Isolates Of Fusarium Species Research Articles

Molecular delineation and genetic diversity of Fusarium species complex causing tea dieback in India and their sensitivity to fungicides

Fusarium dieback is a prevalent disease of tea (Camellia sinensis (L.) Kuntze) in India and China. The pathogen affects plucking shoots and causes complete crop loss under favourable conditions. Although, other fungal diseases that infect tea were widely explored for pathogen identification and characterization, little is known about Fusarium dieback in major tea growing regions of India. Therefore, in this study 24 isolates of Fusarium species causing dieback on tea in 24 tea gardens of Assam and North Bengal were isolated and characterized through micro-morphological and molecular analysis using multi-locus DNA sequences to determine whether multiple species of Fusarium are responsible for dieback disease. Molecular analysis revealed the association of four species of Fusarium, namely F. concentricum, F. solani, F. fujikuroi, and F. oxysporum. The most dominant species was F. concentricum (62.5%), whereas the occurrence frequencies of F. solani, F. fujikuroi, and F. oxysporum were 20.8%, 12.5%, and 0.04%, respectively. All Fusarium isolates were pathogenic to tea leaves when individually and co-inoculated, with F. concentricum HPE0F10 and NHT0F17 exhibiting 19.3 mm lesion length being the most virulent isolates. The growth rate of the pathogen was positively correlated with lesion lengths (P < 0.001). Co-infection of two or multiple Fusarium species enhanced the disease severity and quicker disease development compared to single inoculation. All the isolates showed diverse genetic backgrounds based on Inter Simple Sequence Repeat (ISSR) primers and principal coordinate analysis. In fungicide screening test, all isolates except HPE0F10, NDS0F18, and SNY0F22 were insensitive to M1 fungicide (copper oxychloride). Isolates GNP0F8 and LKW0F16 were insensitive to MBC + M3 (Carbendazim + Mancozeb), whereas HPE0F10, NLG0F11, IND0F13, and NLW0F19 were insensitive to DMI (respective each two to Hexaconazole and Valextra) fungicides. Notably, all the isolates were susceptible to propiconazole. Further, ISSR segregated isolates insensitive to MBC + M3 and M1 fungicides into two separate clusters, representing their distinctiveness. The fungicide screening results indicate that fungicide resistance can be managed by rotating different modes of action of fungicides against multiple Fusarium species causing tea dieback.

Identification and characterizations of a few species of Fusarium infecting cucumber in greenhouse conditions

One of the most problematic and devastating diseases affecting cucumber production is Fusarium wilt (Cucumis sativus L.). The present study aimed to characterize Fusarium species isolated from three different regions of cucumber fields in Babylon province, Iraq and identify them based on morphological features and phylogenetic analyses. This study showed the presence of Fusarium incarnatum, F. solani and F. oxysporum in cucumber roots. Fusarium species were phylogenetically analyzed based on internal transcribed spacer (ITS) regions. All Fusarium isolates were pathogenic to cucumber cultivars but varied significantly in their growth and pathogenicity toward cucumber seeds during the experiment. F. solani-2 was greater in growth and pathogenicity than all other Fusarium species. In contrast, F. solani-1 was the lowest. The data obtained from morphological and molecular studies sufficiently supported each other, and the phylogenetic trees based on ITS were distinguished. Closely related species and distinctly separated all morphological taxa. These findings are reported for the first time for the cucumber plant in Babylon province. All these ITS sequences showed homologous to those of Fusarium species isolates in the GenBank database with a similarity percentage of 99%. To the best of present knowledge, this is the first molecular record of F. incarnatum on the cucumber plants in Iraq. The study concluded that F. incarnatum was reported for the first time in Iraq and worldwide as a causal agent of wilt disease in cucumber plants. The three species of Fusarium have different pathogenic abilities, highlighting their disease incidence, growth, and pathogenicity.

Occurring Fusarium spp. in sorghum (Sorghum bicolor L. Moench) grains

AbstractIn our study, we examined mycotoxin-producing fungi found in sorghum grains (Sorghum bicolor L. Moench). During the experiment, the internal infection of grains was examined on 3 different selective culture media, as individual literature differs as to which selective culture media are the most suitable for the isolation of Fusarium species under laboratory conditions (Leslie and Summerell, 2006). During our experiments, we also used molecular methods to identify the selected Fusarium species down to the species level. In the case of Fusarium species our experiment shows that the best media is Nash &amp; Snyder media. During the morphological identification we worked with 18 Fusarium monosporal cultures and we detected Fusarium avenaceum.

