Gibberella Fujikuroi Species Complex Research Articles

First Report of Fusarium proliferatum Causing Bulb Rot on Lilium davidii var. willmottiae in China.

Lilium davidii var. willmottiae, known as Lanzhou lily, is widely cultivated in China for its edible bulbs. In July 2023, symptoms of bulb rot were observed on Lanzhou lilies harvested from Lanzhou, Gansu Province, during storage at the Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences (Beijing, China), at an incidence of nearly 70%. The surface of the lily scales had dark water-stained spots, after the development of which the color gradually darkened, the bulbs became soft, accompanied by a pungent smell. Finally, the whole bulb became ruined and rotten, and there were thick mycelium layers on the bulbs. The infected bulbs were washed with clean water, sterilized with 75% ethanol for 30 s and 2% sodium hypochlorite for 5 min, and then rinsed three times with sterile distilled water. The 5 mm×5 mm tissue pieces from the junction of the diseased part and the healthy part were clipped, placed on potato dextrose agar (PDA) medium and subsequently incubated at 25 °C. Pure cultures were obtained by transferring hyphal tips to new PDA plates. A total of 10 fungal isolates were obtained, all of which exhibited typical Fusarium characteristics. The colonies were white to pink with white to cream-colored aerial mycelia. After 10 to 15 days of incubation, the macroconidia (n = 50) were hyaline, relatively slender with a curve, three to five septate, and 8.73 to 33.24 × 2.16 to 4.19 μm in length. The microconidia (n = 50) were hyaline and pyriform, without septa, and measured 4.04 to 8.48 × 1.24 to 2.65 μm. These morphological characteristics were similar to those described for Fusarium proliferatum (Leslie and Summerell 2006). For molecular identification, a cetyltrimethylammonium bromide (CTAB) protocol was used to extract total genomic DNA (O'Donnell et al., 1998), after which the internal transcribed spacer (ITS), translation elongation factor subunit 1-alpha (TEF1-α) and RNA polymerase Ⅱ subunit 2 (RPB2) genes were amplified using the universal primers ITS1/ITS4, EF1/EF2 and RPB2-5f2/fRPB2-7cr, respectively, and subsequently sequenced (White et al., 1990; O'Donnell et al., 1998; Liu et al., 1999; Reeb et al., 2004; O'Donnell et al., 2007; Jiang et al., 2018). The sequences of a representative isolate (CAAS01) were analyzed and submitted to GenBank under accession numbers OR554007 (ITS), OR594233 (TEF1-α) and OR603932 (RPB2). A BLAST analysis revealed that the sequences of the ITS, TEF1-α, and RPB2 genes shared 100%, 100%, and 100% identity, respectively, with those of Fusarium proliferatum (MT466521.1, MK952792.1, and LT841266.1) in GenBank. In addition, the ITS, TEF1-α and RPB2 sequences shared 100%, 100%, and 100% identity with those of Fusarium annulatum (LC13675, the Fusarium fujikuroi species complex; previously known as the Gibberella fujikuroi species complex) in the Fusarium-ID database. Fusarium proliferatum, whose common synonyms are Gibberella fujikuroi mating population D and Gibberella fujikuroi var. intermedia, is the anamorphic form of the Gibberella fujikuroi complex that belongs to the Nectriaceae family. A phylogenetic tree was constructed based on the combined TEF1-α and RPB2 sequences of CAAS01 and other Fusarium isolates, revealing that CAAS01 was grouped with Fusarium proliferatum. Based on sequence alignment and phylogenetic analysis, the isolate was identified as Fusarium proliferatum. To determine the pathogenicity of the isolated fungi, healthy bulbs were punctured with disposable sterilized needles and soaked in equal amounts of sterile water and conidial suspension (1×107 conidia/mL) for 30 min respectively. The pathogenicity experiment was repeated three times. After 7 days of inoculation at 25 °C and 80% relative humidity, the surface of the inoculated bulbs produced water-stained spots and mycelium layers consistent with the symptoms exhibited by Lilium davidii var. willmottiae bulbs during storage, while the uninoculated lily bulbs remained symptomless. Fusarium proliferatum was reisolated from the infected bulbs and identified based on morphological and molecular characteristics, fulfilling Koch's postulates. To our knowledge, this is the first report of bulb rot on Lilium davidii var. willmottiae caused by Fusarium proliferatum in China. This study will contribute to the development of management strategies for this postharvest disease in Lilium davidii var. willmottiae.

