Production of moniliformin by Canadian isolates of Fusarium

Twenty-eight Canadian isolates of Fusarium were tested for their ability to produce moniliformin in corn. Both F. moniliforme (2/6 isolates) and F. subglutinans (11/15 isolates) produced the mycotoxin, while F. graminearum did not. Field-corn inoculated with F. moniliforme M3783 was able to support production of both moniliformin and fusarin C.     

Subchronic toxicological investigations of Fusarium moniliforme-contaminated corn,culture material,and ammoniated culture material

The fungus Fusarium moniliforme is ubiquitous on corn throughout the world and is a likely co-contaminant on corn infested with aflatoxin-producing Aspergillus flavus. Ammoniation has been used to detoxify aflatoxin-contaminated commodities. To determine the effect of ammoniation on the toxic potential of Fusarium moniliforme, male Sprague-Dawley rats were fed either diets containing 10% sound corn, ammoniated corn, corn culture material of hepatotoxic F. moniliforme strain MRC 826 (CM), or ammoniated CM for four weeks. They were observed for signs of toxicity and hematological, serum chemical and histopathological evaluations were made. Groups of male Balb/c mice were fed diets fortified with 10% sound corn or CM for four weeks and evaluated by serum chemical and histopathological means to determine the suitability of mice as a model species for investigation of F. moniliforme-induced hepatotoxicity. Ammoniation was ineffective for detoxification of the CM. Hepatotoxicity and renal toxicity of CM and ammoniated CM were qualitatively similar, although renal tubular lesions appeared more advanced in rats fed ammoniated CM. Adrenal cortical cellular vacuolation was also found in CM and ammoniated CM-fed rats, while focal seminiferous tubular degeneration and aspermia were found only in the testes of ammoniated CM-fed rats. Fumonisin B₁ concentrations of the CM and ammoniated CM diets averaged 99 and 75 ppm, respectively. CM containing 99 ppm fumonisin B₁ also produced hepatotoxicity in mice similar to that found in CM-fed rats. Thus, mice may be useful for investigations of F. moniliforme-induced hepatotoxicity.Mention of a trademark, proprietary name or vendor does not imply its approval by the US Department of Agriculture to the exclusion of others that may also be suitable.     

The inability of Fusarium species extracts to induce dieback in pines

Cultures of F. moniliforme var. subglutinans, F. moniliforme, F. lateritium, F. equiseti, F. semitectum and F. solani from pine and F. moniliforme and F. graminearum from southern U.S. corn were grown on rice and corn, extracted, and checked for toxicity in mice, chicken embryos, and pine seedlings, and for mutagenicity by the Ames test. While extracts from both fungal groups contained toxins, none of the extracts induced dieback in pine seedlings. Almost all of the cultures isolated from corn in contrast to those from pine, were mutagenic. Thin-layer chromatography did not detect T-2 toxin, moniliformin, or vomitoxin, indicating that these toxins do not elicit dieback symptoms in pine.     

Production of fumonisins byFusarium species of Taiwan

Twenty-nineFusarium species isolated from various sources in different districts of Taiwan were tested for their ability to produce fumonisins in corn cultures. OnlyFusarium moniliforme produced fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂). The finding that the other 28Fusarium species produced neither FB₁ nor FB₂ is preliminary because only one strain per species was studied. The detection of FB₁ and FB₂ in cultures ofF. moniliforme was demonstrated by TLC and HPLC, and FB₁ was further confirmed by mass spectrometry. In a separate experiment, in which 38 strains ofF. moniliforme were tested for fumonisins, approximately 66% (25/38) produced FB₁ and/or FB₂. Of the 25 strains, 14 produced only FB₁ and 11 produced both FB₁ and FB₂, and the amounts of FB₁ and FB₂ produced by different strains varied greatly. This is the first report that fumonisins are found in corn cultures experimentally infected withF. moniliforme strains from Taiwan. It is safe to assume that fumonisin producing strains ofF. moniliforme are widely distributed among the economic crops such as corn, rice, sugarcane, and sorghum throughout the Island.Abbreviations FB₁ Fumonisin B₁ - FB₂ Fumonisin B₂ - OPA o-phthalidialdehyde     

