Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: Z. Naár x
Clear All Modify Search

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.

Restricted access

Enniatins (ENs), produced by Fusarium 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 and F. sporotrichioides isolated from wheat seeds originated of 30 geographic localities of Hungary. All F. sporotrichoides strains and except two of all F. poae strains gave positive signal to esysp1 and esysp2 primers as well as all F. avenaceum isolates were positive to esya1 and esya2 primers indicating the ability to produce ENs. This is a first report of the enniatin producing ability of Fusarium species associated to wheat in Hungary.

Restricted access

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.

Restricted access

Species-specific PCR assay was used for the identification of Hungarian Fusarium graminearum isolates in pure mycelial culture. The Fg16F/Fg16R primer pair of the three known species-specific primers appeared to be the most appropriate one to identify F. graminearum .Two methods were used for comparative determination of the amplicon size of F. graminearum 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 F. graminearum .The PCR assay described in this study can be used for the routine detection and identification of F. graminearum without isolation and morphological investigation of this fungus.

Restricted access

The species-specific PCR assays correctly identified pure cultures of Fusarium acuminatum (3 isolates), F. avenaceum (22 isolates), F. poae (13 isolates), and F. sporotrichioides (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.

Restricted access
Acta Alimentaria
Authors: Z. Naar, N. Adányi, I. Bata-Vidács, R. Tömösközi-Farkas and R. Tömösközi-Farkas
Restricted access