Katalin Pecsenye

Genetic variations in space and time in Parnassius mnemosyne (L.) (Lepidoptera) populations in north-east Hungary: implications for conservation

Abstract The population structure of the clouded Apollo butterfly Parnassius mnemosyne was investigated by mark–release–recapture studies and by allozyme polymorphism in north-east Hungary. Large differences were observed in the estimated sizes of different populations. The results of the genetic analysis suggest that even large populations may have small effective population sizes, due to uneven sex ratio, recent bottlenecks and founder effect. The results of both the genetic and MRR studies indicated that the Bukk populations exist as a metapopulation. However, populations from different geographical regions were highly differentiated, indicating restricted gene flow between them. Loss of genetic variability was observed in a small, isolated population. Practical advice is given on how to manage woodland to maintain genetic diversity; it is concluded that many small clearings made close to existing habitat patches is superior to making fewer, larger clearings.

Allozyme variation in Parnassius mnemosyne (L.) (Lepidoptera) populations in North-East Hungary: variation within a subspecies group

Allozyme polymorphism was studied in 11 Parnassius mnemosyne (Linnaeus, 1758) populations in North-East Hungary. Significant departures from Hardy-Weinberg equilibrium were observed in several cases due to heterozygote deficiency. Genetic variability did not display geographical pattern; the level of genetic differentiation was similar between adjacent populations and between populations originating from different geographical regions. Even a completely isolated population was not differentiated markedly from the others. Thus, genetic drift can be expected as the main evolutionary force acting in the populations.

Oviposition preferences of Maculinea alcon as influenced by aphid (Aphis gentianae) and fungal (Puccinia gentianae) infestation of larval host plants

Abstract 1. The influence of infestation of the larval host plant Gentiana cruciata on the egg‐laying preferences of the xerophilous ecotype of Alcon Blue butterfly (Maculinea alcon) was studied in a semi‐dry grassland area (Aggtelek Karst Region, Northern Hungary).

Heritabilities and additive genetic variances of the activities of some enzymes in Drosophila melanogaster populations living in different habitats

Drosophila melanogaster samples were collected from a large population in two habitats: farmyards and distilleries. Samples were taken from two villages in each habitat. Three isofemale lines were established from all four samples and full-sib crosses were set in each isofemale line. Activities of four enzymes (ADH, αGPDH, IDH and 6PGDH) were measured in the offspring of each cross on starch gel after electrophoresis. Broad sense heritabilities and additive genetic variances were estimated in all four samples.Most of the activity variation was observed within the isofemale lines. The isofemale lines tended to be more different in the distilleries than in the farmyards. There was no significant difference in the average activities between the two habitats for any of the enzymes investigated. The additive genetic variance of the enzyme activities did not exhibit a consistent habitat pattern. In the farmyard habitat, we detected a higher activity variation in Tiszafüred than in the other village. Strong correlation was observed among the activities of the enzymes investigated. Correlation coefficients indicated higher level of correlation in the samples collected in Tiszafüred than in those originating from Tiszaszőlős. The heritability values were rather high and they had a considerable variation both between the habitats and across the enzymes.

Genetic structure of Parnassius mnemosyne (Lepidoptera: Papilionidae) populations in the Carpathian Basin

The pattern of genetic variation in a butterfly species depends on the past history of the given species and also on recent evolutionary processes affecting its populations. The aim of the present study was (i) to analyse the enzyme polymorphism in the Clouded Apollo populations of the Carpathian Basin to reveal the contemporary pattern of their genetic differentiation and (ii) to compare it with an expanded mitochondrial DNA (mtDNA) haplotype network of the SE European populations. Allozyme polymorphism was analysed in 22 populations of four geographic regions: Transdanubian (TM) and North Hungarian Mountains (NM), Körös (KÖR) and Bereg–Apuseni–East Carpathian regions (BEAC). The results of the Bayesian clustering analyses based on allozymes supported the presence of three main genetic lineages in the Carpathian Basin: One was typical for TM, another was characteristic for NM and the third cluster was predominant in KÖR. The populations of BEAC harboured a mixture of two clusters. The mtDNA haplotype network suggested a fairly similar distribution: The peri-Alpine clade together with the West Balkan clade was detected in TM, while the East Balkan clade occurred in NM, partly in TR and in the two eastern regions of the Basin (KÖR and BAEC). The incongruities between the results of the mtDNA and allozyme studies can be explained by the different timescales represented by the two markers. The mtDNA haplotype network provided strong evidence concerning the existence of two Balkan lineages, which probably formed a ‘zone of admixture’ in the Transdanubian and North Hungarian Mountains. The possibility of Last Glacial survival of Parnassius mnemosyne in the Carpathian Basin and the conservation implications of these results are discussed.

Patterns of genetic and taxonomic differentiation in three Melitaea (subg. Mellicta) species (Lepidoptera, Nymphalidae, Nymphalinae)

In conservation genetics the existence of Evolutionarily Significant Units (ESU) is a crucial question in threatened or vulnerable species. It is of particular concern to determine whether different subspecies or ecotypes of a species can be considered as separate ESUs. Some Melitaea subg. Mellicta species (e.g. Mellicta aurelia, Mellicta britomartis) are declining or scarce in Europe. Therefore, the level of genetic differentiation and pattern of genetic variation were surveyed in three Melitaea (subg. Mellicta) species. Their habitat requirements and food plants partly overlap; accordingly they often co-occur in the same habitat. M. britomartis and M. aurelia have one brood per year in Hungary, while Mellicta athalia has a monovoltine and a bivoltine ecotype. The purpose of the study was to estimate the number of genetically differentiated ESUs among these species in the Carpathian basin. Samples were taken from 5 Hungarian regions and a few samples were collected in Transylvania as well. Enzyme polymorphism was studied using polyacrylamide gel electrophoresis. The structure of genetic variation was analysed by F-statistics, AMOVA, PCA and Bayesian clustering method. UPGMA dendrogram was constructed on the basis of Cavalli-Sforza and Edwards chord distances. The three species are clearly differentiated from each other in all statistical analyses. They are evidently different Evolutionary Significant Units. The two ecotypes of M. athalia, however, do not show any genetic differentiation.