Interactions of Fusarium moniliforme,its metabolites and bacteria with corn

Fusarium moniliforme Sheldon is an economically important pathogen of corn (Zea mays L.) which causes stalk, root and ear rot. Several mycotoxins have also been isolated, identified and implicated in both animal and human toxicoses. The fungus can be disseminated in symptomless corn seed and can also survive in crop residues in the soil. Asymptomatic infection may be related to different corn cultivars, fungal strains, and environmental factors. Symptomatic expression of pathogenicity may vary, but usually the result of such infections is death of the plant. The greatest concern is the asymptomatic infection, since it is in this form that fungal toxins may surreptitiously enter animal and human food chains. F. moniliforme produces both fusaric acid, which is phytotoxic to corn and interferes with seed germination, and plant growth regulators that may affect pathogenicity of the fungus or be associated with the production of mycotoxins. Other metabolites, including fusarin C, moniliformin, and the fumonisins, may or may not be phytotoxic, but are associated with animal and human toxicoses. The control of F. moniliforme in corn is therefore quite important. One potential means to accomplish this reduction is biocontrol by the application of antagonistic rhizobacteria to corn kernels at planting. To be effective the bacteria must be able to colonize the corn root system and be able to prevent root infection by successful competing with F. moniliforme which may be accomplished by siderophore and or antibiotic activity.     

POPULATION DIFFERENCES IN INDIGENOUS FUSARIUM SPECIES BY CORN CULTURE OF PRAIRIE SOIL

Six species of Fusarium were identified among approximately 7,000 cultures isolated from roots and soils collected from prairies and cornfields in southern Minnesota. In both soil sources, F. oxysporum and F. solani predominated, followed in order by F. roseum, F. episphaeria, F. tricinctum, and F. moniliforme. The same order was obtained for the 28 species of prairie grasses and forbs as for corn. From prairie plant and corn roots, respectively, F. oxysporum was isolated from 64 and 90%; F. solani, 26 and 80%; F. roseum, 8 and 35%; and F. tricinctum, 6 % each. In 10 of 17 companion soil pairs, populations of Fusarium species were higher in cornfield than in prairie soils. Populations of F. roseum and F. moniliforme especially, were higher in cornfield soils of sample pairs, but populations of F. solani were higher in prairie soils. Fusarium roseum ‘Equiseti’ was the predominant cultivar of this species in both prairie and cornfield soils. Thus all six species of Fusarium appeared to be indigenous to the prairie, and some, especially F. roseum, apparently had increased in prevalence in soil and roots by corn culture.     

A review and update of animal toxicoses associated with fumonisin-contaminated feeds and production of fumonisins by Fusarium isolates

During the 1989 corn harvest season, numerous reports of equine leukoencephalomalacia (ELEM) outbreaks and a pulmonary edema (PPE) syndrome in swine from several regions of the United States were received by the National Veterinary Services Laboratories (NVSL), Ames, Iowa. Previous and concurrent research linked Fusarium moniliforme and fumonisin-contaminated feeds to both diseases. Chemical and mycological investigations revealed fumonisin B₁ (FB₁) concentrations of 20 to 360 ppm in suspect swine feeds and 8 to 117 ppm in suspect equine feeds. Nonproblem feeds contained concentrations below 8 ppm. Fusarium moniliforme and Fusarium proliferatum were isolated from both problem and nonproblem equine and swine feeds. When cultured on autoclaved corn, the F. moniliforme and F. proliferatum isolates produced respective FB₁ and fumonisin B₂ (FB₂) that range from less than 5 to more than 2450 ppm and less than 5 to more than 1000 ppm, respectively. Isolates from both problem and nonproblem feeds produced high levels (greater than 500 ppm) in culture. Reported here is a review of chemical and mycological data resulting from the study of several cases of PPE and ELEM.     

Moniliformin produced by cultures of Fusarium moniliforme var. subglutinans isolated from swine feed

Feed samples from Iowa suspected of causing vomiting and enlarged vulva as well as mortalities of swine were examined for toxigenic fungi and mycotoxins Fusarium moniliforme Sheldon and F. moniliforme Sheldon var. subglutinans Wollenew. & Reink. accounted for 43% and 18.5%, respectively, of the total count of 4.75×10⁵ propagules filamentous fungi per gram of swine feed, but representatives of various Penicillium spp. and Aspergillus spp. were also found. Eight isolates of F. moniliforme var. subglutinans from the feed produced 51–540 g of moniliformin per g on cracked corn at 25°C for six weeks. Zearalenone was not detected in these corn fermentations. Eight isolates of F. moniliforme from the feed did not produce detectable amounts of either zearalenone or monoliformin on cracked corn. Moniliformin was not detected in the feed samples.     

