The purpose of this study was to
survey the growth inhibition with volatile antibiosis and killing of Pythium
irregulare by Trichoderma species of various origin under heavy metal stress.
Fourteen strains of T. harzianum, 10 strains of T. virens, and 14 strains of T.
viride were tested in dual culture with the pathogen on heavy metal poisoned
media. Minimum inhibitory concentrations (MIC) for mycelial growth, antibiosis
and Pythium-killing were determined. Although the decreasing order of toxicity
(Cd≯Ni≯Zn) was the same for the growth of Pythium and the antagonists,
the pathogen tolerated 2-4 times higher doses of toxic metals
than Trichoderma strains did. The antagonistic activities proved to be more
sensitive, they were blocked by 0.16-0.67
mM Cd, 0.16-1.25 Ni or Zn. Pythium-killing was observed at higher doses
of Ni than that of Cd or Zn, which were similar toxic to the both investigated
activities. The history of long-term heavy metal exposure of some investigated
Trichoderma strains did not increase the tolerance of mycelial growth, but the
antagonistic activities were more sensitive in those strains that had
originated from not polluted arable soils.
Authors:J. Szarvas, A. Geösel, K. Pál, Z. Naár, and J. Győrfi
The king oyster mushroom (Pleurotus eryngii) is becoming more and more popular amongst the producers due to its excellent taste and relatively easy cultivation technology. Though investigations aiming to involve the mushroom in industrial cultivation had started in Hungary already in the 1950s, significant efforts were not made until 2002. In contrast to this, the volume of production in Europe and the United States has been growing continuously in the last decade. Although the species have been subjected to some taxonomical investigations, there are still a lot of contradictions in the taxonomic positioning of the P. eryngii species complex. In this study we investigated the genetic variability and taxonomic relationships among P. eryngii strains by using the RAPD-PCR method. Fifteen strains were analysed from our collection that represents mostly the Eastern-Hungarian habitats. Twenty-five random decamer primers were tested in the preliminary experiments and six were chosen that were used for binary coding. A neighbour-joining tree prepared from this matrix shows the coherence among the taxonomic relations and production sites of the potentially cultivable Hungarian strains.
Authors:Zs. Koncz, D. Magyar, Z. Naár, A. Kiss, and Á. Szécsi
The species-specific PCR assays correctly identified pure cultures of
(13 isolates), and
(6 isolates) originated from Hungarian wheat grain.The PCR-based assays described in this study can be used for the routine detection and identification of above-mentioned Fusaria without morphological determination.
Authors:Zs. Koncz, K. Huszti, Z. Naár, A. Kiss, and Á. Szécsi
Species-specific PCR assay was used for the identification of Hungarian
isolates in pure mycelial culture. The
primer pair of the three known species-specific primers appeared to be the most appropriate one to identify
.Two methods were used for comparative determination of the amplicon size of
strains: traditional agarose gel electrophoresis, and chip electrophoresis. Our results have shown that the chip electrophoresis is an easy-to-use, time-efficient substitute for conventional agarose gel electrophoresis; moreover it provides a more precise size determination of amplicons. Amplicon size ranging from 415 bp to 421 bp in tested isolates may be associated with genetic diversity in the Hungarian population of
.The PCR assay described in this study can be used for the routine detection and identification of
without isolation and morphological investigation of this fungus.
Authors:Zs. Koncz, Z. Naár, A. Kiss, and Á. Szécsi
Enniatins (ENs), produced by
species are a group of mycotoxins with antimicrobial, insecticidal (GROVE & POPLE, 1980) and phytotoxic activities. PCR based assays were applied for detecting enniatin-producing strains of
Fusarium avenaceum, F. poae
isolated from wheat seeds originated of 30 geographic localities of Hungary. All
strains and except two of all
strains gave positive signal to
primers as well as all
isolates were positive to
primers indicating the ability to produce ENs. This is a first report of the enniatin producing ability of
species associated to wheat in Hungary.