P024 Genetic determinants of antifungal drug resistance in Fusarium solani species complex

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMDue to its challenging diagnosis and treatment, fungal keratitis is one of the most serious kinds of corneal infection. The Fusarium solani species complex is responsible for nearly half of all fungal keratitis cases. Fusarium infection is difficult to treat because of the increased antifungal resistance of Fusarium species.ObjectiveTo check the antifungal susceptibility in keratitis-causing isolates of F. solani species complex.To find the genetic determinants of resistance using whole genome sequencing.MethodologyPrior to AFST and according to CLSI, clinical isolates of Fusarium species (n = 5) were cultured on potato dextrose agar for 7 days at room temperature. Fungal spores were harvested using 0.8% NaCl and antifungal drug susceptibility testing of 6 different antifungal drugs were tested using CLSI standards broth microdilution method and minimum inhibitory concentrations were obtained. After 24 and 48 h, broth microdilution plates were manually examined. The wells for growth control were also examined. The minimum inhibitory concentration of anti-fungal drugs was the lowest dose that inhibits growth completely (compared to the growth control well). Minimal effective concentration (MEC) was also determined against antifungal drugs. Whole genome sequencing was done using Illumina Hiseqx10. Bioinformatics analysis was done using different bioinformatics tools and software (FASTQC, SPAdes, OmicsBox, AUGUSTUS, etc.).ResultsIn this study the antifungal drug susceptibility from average MIC value were found as fluconazole (512 μg/ml) > itraconazole (32 μg/ml) > amphotericin B (8 μg/ml) > natamycin (8 μg/ml) > posaconazole (2 μg/ml) > voriconazole (1 μg/ml). Fluconazole had a higher MIC value (512 g/ml) in all isolates, however, voriconazole was shown to be more sensitive, with a lower MIC range (0.25-4 g/ml). Glyoxalase/Bleomycin resistance protein, mfs—multidrug resistance transporter, fusaric acid resistance protein, efflux pump antibiotic resistance protein, and copper resistance protein were found by genome-based analysis.ConclusionAs a conclusion of this study, we observed antifungal drug resistance in Fusarium spp., which is often used to treat keratitis in patients, employing fluconazole, itraconazole, and amphotericin B. Resistance to first-line azoles was as a gene variant which contributed to antifungal drug resistance. This study using the phenotypic and genotypic characterization of drug resistance patterns will help to combat antifungal drug resistance.

P036 Epidemiology and antifungal susceptibility profile of infections caused by Fusarium species

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMAimThis study was performed to evaluate the clinical, epidemiological, and antifungal susceptibility profile of Fusarium species from clinical cases.MethodsThis study was conducted over a period of 14 years in a tertiary hospital in North India, 84 clinical isolates of Fusarium species isolated from various clinical samples like corneal scrapings, nail, tissue, and blood. The isolates were characterized phenotypically, and antifungal susceptibility testing was performed by broth microdilution method as per document CLSI M38-A3.ResultsOn phenotypic identification, 69.04% were Fusarium solani sensu stricto, followed by Fusarium oxysporum (22.61%), Fusarium dimerum (8.33%) and Fusarium incarnatum (1.19%). The infection spectrum of Fusarium spp. was onychomycosis (54.76%), keratomycosis (19.04%), fusariosis (15.47%), white grain mycetoma (3.57%), burn wound infection (3.57%), hyalohyphomycosis (3.57%). In all 92.85% isolates were susceptible to amphotericin B (0.125-1 μg/ml). For voriconazole, 70.23% strains had MIC ranging between 0.5-1 μg/ml, while 29.76% had MIC >4 μg/ml. High MICs were found to itraconazole (>16 μg/ml), caspofungin (>16 μg/ml) and fluconazole (>64 μg/ml).Conclusion Fusarium solani is the most common species isolated. Fusarium spp. causes a broad spectrum of infections in humans including superficial, locally invasive, and disseminated infections. The clinical form of Fusarium species infections depends largely on the immune status of the host and the portal of entry of pathogen. Antifungal susceptibility testing is recommended owing to the variable susceptibility pattern of Fusarium spp. Large-scale studies are required to know the exact epidemiological, clinical factors, and antifungal susceptibility patterns of Fusarium infections.

