Cytogenetic abnormalities in Norway spruce (Picea abies (L.) Karst.) seedlings from natural populations and an introduction plantation

Comparative studies of the frequency and spectrum of pathological mitoses (PMs), as well as of the nucleolus number in the interphase nucleus, in cells of Norway spruce (Picea abies (L.) Karst.) seedlings were carried out in two natural populations of Ukrainian Polesie and plants from an introduction plantation in Donbass. Low levels of PMs in the seed progeny of the populations (0.32?C0.38%) and a slightly higher level in the plantation progeny (0.40%) are established. The number of nucleoli was somewhat higher in the progeny of the populations (5.35?C5.85) than that of the plantation plants (4.95). The PMs frequency was higher (0.43%) in the progeny of low-heterozygous plants than in highly heterozygous ones (0.28%).     

Diversity of Arabidobsis thaliana (L.) Heynh. natural populations at the northern limits of the species range: RAPD analysis

In natural populations of Arabidobsis thaliana (L.) Heynh., occupying northern limits of the species range (Karelia), the level of genetic diversity was evaluated. In two insular and one mainland population variability at 82 RAPD loci was tested. Considerable genetic diversity revealed (P = 4.5%; H _exp = 0.177) was not typical of self-pollinating plant species. It was demonstrated that genetic differentiation among the populations (G _ST = 0.680) was rather high, pointing to the low level of gene flow in the isolated insular populations. It was suggested that the high level of Arabidopsis population polymorphism in Karelia could be associated with extreme growing conditions at the northern limits of the species range.     

Variation in the chloroplast DNA of Swiss stone pine (Pinus cembra L.) reflects contrasting post-glacial history of populations from the Carpathians and the Alps

Aim To characterize the genetic structure and diversity of Pinus cembra L. populations native to two disjunct geographical areas, the Alps and the Carpathians, and to evaluate the rate of genetic differentiation among populations. Location The Swiss Alps and the Carpathians. Methods We screened 28 populations at three paternally inherited chloroplast simple sequence repeats (cpSSRs) for length variation in their mononucleotide repeats. Statistical analysis assessed haplotypic variation and fixation indices. Hierarchical analysis of molecular variance (AMOVA), Mantel test, spatial analysis of molecular variance (SAMOVA) and barrier analyses were applied to evaluate the geographical partitioning of genetic diversity across the species’ range. Results Haplotypic diversity was generally high throughout the natural range of P. cembra, with the mean value substantially higher in the Carpathians (H = 0.53) than in the Alps (H = 0.35). The isolated Carpathian populations showed the highest haplotype diversity among the populations originating from the High Tatras (Velka Studena Dolina) and South Carpathians (Retezat Mountains). AMOVA revealed that only 3% of the total genetic variation derived from genetic differentiation between the two mountain ranges. Differentiation among Carpathian populations was higher (F_ST = 0.19) than among Alpine populations (F_ST = 0.04). Low, but significant, correlation was found between the geographical and genetic distances among pairs of populations (r = 0.286, P < 0.001). SAMOVA results revealed no evident geographical structure of populations. barrier analysis showed the strongest differentiation in the eastern part of the species’ range, i.e. in the Carpathians. Main conclusions The populations of P. cembra within the two parts of the species’ range still share many cpDNA haplotypes, suggesting a common gene pool conserved from a previously large, continuous distribution range. Carpathian populations have maintained high haplotypic variation, even higher than Alpine populations, despite their small population sizes and spatial isolation. Based on our results, we emphasize the importance of the Carpathian populations of Swiss stone pine for conservation. These populations comprise private haplotypes and they may represent a particular legacy of the species’ evolutionary history.     

Genetic variability of tall junipers (Juniperus excelsa Bieb.) on the northern and southern boundaries of their natural distribution

The genetic structure, subdivision, and differentiation of six populations of tall junipers (Juniperus excelsa Bieb.) in the Crimean Mountains and one population in Lebanon were investigated using 18 polymorphic allozyme loci as genetic markers. A high level of genetic variability of J. excelsa was established at the northern and southern boundaries of their natural habitats. The mean values of the main indicators of genetic polymorphism were P₉₉ = 1.000, A = 3.167, H_E = 0.370, and H_O = 0.405. The subdivision and differentiation of populations were low (F_ST = 0.032, D_N = 0.026), indicating the similarity of their gene pools.     

