Soil-borne Fungal Pathogens Research Articles

Antagonistic Effect of Biocontrol Agents on Aflatoxin producing Fungal Isolates from Contaminated Peanuts

Aflatoxins are the major and global concern in food and feed matrices. These fungi affect cereals, nuts and spices commodities during the pre and post harvesting treatments, handling and storage. The fungal isolates harbour within the crop or food material and lead to the production of toxin in these materials. Soil borne pathogenic fungi are responsible for significantly decreasing yield by affecting the crop. Aspergillus spp. is the prominent pathogen responsible for Aflatoxin contamination. Chemical control of this fungal pathogen may be harmful or can cause dangerous effects on consumers as well as on soil quality. However, the use of biological methods in controlling this plant pathogen is a beneficial technique for ecology and environment. So, these biocontrol agents are recommended as these are eco-friendly and reduce the growth of fungal pathogens and contaminants. Considering this in our current investigation, we have studied in vitro antagonistic activity of biocontrol agent- Trichoderma asperelloides against the aflatoxin producing fungi isolated from peanut. The study was carried out by performing the dual culture technique. Further the medium was also analysed for Aflatoxin content by using Ultra High-Performance Liquid Chromatography with Fluorescence Detection (UHPLC-FLD) technique.

Histone deacetylase SirE regulates development, DNA damage response and aflatoxin production in Aspergillus flavus.

Aspergillus flavus is a ubiquitous saprotrophic soil-borne pathogenic fungus that causes crops contamination with the carcinogen aflatoxins. Although sirtuin E (SirE) is known to be a NAD-dependent histone deacetylase involved in global transcriptional regulation. Its biological functions in A. flavus are not fully understood. To explore the effects of SirE, we found that SirE was located in the nucleus and increased the level of H3K56 acetylation. The ΔsirE mutant had the most severe growth defect in the sirtuin family. The RNA-Seq revealed that sirE was crucial for secondary metabolism production as well as genetic information process and oxidation-reduction in A. flavus. Further analysis revealed that the ΔsirE mutant increased aflatoxin production. Both the sirE deletion and H3K56 mutants were highly sensitive to DNA damage and oxidative stresses, indicating that SirE was required for DNA damage and redox reaction by the H3K56 locus. Furthermore, the ΔsirE mutant displayed high sensitivity to osmotic stress and cell wall stress, but they may not be associated with the H3K56. Finally, the catalytic activity site N192 of SirE was required for regulating growth, deacetylase function and aflatoxin production. Together, SirE is essential for histone deacetylation and biological function in A. flavus.

Plant growth promoting activities of P solubilizing bacteria and their impact on disease resistance in groundnut, <em>Arachis hypogaea</em> L. against soil borne fungal pathogens

Plant growth promoting (PGP) activities of soil bacteria directly help plants in taking up the nutrients, attuning the growth hormones and indirectly safeguard by inhibiting diverse groups of fungal pathogens. In this study, we explored the native P solubilizing bacteria (PSB) isolated from the acid soils (pH < 5.5) of Odisha for selection of efficient PGPR with antifungal potential. Five PSB strainswere checked for their P solubilization efficiencies with Ca3(PO4)2,AlPO4,FePO4 and Fe3(PO4)2. The bioconversion of P by all the five strains in the broth medium followed the order Ca-P > Fe(III)-P > Fe(II)-P >Al-P. The strains interestingly showed potential plant growthpromoting properties including indole acetic acid (IAA) andsiderophore production in in vitro tests. These five strains also exhibited antifungal activities against fungal pathogens( Pythium aphanidermatum, Fusarium oxysporum, Pythium debaryanum, Thanatephorus cucumeris and Aspergillus niger )of groundnut. A field study was carried out with two of the above PSB strains [identified as Bacillus amyloliquefaciens (KT633845) and Burkholderia cepacia (KT717633)] with groundnut. Both the stains significantly influenced the plantgrowth (plant height, nodule no. and nodule dry weight) and pod yield. However, these two strains inoculated along withdoses of inorganic phosphate (SSP, single super phosphate) resulted in significantly higher pod yield as well as residual soil P.Additionally; the prevalence of both seedling mortality and plant mortality due to collar rot and stem rot were found to bereduced significantly in the inoculated plots. The findings substantiate the growth promoting ability of the two P solubilizingstrains, and thus qualifies to be used as biofertilizers either alone or as components of INM practices

Synthetic microbial consortia derived from rhizosphere soil protect wheat against a soilborne fungal pathogen.

