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Severe leaf spot disease was observed on Aloe vera plants in the winters of 2011 and 2012 during a survey of various nurseries of Gwalior, India. Irregular, sunken, dark creamish brown spots having reddish brown margin were noticed on both surfaces of the leaves. The causal organism was consistently isolated from symptomatic leaves on potato dextrose agar media (PDA). A total 59 isolates of fungi were recovered from diseased A. vera leaves, and 37 isolates were identified as belonging to the genus Fusarium. On the basis of morphological characteristics and internal transcribed spacer (ITS) region of rDNA amplified using the primers ITS4/ITS5 the pathogen was identified as Fusarium proliferatum (Matsushima) Nirenberg and pathogenicity of the isolate was confirmed by using Koch’s postulates. To the best of our knowledge, this is the first report of leaf spot disease caused by Fusarium proliferatum on A. vera plants in India.
A total of 26 isolates of Fusarium proliferatum and F. sacchari were isolated from rice in the Peninsular Malaysia and Kalimantan, Indonesia. Spontaneous chlorate-resistant sectors (CRSs) were recovered from all wild type of both Fusarium species when cultured on two chlorate media. The non-utilizing (nit) mutants were generated as crn (chlorate resistant, nitrate utilizing), nit1, nit3 and nitM based on phenotyping growth-types on diagnostic media with different sources of nitrogen. The nit mutants were paired on minimal medium (MM) for examining the vegetative compatibility. The majority of nit mutants (32.3-46.5%) recovered were nit1. Eight and seven vegetative compatibility groups (VCGs) of F. proliferatum and F. sacchari were identified, respectively. The isolates of F. proliferatum and F. sacchari were genetically diverse as shown by the number and distribution of the VCGs. No strong correlation was observed between VCGs of both species and location.
The subject of this work was fumonisin B1 (FB1) and moniliformin (MON) biosynthesis by three isolates of Fusarium oxysporum and three isolates of F. proliferatum of asparagus spears origin. The cultures of fungi were grown on rice and asparagus media for 3 weeks at 20°C. Experiment was carried out in 3 replicates. FB1 and MON occurrence was evaluated with high-performance liquid chromatography (HPLC) analyses. Analysis of variance was carried out to determine biosynthesis of FB1 and MON by F. oxysporum and F. proliferatum. FB1 was found in the amount up to 2012.8 μg/g in cultures of F. proliferatum on rice and in a very small amount in two cultures on asparagus medium. F. oxysporum did not produce FB1 on any of the media. MON was biosynthesized by two the same isolates of F. oxysporum in the amount up to 182.8 μg/g on rice and up to 743.3 μg/g on asparagus medium and one isolate (different on each medium) of F. proliferatum.
Fusarium oxysporum and/or F. proliferatum were isolated from all asparagus spears with brown spots (which indicate an infection) and from almost all spears without spots. The presence of Fusarium spp. And their toxins in the basal parts of asparagus spears was analyzed. Fumonisin B₁ (FB₁) and moniliformin (MON) were found in spears with brown spots and those without disease symptoms. FB₁ was determined in the concentration range 0.16-152.68 ng g⁻¹ (mean 7.52), while moniliformin was detected in the range 15.30-585.00 ng g⁻¹ (mean 121.00). Only in 10% analyzed spears were metabolites not detected.
Isolates of Fusarium from rice, sugarcane and maize were identified as F. verticillioides, F. sacchari, F. proliferatum F. subglutinans, F. fujikuroi and F. oxysporum. The species were then characterized by restriction analysis of intergenic spacer (RFLP-IGS) using AluI, Eco88I, RsaI and XhoI. Twenty-five haplotypes were identified among the isolates of Fusarium which indicated high levels of variations. UPGMA cluster analysis was conducted to cluster the isolates and to estimate the intraspecific and interspecific variability. Isolates of F. fujikuroi from rice were clustered together with isolates of F. proliferatum from rice and maize with a similarity value of 88–100%. Isolates of F. verticilliodes from maize and sugarcane were clustered together with a similarity value ranging from 92–100%, and two isolates from rice formed another cluster. Isolates of F. oxysporum from maize and rice were clustered together with a similarity value ranging from 87–95%. Isolates of F. subglutinans from rice and maize, and F. sacchari from rice and sugarcane were also clustered together with a similarity value of 77–100%. Based on RFLP-IGS analysis, variability was observed within and between species of Fusarium from rice, maize and sugarcane and the technique could be use to complement morphological characterization and to determine genetic relationships between the species.
A total of 50 samples of poultry feed mixtures of Slovak origin were analysed for fumonisin B1 and B2 (FB1, FB2) and moniliformin (MON) using SAX-clean up procedure being detected by high pressure liquid chromatography with mass spectrometry (HPLC-MS) and diode array detection (HPLC-DAD), respectively. The samples were also simultaneously investigated for Fusarium species occurrence, and for the capability of Fusarium isolates recovered to produce FB1 and MON in vitro. FB1 was detected in 49 samples (98%) in concentrations ranging from 43 to 798 µg.kg-1, and FB2 in 42 samples (84%) in concentrations ranging from 26 to 362 µg.kg-1. MON was detected in 26 samples (52%) in concentrations that ranged from 42 to 1,214 µg.kg-1. Only two Fusarium populations were encountered, namely F. proliferatum and F. subglutinans, of which the former was the most dominant and frequent. All 86 F. proliferatum isolates tested for FB1-production ability proved to be producers of the toxin although none of them produced MON. On the contrary, MON production was observed in a half out of 16 F. subglutinans isolates tested, yet no FB1 production was detected in this case. Despite the limited number of samples investigated during this study, it is obvious that poultry feed mixtures may represent a risk from a toxicological point of view and should be regarded as a potential source of the Fusarium mycotoxins in central Europe. This is the first reported study dealing with fumonisin and moniliformin contamination of poultry feeds from Slovakia.
Thirty-three samples of poultry mixed feeds collected in the region of Nitra (Slovakia) from August 2001-April 2002 were assayed for the incidence of Fusarium Link: Fr. species. In tested samples, the total frequency of isolated fusaria was determined to be 48 % (16 samples) and their counts ranged from 0.2 × 102 to 2.4 × 104 CFU per g of the sample on Dichloran Chloramphenicol Peptone Agar (DCPA). Of the total amount of Fusarium isolates (609), the highest part (i.e. 584 isolates) was represented by Fusarium proliferatum (Matsushima) Nirenberg, being isolated in all the samples tested. Fusarium subglutinans (Wollenw. et Reinking) Nelson, Tousson et Marasas (in total 24 isolates) was found in 3 positive samples (9%) and Fusarium oxysporum Schlecht. Fr. (a single isolate) was found in one positive sample only (3%). Data of these significant mycotoxin producers found in examined samples with particular mycotoxins as well as their habitats were summarised briefly. The results refer to a large incidence of the potentially toxinogenic Fusarium species, mainly F. proliferatum, in the feeds of Slovakian origin which represent entry components of the food chain. The study also points out a potential risk of feed contamination with hazardous toxic compounds, especially by carcinogenic fumonisins and cardiotoxic moniliformin. From the hygienic point of view, it will be necessary to continue monitoring and evaluating this occurrence.
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