Isoenzyme Loci Research Articles

The growth rate and genetic variability of Scots pine (Pinus sylvestris L.) half-sibs in test crops of Northern Kazakhstan

Scots pine (Pinus sylvestris L.) is a valuable tree species, playing an important role in maintaining the ecological and economic balance not only in Kazakhstan, but also in many countries around the world. The purpose of this study was to assess the growth rate and to identify the genotypes of the half-sib progeny of Scotch pine plus trees in order to further obtain high-quality seeds with valuable genetic traits. A molecular genetic analysis was carried out using six microsatellite and 20 isoenzyme loci on 15 Scots pine half-sib families, represented by two samples of seeds collected in the subsequent harvesting periods (planted in 1986 and 1987), that evaluated the taxonomic characteristics such as tree height and trunk diameter (DBH, measured at 1.3 meters). Families with the highest growth rate in both samples were selected as candidates for the elite group. During the SSR analysis, a decrease in the level of expected heterozygosity (0.2377-0.5362 with an average value of 0.4593) was observed in P. sylvestris L. half-sibs compared to the sample of maternal plus trees (0.5444), with similar results to that of the “founder effect”. At the same time, the level of observed heterozygosity remained sufficiently high (0.3333-0.7037 with an average value of 0.4980 and 0.4556, respectively). During the isoenzyme analysis, the level of genetic variability either decreased or was similar to that of the maternal trees. Rare and unique alleles were found in seed samples of the analysed tree families. In general, this research showed that a comprehensive evaluation combining both traditional breeding methods (genetic assessment of progeny in the course of growth) and molecular genetic analysis is required for the selection of elite trees.

The analysis of the variability of morphogenetic traits in the populations of <i>Helix pomatia </i>(Linnaeus, 1758) from Belgorod and Lugansk regions

The state of three populations of the adventitious species H. pomatia was studied on the basis of conchiometric, phenetic and genetic methods. According to the obtained data, the two newly described populations from the Belgorod and Lugansk regions differ both in metric and morphological indicators, as well as in the frequencies of alleles of isoenzyme loci. The reason for such disparity may be genetic-automatic processes, natural selection in newly developed territories, as well as chaotic invasion from various localities, either from native range, or from nearby biotopes.

Gene pool state and degree of infestation by bark beetle (Ips tipographus L.) of Norway spruce (Picea abies L. Karst.) natural populations and planted stands in Moscow region

A comparative analysis of the gene pool state in natural populations and planted stands of Norway spruce and the degree of their infestation by the bark beetle in the Moscow region was conducted taking into account the dynamic state of communities (4 populations, 148 samples, 24 isoenzyme loci). The degree of infestation by the bark beetle of conditionally native communities is 0%; for planted stands, it is 90–100%; and for a short-term community, it is 15–20%. The comparison of “healthy” populations and those infested with bark beetle by average values of observed heterozygosity (H O) detected no significant differences. However, the test on allelic frequency heterogeneity demonstrated the difference of planted stands from conditionally native populations both by three loci (Fe-2, Idh-1, Mdh-3) and by the totality of 18 polymorphic isoenzyme loci; the short-term population differs from conditionally native population only by two loci. The value of the inbreeding coefficient by the Idh-1 locus is significantly higher in both populations infested with the bark beetle than in “healthy” populations. The results of conducted studies demonstrate the necessity of continuation of the study on the gene pool state in Norway spruce populations owing to the degree of their infestation by the bark beetle along with the study on the dynamic state of the communities; this can provide a key to solving the problem of the forest preservation from pests.

Peculiarities of Trypanosoma rangeli KP1(-) Strains Isolated from the Wild Rodent Phyllomys dasythrix (Santa Catarina, Brazil): Comparisons with T. rangeli KP1(+) strains and Trypanosoma lewisi (Kinetoplastea, Trypanosomatidae)

