ABSTRACT
F. moniliforme and other species of Liseola section, F. culmorum, F. dlamini, and F. nygamai, were examined for their ability to produce gibberellic acid (GA3), fumonisins, trichothecenes, zearalenone, moniliformin, and bikaverin (TLC method). Gibberellic acid was produced by F. moniliforme strains in liquid medium and on rice kernels with a maximum concentration level of 470 mg/dm3 and 1 g/kg, respectively. No strain isolated in Poland produced GA3. High-yielding gibberellic acid strains produced neither trichothecenes and fumonisins nor other tested compounds. Also the rest of strains of examined species did not produce trichothecenes and other mycotoxins except for fumonisins which were found in rice cultures of F. moniliforme, F. proliferatum, and F. subglutinans. Bikaverin was produced by F. moniliforme always together with fumonisins. Filtrates of liquid cultures of gibberellin producing strains were tested for their toxicity to brine shrimps larvae (Artemia salina). It was found that GA3 presence does not increase toxicity of these filtrates.
Subject(s)
Fusarium/metabolism , Gibberellins/biosynthesis , Mycotoxins/biosynthesis , Xanthones , Animals , Artemia/drug effects , Mycotoxins/toxicity , Xanthenes/metabolismABSTRACT
Maize ears naturally infected withF. graminearum (6 samples) andF. crookwellense (6 samples) were collected in 1990 and 1991. All samples exhibited symptoms of severe ear rot with high percentage ofFusarium damaged kernels. Thousand kernels weight ranged 108.5 - 235.0g and was significantly lower than in control, not infested kernels (330g). All ears were contaminated withFusarium toxins but DON and NIV were the most frequently analyzed metabolites. Distribution of trichothecene mycotoxins in different parts of ear as well as toxicity of extracts toArtemia salina is reported in this paper.
ABSTRACT
Toxicity toA. salina, of the Fusarium metabolites: deoxynivalenol (DON), its acetylated derivatives (3- and 15-AcDON), zearalenone (ZON), neosolaniol (NEO), nivalenol (NIV), T-2, HT-2 toxins, has been examined and compared with toxicity of extracts of barley kernels (8 cultivars and 4 lines) inoculated withFusarium culmorum, F. graminearum andF. sporotrichioides respectively. Estimated LC50 values were expressed as relative toxicity (RT) in mg DON/kg for samples inoculated withF. culmorum, F. graminearum or in mg T-2/kg forF. sporotrichioides inoculations.Toxicity of extracts of the same genotype/line kernels was compared among different pathogens used for inoculation and differences in Fusarium head blight susceptibility of different genotypes/lines inoculated with the sameFusarium strain were found. Significant correlation between toxicity of extracts (LC50, RT) and toxic metabolites concentration was found ([Formula: see text]; P = 0.01).Bioassays withA. Salina offer a fast, easy and inexpensive method to examine cereal genotypes susceptibility to Fusarium head blight and mycotoxins accumulation in kernels.
ABSTRACT
Strains of fungi isolated from pulse crops: pea (Pisum sativum) and faba beans (Vicia faba) plants with symptoms of Ascochyta blight, footrot and stems lesions have been examined under laboratory conditions for their ability to produce ascochitine and metabolites toxic toArtemia salina. BothAscochyta pisi Lib and Ascochyta fabae LK Jones isolates formed ascochitine in yields of 20-480mg/kg. The highest yield of ascochitine was produced on rice and the lowest on maize grain.Ascochyta pinodes andPhoma medicaginis varpinodella (LK Jones) Boerema (formerlyAscochyta pinodella LK Jones) did not produce ascochitine.Crystalline ascochitine was found to be of moderate toxicity toArtemia salina larvae (LC50 = 85µg/cm(3)BSM*). Extracts ofPhoma medicaginis var,pinodella cultures were found to be highly toxic toArtemia salina.
ABSTRACT
The amount of diacetoxyscirpenol (DAS) produced by 14 isolates ofFusarium sambucinum under laboratory conditions has been examined. The isolates were obtained from potato tubers with dry rot symptoms. Yields of DAS ranged from 20 to 330 mg/kg of wheat grain culture (chemical analysis -TLC). Chemical analysis and biological tests showed very similar results.
ABSTRACT
Extracts of the followingFusaria cultures, isolated from cereals were examined for toxicity to Artemia salina:F. avenaceum (6 isolates),F. crookwellense (7),F. graminearum (11),F. nivale (5) andF. Sporotrichioides (2). The same cultures, growing on wheat grain, were assayed also mycotoxins presence using TLC method. Most toxic were found cultures ofF. Sporotrichioides and results of bioassay was similar to results of their TLC analysis. We found cultures of newly described speciesF. Crookwellense to be more toxic than cultures ofF. Graminearum.