Differentiation of the Pea Wilt Pathogen Fusarium oxysporum f. sp. pisi from Other Isolates of Fusarium Species by PCR.

Pea wilt disease, caused by the soilborne and seedborne fungal pathogen Fusarium oxysporum f. sp. pisi (Fop), first appeared in Japan in 2002. We herein investigated the molecular characteristics of 16 Fop isolates sampled from multiple locations and at different times in Japan. The 16 isolates were divided into three clades in molecular phylogenic ana­lyses based on both the TEF1α gene and the rDNA-IGS region. All of the Fop isolates harbored a PDA1 gene, which encodes the cytochrome P450 pisatin demethylase (Pda1), and also carried one or both of the SIX6 and SIX13 genes, which encode secreted in xylem (Six) proteins. Other forms of F. oxysporum and other species of Fusarium did not carry these sets of genes. Based on these results, a PCR method was developed to identify Fop and differentiate it from other forms and non-pathogenic isolates of Fusarium spp. We also demonstrated that the PCR method effectively detected Fop in infected pea plants and infested soils.

Current Classification and Diversity of Fusarium Species Complex, the Causal Pathogen of Fusarium Wilt Disease of Banana in Malaysia

The re-emergence of the Fusarium wilt caused by Fusarium odoratissimum (F. odoratissimum) causes global banana production loss. Thirty-eight isolates of Fusarium species (Fusarium spp.) were examined for morphological characteristics on different media, showing the typical Fusarium spp. The phylogenetic trees of Fusarium isolates were generated using the sequences of histone gene (H3) and translation elongation factor gene (TEF-1α). Specific primers were used to confirm the presence of F. odoratissimum. The phylogenetic trees showed the rich diversity of the genus Fusarium related to Fusarium wilt, which consists of F. odoratissimum, Fusarium grosmichelii, Fusarium sacchari, and an unknown species of the Fusarium oxysporum species complex. By using Foc-TR4 specific primers, 27 isolates were confirmed as F. odoratissimum. A pathogenicity test was conducted for 30 days on five different local cultivars including, Musa acuminata (AAA, AA) and Musa paradisiaca (AAB, ABB). Although foliar symptoms showed different severity of those disease progression, vascular symptoms of the inoculated plantlet showed that infection was uniformly severe. Therefore, it can be concluded that the Fusarium oxysporum species complex related to Fusarium wilt of banana in Malaysia is rich in diversity, and F. odoratissimum has pathogenicity to local banana cultivars in Malaysia regardless of the genotype of the banana plants.

Identification of Pathogens Causing Bulb Rot Disease on Garlic (Allium sativum L.) in Central Java, Indonesia

Garlic bulb rot disease was found from garlics (Allium sativum L.) cultivated from 2017 to 2019 by farmers in Central Java Province, Indonesia. The initial symptoms of the disease were stunted, leaf yellowing, and necrotizing to rotten bulbs. This research was conducted to determine the major causal agent of garlic bulb rot disease in Central Java. A survey was carried out in five regencies across Central Java that were major garlic-producing areas. Nematodes were isolated using water immersion methode and pathogenic fungi were isolated on Potato Dextrose Agar (PDA). Nematode identification was carried out based on the Ditylenchus dipsaci morphological and morphometric character. Seven isolates of Fusarium species were obtained from infected garlic. Identification of four chosen isolates were performed by sequencing the TEF-1α gene. The TEF sequence of isolate TB3, KK1, and KK4 showed 99% similarity with several F. oxysporum, BT3 sequences showed 98% identity with several F. solani, and all were deposited in the NCBI GenBank. Three locations were positively infected by the interaction between D. dipsaci and Fusarium sp. Based on the results of the morphological identification, parasitic nematode was identified as D. dipsaci, while based on the morphological and molecular identification isolates Fusarium were identified as F. oxysporum and F. solani, respectively, as first report causal agents of garlic bulbs rot in Central Java.