Two KP1(–) strains of Trypanosoma rangeli (SC-58, SC-61) isolated from the wild rodent Phyllomys dasythrix from Santa Catarina (Brazil) were compared with some KP1(+) reference stocks from different Latin America countries, and also with Trypanosoma lewisi. The strains were analyzed by some morphological and biological features, and by biochemical and molecular techniques. The mean total length (TL) of the bloodstream trypomastigotes of T. rangeli varied between 31.3–33.0 μm, and those of T. lewisi (adult forms) was 28.2 μm, values within the variation known for each species. In T. rangeli KP1(+) and T. lewisi, the nucleus was located in the anterior portion of the body, with nuclear indexes (NI) ≥ 1.2, as typically described for both species. Differently, most trypomastigotes of the KP1(–) stocks presented NI ≤ 1.0. Another striking feature of the KP1(–) strains was their very fastidiously growth in axenic cultures when compared with the KP1(+) stocks and T. lewisi. Three isoenzyme loci (MDH, IDH and PGM) clearly distinguished T. rangeli and T. lewisi, and the distinction between the KP1(+) and KP1(–) strains was possible at MDH, PGM and GPI loci. All T. rangeli strains presented the typical 760 bp amplicon derived from their KP2 minicircles. However, the KP3 products of the KP1(+) strains were a single large band (~330bp), whereas those of the KP1(–) had two distinct bands (350 and 300 bp). T. lewisi presented 700 and 400 bp amplicons, as previously reported. The peculiarities of T. rangeli isolates from P. dasythrix corroborate a possible speciation process within this taxon.

Discriminating micropathogen lineages and their reticulate evolution through graph theory-based network analysis: the case of Trypanosoma cruzi, the agent of Chagas disease.

Micropathogens (viruses, bacteria, fungi, parasitic protozoa) share a common trait, which is partial clonality, with wide variance in the respective influence of clonality and sexual recombination on the dynamics and evolution of taxa. The discrimination of distinct lineages and the reconstruction of their phylogenetic history are key information to infer their biomedical properties. However, the phylogenetic picture is often clouded by occasional events of recombination across divergent lineages, limiting the relevance of classical phylogenetic analysis and dichotomic trees. We have applied a network analysis based on graph theory to illustrate the relationships among genotypes of Trypanosoma cruzi, the parasitic protozoan responsible for Chagas disease, to identify major lineages and to unravel their past history of divergence and possible recombination events. At the scale of T. cruzi subspecific diversity, graph theory-based networks applied to 22 isoenzyme loci (262 distinct Multi-Locus-Enzyme-Electrophoresis -MLEE) and 19 microsatellite loci (66 Multi-Locus-Genotypes -MLG) fully confirms the high clustering of genotypes into major lineages or “near-clades”. The release of the dichotomic constraint associated with phylogenetic reconstruction usually applied to Multilocus data allows identifying putative hybrids and their parental lineages. Reticulate topology suggests a slightly different history for some of the main “near-clades”, and a possibly more complex origin for the putative hybrids than hitherto proposed. Finally the sub-network of the near-clade T. cruzi I (28 MLG) shows a clustering subdivision into three differentiated lesser near-clades (“Russian doll pattern”), which confirms the hypothesis recently proposed by other investigators. The present study broadens and clarifies the hypotheses previously obtained from classical markers on the same sets of data, which demonstrates the added value of this approach. This underlines the potential of graph theory-based network analysis for describing the nature and relationships of major pathogens, thereby opening stimulating prospects to unravel the organization, dynamics and history of major micropathogen lineages.

Low level of isoenzyme variation in an island population of Juniperus oxycedrus subsp. macrocarpa (sm. ex sibth.) ball

The isoenzyme variation in a geographically well isolated population of <em>Juniperus oxycedrus</em> subsp. <em>macrocarpa</em> from Korfu island was investigated. Based on the 18 putative isoenzyme loci a very low level of variation has been observed. In the studied material only 11% (95% criterion) of the loci were polymorphic. The number of alleles per locus was 1.17 and the observed, and expected heterozygosities were 0.016, and 0.024, respectively.

COMPARATIVE PHYSIOLOGICAL AND MOLECULAR STUDY OF SOME SHEEP BREEDS IN SAUDI ARABIA

Naemi, Heri, Najdi and Sawakni sheep breeds inhabiting Kingdom of Saudi Arabia were studied on both physiological and molecular bases. Native polyacryl amide gel-electrophoreses for two enzymes Malate Dehydrogenase (Mdh ) and Malic Enzyme (Me ) recorded 5 isoenzyme loci from which 4 were polymorphic and 1 was monomorphic. Mdh showed three fractions, the first was recorded in Sawakni and Najdi breeds, the second was monomorphic and was recorded in all breeds while the third was recorded in all except H eri. Malic enzyme showed two polymorphic fractions, the first was recorded in Heri and Naemi and the second was recorded in all breeds. Both metabolic enzymes activities were higher in Sawakni than in the nativ e breeds. 607, 227, 498 and 595 bp nucleotides from CO1, ND4, cytb genes and d-loop, respectively, were sequenced with no base substitutions among and/or within breeds except for ND4 gene and d-loop. The molecular tree clustered the three breeds other tha n Naemi in one group and Naemi was basal. Isoenzymes therefore, discriminate clearly the studied breeds although they are not as accurate as molecular tool s indicating their applicability with more efficiency in physiology than in genetics while the d-loop wa s efficient in discriminating the studied breeds phyn otypically.