Morphological and phylogenetic characterization of Fusarium Link

Identification of Fusarium isolates in a sample at the species level is an important and difficult task because many Fusarium species have similar morphological characteristics. The phylogenetic relations of species have been applied in Fusarium systematic and may solve taxonomic difficulties. The aim of the present study is to characterize pathogeny of Fusarium isolates through morphological analysis (concept of morphological species) associated with symptoms in hosts together with phylogeny analysis (concept of phylogenetic species) using internal transcribed spacer region (ITS) of ribosomal DNA for species identification. For the morphological characterization, Fusarium isolates were grown in PDA culture medium. Then, they were classified based on colony color and the microconidial, macroconidial and chlamydospore structures. The isolates were characterized molecularly by amplifying and sequencing the ITS region of the ribosomal DNA. The sequences generated were compared with those placed in the Genbank and Maximum Likelihood phylogenetic trees were constructed. Out of 14 isolates characterized morphologically and molecularly, five isolates were grouped in the Gibberella fujikuroi species complex in the Liseola section, seven presented characteristics of species from the Elegans section within the F. oxysporum species complex and two isolates presented characteristics of the section Gibbosum species complex in the F. incarnatum-equiseti species complex. Thus, seven isolates (section Elegans) belonged to the species F. oxysporum, two isolates (section Gibbosum) to the species F. equiseti. However, the ITS region of the ribosomal DNA did not provide sufficient evidence to define the species of G. fujikuroi species

Biological Species and Effective Population Number in Gibberella fujikuroi Species Complex Recovered from Sorghum in Egypt

Sorghum growing fields surveyed for the infection by Fusarium stalk and head rots throughout five locations in Egypt were screened depending on section Liseola characteristics. A number of 137 isolates from total recovered in average 87.8% isolates belonged to this section. These isolates selected from the whole number recovered from this group of fungi were subjected to the identified biologically and screened for fumonisin FB1 production. A number of 111 isolates produced fumonisin FB1 in average 81% from total isolates belonged to section Liseola. Four mating populations were identified, a number of 70 isolates mating population (MATP-A) F. verticillioides, 29 (MATP-D) F. proliferatum, 21 (MATP-F) F. thapsinum and 17 (MATP-G) F. nygamai. Mating population, A F. verticillioides consisted of 46 mating type 1 (MAT-1) and 24 mating type 2 (MAT-2), (MATP-D) F. proliferatum consisted of only 18 strains of (MAT-1) and 11 of (MAT-2). Whereas (MATP-F) F. thapsinum consisted of 14 strains of (MAT-1) and 7 of (MAT-2) and (MATP-G) F. nygamai consisted of only 12 strains of (MAT-1) and 5 of (MAT-2). Isolates belong to MATP-A produced considerable amounts of fumonisin compared to those belong to MATP-D,F and G. Female fertile strains could produce higher amounts of the toxin than female sterile. Measuring the parameters of the effective population number in four biological species recovered from sorghum, it was found that the female sterility was lesser than 50% in mating population A (21.4%) and were high in MATP- D, F and G (58.6%, 61.9% and 64.7%, respectively). This caused decrease in effective population number based on female fertility (Nef) overall locations in MATP- D, F and G, but it was high in MATP-A. Ration between Mating types (Mat-1, Mat-2) were differed from location to other also differed in population, it was high in all Mating populations than (Nef). These results in MATP-A led to an advantage during sexual reproduction occurs. Whereas MAT-D, F and G population vegetative propagation were significant component of the fungus especially in Assiut MATP-D, based on (Nemt) and population of Minia MATP-G, Sohag MATP-F based on (Nef).

First report of Bakanae disease caused by Fusarium proliferatum on rice in Turkey

The Bakanae disease caused by Gibberella fujikuroi species complex is one of the major fungal diseases of rice. It is present in the major rice production areas in the world. In 2016, field surveys were conducted from rice germination to maturity. Four isolates of Fusarium proliferatum associated with Bakanae disease were obtained from infected rice plants and identified using morphological and molecular-based methods. Pathogenicity tests were carried on susceptible rice variety. Initially, pale green to yellowing of leaves and thinner plants were observed. Then, these plants turned brownish and died, while control plants showed no symptoms. All isolates were found to be pathogenic. The disease severity values ranged from 27 to 66%. To our knowledge, this is the first report of the presence of F. proliferatum causing Bakanae disease on rice in Turkey.