Synthetic microbial communities (SynComs) could potentially enhance some functions of the plant microbiome and emerge as a promising inoculant for improving crop performance. Here, we characterized a collection of bacteria, previously isolated from the wheat rhizosphere, for their antifungal activity against soilborne fungal pathogens. Ten SynComs with different compositions from 14 bacterial strains were created. Seven SynComs protected wheat from Rhizoctonia solani AG8 infection, although SynComs were not more effective than single strains in reducing wheat root rot disease. Further, the mechanisms of interaction of the tested bacteria with each other and plants were explored. We found that nine bacteria and nine SynComs impacted the root growth of Arabidopsis. Nine bacteria and four SynComs significantly inhibited the growth of AG8 by producing volatiles. The cell-free supernatants from six bacteria inhibited the growth of AG8. Together, this study provided the potential for improving crop resilience by creating SynComs.

FoCupin1, a Cupin_1 domain-containing protein, is necessary for the virulence of Fusarium oxysporum f. sp. cubense tropical race 4.

Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) is an important soilborne fungal pathogen that causes the most devastating banana disease. Effectors secreted by microbes contribute to pathogen virulence on host plants in plant-microbe interactions. However, functions of Foc TR4 effectors remain largely unexplored. In this study, we characterized a novel cupin_1 domain-containing protein (FoCupin1) from Foc TR4. Sequence analysis indicated that the homologous proteins of FoCupin1 in phytopathogenic fungi were evolutionarily conserved. Furthermore, FoCupin1 could suppress BAX-mediated cell death and significantly downregulate the expression of defense-related genes in tobacco by using the Agrobacterium-mediated transient expression system. FoCupin1 was highly induced in the early stage of Foc TR4 infection. The deletion of FoCupin1 gene did not affect Foc TR4 growth and conidiation. However, FoCupin1 deletion significantly reduced Foc TR4 virulence on banana plants, which was further confirmed by biomass assay. The expression of the defense-related genes in banana was significantly induced after inoculation with FoCupin1 mutants. These results collectively indicate FoCupin1 is a putative effector protein that plays an essential role in Foc TR4 pathogenicity. These findings suggest a novel role for cupin_1 domain-containing proteins and deepen our understanding of effector-mediated Foc TR4 pathogenesis.

Members of the Fusarium oxysporum Complex Causing Wilt Symptoms inMedical Cannabis in Israel, Italy, and North America Comprise a Polyphyletic Assemblage.

Members of the Fusarium oxysporum complex are ubiquitous soilborne fungal pathogens causing wilt diseases in various plant hosts. Fusarium oxysporum (Fo) f. sp. cannabis was first reported causing wilt disease in hemp in Italy in 1962. To date, Fusarium wilt continues to cause concern in industrial and medicinal cannabis cultivation worldwide. During a 3-year period (2018 to 2021), Fo strains were isolated from medical cannabis plants (Cannabis sativa) exhibiting wilt symptoms that were cultivated in numerous commercial farms in Israel. A diverse set of these strains was subjected to molecular phylogenetic analyses to assess their genetic diversity and to compare them with other f. sp. cannabis isolates included in prior studies. Maximum likelihood bootstrap analysis of a partial translation elongation factor (TEF1) dataset, which included 24 f. sp. cannabis sequences, revealed that the 11 strains from Israel comprised five TEF1 haplotypes. Two of the haplotypes from Israel were identical to isolates previously reported from British Columbia and California and British Columbia and Ontario. Overall, the 24 f. sp. cannabis sequences included 12 unique TEF1 haplotypes. These were phylogenetically diverse, suggesting that pathogenicity to C. sativa may have evolved independently within the F. oxysporum complex. Pathogenicity tests of the Israeli strains were confirmed by Koch's postulates assays. Strains of the five different f. sp. cannabis TEF1 haplotypes all caused wilt in cannabis seedlings but with varying levels of aggressiveness. The same isolates that originated from asymptomatic infected mother plants were found in wilted cuttings indicating that the pathogen can be spread via propagation material.