Genetic variation of isolated and peripheral populations of Pinus sylvestris (L.) from glacial refugia

Analysis of variation at 10 polymorphic isoenzyme loci in 51 European populations of Pinus sylvestris both from its main continuous range and from isolated, marginal populations out of the continuous range, revealed differences in genetic structure. The highest genetic richness, measured as mean number of alleles per locus, was recorded for populations from the Iberian Peninsula, followed by those from Scotland and the Balkans. Marginal, isolated populations were characterized by much greater interpopulation variation than populations from the continuous range of the species. The highest mean observed heterozygosity was recorded for the Iberian populations. The highest gene flow was observed among populations in the continuous range of the species. The populations could be classified into five groups based on genetic similarities. Populations from the continuous range formed one group, those from Spain two groups, pines from Scotland one group and those from the Balkans one group. One population from Scotland was found to be most distinct from the other Scottish pines and was found to be grouped with the Balkan populations. The occurrence and frequencies of rare alleles in the populations showed a characteristic pattern, suggesting that populations from the Iberian Peninsula probably did not participate in the colonization of Europe by Pinus sylvestris after the last glaciation. In contrast, the migration of populations from the Balkan refugium into Central and Western Europe had a significant effect on the contemporary gene pools of populations of Pinus sylvestris in its continuous range.

Genetic profiles and diversity of Baltic spring barley material

Genetic profiles and diversity of Baltic spring barley material The objectives of this study were to generate molecular passport data for identification and differentiation of Baltic spring barley accessions (cultivars, landraces and breeding lines) and to estimate the genetic variation within and among these accessions. Allelic profiles of 21 microsatellite and 8 isoenzyme loci were obtained and analysed for 64 Baltic spring barley accessions. The microsatellite data was successfully used to separate all of the accessions by individual allelic pattern and frequencies, whereas only 30 of the studied accessions could be distinguished by isozyme data. Variation was detected both among and within the accessions and was significant. The variation within accessions accounted for 20.6% and 14.3% of the total variation, based on microsatellite and isozyme data, respectively. The six-rowed and two-rowed material was well differentiated by both types of marker data: according to AMOVA this differentiation accounted for 16.9% of the microsatellite variation and 26.8% of isozyme variation. Differentiation of accessions based on the country of origin could be detected only by isozyme markers and accounted for 9% of the total izozyme variation. Both isozyme and microsatellite data showed that accessions of Latvian origin had the highest total diversity values, while material from Estonia was the least diverse.

Population genetic structure of the noxious weed Amaranthus retroflexus in Central Europe

Genetic variation was assessed in a range of populations of Amaranthus retroflexus using isoenzyme analysis. Population genetic diversity was measured by evaluating patterns of variation at six putatively neutral isoenzyme loci (comprising 24 putative alleles) within and among 20 populations of A. retroflexus collected in different habitats: ruderal habitats, cereal fields and hop gardens. Amaranthus retroflexus is a noxious weed of North American origin that infests various crops. Overall, A. retroflexus displayed moderate levels of genetic diversity in comparison with other herbaceous plants. The percentage of polymorphic loci was 50.0%, with mean values of 2.01, 0.142 and 0.227 for the average number of alleles per polymorphic locus ( A), observed heterozygosity ( H o) and expected heterozygosity ( H e), respectively. A discrepancy between observed and expected heterozygosity and significant differences from H-W expectation indicate that there is an excess of homozygotes in many populations. As a result, there is strong evidence of inbreeding within populations ( F IS = 0.382) and significant population differentiation ( F ST = 0.270). Even though the species is partly autogamous, inbreeding does not lead to strong inbreeding depression resulting from self-pollination, as inbreeding has no effect on the success of the species in today's countryside. Moreover, allele frequencies detected in agricultural habitats (i.e., cereal fields and hop gardens) differed from those detected in populations collected from ruderal habitats, which is probably caused by systematic application of herbicides in agricultural ecosystems.