Morphology, pathogenicity and molecular identification of some Fusarium species within the Gibberella fujikuroi species complex from wheat in Syria

Morphology, pathogenicity and molecular identification of some Fusarium species within the Gibberella fujikuroi species complex from wheat in Syria

Occurrence of Maize Ear Rot Caused by Fusarium fujikuroi in China

Maize (Zea mays L.) is one of the most important crops in China. Ear rot is a serious disease that often leads to a decline in maize yield and quality and is a hazard to human and livestock health owing to potential mycotoxin contamination of grain. The incidence of maize ear rot usually ranges from 20 to 40% at different fields, even reaching as high as 70% at certain plots in Chongqing and surrounding areas (Zhou et al. 2018). In August 2016, a survey to determine population composition and distribution of Fusarium spp. causing maize ear rot was conducted in 22 counties in Chongqing. Maize ears with white, pink, or salmon-colored mold were collected from fields for further analysis. Symptomatic kernels were soaked in 2% sodium hypochlorite solution for 3 min, rinsed with sterile water three times, placed on acidified potato dextrose agar (PDA), and incubated at 26 ± 1°C for 3 to 5 days. The newly grown-out fungal colonies displaying morphological characteristics of Fusarium spp. were transferred onto fresh PDA and Spezieller Nahrstoffarmer agar and purified by the single-spore isolation method (Yang et al. 2008). Fusarium spp. were identified based on morphological characteristics (Leslie and Summerell 2006) and sequence analysis of the translation elongation factor-1α (TEF-1α), β-tubulin, and mitochondrial small subunit (mtSSU) genes (Jiang et al. 2018). The predominant Fusarium spp. were Fusarium verticillioides, F. proliferatum, and F. meridionale, which were the main causal agents of maize ear rot in these areas. In addition, morphological characteristics of several isolates from Beibei, Jiangjin, Xiushan, Rongchang, Kaixian, and Wanzhou Districts were found to be identical to those of Fusarium fujikuroi Nirenberg, which grouped into the Gibberella fujikuroi species complex. Colonies on PDA produced abundant white aerial mycelia initially, but the mycelia became pale pinkish and dark violet with age. Microconidia were abundant and small in size (4.9 to 11.3 × 2.2 to 3.2 µm), colorless, oval to club shaped, and 0- to 1-septate. Macroconidia were slender, almost straight, sickle shaped, medium length, with three to five septa (17.1 to 39.2 × 2.6 to 3.3 µm). No chlamydospores were observed. Identity of the fungus was also confirmed by sequence comparison of the partial TEF-1α, β-tubulin, and mtSSU genes of two representative isolates. The resulting sequences of the TEF-1α, β-tubulin, and mtSSU genes showed 100, 100, and 99% sequence identity to those of F. fujikuroi (GenBank accession nos. MH263736.1, MH263737.1, and MF984420.1, respectively). DNA sequences of partial TEF-1α, β-tubulin, and mtSSU genes from two representative isolates (FCQD90 and FCQD97) were deposited in GenBank under accession numbers MK328875 and MK328876, MK385626 and MK385627, and MK385628 and MK385629, respectively. A pathogenicity test was performed on maize inbred lines B73 and Ye 107. Four days after silk emergence, 2 ml of conidial suspension (1 × 10⁶ conidia /ml) of each isolate was injected into each of 10 maize ears through the silk channel. Control plants were inoculated with sterile distilled water. The typical Fusarium ear rot symptom (white or white-pink mold) was observed on inoculated ears and the infected kernels. No symptom developed on the water-inoculated controls. F. fujikuroi was reisolated from the symptomatic ears but not from the control. F. fujikuroi was previously reported associated with seedling damping-off on soybean, stem wilt of Canna edulis, and root rot of Reineckia carnea (Jiang et al. 2018; Pedrozo et al. 2015; Sun et al. 2018). To our knowledge, this is the first report of F. fujikuroi causing maize ear rot in China, and this disease should be paid sufficient attention owing to a serious risk of mycotoxin contamination in maize.