Phylogenetic, phenotypic and host range characterization of five Fusarium species isolated from chickpea in Alberta, Canada

Chickpea (Cicer arietinum L.) is an important food legume worldwide, providing a source of high-quality protein. Fifteen chickpea samples showing leaf yellowing and root rot were obtained from southern Alberta, Canada, in 2018. Twenty single-spore Fusarium isolates were obtained from those samples. Based on the morphological characteristics, five species of Fusarium were identified, with F. redolens as the predominant species (11 isolates), followed by F. culmorum (3), F. sporotrichioides (3), F. oxysporum (2) and F. equiseti (1). The identification of each isolate was confirmed using partial sequences of the translation elongation factor 1-alpha (EF-1α) gene. Each EF-1α sequence displayed 99.54% to 100% similarity to sequences for each corresponding species in the GenBank database. The Fusarium isolates were tested for pathogenicity on chickpea ‘CDC Frontier’ in a greenhouse. Isolates recovered from inoculated plants were confirmed as the respective Fusarium species, fulfiling Koch’s postulates. Selected isolates of each Fusarium species were able to infect common crops including barley, corn, canola, and lentil in Alberta. This is the first report of F. redolens on chickpea in Alberta, F. equiseti on chickpea in Canada, and F. culmorum and F. sporotrichioides on chickpea in the world.

Fumonisin B1 Production by Fusarium Species and Mycotoxigenic Effect on Larval Zebrafish.

Fumonisin B1 (FB1) is a common mycotoxin produced by Fusarium species particularly F. proliferatum and F. verticillioides. The toxin produced can cause adverse effects on humans and animals. The objectives of this study were to detect the production of FB1 based on the amplification of FUM1 gene, to quantify FB1 produced by the isolates using Ultra-fast Liquid Chromatography (UFLC) analysis, to examine the embryotoxicity effect of FB1 and to determine EC50 toward the larvae of zebrafish (Danio rerio). Fifty isolates of Fusarium species were isolated from different hosts throughout Malaysia. Successful amplification of the FUM1 gene showed the presence of this gene (800 bp) in the genome of 48 out of 50 isolates. The highest level of FB1 produced by F. proliferatum isolate B2433 was 6677.32 ppm meanwhile F. verticillioides isolate J1363 was 954.01 ppm. From the assessment of embryotoxicity test of FB1 on larvae of zebrafish, five concentrations of FB1 (0.43 ppm, 0.58 ppm, 0.72 ppm, 0.87 ppm and 1.00 ppm) were tested. Morphological changes of the FB1 exposed-larvae were observed at 24 to 168 hpf. The mortality rate and abnormality of zebrafish larvae were significantly increased at 144 hpf exposure. Meanwhile, the spontaneous tail coiling showed a significant difference. There were no significant differences in the heartbeat rate. As a conclusion, the presence of FUM1 in every isolate can be detected by FUM1 gene analysis and both of the species produced different concentrations of FB1. This is the first report of FB1 produced by Fusarium species gave a significant effect on zebrafish development.

Mycotoxigenic potential of Fusarium species associated with pineapple diseases

Five species of Fusarium, F. proliferatum, F. fujikuroi, F. verticillioides, F. sacchari, and Fusarium sp. are associated with pineapple fruit rot and leaf spot diseases in Malaysia. Their ability to produce mycotoxins was analysed by the detection of the FUM1 gene as an indicator of fumonisin B1 (FB1) production and by quantification of FB1, moniliformin (MON), and beauvericin (BEA) using ultra performance liquid chromatography. All isolates of F. proliferatum, F. fujikuroi, and F. verticillioides showed the presence of FUM1 band and were able to produce FB1 in vitro. MON was produced by all isolates of Fusarium species, however, BEA was produced only by F. verticillioides isolates and some F. proliferatum, F. fujikuroi, and Fusarium sp. isolates. Production of FB1, MON, and BEA in vitro can be used to predict mycotoxigenic potential of the Fusarium spp. associated with pineapple diseases.