Genetic structure of populations of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> (L.) Karst. from Ukrainian Carpathians

The genetic diversity, subdivision, and differentiation of nine populations of Norway spruce (Picea abies (L.) Karst.) in Ukrainian Carpathians were studied using electrophoretic analysis of variability of enzyme systems in 346 trees aged from 80 to 150 years. Based on electrophoretic fractionation of enzymes extracted from seed endosperms in vertical slabs of 7.5% polyacrylamide gel, 20 loci of nine enzyme systems (ADH, ACP, DIA, GDH, GOT, MDH, LAP, FDH, SOD) were identified, and 71 allele variant were revealed. Each tree was heterozygous on average in 15.8% of its genes. The populations were characterized by low subdivision (F _ST = 0.017) and differentiation (D _N = 0.005). The main contribution to heterogeneity of population genetic structure was made by loci Dia-3, Lap-1, and Sod-3. Clustering and multivariate analysis revealed no observed trends in geographical or altitudinal position of the populations.     

Microsatellite loci polymorphism of chloroplast DNA of scots pine (Pinus sylvestris L.) in Asia and eastern Europe

The variability of four microsatellite loci of chloroplast DNA was studied in 38 populations of Pinus sylvestris in the European part of Russia, in Siberia, Kazakhstan, Transbaikalia and Mongolia. High variability was observed in all regions. In total, 152 haplotypes were identified. The level of population differentiation R _ST was 2.1%. The differentiation of three geographical groups of populations (European, Siberian-Kazakhstan and Transbaikalian-Mongolian) was insignificant (R _CT = 0.004). At the same time, some rare haplotypes were found to be specific for a certain geographical region. Distribution of the rare haplotypes, which differentiated European populations from Asian populations and Mongolian and Transbaikalian populations from the Siberian, showed the independence of the history of these regions. This corresponds more to the hypothesis that the modern area of Pinus sylvestris originated via settlement from many origins than to the hypothesized single center of the post-glacial recolonization. The distribution of the pairwise differences between the individual specimens corresponded to the model of sudden population growth. The assessments of the age of this event for Pinus sylvestris (4.5–4.7 million years), which were obtained on the basis of this model, significantly exceeded the age of the Quaternary. Therefore, the revealed population growth is hardly due to the changes in flora related with the glaciation, but rather mirrors the moment of the species formation.     

Genetic variability of natural populations and man-made stands of common pine (Pinus sylvestris L.) in Kremenets Hills and Maloe Polese

Comparative analysis of 19 allozyme loci of Pinus sylvestris L was performed on three relic populations and six uneven-aged man-made stands to evaluate genetic variability of common pine in Kremenets Hills and Maloye Polesye. Low heterozygosity was characteristic of all natural populations and of four forest stands (H_o = 0.182–0.205), whereas in two forest stands the level of heterozygosity was noticeably higher (H_o = 0.245–0.300). Both allelic and genotypic variability of natural populations was reproducible in the man-made forest. However, the genetic distance between forest stands and natural populations was considerably higher than that among three natural populations (D_Nav = 0.014 and D_Nav = 0.003, respectively).     