Inoculation methods and aggressiveness of five Fusarium species against peach palm

ABSTRACT: Fusarium wilt is a major disease which affects peach palm (Bactris gasipaes Kunth.var gasipaes Henderson). This study aimed to evaluate inoculation methods and aggressiveness of isolates of five Fusarium species on peach palm. Fusarium proliferatum can infect the leaves, stem, and roots of peach palm. F. proliferatum, F. oxysporum species complex (FOSC), F. verticillioides, F. solani species complex (FSSC), and Gibberella fujikuroi species complex (GFSC) are pathogenic to peach palm. The use of Fusarium-colonized ground corn for root inoculation was effective and reduced the level of damage to plants.

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.

Morphological Characteristics and Mating Populations of Fusarium Species in Gibberella fujikuroi Species Complex (Gfsc) Associated with Stalk Rot Disease of Maize in Indonesia, Malaysia and Thailand

Morphological Characteristics and Mating Populations of Fusarium Species in Gibberella fujikuroi Species Complex (Gfsc) Associated with Stalk Rot Disease of Maize in Indonesia, Malaysia and Thailand

The puzzle of bakanae disease through interactions between Fusarium fujikuroi and rice.

Bakanae disease, one of the most noteworthy seedborne rice diseases, is caused by Fusarium fujikuroi, a member of the Gibberella fujikuroi species complex. The decreasing availability of chemical seed-dressing products over the last few years has raised the concerns of rice seed companies regarding bakanae disease. Therefore, new research trends require a deeper investigation into the main aspects of bakanae disease through interactions between rice and F. fujikuroi, in order to find new resistant or tolerant cultivars and alternative bakanae disease control strategies, as well as to develop more sensitive molecular diagnostic techniques. Here, some new aspects of F. fujikuroi epidemiology and pathogenicity, as well as its interactions with rice, are reported, and recent approaches applied to control bakanae disease are summarized.

Aflatoxin in maize, a multifaceted answer of Aspergillus flavus governed by weather, host-plant and competitor fungi

Aspergillus section Flavi is able to produce aflatoxins (AFs) in vitro down to 0.85 aw with a potential maximum occurring between 0.95 and 0.99 aw, while in the field AFs increased significantly with kernel humidity below 0.95 aw. In order to clarify this apparent discrepancy, a 3-year field trial with artificial inoculation of maize ears with Aspergillus flavus strains was organised. The co-occurrence of Aspergillus section Flavi and Gibberella fujikuroi species complex (Gfsc) was observed. The incidence of A. flavus was significantly influenced by the year and negatively related to Gfsc incidence. In 2012, when the highest temperature and the lowest rain were registered, aflatoxin B1 (AFB1) content was the highest and aw < 0.95 in kernels was measured early throughout the growing season. In 2013 and 2014, the temperature was lower and rain more abundant, and aw decreased below 0.95 only close to harvest and AFB1 contamination was limited. The possibility of describing/predicting reasonably well aw dynamic based on temperature, (degree day) was confirmed. With aw > 0.95, a positive correlation between AFB1 production rate and aw was found, but a negative correlation resulted with aw < 0.95. Other factors than aw play a role, but aw = 0.95 should be considered as an indicator of suitable conditions for rapid aflatoxin accumulation.

The biosynthesis of gibberellic acids by the transformants of orchid-associated Fusarium oxysporum

The genus Fusarium, including multiple strains in the Gibberella fujikuroi species complex (GFC), is well known for its production of diverse secondary metabolites. F. fujikuroi, associated with the “bakanae” disease of rice, is an active producer of gibberellins (GAs), a wide class of plant hormones. In addition to some members of the GFC, the GA biosynthetic gene cluster, or parts of it, occurs also in some isolates of the closely related species of F. oxysporum, which does not belong to the GFC. However, production of GAs has never been observed in any F. oxysporum strain. In this study, we report on the GA biosynthetic activity in an orchid-associated F. oxysporum strain by transforming a cosmid with the entire F. fujikuroi GA gene cluster. Southern and Northern blot analyses confirmed not only the integration of the entire gene cluster into the genome but also the active expression of the seven GA biosynthetic genes under nitrogen-limiting conditions. The transformants produced GAs at levels similar to those of F. fujikuroi. These data show that the regulatory network for expression of GA genes is fully active in the F. oxysporum background.