Interaction between the Ectomycorrhizal Fungus Paxillus involutus, Damping-off Fungi and Pinus resinosa Seedlings

Paxillus involutus, an ectomycorrhizal fungus, had an inhibitory effect on the root pathogenic fungus Fusarium moniliforme and two isolates of F. oxysporum when grown in paired cultures on modified Melin Norkrans’ medium. In contrast, one isolate of F. oxysporum was not inhibited and another damping-off fungus, Cylindrocarpon destructans inhibited growth of Pax. involutus in similar paried cultures. Survival of Pinus resinosa (red pine) seedlings was increased significantly when they were grown in vitro concomitantly with either Pax. involutus and F. moniliforme or Pax. involutus and the three isolates of F. oxysporum, compared with seedlings inoculated with either F. moniliforme or F. oxysporum isolates alone. pax. involutus showed no protective effect against C. destructans. The number of colony forming units of Fusarium spp. was reduced significantly in the root extract and rhizosphere substrate of P. resinosa seedlings inoculated with Pax. involutus. Spore germination of Fusarium spp. was reduced significantly when treated with culture filtrate of Pax. involutus and root extract of P. resinosa seedlings inoculated with Pax. involutus. Neither colony forming units nor spore germination of C. destructans was affected either by culture filtrate of Pax. involutus or root extract of P. resinosa seedlings inoculated with Pax. involutus.     

Survival of Aspergillus flavus and Fusarium moniliforme in High-Moisture Corn Stored Under Modified Atmospheres

Freshly harvested high-moisture corn with 29.4% moisture and corn remoistened to 19.6% moisture were inoculated with Aspergillus flavus Link ex Fr. and stored for 4 weeks at about 27 C in air (0.03% CO₂, 21% O₂, and 78% N₂) and three modified atmospheres: (i) 99.7% N₂ and 0.3% O₂; (ii) 61.7% CO₂, 8.7% O₂, and 29.6% N₂; and (iii) 13.5% CO₂, 0.5% O₂, and 84.8% N₂. Kernel infections by A. flavus, Fusarium moniliforme (Sheld.) Snyd. et Hans., and other fungi were monitored weekly. The modified-atmosphere treatments delayed deterioration by A. flavus and F. moniliforme, but their growth was not completely stopped. A. flavus survived better in the remoistened than in the freshly harvested corn. F. moniliforme survived in both. A. flavus and F. moniliforme were the dominant fungi in corn removed from the modified atmospheres and exposed to normal air for 1 week.     

Preharvest aflatoxin contamination of maize inoculated withAspergillus flavus andFusarium moniliforme

A two-year factorial experiment was utilized to test plants field-inoculated singly and in combination withAspergillus flavus andFusarium moniliforme. Pinbar inoculations were made through the husks with conidial suspensions, and 10-ear maize samples were harvested at 60 days post-silking for aflatoxin determinations. When ears were inoculated with both fungi simultaneously,F. moniliforme reduced aflatoxin formation byA. flavus isolate NRRL 3357 by approximately two-thirds.F. moniliforme had no significant effect on naturally occurring aflatoxin contamination byA. flavus. This may be due to the timing of infection by both fungi in the field. In nature,A. flavus andF. moniliforme respond differently to the environment, offering one explanation of whyF. moniliforme did not measurably affect the other fungus.     

Screening of zearalenone-producing Fusarium species in Egypt and chemically defined medium for production of the toxin

296 isolates of Fusarium spp. from 100 samples of cereale grains were examined for their ability to produce zearalenone on liquid culture medium. Thin layer Chromatographic analysis revealed that the mycotoxin was detected from 45 isolates, (F. oxysporum, 36; F. moniliforme, 8; and F. equiseti, one isolate). A suitable liquid medium and some optimal conditions for the biosynthesis of zearalenone were reported. Glutamine and riboflavin stimulated the production of the toxin. The maximum amount of zearalenone appeared at pH 7, after 12 days of incubation at 20 °C.     

A Comparative Anatomical Study of Organogenesis in Cultured Tissues of Maize, Wheat and Oats

Five cereals and two related grasses were tested for adventitious shoot production from tissue cultures using methods concordant with those reported to be successful for cereals. The five cereals I wheat (Triticum aestivum L.), oats (Avena sativa L.), and maize (Zea mays L.) Pioneer hybrid 3369A, the Bolivian race Pororo and the Equadorian race Chococenõl were all found to proliferate in culture through an aberrant root-like mechanism of growth which had the external appearance of callus. Two related species, teosinte (Zea mexicana Reeves and Mangelsdorf) and tripsacum (Tripsacum dactyloides L.), were less successful in culture, but grew in the same way. Oats, and probably Pororo and Chococeño, initiated presumptive shoot meristems directly from root vascular tissues within this root-like growth. Hybrid maize and wheat initiated no shoot meristems and produced only roots. The occasional shoot production observed in wheat was discounted as simple carryover of existing shoot apices from the primary embryo cultures. This study suggests that the incidence of shoot regeneration in cultures of these cereals may be related more directly to adventitious bud formation on roots than to any controlled de novo organogenesis from undifferentiated callus.     