Morphological and molecular analyses of Leafhopper,Amrasca biguttula (Ishida) (Hemiptera: Cicadellidae) infesting eggplant (Solanum melongena L.) in Luzon Island,Philippines

Eggplant (Solanum melongena L.) is the leading vegetable grown and consumed in the Philippines, and the eggplant leafhopper is one of its most important insect pests. Nine local populations of leafhopper infesting eggplants were collected from major eggplant growing areas in Luzon Island to determine if these populations are constituted singly or by different species and to assess the level of variability among them. Morphological analysis of the adult male abdominal and genital traits and partial mitochondrial COI gene sequence identified the eggplant leafhopper populations in Luzon Island as belonging to Amrasca (=Sundapteryx) biguttula (Ishida) (Hemiptera:Cicadelliae). Observed male specimens exhibited modifications in the pregenital abdominal tergites VII and VIII that were previously reported to not be found in other Amrasca species. Principal Component Analysis of four morphometric genital traits revealed high similarity among the leafhopper populations regardless of eggplant production areas. Partial COI sequence analysis idenfitied 11 sequence variants (haplotypes), with one predominant haplotype. Overall, the leafhopper populations from Luzon Island exhibited moderate haplotype diversity and low nucleotide diversity, indicating low genetic diversity. Topologies from a maximum likelihood tree indicate all eleven haplotypes cluster in a single clade with other A. biguttula infesting cotton and potato in India, but the Philippine population forms a separate subgroup although with weak bootstrap support. Further analysis with the Generalized Mixed Yule Coalescent (GMYC) method classified the different haplotypes into a single GMYC entity.     

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.     

Developmental stability is not disrupted by extensive hybridization and introgression among populations of the marine bivalve molluscs Mytilus edulis (L.) and M. galloprovincialis (Lmk.) from south-west England

The effects of hybridization and introzgression were assessed among two naturally hybridizing bivalve molluscs (the mussels Mytilus edulis and M. galloprovincialis) from western Europe to estimate how disruptive these processes are to developmental stability (measured in terms of morphological variability). Ten shell traits were measured for 392 mussels from four allopatric populations (two each of At. edulis and At. galloprovincialis) and two hybrid populations. An index of variability (defined as Z_i= |y_i–y_i where y_; is the population mean of the length-standardized trait, and y_i is the individualcar;s length-standardized trait value) was constructed for each trait, and for the sum of the traits. The hybrid populations did not exhibit greater mean variability than the allopatric populations for any of the indices. Upon pooling, the hybrid populations had significantly lower variability than the pooled M. edulis populations and the pooled M. galloprovincialis populations in two analyses, and had similar means in the remaining nine analyses. Where significant differences existed, the pooled M. galloprovincialis had lower levels of mean trait variability than the pooled M. edulis. Among the two hybrid populations, the putative Fl hybrids and backcross individuals exhibited means of trait variability which were similar to those of the parental types. Thus, extensive hybridization and introgression do not adversely affect developmental stability among these mussel populations. There was a strong significant correlation between the ranking of indices (based on the amount of variability) across all six populations, indicating that a large genetic component determines the measured morphological variability. It is concluded that the genes or gene complexes which control morphological development in M. edulis and M. galloprovincialis arc very similar, providing further evidence of the close evolutionary relatedness of these mussel taxa.     

Population genetic structure of wild daffodils (Narcissus pseudonarcissus L.) at different spatial scales

We studied the population genetic and clonal structure of the endangered long-lived perennial plant Narcissus pseudonarcissus using random amplified polymorphic markers. Estimates for mean gene diversity within 15 populations of N. pseudonarcissus of three neighbouring geographical regions were high in comparison to other long-lived perennials (H _eN = 0.33). The genetic diversity of the two smallest populations (<200 plants) was significantly reduced, indicating loss of genetic variability due to drift. The analysis of the population genetic structure revealed a significant genetic differentiation both between regions (Φ_ST = 0.06) and between populations within regions (Φ_ST = 0.20). However, there was incomplete correspondence between geographical regions and the population genetic structure. In order to preserve the overall genetic variation in wild populations of N. pseudonarcissus, management measures should thus aim to protect many populations in each region. The spatial genetic structure within populations of N. pseudonarcissus was in agreement with an isolation by distance model indicating limited gene flow due to pollinator behaviour and restricted seed dispersal. The very restricted spatial extent of clonal growth (<5 cm) and the high level of clonal diversity indicate that clonal growth in N. pseudonarcissus is not an important mode of propagation and that management measures should favour sexual reproduction in order to avoid further reductions in the size and number of populations.     