Morphological and molecular characterization, enzyme production and pathogenesis of Fusarium temperatum on corn in Mexico

A Fusarium sp. from a corn field in Chapingo, Estado de Mexico, Mexico was identified and characterized by morphological and molecular approaches. Colony growth on Czapek's medium and potato dextrose agar and pigment formation was assessed. Microscopically, the isolate displayed typical hyaline septate mycelium with long-beaked macroconidia with one to six septa, with a curved apical cell and a foot-like basal cell. Molecular characterization was performed by PCR of the ITS1-5.8S rDNA-ITS2 region and a portion of the elongation factor 1 alpha (EF-1α) followed by sequencing. The isolate was identified as Fusarium temperatum, an important corn pathogen in Europe, Asia and South America. A phylogenetic analysis employing the EF-1α sequence showed the isolate grouped with several species of the Gibberella fujikuroi species complex. Additionally, the isolate produced pectinase, xylanase, cellulase and lipase in culture and at 15 days post-inoculation, was able to infect the roots of corn. To our knowledge, this is the first confirmed identification and characterization of a phytopathogenic F. temperatum isolate from Mexico.

Molecular identification and in vitro susceptibility of Fusarium from fungal keratitis in central China

To detect the genotypes and in vitro antifungal susceptibility of Fusarium isolated from patients with fungal keratitis in central China. Partial translation elongation factor (EF) 1-α of 758 strains of Fusarium isolated from patients with fungal keratitis in Henan Eye Institute during 2002 to 2011 were sequenced. Species and genotypes of Fusarium were identified by conducting BLAST searches of the Fusarium ID database with partial EF1-α sequences as the query. The minimum inhibitory concentrations (MIC) of vorionazole, ketoconazole, terbinafine, natamycin, 5-flucytosine, fluconazol, amphotericin B, nystatin, econazole, clotrimazole, miconazole and itraconazole to 145 isolates of Fusarium were determined by microbroth dilution method according to Clinical Laboratory Standards Institute (CLSI) M38-A program. Among the 758 strains of Fusarium isolates, species of 653 strains were identified. 99.69% of the Fusarium strains were identified by EF1-asequences as Fusarium solani species complex (FSSC), Fusarium oxysporum species complex (FOSC) and Gibberella fujikuroi species complex (GFSC), 0.31% as Fusarium sp. Among the 653 isolates from cornea, FSSC was the predominant Fusarium, 386 isolates (59.11%), with 43 genotypes. The most common seen FSSC genotype was FSSC5-d (132/20. 21%), followed by FSSC3+4-eee (58/8.88%), FSSC3+4-ii (37/5.67%) and FSSC3+4-z (31/4.75%). The second complex was GFSC, 254 isolates (38.90%), with 3 species which were F.proliferatum (124 strains/18.99%), F.verticillioides (112 strains/17.15%) and GFSC (18 strains/2.76%) respectively. The third complex was FOSC, 11 (1.68%) strains, with 6 genotypes. The results of in vitro drug sensitivity test showed that Fusarium strains were sensitive to natamycin, vorionazole and amphotericin B, resistant to 5-fluorocytosine, fluconazole, nystatin, clotrimazole, miconazole. More than 50% of Fusarium strains were sensitive to econazole, ketoconazole, itraconazole and terbinafine. The MIC50 of FSSC to vorionazole, miconazole, terbinafine, Econazole and natamycin was higher than that of F.verticillioides, F.proliferatum and GFSC respectively. The predominant Fusarium complex of fungal keratitis in central China was FSSC, followed by GFSC. 43 genotypes were included in FSSC in which the most common seen FSSC genotype was FSSC5-d, followed by FSSC3+4-eee, FSSC3+4-ii and FSSC3+4-z. GFSC contained 3 species which were F.proliferatum, F.verticillioides and GFSC respectively. Different genotypes of Fusarium from keratitis had different susceptibility to vorionazole, terbinafine, natamycin and miconazole.

Isolation and Structure Elucidation of Fujikurins A-D: Products of the PKS19 Gene Cluster in Fusarium fujikuroi.