Relationship and genetic diversity of mistletoe (Viscum album L.) subspecies

With the help of 21 putative isoenzyme loci, the genetic diversity and variations of <em>Viscum album</em> ssp. <em>album</em> L. from 42 species, subspecies, varieties and hybrids of broadleaf trees, <em>Viscum album</em> ssp. <em>austriacum</em> (Wiesb.) Vollmann, from 4 populations of Scots pine (<em>Pinus sylvestris</em> L.) and <em>Viscum album</em> ssp. <em>abietis</em> (Wiesb.) Abromeit, from 8 populations of European silver fir (<em>Abies alba</em> Mill.) were analyzed. On the dendrogram, the three investigated subspecies form three clusters, each clearly separated from the other, so we suggest a revision of the systematic nomenclature proposed to take into consideration a return to an earlier system of dividing the European mistletoe into three species: <em>Viscum album</em> L., <em>Viscum abietis</em> Beck, and <em>Viscum laxum</em> Boiss. et Reut. From among the 21 tested loci only one locus, SOD-A, was monomorphic. The average number of actual alleles (Na) and effective alleles (Ne) was 2.23 and 1.61 respectively. The observed heterozygosity (Ho) varied from 0.199 in <em>V. album</em> ssp. <em>abietis</em> to 0.345 in the <em>V.a.</em> ssp. <em>album</em> populations. Average FST = 0.277 indicates that about 28% of genetic differentiation is due to an interpopulation diversity of <em>Viscum album</em> populations. There is a small gene flux between <em>Viscum album</em> populations with only one immigrant successfully entering a population per two generations (Nm = 0,653).

Mismatched Multiplex PCR Amplification and Subsequent RFLP Analysis to Simultaneously Identify Polymorphisms of ErythrocyticESD,GLO1, andGPTGenes*

ESD (esterase D), GLO1 (glyoxalase I), and GPT (glutamate pyruvate transaminase) are human erythrocytic isoenzymes and have previously been applied in forensic medicine caseworks. The molecular bases of the polymorphic gene expression products have been demonstrated to be because of SNPs in respective coding regions. However, it has not been revealed whether the SNPs conferring the polymorphisms to the aforementioned erythrocytic isoenzymes could be simultaneously detected by using a simple PCR method. In this study, we used mismatched primers to simultaneously amplify three common isoenzyme loci so that all amplified products contained the same Hph I cleavage sites. The products were then digested with Hph I and electrophoretically separated and stained so that alleles were identified. The accumulated values for the probability of discrimination power and excluding the probability of paternity to the aforementioned systems attained 90.41% and 41.72%, respectively, in the Chinese Han population. This assay could be extremely valuable for future forensic medicine practices.

GENETIC DIVERSITY OF INTENSIVELY AND EXTENSIVELY MANAGED CHESTNUT (CASTANEA SATIVA) ORCHARDS IN GREECE

Chestnut (Castanea sativa) orchards in Greece can be broadly classified in two categories: intensively managed (commercial cultivars grafted on selected rootstock established on agricultural land in the vicinity of rural communities) and extensively managed (local scions grafted on wild trees demarcating areas within natural forests, away from rural communities). The genetic diversity and multilocus genetic structure of two intensively and two extensively managed orchards is reported and compared based on 17 isoenzyme loci. Results indicated that intensively managed orchards present a high number of unique genotypes (85% of the total number of individuals), while extensively managed orchards have a rather low-number of unique genotypes (21% of the total number of individuals). In one intensively managed orchard, interspecific C. sativa × C. crenata hybrids were identified in 22% of the individuals studied. Genetic diversity parameters were higher in the intensively managed orchards evidently as a result of the higher number of alleles present (mean average number of alleles per locus in the intensively and the extensively managed orchards was 2.31 versus 1.50 respectively). The genetic diversity of intensively managed orchards is comparable to that of adjacent natural populations and higher than the diversity reported in western European orchards. It is postulated that the greater number of unique genotypes in intensively managed orchards may reflect the traditional arboricultural practices of the local growers. It can present an obstacle regarding the nut uniformity for industrial processing; nevertheless it may be beneficial under climatic change scenarios. The implementation of the above results for further selection and breeding is discussed.