Natural occurrence of Fusarium species and fumonisin-production by toxigenic strains isolated from poultry feeds in Argentina

Fusarium species and fumonisin production by toxigenic strains were investigated. During 1996–1998, 158 samples of poultry feeds were collected from a factory located in the department of Río Cuarto Córdoba province, Argentina. The most common species of Fusarium were F. moniliforme (60.7%) and F. nygamai (35.4%) followed by F. semitectum, F. subglutinans, F. proliferatum, F. dlamini, F. solani, F. oxysporum and F. napiforme. Fungal counts ranged from 1 × 10³ to 8 × 10⁵ CFU/g with mean values from 1.5 × 10³ to 2.3 × 10⁵ CFU/g. The highest counts were for F. dlamini, F. subglutinans, F. moniliforme and F. nygamai. Strains of F. moniliforme, F. nygamai, and F. proliferatum were screened for their potential to produce fumonisin B₁ (FB₁), fumonisin B₂ (FB₂) and fumonisin B₃ (FB₃) in corn grain. The samples were analysed using a modified high performance liquid chromatography method. The strains assayed, 43 strains, produced three fumonisins. There was a high degree of variability in the quantities of FB₁, FB₂, and FB₃ produced. The toxin produced in highest levels by the majority of the strains was FB₁. The range of concentration varied from 5.4 to 3,991, 1.01 to 189 and 0.4 to 765 ppm per gram of corn for FB₁, FB₂ and FB₃ respectively. The toxigenic pattern of strains was normal, although two strains of F. moniliforme produced exceptionally high concentrations of FB₃ and minor concentrations of FB₂ and FB₁. This is the first report from Argentina on Fusarium species in poultry feeds and fumonisin production by these strains.This revised version was published online in October 2005 with corrections to the Cover Date.     

A new fumonisin from solid cultures of Fusarium moniliforme

A new fumonisin has been isolated from Fusarium moniliforme isolate MRC826 grown on corn. It was shown by NMR and mass spectrometry to be an isomer of fumonisin B₂ that has free hydroxyl groups at C-3 and C-10 instead of the normal C-3 and C-5. This new fumonisin was detected in cultures of most isolates of F. moniliforme that were examined and was usually present at concentrations similar to those of fumonisin B₂. Two isolates of F. moniliforme that produce significantly higher levels of this new isomer were identified.Abbreviations ELEM equine leukoencephalomalacia Mention of companies or products by name does not imply their endorsement by the US Department of Agriculture over others not cited.     

Some aspects of Late Iron Age agriculture based on the first results of an archaeobotanical investigation at Corvin tér, Budapest, Hungary

Until now, very little was known about the agriculture of the Late Iron Age in Hungary. This paper describes the first results of an archaeobotanical examination of a late Iron Age, Celtic settlement in Budapest. It is the first systematically sampled and representatively investigated site of this time period in Hungary. Most of the samples come from different types of pits, which were subjectively sampled. The macrofossils were carbonised and, apart from many seeds and fruit stones, consisted mostly of charcoal. Among the seed remains both cultivated and wild species were present. The spectrum of cultivated plants was marked by a large number of cereals. The dominant cereals were Triticum spelta L. (spelt wheat) and Panicum millaceum L. (broomcorn millet), but also common were Avena sativa L., Avena sp. (oats), Triticum monococcum L. (einkorn), Hordeum vulgare L. (barley); Triticum aestivum/durum/turgidum L./Desf./L., incl. T. compactum Host. (bread wheat, including club wheat). Secale cereale L. (rye) and Triticum dicoccum (Schrank) Schübl. (emmer) were rare and seemed to be less important. The weeds and synanthropic vegetation, including ruderals, were represented by many taxa, and some of them also occurred in large amounts. The main cereals were sown as winter crops, judging from the rarely occurring of plants accompanying the cereals. Wild fruits contributed to the daily diet, too – as seen from the stones of Cornus mas (cornelian cherry), Crataegus sp. (hawthorn) and Prunus spinos (sloe, blackthorn). There were no finds of cultivated fruits. Received October 19, 2001 / Accepted January 30, 2002     

