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On the basis of morphological features and RAPD markers the strains of Chalara ovoidea found in Poland on planks and on stems of beech trees were identified. As reference strains the cultures taken from CBS Utrecht were employed; they were cultures CBS 354.76 and CBS 136.88. The amplification of genomic DNA was conducted using 10 primers (OPA01-OPA10), 7 of which (OPA01-OPA05, OPA09, OPA10) gave positive results. In total 42 fragment of DNA (bands) were obtained. In case of primers OPA03, OPA04, OPA05, and OPA09 all obtained fragments for analyzed strains were fully monomorphic. This means, that no genetic variability was found using the above mentioned primers. Low genetic variability was ascertained in the analysis of frequency of occurrence of DNA fragments using other primers, namely OPA01, OPA02, and OPA10. The matrix and dendrogram of genetic affinities among different strains of Chalara, calculated using the Jaccard’s similarity coefficient suggested, that the most similar strains are the ones coming from Poland (HMIPC 16136 and HMIPC16664) as well as the strain CBS 136.88, while somewhat different from them is the strain CBS 354.76. To determine, how exactly did the dendrogram reflect genetic affinity among analyzed strains, the Mantel’s test was employed. The correlation coefficient amounted to 0.78, suggesting that the strains under study had been grouped properly. The results showed, that the fungal strains found in southern Poland represent the species Chalara ovoidea.
The 18 RHDV strains, isolated between 1993 and 2005 in Poland, as well as one standard strain were used in these studies. The RT-PCR technique was carried out in order to amplify the 538 bp fragment located in the variable region of gene encoding capsid protein (VP60). The phylogenetic analysis of nucleotide sequences of 18 Polish and 25 foreign strains revealed that Polish strains were clustered to 4 genogroups. One of them from 1993 was grouped together with old European strains isolated between 1987 and 1990. Thirteen strains isolated between 1994 and 2004, as well as two strains isolated in 1994 and 1996, were clustered to two separate genetic groups. Two strains detected in 2004 and 2005, were located in genogroup of antigenic variants. The maximum nucleotide divergence among Polish strains (10.3%) was found between strain isolated in 1996 and antigenic variants. The alignment of deduced amino acid sequences of the VP60 confirmed the localisation of 2 Polish strains in genetic group of antigenic variants. The identical amino acid substitutions in the same positions, like in other antigenic variants, were observed. The relation between antigenic properties and genetic variations of strains was taken under consideration.
The aim of this study was to come up with molecular characteristics of Polish strains of goose parvovirus (GPV) on the basis of genes encoding their structural proteins. Ten field GPV strains and two vaccine strains: B-38 and MFP were used. The PCR- RFLP method based on three distinct endonucleases: HinfI, MboI, and RsaI, which had restriction sites within the sequences of examined genes, was applied. It was found that the homology of VP1, VP2, and VP3 among the studied strains ranged from 50% to 100%. The major differences in restriction patterns were found after application of HinfI, whereas 100% homology was observed after Rsal digestion. Significant differences were observed in restriction profiles of vaccine GPV strains. The study revealed that the application of PCR-RFLP for the analysis of VP1, VP2, and VP3 genes allowed for their molecular characteristics and differentiation between the vaccine and field strains.
Thirty-three type A strains of G. abietina from diseased shoots or needles of P. sylvestris, P. nigra and P. armandii and three strains of Brunchorstia pinea var. cembrae from P. mugo were isolated from four regions of Poland differing with respect to climatic conditions. Genetic polymorphism of the mitochondrial small subunit rRNA (mtSSU rRNA), ribosomal RNA fragment including ITS1, 5.8S and ITS2 and glyceraldehyde phosphate dehydrogenase (GPD) gene was examined by the PCR-RFLP method. Genetic distance was ascertained with respect to B. pinea var. cembrae strains from G. abietina isolated from the examinedpine species (average Nei coefficient 0.137). The smallest genetic distance occurred between the strain groups of G. abietina isolated from P. nigra and P. armandii (0.059) and P. nigra and P. sylvestris (0.061), whereas the highest occurred between the groups of strains deriving from P. armandii and P. sylvestris (0.096). The impact of geographic distance on genetic distance between groups of strains from individual regions has been shown. G. abietina strains originating from mountainous areas were more distanced genetically (on average 0.031) from populations from other regions (Nei genetic distance 0.023). The main factors influencing genetic differences of the pathogen were specificity with respect to the species of the host plant and climate conditions, whereas geographic distance had lesser significance.
Peanut stunt virus (PSV) is a common legume pathogen present worldwide. It is also infectious for many other plants including peanut and some vegetables. Viruses of this species are classified at present into three subgroups based on their serology and nucleotide homology. Some of them may also carry an additional subviral element — satellite RNA. Analysis of the full genome sequence of a Polish strain — PSV-P — associated with satRNA was performed and showed that it may be classified as a derivative of the subgroup I sharing 83.9–87.9% nucleotide homology with other members of this subgroup. A comparative study of sequenced PSV strains indicates that PSV-P shows the highest identity level with PSV-ER or PSV-J depending on the region used for analysis. Phylogenetic analyses, on the other hand, have revealed that PSV-P is related to representatives of the subgroup I to the same degree, with the exception of the coat protein coding sequence where PSV-P is clustered together with PSV-ER.
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