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Activities of cellulase of twenty strains of Fusarium verticillioides isolated from different sources were studied by means of three types of plate assays (CMC-plate, cup-plate, AZCL-plate). Strains were cultivated in CMC— liquid media and culture filtrates were used as source of cellulase. All the isolates studied were able to produce the cellulase activity, however, marked differences were observed in the rate of cellulase production. AZCL-plate assay is simple and very suitable for screening many isolates at the same time.
The „true” fungi have been referred to as the KingdomFungi,the KingdomEumyceteae,or theEumycota[1].The fungi are eukaryotic organisms, characterized by: (i) a diversity of microbodies; (ii) cell walls that have a great similarity of architecture; (iii) hyphae that have a major chitin component, extended apically, and divide by centripetal invagination of the plasma membrane; (iv) lomasomes: sponge-like intumescences seen on the inside of the cell wall; (v) complete absence of the Golgi organelle in the terrestrial assemblages (zygomycetes, ascomycetes, and basidiomycetes) and some of the aquatic taxa; and (vi) nuclei in which most, if not all, gene products involved in mitosis probably have higher eukaryotic paramologues but which, in other ways, are exceptional [2]. Fungi are reproducing sexually or asexually, the diploid phase generally short-lived. Fungi parasitize a wide range of plants, animals, and other fungi [3].
An ability to switch between a yeast-like form and a filamentous form was found among fumonisin-producing Fusarium verticillioides strains. These strains form yeast-like colonies in Sabouraud’s agar plates, containing 9%NaCl at 37°C in the dark. F. verticillioides strains in blood agar plates produce grass-green haemolytic reactions as a result of haemoglobin degradation. The possible role of these morphological forms in infectious diseases of humans and animals is discussed.
Cellulose-acetate electrophoresis (CAE) was used to investigate isozyme polymorphisms among different isolates of Fusarium cerealis, F. culmorum, F. graminearum and F. pseudograminearum. After initial testing of 18 enzymes in three buffer systems for activity and resolution of bands, 12 proved to be appropriate for analysis of the full sample set. Comparing the different electrophoretic types (ETs), adenylate kinase (AK), NADP dependent glutamate dehydrogenase (NADP GDH), peptidase B (PEP B), peptidase D (PEP D) and phosphoglucomutase (PGM) proved to be diagnostic for at least one species examined. However, only PEP D was useful alone as a marker to distinguish the four taxa studied providing a rapid and simple CAE based diagnostic protocol.
Airborne propagules of Fusarium spp. were collected on Fusarium selective medium with Andersen sampler in maize field. Fusarium isolates were identified based on morphological characters and using speciesspecific primersVERT 1/2, PRO 1/2 and SUB 1/2. The PCR analysis confirmed morphological identification of F. verticillioides, F. proliferatum and F. subglutinans. The VERTF 1/2 set of primers were used to discriminate potential fumonisin-producing strains of F. verticillioides, and all F. verticillioides strains scored positive for VERTF 1/2 pair of primers. This is the first study where specific primers were used for the confirmation of morhological determination of the above-mentioned Fusarium species, and selection of fumonisin-producing airborne isolates of F. verticillioides in Hungary.
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.
Fusarium is globally one of most important genera of fungi, causing an array of plant diseases, producing mycotoxins and adversely affecting human health. Some Fusarium species are associated with grasses, as saprophytes, endophytes or pathogens. A study was carried out on the distribution and diversity of Fusarium species associated with non-agricultural grasses, maize, sorghum and millet in Hungary. Grasses (Poaceae), both agricultural and wild, are important hosts of pathogenic Fusarium species. Little is known, however, about endophytic fusaria in wild grasses in Hungary.The aim of this paper was to present data on the occurrence of fusaria on grass species collected from wild populations. A total of 106 plants belonging to 43 different grass species were collected in different locations in Hungary, and 11 different Fusarium species were isolated from the stems of 62.3% of the plant samples. The most common species were F. compactum (19.1%), F. equiseti (16.2%) and F. graminearum (14.7%). Wild grasses are a rich source of endophytic Fusarium isolates for the production of metabolites with antimicrobial and anticancer activity. This is the first report on the diversity of endophytic Fusarium associated with grasses in Hungary.
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.
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.