Overexpression of 42 kDa chitinase genes from Trichoderma asperellum SH16 in peanut (Arachis hypogaea)

ABSTRACT In tropical and subtropical areas, peanuts are a very important legume crop that is widely cultivated for food and cooking oil. They are, however, extremely susceptible to a wide range of phytopathogens, particularly soil-borne fungi, which result in low yields and poor seed quality. This study aimed to express three Trichoderma asperellum SH16 42 kDa chitinase-encoding genes in peanut to improve their resistance to some soil-borne fungi. Chi42 is a synthetic, intronless, wild-type gene, whereas syncodChi42-1 and syncodChi42-2 are peanut codon-optimized synthetic genes. These genes were introduced into a local peanut strain through Agrobacterium-mediated transformation. Analysis of the transgenic peanut lines showed that chitinase-specific activities from the syncodChi42-1 and syncodChi42-2 genes were approximately 1.2 and 1.4 times higher than those of the wild-type gene, respectively. The engineered peanut plants also exhibited antifungal activity against the soil-borne pathogenic fungus Sclerotium rolfsii. The transgenic peanut lines transformed with the two synthetic genes have stronger antifungal activities than those transformed with the wild-type version, suggesting that they could be used as novel peanut lines to combat phytopathogenic fungi.

Identification of Pseudomonas strains for the biological control of soybean red crown root rot

Soybean red crown root rot (RCR), caused by the soil-borne fungal pathogen, Calonectria ilicicola, is the most destructive disease affecting soybean production in Japan. To date, no resistant cultivars or effective fungicides have been developed to control this disease. In this study, we evaluated 13 bacterial strains to determine their efficacy in controlling C. ilicicola. We first investigated whether the volatile organic compounds (VOCs) emitted by the bacterial strains exhibited any antifungal activity against C. ilicicola using the double-plate chamber method. The results showed that VOCs from three Pseudomonas bacterial strains, OFT2 (Pseudomonas sp.), OFT5 (Pseudomonas sp.), and Cab57 (Pseudomonas protegens), exhibited strong inhibitory activity against C. ilicicola mycelial growth. Some antifungal activity was also observed in the culture supernatants of these Pseudomonas strains. Greenhouse soil inoculation tests showed that application of OFT2, OFT5, and Cab57 cultures around soybean seeds after seed sowing significantly reduced the severity of RCR, as shown by up to 40% reduction in C. ilicicola fungal growth in the roots and 180–200% increase in shoot and root fresh weights compared to the water control. Our results suggest that OFT2, Cab57, and OFT5 produce potent antifungal compounds against C. ilicicola, thereby showing considerable potential for the biological control of C. ilicicola during soybean production.

Meta-analysis of fungal plant pathogen Fusarium oxysporum infection-related gene profiles using transcriptome datasets.