Enzyme polymorphism inDrosophila melanogaster populations collected in two different habitats in Hungary

The level of enzyme polymorphism was compared in tenDrosophila melanogaster populations collected in farmyards and distilleries in two regions of Hungary. The total genetic diversity was partitioned into between-and within-population components at each investigated locus using Wrights F-statistics. Population differentiation was studied in two different ways. Genetic distances between pairs of populations were calculated and a hierarchical analysis of gene diversity was performed. Based on the F values gene flow was estimated among the populations at different levels of the hierarchy. The results indicated that our ‘farmyard populations’ collected within a region could be considered as parallel samples from a panmictic population rather than samples of distinct populations. In distilleries, the flies might be influenced by two different evolutionary forces: (i) selection due to the extremely high concentration of ethanol in the fermenting mash and (ii) genetic drift due to the combination of repeated founder effects and fluctuating population size. Our results suggested that ‘distillery populations’ could not be regarded as real populations either. They could be considered as peculiar cases: founder individuals taken from the total population (region) established special populations which survived in the distilleries for many generations. Thus the dominating force acting on the ‘distillery populations’ was genetic drift.

Pattern of genetic differentiation in two Isophya species (Orthoptera: Tettigonoidea) in north-east Hungary

Allozyme polymorphism was studied in two populations of Isophya kraussi and Isophya stysi. Both species are flightless and have low dispersal ability. As a consequence, we expected high level of genetic differentiation among their local populations. Samples were collected in three regions of Hungary. Enzyme polymorphism was investigated at 10 loci (Aldox, Est, Got, αGpdh, Hk, Idh, Mdh, Me, Pgi and Pgm) in both species. High levels of polymorphism were detected in all samples. αGpdh proved to be diagnostic as there were no common alleles in the two species. At four further loci (Got, Hk, Mdh and Me), the two species had one common allele together with one or more differentiating alleles. We detected high FIT values implying a high level of genetic variation. The positive FIS values suggested a tendency of heterozygote deficiency in both species. The highly significant overall FST values indicated clear genetic differentiation among the local populations. Thus our results confirmed the taxonomic status of these two species. The dendrogram constructed on the basis of Neis genetic distances and the results of the PCA analyses fully confirmed those obtained by F-statistics.

Regional pattern of genetic variation in the Eastern Central European populations of Euphydryas maturna (Lepidoptera: Nymphalidae)

The aim of this study was to delineate functional conservation units (FCUs) in Scarce Fritillary Euphydryas maturna (Linnaeus, 1758) populations in eastern Central Europe. We analyzed the level and structure of genetic variation using allozymes as markers in 26 Scarce Fritillary populations originating from nine geographic regions. Considering the reproductive strategy of E. maturna, we assumed that populations are strongly exposed to genetic drift. Accordingly, we hypothesized: (i) A low level of genetic variation within populations, and; (ii) A high level of differentiation among them with little evidence of geographic pattern. The results of this study mostly fulfilled our expectations: (i) Scarce Fritillary populations of eastern Central Europe exhibited a relatively low level of polymorphism at investigated enzyme loci, and; (ii) Comparatively strong differentiation was detected among populations. As opposed to our expectation, however, a more-or-less clear pattern of differentiation was revealed by the results of our Bayesian-clustering analysis. Four genetic regions were distinguished on the basis of their average cluster membership coefficients, specifically Dobrogea (Romania), North and East Hungary (composed of four geographic regions), Central and West Hungary (involving three geographic regions), and Transylvania. Three of these genetic regions were previously distinguished as separate subspecies, comprising E. maturna idunides (Central and West Hungary), E. maturna partiensis (North and East Hungary including Transylvania), and E. maturna opulenta (Dobrogea, Romania). These three putative subspecies can be considered as Scarce Fritillary FCUs in eastern Central Europe.

Loss of genetic variation in declining populations of Aricia artaxerxes in Northern Hungary

Rapid decline of population size often gives rise to loss of genetic variation and may result in a reduction in fitness. It is, therefore, essential to detect past demographic changes in populations of endangered species. Aricia artaxerxes occurs in two regions of Northern Hungary: Bükk Mts. and the Aggtelek Karst region. The species prefers short-grass habitats, which are subject to succession. Due to climatic differences between the two regions succession is more rapid in the Bükk plateau resulting in the decline and isolation of A. artaxerxes populations there. In contrast, most populations have remained rather large and stable in the Karst region. This situation provides an excellent possibility to compare the genetic composition of stable and declining populations. A. artaxerxes was collected in four populations of the Bükk Mountains and in ten in the Aggtelek Karst region in 2002 and 2005. We analysed 19 polymorphic allozyme loci in all samples. The results revealed an extremely high level of enzyme polymorphism in A. artaxerxes. Most parameters of polymorphism proved to be significantly higher in the Karst region compared to the Bükk. The shape of the distribution of alleles among the frequency classes indicated the effect of bottleneck in three Bükk and one Karst population. Though heterozygote excess was only significant in one Bükk population a tendency was observed for higher values of standardised heterozygote excess in those populations that had a typical bottleneck distribution of alleles. Our results clearly demonstrated that those populations/subpopulations that compose a network with intense migration are able to maintain their genetic diversity in a long run, while the isolated small populations of the Bükk plateau have lost a sizeable part of their variation.