Fusarium fujikuroi is a member of the Gibberella fujikuroi species complex and well known for the production of gibberellins and mycotoxins including fusarins and fusaric acid. A recent genome sequencing study revealed that the fungus has the genetic potential to produce many more secondary metabolites than have been reported. This paper describes the structure elucidation of the products of the cryptic and silent PKS19 gene cluster that were recently identified (fujikurins A-D). We present the complete NMR data for the structure elucidation of the main compound fujikurin D, which shows tautomeric 1,3-diketo elements. The different tautomeric structures could be confirmed using quantum chemical calculations. Additionally, the structures of the minor compounds fujikurins A-C were elucidated by high-resolution mass spectrometric fragmentation experiments. It emerged that fujikurin A was identical to the bioactive compound CR377 of the taxonomically unclassified Fusarium strain CR377, while fujikurins B-D have not been reported from other fungi.

Inhibitory effects of antimicrobial agents against Fusarium species.

We investigated the inhibitory effects of antibacterial, biocidal, and antifungal agents against Fusarium spp. Seven Fusarium spp: four F. falciforme (Fusarium solani species complex), one Fusarium spp, one Fusarium spp. (Fusarium incarnatum-equiseti species complex), and one F. napiforme (Gibberella fujikuroi species complex), isolated from eyes with fungal keratitis were used in this study. Their susceptibility to antibacterial agents: flomoxef, imipenem, gatifloxacin, levofloxacin, moxifloxacin, gentamicin, tobramycin, and Tobracin® (contained 3,000 μg/ml of tobramycin and 25 μg/ml of benzalkonium chloride (BAK), a biocidal agent: BAK, and antifungal agents: amphotericin B, pimaricin (natamycin), fluconazole, itraconazole, miconazole, voriconazole, and micafungin, was determined by broth microdilution tests. The half-maximal inhibitory concentration (IC50), 100% inhibitory concentration (IC100), and minimum inhibitory concentration (MIC) against the Fusarium isolates were determined. BAK had the highest activity against the Fusarium spp. except for the antifungal agents. Three fluoroquinolones and two aminoglycosides had inhibitory effects against the Fusarium spp. at relatively high concentrations. Tobracin® had a higher inhibitory effect against Fusarium spp. than tobramycin alone. Amphotericin B had the highest inhibitory effect against the Fusarium spp, although it had different degrees of activity against each isolate. Our findings showed that fluoroquinolones, aminoglycosides, and BAK had some degree of inhibitory effect against the seven Fusarium isolates, although these agents had considerably lower effect than amphotericin B. However, the inhibitory effects of amphotericin B against the Fusarium spp. varied for the different isolates. Further studies for more effective medications against Fusarium, such as different combinations of antibacterial, biocidal, and antifungal agents are needed.

Novel taxa in the Fusarium fujikuroi species complex from Pinus spp.

The pitch canker pathogen Fusarium circinatum has caused devastation to Pinus spp. in natural forests and non-natives in commercially managed plantations. This has drawn attention to the potential importance of Fusarium species as pathogens of forest trees. In this study, we explored the diversity of Fusarium species associated with diseased Pinus patula, P. tecunumanii, P. kesiya and P. maximinoi in Colombian plantations and nurseries. Plants displaying symptoms associated with a F. circinatum-like infection (i.e., stem cankers and branch die-back on trees in plantations and root or collar rot of seedlings) were sampled. A total of 57 isolates were collected and characterised based on DNA sequence data for the translation elongation factor 1-α and β-tubulin gene regions. Phylogenetic analyses of these data allowed for the identification of more than 10 Fusarium species. These included F. circinatum, F. oxysporum, species within the Fusarium solani species complex and seven novel species in the Fusarium fujikuroi species complex (formerly the Gibberella fujikuroi species complex), five of which are described here as new. Selected isolates of the new species were tested for their pathogenicity on Pinus patula and compared with that of F. circinatum. Of these, F. marasasianum, F. parvisorum and F. sororula displayed levels of pathogenicity to P. patula that were comparable with that of F. circinatum. These apparently emerging pathogens thus pose a significant risk to forestry in Colombia and other parts of the world.

