Disease Of Wheat Research Articles

A cell wall invertase modulates resistance to fusarium crown rot and sharp eyespot in common wheat.

Fusarium crown rot (FCR) and sharp eyespot (SE) are serious soil-borne diseases in wheat and its relatives that have been reported to cause wheat yield losses in many areas. In this study, the expression of a cell wall invertase gene, TaCWI-B1, was identified to be associated with FCR resistance through a combination of bulk segregant RNA sequencing and genome resequencing in a recombinant inbred line population. Two bi-parental populations were developed to further verify TaCWI-B1 association with FCR resistance. Overexpression lines and ethyl-methanesulfonate (EMS) mutants revealed TaCWI-B1 positively regulating FCR resistance. Determination of cell wall thickness and components showed that the TaCWI-B1-overexpression lines exhibited considerably increased thickness and pectin and cellulose contents. Furthermore, we found that TaCWI-B1 directly interacted with an alpha-galactosidase (TaGAL). EMS mutants showed that TaGAL negatively modulated FCR resistance. The expression of TaGAL is negatively correlated with TaCWI-B1 levels, thus may reduce mannan degradation in the cell wall, consequently leading to thickening of the cell wall. Additionally, TaCWI-B1-overexpression lines and TaGAL mutants showed higher resistance to SE; however, TaCWI-B1 mutants were more susceptible to SE than controls. This study provides insights into a FCR and SE resistance gene to combat soil-borne diseases in common wheat. Short Summary: A cell wall invertase gene TaCWI was cloned and associated with resistance against Fusarium crown rot and sharp eyespot in common wheat, and an underlying molecular mechanism was proposed, in which TaCWI conferring thickened cell wall counteracts the effects of TaGAL, an alpha-galactosidase gene associated with susceptibility to the two diseases. This article is protected by copyright. All rights reserved.

Lightweight Multiscale CNN Model for Wheat Disease Detection

Wheat disease detection is crucial for disease diagnosis, pesticide application optimization, disease control, and wheat yield and quality improvement. However, the detection of wheat diseases is difficult due to their various types. Detecting wheat diseases in complex fields is also challenging. Traditional models are difficult to apply to mobile devices because they have large parameters, and high computation and resource requirements. To address these issues, this paper combines the residual module and the inception module to construct a lightweight multiscale CNN model, which introduces the CBAM and ECA modules into the residual block, enhances the model’s attention to diseases, and reduces the influence of complex backgrounds on disease recognition. The proposed method has an accuracy rate of 98.7% on the test dataset, which is higher than classic convolutional neural networks such as AlexNet, VGG16, and InceptionresnetV2 and lightweight models such as MobileNetV3 and EfficientNetb0. The proposed model has superior performance and can be applied to mobile terminals to quickly identify wheat diseases.

Mapping of leaf rust resistance genes in common wheat ‘Guinong08-6’

Wheat leaf rust (Puccinia triticina Eriks.), a devastating disease of wheat in the world, causes severe yield losses and therefore the development of resistant cultivars is very important. Here, a Chinese wheat line (Guinong08-6) showed adult-plant resistance against mixed fungal isolates of leaf rust, which is common in Guiyang region. It was crossed with a susceptible wheat line (Guinong19) to develop F1, F2, and F3 hybrids. Combined SSR and STS markers were used to map leaf rust resistance genes in Guinong08-6, and the resistance phenotype of Guinong08-6 was co-regulated by two complementary dominant genes, named LrGn08-6A and LrGn08-6B. LrGn08-6A was mapped to chromosome 2AS with markers URIC-LN2 and Xgpw2204, which flanked the gene at distances of 1.8 centimorgan (cM) and 14.83 cM, respectively. LrGn08-6B was mapped to chromosome 4DL with markers Xgpw342 and Xbarc93, which both flanked the gene at a distance of 26.57 cM. Genetic and molecular marker analyses demonstrated that LrGn08-6A, which was inherited from Aegilops ventricosa may be the resistance gene Lr37, while LrGn08-6B may be a newly discovered leaf rust resistance gene.