Can gene flow among populations counteract the habitat loss of extremely fragile biotopes? An example from the population genetic structure in Salix daphnoides

Wild river gravel banks (RGB) represent an extremely fragile biotope that is significantly endangered by human activities due to its fragmentation over the past century. The consequences of such processes were studied using the endangered violet willow (Salix daphnoides) at the westernmost foothills of the Carpathian Mountains. We quantified population genetic characteristics for 14 ecologically and demographically characterised populations using simple sequence repeats (SSR) and amplified fragment length polymorphism (AFLP) markers. We found a significant correlation between the biotope, sex, age and genetic structure of the populations. The natural RGB populations revealed high genotypic variability when using SSR markers, in contrast to low genotypic variability of the populations of other biotopes of Cirsium wet meadows (CWM) and Ash-alder forests (AAF) that consisted of one to two clones at each site. High heterozygosity (H _obs?=?0.428–0.532) was similar across all natural (RGB) populations; however, these populations were deficient in heterozygotes (F _IS/ρ _IS?>?0). All RGB populations exhibited moderate to very significant genetic differentiation for microsatellites, despite the fact that the AFLP data showed strong differentiation only between CWM and AAF populations. Division into clusters by Structure confirmed consistent geographic groups for the RGB populations. According to our results, the strong decrease in previously continuous and large natural habitats for the violet willow is slightly counterbalanced by among-population gene flow. However, the survival of natural populations is tightly linked to the presence of river gravel banks and bars. Strict protection of this habitat is therefore essential for the conservation of the species.     

Genetic diversity within and among the wild populations of Murraya koenigii (L.) Spreng., as revealed by ISSR analysis

Murraya koenigii (L.) Spreng., commonly known as curry leaf plant, is found in the different hilly regions of India. In the present study, fifty-nine accessions representing eight wild populations of M. koenigii were analyzed using thirteen ISSR primers. A total of 152 bands were amplified, out of which, 136 were polymorphic corresponding to 89.47% polymorphism across the accessions. The pairwise population genetic distances were calculated for all the populations that varied from 0.05 to 0.13 between the populations of M. koenigii. AMOVA and Nei’s genetic diversity analysis revealed higher genetic variations within populations than among the populations. The clustering of populations in the dendrogram was not in congruence with geographical affiliations. The results indicate that the ISSR method is sufficiently informative and powerful to estimate the genetic diversity in M. koenigii populations. As M. koenigii is an important wild plant genetic resource, therefore, information on genetic variability might be a potential source as breeding material for development of commercially valuable traits in M. koenigii plants.     

Allozyme Polymorphism of Swiss Stone Pine <Emphasis Type="Italic">Pinus cembra</Emphasis> L. in Mountain Populations of the Alps and the Eastern Carpathians

Swiss stone pine Pinus cembra L. is a species with fragmented range, occurring in the Alpine-East Carpathian mountain system. Seeds of P. cembra are dispersed by nutcrackers, which offers potential possibilities for gene exchange among populations. Using isozyme analysis, we have examined five samples from two parts of the Swiss stone pine range: the Alps (Switzerland and Austria) and the Carpathians (two samples from the northern macroslope of the Gorgany Ridge, Eastern Carpathians, Ivano-Frankivs'ka oblast and one sample from Zakarpats'ka oblast of Ukraine). The allele frequencies of 30 isozyme loci, coding for enzymes ADH, FDH, FEST, GDH, GOT, IDH, LAP, MNR, MDH, PEPCA, 6-PGD, PGI, PGM, SDH, SKDH, SOD, were analyzed using cluster analysis and Principal Component Analysis. Two clusters, corresponding to the isolated Alpine and Carpathian parts of the range, were found. The main contribution to these differences were made by loci Adh-1, Adh-2, Fest-2, Lap-3, Mdh-4, and Sod-4. The interpopulation differentiation proved to be somewhat higher than that typical for pines (F_ST = 7.4%), but within the limits characteristic for taxonomically close species. Thus, isolation of the populations did not lead to their marked differentiation, which may be explained by gene flow and balancing selection, which equalizes gene frequencies across the fragmented species area. Interlocus (F_ST heterogeneity (from 0.003 to 0.173) suggests adaptive significance of some of the allozyme polymorphisms or linkage of some loci with adaptive genes. The Carpathian populations were shown to have higher gene diversity than the Alpine ones (expected heterozygosities 0.095–0.114 and 0.060–0.080, respectively). A deficiency of heterozygotes (as compared to the Hardy-Weinberg proportions), observed in the embryo sample, was probably explained by inbreeding. The reduction in the area of Carpathian pine forests in Holocene, caused by the global climatic changes and the anthropogenic impact, is hazardous for the gene pool of the species. The maintenance of genetic uniqueness of both Carpathian populations of P. cembra in general, and individual stands in particular, requires special measures for protection of Swiss stone pine in the Eastern Carpathians.     