Fusarium oxysporum is a serious soil-borne fungal pathogen that affects the production of many economically important crops worldwide. Recent reports suggest that this fungus is becoming the dominant species in soil and could become the main infectious fungus in the future. However, the infection mechanisms employed by F. oxysporum are poorly understood. In the present study, using a network meta-analysis technique and public transcriptome datasets for different F. oxysporum and plant interactions, we aimed to explore the common molecular infection strategy used by this fungus and to identify vital genes involved in this process. Principle component analysis showed that all the fungal culture samples from different datasets were clustered together, and were clearly separated from the infection samples, suggesting the feasibility of an integrated analysis of heterogeneous datasets. A total of 335 common differentially expressed genes (DEGs) were identified among these samples, of which 262 were upregulated and 73 were downregulated significantly across the datasets. The most enriched functional categories of the common DEGs were carbohydrate metabolism, amino acid metabolism, and lipid metabolism. Nine co-expression modules were identified, and two modules, the turquoise module and the blue module, correlated positively and negatively with all the infection processes, respectively. Co-expression networks were constructed for these two modules and hub genes were identified and validated. Our results comprise a cross fungal-host interaction resource, highlighting the use of a network biology approach to gain molecular insights.

Antifungal Activity and Plant Growth-Promoting Properties of Bacillus mojovensis B1302 against Rhizoctonia Cerealis.

Rhizoctonia cerealis is a worldwide soil-borne pathogenic fungus that significantly infects wheat and causes sharp eyespot in China. However, the biocontrol strains used for the control of Rhizoctonia cerealis are insufficient. In the present study, antagonistic strain B1302 from the rhizosphere of wheat were isolated and identified as Bacillus mojovensis based on their morphological, physiological, and biochemical characteristics, and their 16S rDNA sequence. Culture filtrate of strain B1302 had a broad antifungal spectrum. In order to improve the antifungal activity of B1302, response surface methodology (RSM) was used to optimize the culture conditions. The final medium composition and culture conditions were 13.2 g/L of wheat bran, 14.1 g/L of soybean meal, 224 r/min of rotation speed, 7.50 of initial pH, and 1.5 × 108 CFU/mL of inoculation amount at 35 °C for a culture duration of 72 h. B. mojavensis B1302 inhibited the hyphae growth of R. cerealis and produced hydrolytic enzymes (protease, chitinase, and glucanase), IAA, and had N-fixing potentiality and P-solubilisation capacity. It can also promote wheat seedling growth in potted plants. The disease incidence and index of wheat seedlings were consistent with the effect of commercial pesticides under treatment with culture filtrate. The biocontrol efficacy of culture filtrate was significant—up to 65.25%. An animal toxicological safety analysis suggested that culture filtrate was safe for use and could be developed into an effective microbial fungicide to control wheat sharp eyespot.

Identification of reference genes and their validation for gene expression analysis in phytopathogenic fungus Macrophomina phaseolina.

Macrophomina phaseolina is a soil-borne pathogenic fungus that infects a wide range of crop species and causes severe yield losses. Although the genome of the fungus has been sequenced, the molecular basis of its virulence has not been determined. Identification of up-regulated genes during fungal infection is important to understand the mechanism involved in its virulence. To ensure reliable quantification, expression of target genes needs to be normalized on the basis of certain reference genes. However, in the case of M. phaseolina, reference genes or their expression analysis have not been reported in the literature. Therefore, the objective of this study was to evaluate 12 candidate reference genes for the expression analysis of M. phaseolina genes by applying three different fungal growth conditions: a) during root and stem infection of soybean, b) in culture media with and without soybean leaf infusion and c) by inoculating a cut-stem. Based on BestKeeper, geNorm and NormFinder algorithms, CYP1 was identified as the best recommended reference gene followed by EF1β for expression analysis of fungal gene during soybean root infection. Besides Mp08158, CYP1 gene was found suitable when M. phaseolina was grown in potato-dextrose broth with leaf infusion. In the case of cut-stem inoculation, Mp08158 and Mp11185 genes were found to be most stable. To validate the selected reference genes, expression analysis of two cutinase genes was performed. In general, the expression patterns were similar when the target genes were normalized against most or least stable gene. However, in some cases different expression pattern can be obtained when least stable gene is used for normalization. We believe that the reference genes identified and validated in this study will be useful for gene expression analysis during host infection with M. phaseolina.

Root-secreted bitter triterpene modulates the rhizosphere microbiota to improve plant fitness.