Genetic variation in northern marginal Taxus baccata L. populations. Implications for conservation

Summary Taxus baccata L. is a dioecious gymnosperm with a wide but scattered distribution in Europe. Small populations are inclined to genetic drift, and we therefore studied genetic structure in 13 T. baccata populations of the northern range margin in coastal areas of Norway by means of 13 isoenzyme loci. The average observed ( H o ) and expected ( H e ) heterozygosities were 0.143 and 0.150, respectively. The genetic differentiation was considerable ( F st = 0.166), and the derived gene fl ow was correspondingly modest ( N m = 1.26). The fi xation index ( F is ) across all populations was 0.039, but with consistently higher values (0.119 – 0.226) in the northernmost populations, suggesting inbreeding. The poor regeneration, associated with extensive browsing, may impede adaptation to environmental changes. If also the effective population sizes are reduced, drift and differentiation may increase in future generations. Implications for conservation are discussed in light of the genetic structure, longevity and the poor regeneration of the species.

The land-snail species of cochlicopa (Gastropoda: Pulmonata: Cochlicopidae): presentation of taxon-specific allozyme patterns, and evidence for a high level of self-fertilization

Genetic differentiation in the four nominal species C. nitens (Gallenstein, 1848), C. lubricella (Porro, 1838), C. lubrica (O. F. Müller, 1774) and C. repentina Hudec, 1960 was studied by investigating 21 isoenzyme loci. Allozymic markers exist, which clearly separate the first three taxa from each other, including in sympatric areas. By contrast, C. repentina and C. lubrica exhibit almost no isozymic differentiation and therefore, C. repentina should not be considered as a separate species, but as a member of C. lubrica sensu lato. The high frequency of homozygotes within all populations of all species shows that self-fertilization is the main breeding system of Cochlicopa. Genetic relationships between the various populations were inferred with different tree-constructing methods. In all phenograms, populations of C. nitens appear in one distinct cluster, whereas the grouping of C. lubricella changes when different clustering-procedures are used. Therefore, it remains unclear whether the three populations of C. lubricella have a common origin or whether they are polyphyletic with at least two independent ancestors.

A cherry map from the inter-specific cross Prunus avium ‘Napoleon’ × P. nipponica based on microsatellite, gene-specific and isoenzyme markers

One hundred and sixty microsatellite (simple sequence repeat (SSR)) and six gene-specific markers revealing 174 loci were scored in 94 seedlings from the inter-specific cross of Prunus avium ‘Napoleon’ × Prunus nipponica accession F1292. The co-segregation data from these markers were used to construct a linkage map for cherry which spanned 680 cM over eight linkage groups with an average marker spacing of 3.9 cM per marker and just six gaps longer than 15 cM. Markers previously mapped in Prunus dulcis ‘Texas’ × Prunus persica ‘Earlygold’ allowed the cherry map to be anchored to the peach × almond map and showed the high level of synteny between the species. Eighty-four loci segregated in P. avium ‘Napoleon’ versus 159 in P. nipponica. The segregations of 32 isoenzyme loci in a subset of 47 seedlings from the progeny were scored, using polyacrylamide gel electrophoresis and/or isoelectric focusing separation followed by activity staining, and the co-segregation data were analysed along with those for 39 isoenzymes reported previously and for the 174 sequence-tagged site loci plus an additional two SSR loci. The second map incorporates 233 loci and spans 736 cM over eight linkage groups with an average marker spacing of 3.2 cM per marker and just two gaps greater than 15 cM. The microsatellite map will provide a useful tool for cherry breeding and marker-assisted selection and for synteny studies within Prunus; the gene-specific markers and isoenzymes will be useful for comparisons with maps of other rosaceous fruit crops.

Distribution of isoenzyme markers at 37 loci in a pedigree of European spring barley

Linde-Laursen, I., Nielsen. G. and Johansen. H.B. 1987. Distribution of isoenzyme markers at 37 loci in a pedigree of European spring barley. —Hereditas 106: 241–251. Lund, Sweden. 018–0661. Received September 19, 1986 Inheritance of isoenzymes controlled by from 2 to 4 alleles at each of 17 loci was investigated in 59 related varieties or lines and one population of European 2-rowed spring barley. A further 20 isoenzyme loci showed no variation. Altogether the material spanned the last 150 years. Inheritance of alleles normally was as expected; however, in some cases allowance should be made for now lost polymorphism in parent(s). Polymorphism was more common in old than in recent varieties and in some varieties affected alleles at more than one locus. Some gene depletion had taken place during the period studied. However, a number of “new” alleles had been introduced together with, e.g., resistance genes from exotic lines. The variation present in modern European 2– rowed spring barley comprises a restricted part only of the variation present in the species. Isoenzyme patterns separated the material into 48 groups of one variety each. and 11 groups of two and one group of three normally closely related varieties or lines. The combined use of the isoenzyme loci was superior to the use of either hordeins or Giemsa C-banding patterns for the identification of lines.