イプコナゾール上市前後における&lt;i&gt;Fusarium fujikuroi&lt;/i&gt;種複合体の菌種構成，ジベレリン生産性および同剤に対する感受性

Sensitivities to ipconazole of 50 isolates of the Fusarium (Gibberella) fujikuroi species complex (Ff complex) obtained from rice in Japan before 1994 (group A: before the launch of ipconazole) and 65 isolates after 1994 (group B) were investigated. Most isolates were identified as Fusarium fujikuroi, while 5 isolates in group A and 4 isolates in group B were identified as Fusarium proliferatum with species diagnostic PCR-RFLPs. The minimum inhibitory concentration (MIC) range, profiles in sensitivity to ipconazole and gibberellin production were similar in both groups. Gibberellin production was detected in the F. fujikuroi isolates with higher sensitivity to ipconazole but not in the isolates with lower sensitivity and F. proliferatum. High efficacy of ipconazole against rice “Bakanae” disease was confirmed by using the gibberellin-producing F. fujikuroi isolates in group B. No shift in sensitivity to ipconazole was verified and this may contribute to the stable efficacy against rice “Bakanae” disease.

Identification and Characterization of Fusarium Species Associated with Wilt of Eleocharis dulcis (Chinese water chestnut) in China.

Fusarium wilt is one of the most important diseases of Eleocharis dulcis (Chinese water chestnut) in China. In order to characterize the pathogens responsible, 69 Fusarium isolates were collected from diseased plants in E. dulcis production areas of the Chinese provinces Anhui, Fujian, Hubei, Hunan, Jiangsu, and Zhejiang. These were then identified based on morphological and molecular characteristics. F. commune was the most common species (92.8%) and was widely distributed in the six provinces. A novel species within the Gibberella fujikuroi species complex (GFSC) was found in Hubei and Zhejiang provinces (5.8%), and an unidentified Fusarium sp. was found only in Hubei province (1.4%). Thirty F. commune isolates from different provinces and four GFSC isolates were selected for sequence analyses of the translation elongation factor 1-α (EF-1α), the mitochondrial small subunit (mtSSU) ribosomal DNA, and the nuclear ribosomal intergenic spacer region (IGS). Maximum parsimony and Bayesian analyses of the multilocus sequence data of these two species plus other taxa showed that the two species formed two distinct, well-supported clades among the three individual and combined gene genealogies. Isolates from different locations were scattered, with no evidence of geographic specialization. Pathogenicity assays showed that the two Fusarium spp., including the unidentified Fusarium sp., were pathogenic to E. dulcis 'Tuanfeng seven'. There was no relationship between the source of isolates and their pathogenicity. This is the first description of F. commune, a novel species within the GFSC, and an unidentified Fusarium sp. as causal agents of Fusarium wilt of E. dulcis in China.

European Confederation of Medical Mycology (ECMM) epidemiological survey on invasive infections due to Fusarium species in Europe.

In order to better understand the epidemiology of fusariosis in Europe, a survey collecting information on the clinical characteristics of the patients infected by Fusarium as well as on the infecting isolates was launched. A total of 76 cases of invasive fusariosis occurring from January 2007 to June 2012 were collected and Fusarium isolates were identified by sequencing the translation elongation factor 1α (TEF) gene. Also, antifungal susceptibility was tested by broth microdilution according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Etest. Disseminated disease was considered proven in 46 cases and probable in 17 cases. Localised infection was seen in 13 cases. Gibberella fujikuroi species complex (SC), including Fusarium verticillioides and F. proliferatum, and F. solani SC were the most frequent aetiology of disseminated and localised infections, respectively. The crude mortality rate was 46 %, the highest associated with F. solani SC (67 %) and F. proliferatum (62.5 %). A wide range of antifungal susceptibilities was observed. Amphotericin B was the most potent antifungal in vitro, and itraconazole the least effective. The azoles exhibited lower minimum inhibitory concentrations (MICs) against F. verticillioides strains, with posaconazole having a slightly better performance, while F. solani SC isolates were resistant to all three azoles tested. The essential agreement between the Etest and the EUCAST method was 100 % for itraconazole and voriconazole, and 96 % for amphotericin B and posaconazole. In conclusion, we confirm that fusariosis is a rare but severe event in Europe, that G. fujikuroi SC is the predominant cause of deep infections and that different species have different antifungal in vitro susceptibility patterns.