Underground microbial ecosystems have profound impacts on plant health1-5. Recently, essential roles have been shown for plant specialized metabolites in shaping the rhizosphere microbiome6-9. However, the potential mechanisms underlying the root-to-soil delivery of these metabolites remain to be elucidated10. Cucurbitacins, the characteristic bitter triterpenoids in cucurbit plants (such as melon and watermelon), are synthesized by operon-like gene clusters11. Here we report two Multidrug and Toxic Compound Extrusion (MATE) proteins involved in the transport of their respective cucurbitacins, a process co-regulated with cucurbitacin biosynthesis. We further show that the transport of cucurbitacin B from the roots of melon into the soil modulates the rhizosphere microbiome by selectively enriching for two bacterial genera, Enterobacter and Bacillus, and we demonstrate that this, in turn, leads to robust resistance against the soil-borne wilt fungal pathogen, Fusarium oxysporum. Our study offers insights into how transporters for specialized metabolites manipulate the rhizosphere microbiota and thereby affect crop fitness.

TOUCH 3 and CALMODULIN 1/4/6 cooperate with calcium-dependent protein kinases to trigger calcium-dependent activation of CAM-BINDING PROTEIN 60-LIKE G and regulate fungal resistance in plants.

Plants utilize localized cell-surface and intracellular receptors to sense microbes and activate the influx of calcium, which serves as an important second messenger in eukaryotes to regulate cellular responses. However, the mechanisms through which plants decipher calcium influx to activate immune responses remain largely unknown. Here, we show that pathogen-associated molecular patterns (PAMPs) trigger calcium-dependent phosphorylation of CAM-BINDING PROTEIN 60-LIKE G (CBP60g) in Arabidopsis (Arabidopsis thaliana). CALCIUM-DEPENDENT PROTEIN KINASE5 (CPK5) phosphorylates CBP60g directly, thereby enhancing its transcription factor activity. TOUCH 3 (TCH3) and its homologs CALMODULIN (CAM) 1/4/6 and CPK4/5/6/11 are required for PAMP-induced CBP60g phosphorylation. TCH3 interferes with the auto-inhibitory region of CPK5 and promotes CPK5-mediated CBP60g phosphorylation. Furthermore, CPKs-mediated CBP60g phosphorylation positively regulates plant resistance to soil-borne fungal pathogens. These lines of evidence uncover a novel calcium signal decoding mechanism during plant immunity through which TCH3 relieves auto-inhibition of CPK5 to phosphorylate and activate CBP60g. The findings reveal cooperative interconnections between different types of calcium sensors in eukaryotes.

Identification of Genomic Regions Associated with Fusarium Wilt Resistance in Cowpea

Fusarium wilt (FW), caused by the soil-borne fungal pathogen Fusarium oxysporum f. sp. Tracheiphilum, is a serious threat to cowpea production worldwide. Understanding the genetic architecture of FW resistance is a prerequisite to combatting this disease and developing FW resistance varieties. In the current study, a genetic diversity panel of 99 cowpea accessions was collected, and they were infected by a single strain, FW-HZ. The disease index (DI) based on the two indicators of leaf damage (LFD) and vascular discoloration (VD) varied highly across the population: most accessions were susceptible, and only seven accessions showed resistant phenotypes by both indicators. Through a genome-wide association study (GWAS), 3 and 7 single nucleotide polymorphisms (SNPs) significantly associated with LFD and VD were detected, respectively, which were distributed on chromosomes 3, 4, 5, 6 and 9, accounting for 0.68–13.92% of phenotypic variation. Based on the cowpea reference genome, 30 putative genes were identified and proposed as the likely candidates, including leucine-rich repeat protein kinase family protein, protein kinase superfamily protein and zinc finger family protein. These results provide novel insights into the genetic architecture of FW resistance and a basis for molecular breeding of FW resistant cultivars in cowpea.