Genetic structure, subdivision, and differentiation in stankewiczii pine (Pinus stankewiczii (Sukacz.) Fomin) populations from mountainous Crimea

In order to analyze the genetic structure, subdivision and differentiation within and between two small isolated populations of the Crimea relict endemic, Pinus stankewiczii (Sukacz.) Fomin, electrophoretic analysis of the isozyme variation at nine enzymatic systems was carried out using 183 oldest trees. It was demonstrated that in populations of P. stankewiczii, 80% of the genes were in polymorphic state. Each tree was heterozygous at 19.1% loci, and at 21.6% loci in artificial 50-year-old plantation. The genetic structure of two populations was less differentiated (D _N = 0.006), compared to their individual localities (D _N = 0.008?0.009). Within-population subdivision of the diffusely dispersed populations was higher (F _ST -G _ST = 1.8–2.0%) than that of the populations themselves (0.8%).     

Genetic variability and population structure of grey wolf (<Emphasis Type="Italic">Canis lupus</Emphasis>) in Serbia

Results of previous morphometric and genetic analyses of grey wolf (Canis lupus L.) population from Serbia indicated different patterns of population subdivision. In order to explore population structure, level of genetic variability, genetic drift, inbreeding and signals of bottleneck for grey wolves from Serbia, we applied highly polymorphic genetic markers (microsatellites). Obtained data are valuable in determination of conservation units and creation of appropriate management plans. We have amplified 18 highly polymorphic microsatellites, in a total sample of 75 grey wolves, from different localities across Serbia and multilocus genotypes were analyzed using appropriate software. Observed values of the basic genetic parameters (H_O = 0.69; H_E = 0.75) indicated moderate level of genetic variability, similar to genetic variability in other populations belonging to the Dinaric-Balkan population of grey wolf. In STRUCTURE analysis, although ΔK was estimated to be at first peak K = 2, and second peak K = 4, CLUMPAK analyses showed that there’s no structuring for any of assumed K, and therefore the population of grey wolf from Serbia may be considered as one continuous population and treated as one conservation unit in future management plans. Signals of bottleneck haven’t been observed (Wilcoxon test two phase mutation model p = 0.247; and stepwise mutation model p = 0.815).     

Impacts of laurel wilt disease on redbay (Persea borbonia (L.) Spreng.) population structure and forest communities in the coastal plain of Georgia, USA

Laurel wilt disease (LWD), a fungal disease vectored by the non-native redbay ambrosia beetle (Xyleborus glabratus Eichhoff), has caused mortality of redbay (Persea borbonia (L.) Spreng.) in the coastal plain of Georgia since 2003. Despite its rapid spread, little research has evaluated its impacts on redbay population structure and forest communities. Diseased populations of redbay in five sites (2–4 years post infestation) were compared to healthy populations in three uninfested sites in five counties in Georgia. The results showed high redbay mortality, shifts in size structure, and changes in community composition. An average of 90 % of redbay trees ≥3 cm diameter at breast height (DBH) were dead in infested sites, compared to 0–35 % in control sites. Mortality was seen in individuals of the smallest stem diameter category (<1.00 cm diameter at ground height). DBH of live redbay trees in control sites was twice that of those in infested sites. Photosynthetically active radiation was 4.8 times greater at infested sites than control sites due to loss of redbay canopy. Community structure measurements showed redbay trees had the greatest mean importance value (IV) at control sites compared to the 8th mean IV at infested sites for live stems. Two species co-dominant to redbay, sweetbay (Magnolia virginiana L.) and loblolly bay (Gordonia lasianthus (L.) J. Ellis), were of higher importance at infested than control sites, suggesting they are increasing in dominance following the mortality of redbay. This study shows LWD has impacted redbay populations and altered associated forest communities in Georgia.     