Biological control of Fusarium wilt in crop plants using non-pathogenic isolates of Fusarium species

Many species of the genus Fusarium resemble each other morphologically. In many cases morphological differentiation is difficult, molecular tools are used. Pathogenic as well as non-pathogenic isolates have same habitat and colonize plant root system with equal measure. Since non-pathogenic isolates resemble pathogenic isolates in their nutritional and abiotic requirements, many attempts have been made to utilize them as biocontrol agents to manage Fusarium wilt diseases. Although these isolates colonize plants, they do not induce disease symptoms. They are primarily soil inhabiting in nature; once introduced in it remain in the soil for very long time providing significant and consistent disease control. Herewith we give a review and summary of different reports of non-pathogenic Fusarium in different cropping systems, mode of action (antibiosis, plant growth promotion and induced systemic resistance), molecular basis of bioassay and identification, environmental conditions, different formulations, cross protection as well as effects on non-target crops.

Pathogenicity of Fusarium species associated with crown and root rot of wheat (Triticum aestivum) under different condition

This study was conducted to test the pathogenicity of Fusarium species, the causes of crown and root rot disease of wheat crop, under three different conditions (Laboratory, Greenhouse and Field) and to show the best method for pathogenicity among different conditions. Pathogenicity test of six isolates of Fusarium species (F. graminearum, F. oxysporum, F. avenaceum, F. nivale, F. solani and F. udum) was tested on durum (Simeto) cultivar of wheat by test tube method in the laboratory, the tested fungi had substantial effect on seed germination. F. oxysporum showed the highest germination failure (44.44%) which significantly differed with other species. In the greenhouse, seedlings were inoculated by spore suspension at the base of each plant stem. The most virulent fungus after 35 days of inoculation was F. oxysporum (0.78) followed by F. solani (0.70) and F. graminearum (0.66), while the lowest disease severity was recorded by F. udum (0.16). Also in the field pathogenicity experiments of three Fusarium species (F. graminearum, F. oxysporum and F. solani) were performed on a durum (Simeto) and soft (Cham6) cultivars. Spore suspension was applied at the 2- to 3-leaf Zadoks’s growth stage. Disease severity was calculated at two stages of wheat growth (Booting and Ripening).The most virulent fungus was F. graminearum (0.42) that was significantly different from other fungi. This work indicated that F. graminearum, F. oxysporum and F. solani showed higher infection than remaining tested species under threeconditions. Pathogenicity test in laboratory by test tube method (In-vitro) appeared more effective than greenhouse and field experiments

Isolation, Molecular Identification and Mycotoxin Profile of Fusarium Species Isolated from Maize Kernels in Iran.

Fusarium species are among the most important fungal pathogens of maize, where they cause severe reduction of yield and accumulation of a wide range of harmful mycotoxins in the kernels. In order to identify the Fusarium species and their mycotoxin profiles associated to maize ear rot and kernel contamination in Iran, a wide sampling was carried out from field in ten major maize-producing provinces in Iran, during 2015 and 2016. From 182 samples of maize kernels, 551 strains were isolated and identified as belonging to Fusarium genus. Among the 234 representative strains identified at species level by translation elongation factor (EF-1α) sequences, the main Fusarium species were F. verticillioides and F. proliferatum, together representing 90% of the Iranian Fusarium population, and, to a lesser extent, F. incarnatum equiseti species complex (FIESC), F. thapsinum and F. redolens. Fumonisin (FBs) production by F. verticillioides and F. proliferatum representative strains was analysed, showing that all strains produced FB1. None of F. verticillioides strains produced FB2 nor FB3, while both FB2 and FB3 were produced only by F. proliferatum. Total mean of FBs production by F. verticillioides was higher than F. proliferatum. The occurrence of different Fusarium species on Iranian maize is reason of great concern because of the toxigenic risk associated to these species. Moreover, the diversity of the species identified increases the toxigenic risk associated to Fusarium contaminated maize kernels, because of the high possibility that a multi-toxin contamination can occur with harmful consequences on human and animal health.

Multiplex Polymerase Chain Reaction Assay for Screening of Mycotoxin Genes From Ocular Isolates of Fusarium species.