Soil-borne plant pathogenic fungi biodiversity of sunflower

Diseases caused by soil-borne phytopathogenic fungi are a serious problem for agricultural crops, including sunflower crops. The limited possibilities of measures to control them further increases the interest and focus on them. This article reveals data on the species composition, occurrence rate of soil-borne plant pathogenic fungi isolated from the soil of sunflower. Here, 11 species of true fungi and 1 species of oomycetes have been isolated. The highest incidence rate was recorded in the Fusarium oxysporum fungi species. During the study, pathogenic fungi specific to sunflower have also been isolated.

Impact of Collembola on the Winter Wheat Growth in Soil Infected by Soil-Borne Pathogenic Fungi

The activity of some soil organisms can significantly influence the growth of plants. One of the more common are Collembola, which play an important role in suppressing soil-borne pathogens such as Fusarium spp. Here, Folsomia candida was taken for laboratory studies. The aim of the study was to assess whether springtails influence the growth of wheat and pea plants. The purpose was also to evaluate whether Collembola will reduce the occurrence of fungal diseases, presumably by feeding on fungi. The factors tested were (1) wheat grown individually or in the mixture with pea; (2) number of Collembola; and (3) the pathogenic presence of the plant fungus Fusarium culmorum. The experiment was carried out in four replicates for each treatment in two series. The soil used for the test was a mixture of field soil, sand, and peat. The following analyses were performed: measuring plant growth and decomposition rate, assessment of plant infection, and assessment of F. culmorum in springtails bodies. There was no effect of F. culmorum infection on plant growth, although the pathogen was present in the root neck of the plants incubated with this fungus. Collembola decreased the number of fungus colonies isolated from plants by about 45% in comparison to pots incubated without these organisms. The decomposition of plant biomass was accelerated by springtails by about 7% in the pots with moderate Collembola number. However, this was not related to improved plant growth. Additionally, F. culmorum was isolated from the bodies of Collembola, indicating its ability to feed on this fungus. To conclude, it was found that Collembola can decrease pathogenic fungal growth. This issue needs further studies in relation to other plants and fungus species, as well to study observed effects in the field conditions.

Comparative transcriptome analysis reveals the resistance regulation mechanism and fungicidal activity of the fungicide phenamacril in Fusarium oxysporum

Fusarium oxysporum (Fo) is an important species complex of soil-borne pathogenic fungi that cause vascular wilt diseases of agricultural crops and some opportunistic diseases of humans. The fungicide phenamacril has been extensively reported to have antifungal activity against Fusarium graminearum and Fusarium fujikuroi. In this study, we found that the amino acid substitutions (V151A and S418T) in Type I myosin FoMyo5 cause natural low resistance to phenamacril in the plant pathogenic Fo isolates. Therefore, we compared the transcriptomes of two phenamacril-resistant Fo isolates FoII5, Fo1st and one phenamacril-sensitive isolate Fo3_a after 1 μg/mL phenamacril treatment. Among the 2728 differentially expressed genes (DEGs), 14 DEGs involved in oxidation–reduction processes and MFS transporters, were significantly up-regulated in phenamacril-resistant isolates. On the other hand, 14 DEGs involved in ATP-dependent RNA helicase and ribosomal biogenesis related proteins, showed significantly down-regulated expression in both phenamacril-resistant and -sensitive isolates. These results indicated that phenamacril not only seriously affected the cytoskeletal protein binding and ATPase activity of sensitive isolate, but also suppressed ribosome biogenesis in all the isolates. Hence, this study helps us better understand resistance regulation mechanism and fungicidal activity of phenamacril and provide reference for the development of new fungicides to control Fo.