Fusarium species and their mycotoxins in infected corn in Italy

Surveys of corn (infected plants and commercial kernels) forFusarium species and their mycotoxins were carried out on samples collected all over Italy and from some European and mediterranean countries.Investigations on samples of corn stalk and ear rot standing in the field, mainly collected in southern Italy, proved to be contaminated with zearalenone (ZON), zearalenols (ZOL), and deoxynivalenol (DON). TheFusarium species most frequently isolated, and their recorded toxigenic capability (in parentheses), were:F. moniliforme;F. culmorum (ZON, ZOL, DON, 3AcDON);F. equiseti (ZON, ZOL); andF. proliferatum (MF). Along with these species,F. graminearum group 2 (ZON, DON and/or 3AcDON or 15AcDON);F. chlamydosporum;F. acuminatum (type-A trichothecene derivatives); andF. semitectum were often found to be associated.F. heterosporum (ZON, ZOL);F. solani;F. crookwellense (ZON, ZOL, FUS, NIV);F. oxysporum (MF);F. avenaceum (MF);F. sporotrichioides (T-2 toxin and derivatives); andF. poae (DAS, MAS) were occasionally isolated.     

Occurrence and toxicity ofFusarium subglutinans from Peruvian maize

Twenty-five samples of maize kernels collected at harvest time from geographically different corn fields in Peru, were examined for the occurrence of toxigenicFusarium species. The most frequently recovered species wereF. subglutinans (48%),F. moniliforme (46%), andF. equiseti (5%). OtherFusarium species isolated (up to 1%) includedF. graminearum, F. acuminatum, F. solani, F. oxysporum, andF. culmorum. Assays ofFusarium culture extracts usingArtemia salina larvae, showedF. subglutinans as one of the most toxigenic species, and its toxicity was mostly correlated to the capability to produce beauvericin (BEA). All eight tested isolates ofF. subglutinans grown on autoclaved corn kernels produced BEA (from 50 to 250 mg/Kg) as well as moniliformin (M) (from 70 to 270 mg/Kg). This is the first report on BEA and M production by maize isolates ofF. subglutinans from South America.     

Nuclear changes in allium cepa in response to infection by fusarium moniliforme

Fusarium moniliforme was isolated [into culture] from white onion and inoculated into holes bored in onion bulbs. After 48 hrs, the nuclear dry mass of onion cells 0–5 mm ahead of the mycelium had decreased by 19% as determined by quantitative interference microscopy as compared to nuclear dry mass decreases of 11 % caused by avirulent Aspergillus niger, 26 % by an unidentified onion pathogen, 41 % by virulent Botrytis allii, and 42 % by virulent Aspergillus niger. In the present study, the nucleolar dry mass declined by 34 % in response to F. moniliforme under the same conditions. Degradation or exit of nuclear and nucleolar macromolecules in response to fungal products secreted in advance of mycelium may be responsible for lower nuclear and nucleolar dry mass.     

Frequency and diversity of Fusarium spp. colonizing roots of Egyptian cottons

Abstract

Fusarium species are known to play a role in several diseases of cotton including the seedling disease complex, wilt, and boll rot. Therefore, a mycoflora study was conducted in 1998 in order to identify Fusarium species found in association with cotton roots. A total of 109 samples of cotton seedlings infected with post-emergence damping-off or rotted roots of adult plants were obtained from different cotton-growing areas in Egypt. Forty-six isolates were recovered and were identified as follows: F. oxysporum (28 isolates), F. moniliforme (9), F. solani (6), F. avenaceum (2), F. chlamydosporum (1). F. oxysporum, F. moniliforme and F. solani, the dominant species, accounted for 60.9%, 19.6% and 13% of the total isolates, respectively in 1998. F. oxysporum showed the highest isolation frequency in Beharia and Minufiya while F. moniliforme showed the most isolation frequency in Minufiya and Gharbiya. F. oxysporum was one of the major taxa of the Fusarium assemblage from Giza 70. F. oxysporum showed the most frequently isolated fungus in May while F. moniliforme and F. solani were the most frequently isolated fungi in August. Isolation frequency of Fusarium spp. during July and August was significantly greater than that of April or June. This implies that cotton roots are subjected more to colonization by Fusarium spp. as plants mature. Regarding pathogenicity, of the 46 isolates of Fusarium spp. tested under greenhouse conditions, 38 isolates (82.4%) were pathogenic to seedlings of Giza 89. This study indicates that F. oxysporum and F. moniliforme are important pathogens in the etiology of cotton damping-off in Egypt.