest tree species that increasingly suffers from climate change-related die-back. Here, we conducted a systematic literature review of neutral genetic diversity in European beech and created a meta-data set of expected heterozygosity (He) from all past studies providing nuclear microsatellite data. We propose a novel approach, based on population genetic theory and a min–max scaling to make past studies comparable. Using a new microsatellite data set with unprecedented geographic coverage and various re-sampling schemes to mimic common sampling biases, we show the potential and limitations of the scaling approach. The scaled meta-dataset reveals the expected trend of decreasing genetic diversity from glacial refugia across the species range and also supports the hypothesis that different lineages met and admixed north of the European mountain ranges. As a result, we present a map of genetic diversity across the range of European beech which could help to identify seed source populations harboring greater diversity and guide sampling strategies for future genome-wide and functional investigations of genetic variation. Our approach illustrates how to combine information from several nuclear microsatellite data sets to describe patterns of genetic diversity extending beyond the geographic scale or mean number of loci used in each individual study, and thus is a proof-of-concept for synthesizing knowledge from existing studies also in other species

AEGIS – Mobile Device for Generating Electromagnetic Curtain for Special Applications and Countering the Threats of RCIED

In the article the concept, design and realization of the technological demonstrator of a mobile device for generating an electromagnetic curtain (with a name AEGIS) were presented, both in the hardware and software areas. The device is designed to block the radio communication which allow detonating the Radio Controlled Improvised Explosive Devices (RCIEDs). The preliminary laboratory tests of the demonstrator for generating the jamming signal, that were presented in the paper, aimed at assessing the correctness of the device operation and verification of generated signal parameters. On the basis of the obtained results, the ability to jam the cellular systems as well as other radio devices operating in the frequency band from 400 MHz to 2700 MHz was assessed

Patterns of Effective Pollen Dispersal in Larch: Linking Levels of Background Pollination with Pollen Dispersal Kernels

Monitoring patterns of mating and pollen dispersal in forest tree populations subjected to nature conservation is essential to understanding the dynamics of their reproductive processes and might be helpful in making management decisions aimed at conserving genetic diversity and integrity over the long term. However, little is known about effective pollen dispersal in natural populations of conifers, particularly in subdominant species such as larch. We investigated patterns of pollen dispersal in the Polish larch population of Świętokrzyski National Park. The studied population was located on Chełmowa Mountain in a forest complex 160 ha in size, which is relatively isolated from other forest stands. We assessed if local pollen dispersal inferred from pollen dispersal kernels could provide indications of the level of background pollination from sources located outside of the forest complex. The analysis focused on two plots, each encompassing 126 adult trees, and seed samples (n = 600) collected from 20 trees. Using 11 nuclear microsatellites and spatially explicit mating models, we identified details of mating patterns. The rate of self-fertilization was low (0.0268). Background pollination was moderate (0.4058), and the mean pollen dispersal was found to be 167 m and 111 m, based on exponential-power and Weibull dispersal kernels, respectively. Specific simulations performed based on the estimated pollen dispersal kernels provided background pollination levels comparable to those observed for real data, suggesting that the pollen contributing to background pollination likely originated from the studied forest complex and not from other surrounding populations. These results confirm the high potential for maintaining the genetic integrity of the larch population and support efforts aimed at promoting regeneration of the stands, either natural or through the artificial planting of seedlings derived from trees growing in the core larch population of the protected area

Preliminary results on allozyme diversity and differentiation of Norway spruce (Picea abies (L.) Karst.) in Poland based on plus tree investigations

Genetic diversity and genetic differentiation among Polish populations of Norway spruce (Picea abies (L.) Karst.) were studied analyzing allozyme variation at 24 loci. Presented investigations based on 81 clones represented 6 populations from three different regions: Sudety Mts., Beskid Mts. and North-East Poland. On average, the expected heterozygosity was 0.134, 52.8% of loci were polymorphic, and the number of alleles per locus was 1.8. Our data confirm the hypothesis that a lower level of variation of Picea abies exists in central Europe, compared to other regions of its natural distribution. Relatively small allozyme differentiation among regions was observed (Fst =0.027, and Nei's genetic distances ranged from 0.005 to 0.008). Reasons for the low genetic differentiation observed between Southern and Northern populations are briefly discussed

Phylogeny of Maleae (Rosaceae) Based on Complete Chloroplast Genomes Supports the Distinction of <em>Aria</em>, <em>Chamaemespilus</em> and <em>Torminalis</em> as Separate Genera, Different from <em>Sorbus</em> sp.