Growth-Promoting and Protective Effect of Trichoderma atrobrunneum and T. simmonsii on Tomato against Soil-Borne Fungal Pathogens

Trichoderma fungi are promising candidates for biocontrol agents and plant growth promoters. Trichoderma atrobrunneum and T. simmonsii were evaluated for the control of soil-borne phytopathogenic fungi, in the present study. Dual culture tests with Rhizoctonia solani and Fusarium oxysporum f. sp. lycopersici were used to conduct in vitro evaluation. In the presence of Trichoderma, phytopathogen’s growth rate was inhibited up to 59.70% for R. solani and 42.57% for F. oxysporum. Greenhouse trials with potted tomato plants demonstrated that Trichoderma caused a significant increase of stem height and fresh stem weight in pathogen-inoculated plants, compared with the negative control (plants artificially inoculated with the phytopathogen only). Except for T. simmonsii, plant growth was not significantly enhanced by a Trichoderma presence in the positive control (healthy plants). The overall performance of the two Trichoderma species studied was equivalent to that of the T. harzianum T22 commercial strain. All the tested species were found to be effective in suppressing colony growth and disease development of the soil borne pathogens in dual cultures and potted plants, indicating that they could be used as biocontrol agents. Our findings are discussed in the context of enhancing endophytic microorganisms’ application in crop production systems.

The secreted ribonuclease T2 protein FoRnt2 contributes to Fusarium oxysporum virulence.

Secreted RNase proteins have been reported from only a few pathogens, and relatively little is known about their biological functions. Fusarium oxysporum is a soilborne fungal pathogen that causes Fusarium wilt, one of the most important diseases on tomato. During the infection of F. oxysporum, some proteins are secreted that modulate host plant immunity and promote pathogen invasion. In this study, we identify an RNase, FoRnt2, from the F. oxysporum secretome that belongs to the ribonuclease T2 family. FoRnt2 possesses an N‐terminal signal peptide and can be secreted from F. oxysporum. FoRnt2 exhibited ribonuclease activity and was able to degrade the host plant total RNA in vitro dependent on the active site residues H80 and H142. Deletion of the FoRnt2 gene reduced fungal virulence but had no obvious effect on mycelial growth and conidial production. The expression of FoRnt2 in tomato significantly enhanced plant susceptibility to pathogens. These data indicate that FoRnt2 is an important contributor to the virulence of F. oxysporum, possibly through the degradation of plant RNA.

Pest categorisation of Fusarium pseudograminearum.

The EFSA Plant Health Panel performed a pest categorisation of Fusarium pseudograminearum O'Donnell & T. Aoki. F. pseudograminearum is a soil‐borne fungal pathogen, able to cause a disease known as Fusarium crown rot (FCR, also known as foot and root rot) and occasionally Fusarium head blight on small grain cereals, particularly Triticum aestivum L., Triticum turgidum L. spp. durum (Dest.), Hordeum vulgare L. and triticale (xTriticosecale). In addition, F. pseudograminearum has been isolated from soybean (Glycine max L.) and from some grass genera, such as Phalaris, Agropyron and Bromus, which represent potentially important inoculum reservoirs. This pathogen has been reported in arid and semi‐arid cropping regions in Australia, New Zealand, North and South America, northern Africa and South Africa, the Middle East and Asia. In the EU, it has been reported in Italy since 1994 and later in Spain on field‐grown durum wheat, but uncertainty remains regarding the actual distribution of the pathogen in the EU. The pathogen is not included in the EU Commission Implementing Regulation 2019/2072. Seeds of host plants and soil and other substrates are the main pathways for the entry and spread of the pathogen into the EU. There are no reports of interceptions of F. pseudograminearum in the EU. Host availability and climate suitability occurring in the EU favour establishment of the pathogen and allow it to establish in areas from which it has not been reported. Phytosanitary measures are available to prevent the introduction of the pathogen into the EU, and additional measures are available to mitigate the risk of spread. In the non‐EU areas of its present distribution, the pathogen has a direct impact on cultivated hosts (e.g. wheat, barley, triticale and soybean) that are also relevant for the EU. However, no crop losses have been reported so far in the EU. The Panel concludes that F. pseudograminearum satisfies all the criteria to be regarded as a potential Union quarantine pest.