Genetic Consequences of Radiation Exposure for the Pine (Pinus sylvestris L.) Population.

We studied the inheritance of isoenzyme loci in seeds of the first post-accidental generation and morphological characteristics in the second generation of irradiated pines. Pine is an appropriate object for genetic monitoring due to its high radiosensitivity. In 2004 we collected seeds from the young pine trees (8-10 years) growing in the 30-km zone around the CNPP. These plants grew as a result of natural revival of population and presented second progeny of the irradiated trees. The absorbed doses in 1986 varied from 0.5 up to 40 Gy. Dose rates in 2004 varied from 0.25 up to 25 μZv/h. We assayed the isoenzyme polymorphism in endosperms using electroforetic analysis in polyacrilamid gel. The haploid endosperm presence allows to study genotype of maternal plant without crossing. The investigation revealed no mutational changes at isoenzyme loci. We observed inheritance of alleles of Gdh, Adh1, Adh2, Skdh1, Skdh2, Got2, Got loci and compared genotypes of heterozygous maternal plants with endospermes. The expected ratio of maternal alleles in haploid endosperm tissues is 1:1 in accordance with Mendelian inheritance. Significant deviation from 1:1 ratio was found at 6 of 7 loci of 50% observed heterozigous trees. The disturbances in the allelic segregation were not found in control. We found high level of morphological abnormalities in second post-accidental generation of pine. The frequency of chlorophyll mutations among two-years-old plants was 1.8%, the growing abnormalities (dwarfness, activation of rest buds)-6.7%, the cases of atavism (dichotomic stem-bifurcation, single sessile needles)-1.6%. Common frequency of morphological abnormalities is 10.1% (not found in control). The length of plants and needles was the same as in control. The quantity of morphological abnormalities didn’t depend on dose rate. Disturbances of allele segregation and high level of morphological abnormalities probably result in genetic injures in the second generation of the irradiated plants.

Population genetic study of allozyme variation in natural populations of Drosophila antonietae (Insecta, Diptera)

Drosophila antonietae is an endemic South American cactophilic species found in relictual xerophytic vegetation, mostly associated with Cereus hildmaniannus cactus. Low differentiation among populations of this species has been detected using several markers. In this work, we performed an allozyme genetic variability analysis of 11 natural populations of D. antonietae and included a discussion about the possible influences of several evolutionary processes that might be acting to maintain the pattern observed. The genetic variability of 14 isoenzyme loci was analysed and showed a high genetic diversity (average observed heterozygosity ¼ 0.319) and a moderate genetic differentiation among populations (F statistics ¼ 0.0723). A correlation between genetic and geographical and ecological distances was detected among pairs of populations and the regional equilibrium analysis was thus applied. This analysis resulted in Nm (number of migrants) of approximately 3.21, indicating that moderate levels of both gene flow and genetic drift occur in this species, with gene flow overlapping genetic drift. However, considering ecological features of drosophilids, we propose a hypothesis to explain the moderate differentiation encountered as a result of three different processes, or a combination of them: (1) gene flow; (2) a short period of differentiation, i.e. maintenance of ancestral polymorphism; and (3) action of natural selection. Moreover, if gene flow is present, the high genetic diversity compared with other cactophilic and non-cactophilic species could be due to differential selection in different populations followed by gene exchange among them. These factors are discussed in the light of D. antonietaes historical and evolutionary association with the host cactus.

Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

Evaluation of genetic variation was performed within 62 local maize populations originating from Slovakia and Czech Republic. In total 48 alleles at 22 analyzed isoenzyme loci with an average of 2.2 alleles per locus were revealed. The percentage of polymorphic loci ranged from 14% to 59% and the frequencies of detected alleles varied from null to four per locus. No polymorphism was detected at the loci <i>Dia2</i>, <i>Got3</i>, <i>Mdh4</i>, <i>Mmm</i>, and <i>Pgm1</i>. The highest number of alleles (four) was detected at loci <i>Acp1</i>, <i>Cat3</i>, <i>Pgm2</i>. No new alleles were identified, nevertheless the frequency of seven alleles was only about 1%. The expected heterozygosity ranged from null to 0.492 with an average of 0.197. The revealed isoenzyme polymorphism confirmed that all analyzed populations were heterogeneous and as many as 17 of them were completely heterogeneous. None of the analyzed populations was identical in the frequency of alleles at all 22 analyzed loci.