Several genera formerly contained within the genus Sorbus L. sensu lato have been proposed as separate taxa, including Aria, Chamaemespilus and Torminalis. However, molecular evidence for such distinctions are rather scarce. We assembled the complete chloroplast genome of Sorbus aucuparia, another representative of Sorbus s.s., and performed detailed comparisons with the available genomes of Aria edulis, Chamaemespilus alpina and Torminalis glaberrima. Additionally, using 110 complete chloroplast genomes of the Maleae representatives, we constructed the phylogenetic tree of the tribe using Maximum Likelihood methods. The chloroplast genome of S. aucuparia was found to be similar to other species within Maleae. The phylogenetic tree of the Maleae tribe indicated that A. edulis, C. alpina and T. glaberrima formed a concise group belonging to a different clade (related to Malus) than the one including Sorbus s.s. (related to Pyrus). However, Aria and Chamaemespilus appeared to be more closely related to each other than to Torminalis. Our results provide additional support for considering Aria, Chamaemespilus and Torminalis as separate genera different from Sorbus s.s

Complete chloroplast genomes of Fagus sylvatica L. reveal sequence conservation in the inverted repeat and the presence of allelic variation in NUPTs

Growing amounts of genomic data and more efficient assembly tools advance organelle genomics at an unprecedented scale. Genomic resources are increasingly used for phylogenetic analyses of many plant species, but are less frequently used to investigate within-species variability and phylogeography. In this study, we investigated genetic diversity of Fagus sylvatica, an important broadleaved tree species of European forests, based on complete chloroplast genomes of 18 individuals sampled widely across the species distribution. Our results confirm the hypothesis of a low cpDNA diversity in European beech. The chloroplast genome size was remarkably stable (158,428 ± 37 bp). The polymorphic markers, 12 microsatellites (SSR), four SNPs and one indel, were found only in the single copy regions, while inverted repeat regions were monomorphic both in terms of length and sequence, suggesting highly efficient suppression of mutation. The within-individual analysis of polymorphisms showed >9k of markers which were proportionally present in gene and non-gene areas. However, an investigation of the frequency of alternate alleles revealed that the source of this diversity originated likely from nuclear-encoded plastome remnants (NUPTs). Phylogeographic and Mantel correlation analysis based on the complete chloroplast genomes exhibited clustering of individuals according to geographic distance in the first distance class, suggesting that the novel markers and in particular the cpSSRs could provide a more detailed picture of beech population structure in Central Europe

Genetic evaluation of seeds of highly endangered Pinus uliginosa Neumann from Węgliniec reserve for ex-situ conservation program

Peat-bog pine Pinus uliginosa Neumann has become extinct or rare in many parts of Europe. We have investigated the levels of genetic variation and inbreeding in seeds collected from a highly endangered reserve of this species in Poland, using allozymes as genetic markers. Generally, a high level of genetic variation was observed. The mean expected heterozygosity was 0.376, while average (Na) and effective (Ne) numbers of alleles per locus were 2.45 and 1.67, respectively. Nevertheless, we have detected relatively low levels of outcrossing, and potential biparental inbreeding. The population-wide multilocus outcrossing rate was estimated to be 0.706 (±0.091), while the minimum variance mean of single-locus estimates was distinctly lower (ts=0.611). The estimates of outcrossing calculated for individual trees ranged widely from 0.051 to 1.017, indicating the complexity of outcrossing patterns. The investigated population of P. uliginasa from Węgliniec is small and surrounded by extensive forest stands of P. sylvestris. Our three-year records of phenological observations demonstrated that flowering periods for P. uliginosa and P. sylvestris overlap, allowing for cross-pollination. The possibility of P. uliginosa pollination by P. sylvestris creates a potential danger of genetic erosion of the P. uliginosa gene pool. Nonetheless, based on a species specific cpDNA marker we have found that among 533 seedlings of P. uliginosa there were only six seedlings carrying cpDNA marker specific for P. sylvestris, indicating that such hybridization seems to be rare

Beech roots are simultaneously colonized by multiple genets of the ectomycorrhizal fungus Laccaria amethystina clustered in two genetic groups

In this study, we characterize and compare the genetic structure of aboveground and belowground populations of the ectomycorrhizal fungus Laccaria amethystina in an unmanaged mixed beech forest. Fruiting bodies and mycorrhizas of L. amethystina were mapped and collected in four plots in the Świȩtokrzyskie Mountains (Poland). A total of 563 fruiting bodies and 394 mycorrhizas were successfully genotyped using the rDNA IGS1 (intergenic spacer) and seven simple sequence repeat markers. We identified two different genetic clusters of L. amethystina in all of the plots, suggesting that a process of sympatric isolation may be occurring at a local scale. The proportion of individuals belonging to each cluster was similar among plots aboveground while it significantly differed belowground. Predominance of a given cluster could be explained by distinct host preferences or by priority effects and competition among genets. Both aboveground and belowground populations consisted of many intermingling small genets. Consequently, host trees were simultaneously colonized by many L. amethystina genets that may show different ecophysiological abilities. Our data showed that several genets may last for at least 1 year belowground and sustain into the next season. Ectomycorrhizal species reproducing by means of spores can form highly diverse and persistent belowground genets that may provide the host tree with higher resilience in a changing environment and enhance ecosystem performance