Distribution of genetic variability in southern populations of Scots pine (Pinus sylvestris L.) from the Alps to the Apennines

Alpine and Northern Apennine populations of Pinus sylvestris collected from eight different Italian sites were analyzed by mitochondrial nadI intron and InterSimple Sequence Repeat (ISSR) markers, in order to describe the natural level of genetic variability and to clarify their genetic relationships. The small Northern Apennine populations are the southernmost populations of this conifer in Italy. All the analyzed populations were spontaneous and reforested areas were excluded. The analysis of the polymorphisms in the nad 1 intron sequence confirmed that the Italian P. sylvestris populations have the same mitotype (mitotype a) as the Central European ones. In the genomic ISSR analysis the proportion of shared alleles between the individuals showed the highest degree of differentiation between French and Italian populations and a divergence between the Alpine and Apennine populations. Alpine populations showed a higher genetic variability (GD 0.310±0.0252) than Apennine samples (GD 0.217±0.019). In addition, the individuals from the Apennines did not show a clear population structure, suggesting a common genetic constitution of Apennine P. sylvestris. It is likely that this constitution is the result of a progressive genetic isolation between the Alpine and the Northern Apennine populations from the early Holocene. The genetic constitution of the Northern Apennine populations suggests the opportunity of a management where in situ conservation of such small populations could be coupled to their use as sources of suitable local reforesting materials.     

Morphological variation and population dynamics of Bosmina (E.) longicornis kessleri Uljanin (Crustacea: Anomopoda: Bosminidae) in the Bukovec Reservoir (S.E. Slovakia)

Bosmina (Eubosmina) longicornis kessleri and B. (Bosmina) longirostris are minor components among the crustacean zooplankton in the pelagial of Bukovec Reservoir. B. (E.) l. kessleri is a recent colonist in the Carpathian region and was first found in the Bukovec reservoir in 1986. The present study gives some information about the niche occupied by B. (E.) l. kessleri in the zooplankton community; the seasonal abundance of zooplankton and phenotypic variability (cyclomorphosis) of B. (E.) l. kessleri are also examined.     

Population structure and genetic analysis of different utility types of mango (Mangifera indica L.) germplasm of Andhra Pradesh state of India using microsatellite markers

Genetic analysis of 90 mango genotypes including juicy, table, dual and pickle types from different parts of Andhra Pradesh of India was carried out employing 143 mango-specific microsatellite markers. Of the 143, 34 were new mango-specific microsatellite loci isolated in the course of the present investigation by constructing an (CA) _n and (TG) _n -enriched genomic library. Characterization of the 90 genotypes resulted in the detection of 301 alleles from 106 polymorphic loci with an average of 2.87 alleles per locus and polymorphism information content of 0.67. UPGMA cluster analysis grouped all the genotypes into two major groups with a genetic similarity range of 47–88 %. Grouping of the genotypes based on the utility type was observed only at sub-cluster level. Study of population structure by a model-based STRUCTURE analysis revealed the germplasm to exist in four gene pools. Overall F _st of 0.11 indicated genetic differentiation between the populations to be low. Analysis of molecular variance revealed that major proportion of the variation was within the individuals (62.25 %). The molecular marker-based study of genetic diversity suggests that the germplasm studied representing the kind of variability would be a valuable genetic resource for future breeding and association mapping in search for new and novel alleles.