To identify mycotoxin genes among clinical ocular isolates of Fusarium species and to correlate these with clinical outcomes of Fusarium keratitis. Fifty-four clinical isolates of Fusarium were retrieved from the Bascom Palmer Eye Institute Ocular Microbiology Laboratory data bank. Multiplex polymerase chain reactions were run to confirm the identification of Fusarium species [internal transcribed spacer sequence, translation elongation factor 1-α (TEF) and β-tubulin] and to detect the presence of genes encoding production of fumonisin B mycotoxins (FUM1 and FUM8) and trichothecene mycotoxins (deoxynivalenol and nivalenol). The presence or absence of mycotoxins was compared with patient outcomes. Forty-three (79%) of the 54 isolates were confirmed as Fusarium species, by an internal transcribed spacer sequence in 3 (5.6%) and by TEF in 43 (79.6%) of the 54 isolates. Fumonisin biosynthetic gene 1 (FUM1) was detected in 57.4% (n = 31/54) of the Fusarium isolates. No FUM8, deoxynivalenol genes, and nivalenol genes were detected among these in the clinical isolates group. Initial best-corrected visual acuity ranged from 20/25 to 20/80 in the FUM1 gene-negative group and from 20/20 to light perception in the FUM1 gene-positive group. There was no difference in the time to cure between both groups. The presence of FUM1 genes in 5 fungal isolates seemed to be associated with progression to penetrating keratoplasty in the 5 patients from whom the fungi were isolated. Fusarium solani was recovered from all patients requiring penetrating keratoplasty. Fumonisin B biosynthetic gene 1 may be common among clinical Fusarium isolates and contribute to worse initial visual acuity and high-risk progression to penetrating keratoplasty.

Taxonomy of Fusarium fujikuroi species complex associated with bakanae on rice in Korea

Bakanae occurs throughout rice growing regions of the world including Asia, Africa, America and Europe. So far the pathogen causing bakanae on rice has been widely known as F. fujikuroi in the Korean peninsula. However, previous studies have shown that Fusarium species within the Gibberella fujikuroi species complex are commonly associated with bakanae. Therefore the objective of this study is to determine the genetic diversity of the Fusarium species responsible for bakanae. Using morphological approaches and translation of DNA sequences belonging to elongation factor 1 α (TEF), histone H3 and calmodulin genes, the pathogen was identified and characterized. A total 590 isolates of Fusarium species were recovered from the rice plants with typical symptoms of bakanae and rice seeds. Out of one set of the 100 Fusarium isolates, the phylogenetic tree of 90 isolates amplified and constructed from DNA sequences of TEF gene consisted of three main clades. Futher it was observed that of the 89 Fusarium isolates amplified and constructed from 474 bp of DNA sequences of histone H3 gene, consisted of F. fujikuroi and F. proliferatum groups. Lastly, based on DNA sequences of clamodulin gene, 89 isolates including F. fujikuroi and F. proliferatum formed one clade with each reference strain. It could be again sub divided into F. proliferatum group and 2 F. fujikuroi groups. As clearly demonstrated in this study, identifying Fusarium species associated with bakanae only depending on morphological investigation is a highly challenging task, owing to its diverse characteristics. Moreover, other Fusarium species such as F. proliferatum, and F. andiyazi besides F. fujikuroi are also capable of causing bakanae. And also besides these there are other non-pathogenic F. fujikuroi which are hard to distinguish even with molecular identification protocols.

Species of genera Botrytis, Fusarium and Rhizopus on grapes of the Slovak origin

Our research was focused to identify the Botrytis, Fusarium and Rhizopus species from grapes of the Slovak origin. A further goal of the project was to characterized toxinogenic potential of chosen strains of species Fusarium. 50 samples of grapes, harvested in years 2011, 2012 and 2013 from various wine-growing regions were analyzed in this study. For the isolation of species the of direct plating method was used: a) surface-sterilized berries (using 1% freshly pre-pared chlorine) b) berries and c) damaged berries on DRBC (Dichloran Rose Bengal Chloramphenicol agar). For each analysis were used 50 berries (or all damaged berries from sample). The cultivation was carried at 25 ±1°C, for 5 to 7 days in dark. After incubation, the colonies of Botrytis, Fusarium and Rhizopus were transferred to identification media and after incubation strains were identified to species level. Thirteen species of fusaria (F. acuminatum, F. avenaceum, F. culmorum, F. equiseti, F. graminearum, F. oxysporum, F. proliferatum, F. semitectum, F. solani, F. sporotrichioides, F. subglutinans F. tricinctum and F. verticilioides) were identified. Frequency of fusaria isolation was 92 %. Botrytis cinerea was determined from 86% samples and Rhizopus from 94%. Chosen strains of species of genus Fusarium were able to produce following mycotoxins: deoxynivalenol, T-2 toxin, HT-2 toxin and diacetoxyscirpenol in in vitro conditions as determinated by thin-layer chromatography. Thirty-two (68%) of tested isolates of Fusarium species were able to produce at least one mycotoxin.

Fumonisin B1-producing Fusarium species from agricultural crops in Malaysia

Many species of Fusarium are pathogenic as well toxigenic to a wide variety of plants. The present study was conducted to determine the ability of four members of Fusarium fujikuroi species complex and F. oxysporum from various crops to produce fumonisin B1 (FB1). Isolates of Fusarium species from infected parts of asparagus, ginger, oil palm, mango, banana, maize, and rice were identified as F. verticillioides (11 isolates), F. proliferatum (50 isolates), F. fujikuroi (24 isolates), F. andiyazi (six isolates), and F. oxysporum (32 isolates). FUM1, a gene involved in fumonisin biosynthesis, was detected in 94 isolates of F. verticillioides (11 isolates), F. proliferatum (49 isolates), F. fujikuroi (24 isolates), and F. oxysporum (10 isolates) but only 61 were positive for FB1 when tested using RIDA®Quick Fumonisin test strip, indicating that the presence of FUM1 was not necessarily associated with FB1 production. Based on ultra-high performance liquid chromatography, all the 61 isolates were detected to produce FB1, at variable levels, with concentrations ranging from 0.60 to 29.2 μg/g. Our results suggested that there is a potential risk of FB1 contamination in agricultural crops in Malaysia.

Characterization of Fusarium proliferatum and Fusarium verticillioides based on Species-Specific Gene and Microsatellites Analysis

Fusarium species are known to cause various diseases on plantations including fruits and vegetables. The most common Fusarium that can cause plant diseases are Fusarium proliferatum and Fusarium verticillioides. Ear rot disease on maize, wilt disease on cucurbits and fruit rot disease on tomato as well as banana are example of diseases caused by these two species. The objectives of this study were to identify F. proliferatum and F. verticillioides based on species-specific primers and polymerase chain reaction (PCR) amplification and to evaluate the genetic diversity of both species based on microsatellite markers. Fifty isolates of Fusarium species that were previously collected throughout Malaysia from different hosts were identified by using species-specific PCR amplification. Twenty-nine isolates were identified as F. proliferatum and 21 isolates were identified as F. verticillioides based on species-specific primer. The genetic diversity of all the fungal isolates was evaluated by using microsatellite analysis with six established primers. Five out of six primers amplified polymorphic bands with the most effective primer showing high polymorphism were (AG)7C and (TCC)5 meanwhile one primer (TTTC)4 gave negative result with no band amplified. The phylogenetic tree that was constructed showing two different clades distinguished between F. proliferatum and F. verticillioides.

Fusarium species associated with Wheat crown and root tissues in the Eastern Iran

From 2012 to 2014, 70 isolates of Fusarium species were recovered from the wheat fields of Khosf, Giuk, Taqab, Amirabad, Mohammadieh and Bojd in the South Khorasan Province, Eastern Iran. Based on morphological characteristics, these isolates belonged to 14 Fusarium species. DNA of 23 isolates was extracted and their ribosomal ITS regions were amplified, sequenced and aligned with Fusarium species sequences of the GenBank. Among Fusarium isolates, the isolates belonging to F. solani (18.6%), F. acuminatum (12.9%), F. longipes (11.4%) and F. nygamai (10%) species had the higher frequencies. Other isolates from wheat crown and root were F. avenaceum, F. compactum, F. crookwellense, F. culmorum, F. diversisporum, F. equiseti, F. fujikuroi, F. javanicum, F. oxysporum and F. semitectum. This study is the first investigation of Fusarium species associated to wheat crown and root in the eastern desert area of Iran.