Fungal Growth Inhibition of Bipolaris sorokiniana Causal Agent of Wheat Diseases and Activating Defense Systems of Plants Using Algae Extracts

Fungal Growth Inhibition of Bipolaris sorokiniana Causal Agent of Wheat Diseases and Activating Defense Systems of Plants Using Algae Extracts

IMPACTS OF CLIMATE CHANGE, FORMS, AND EXCESS OF NITROGEN FERTILIZERS ON THE DEVELOPMENT OF WHEAT FUNGAL DISEASES

Background. Global climate change and excessive nitrogen application has become a significant issue and inevitably threatens sustainable wheat production, not only with direct negative effects on crop growth but also with profound impacts on biology and pest and disease management.
 Purpose. This review addresses the current challenges, namely the negative effects of climate change and the forms and excess of nitrogen-rich fertilizers on the development of fungal diseases in wheat, as well as management strategies.
 Materials and methods. To achieve the stated objective of the study, the scientific literature published during the last 20 years on the impacts of climate change and the forms and excesses of nitrogen fertilizers on the development of fungal diseases and on the yield of wheat were reviewed.
 Results. Thus, in mitigating these challenges, it is necessary to optimize the dose of nitrogen fertilizers, apply nitrogen in the form of nitrate, ammonium sulphate, ammonium nitrate, and coated urea fertilizers, to use silicate fertilizers such as calcium, magnesium, and potassium silicate, and to perform a long rotation of wheat through perennial legumes and leguminous crops, as well as to develop, through genome editing, varieties with high yield potential, resistant to biotic and abiotic stresses, and of good end-use quality, or plant new cereals that have needs for heat and a longer reproductive growth period.
 Conclusion. To develop an effective agricultural management strategy, future research should be based on the study of the interactions among crops, pests, pathogens and farming system under climate change, taking into account all parameters such as temperature increase and CO2, extreme precipitation, etc. A sufficient number of results must be published to be able to draw meaningful conclusions.

Suppression of ZEAXANTHIN EPOXIDASE 1 restricts stripe rust growth in wheat

Reducing losses caused by pathogens is an effective strategy for stabilizing crop yields. Daunting challenges remain in cloning and characterizing genes that inhibit stripe rust, a devastating disease of wheat (Triticum aestivum) caused by Puccinia striiformis f. sp. tritici (Pst). We found that suppression of wheat zeaxanthin epoxidase 1 (ZEP1) increased wheat defense against Pst. We isolated the yellow rust slower 1 (yrs1) mutant of tetraploid wheat in which a premature stop mutation in ZEP1-B underpins the phenotype. Genetic analyses revealed increased H2O2 accumulation in zep1 mutants and demonstrated a correlation between ZEP1 dysfunction and slower Pst growth in wheat. Moreover, wheat kinase START 1.1 (WKS1.1, Yr36) bound, phosphorylated, and suppressed the biochemical activity of ZEP1. A rare natural allele in the hexaploid wheat ZEP1-B promoter reduced its transcription and Pst growth. Our study thus identified a novel suppressor of Pst, characterized its mechanism of action, and revealed beneficial variants for wheat disease control. This work opens the door to stacking wheat ZEP1 variants with other known Pst resistance genes in future breeding programs to enhance wheat tolerance to pathogens.

Integrated management of yellow rust caused by Puccinia striiformis f. sp. tritici in wheat

Introduction. Yellow rust caused by Puccinia striiformis f. sp. tritici, is currently the main disease of wheat (Triticum aestivum) in the north of the province of Buenos Aires, Argentina. It has caused yield losses close to 20 %. Objective. To evaluate the effect of different agronomic management systems on wheat yield and incidence of yellow rust. Materials and methods. The trial was carried out in the town of Pergamino, Buenos Aires, Argentina, during the years 2019, 2020, and 2021. The experimental design was in subdivided plots, the largest plot was with and without cover crop, the subplot was agronomic management, and the sub-subplot the application was foliar fungicide at different phenological stages of the wheat crop. Results. With the use of foliar fungicides in stages close to stem elongation and the use of a cultivar resistant to the disease produced a reduction in the area under the disease progress curve (AUCPE) by 62.50 %, which translated into significant grain yield increases of 29.52 %. Foliar fungicide application resulted in a 16.94 % increase in wheat yield. The implementation of a sustainable integrated management system generated yield increases of 29.52 %. Conclusions. The use of a resistant cultivar and the application of a foliar fungicide at early stages and with low levels of the disease, significantly reduced the AUCPE of yellow rust and increased the wheat yield in experimental plots.

Effective sources of powdery mildew resistance among spring bread wheat for the northwest of the russian federation

Background. Bread wheat (Triticum aestivum L.) is one of the world’s main food crops. In Russia, its gross harvest in recent years has reached 21.079 million tons. Blumeria graminis is one of the most harmful diseases of bread wheat. Annual harvest losses can reach 10–30%. In Leningrad Province, powdery mildew appears almost every year on cereals. Development of cultivars resistant to powdery mildew is the most important trend in spring bread wheat breeding. Its progress is determined by new sources of effective resistance genes and their incorporation into promising spring bread wheat cultivars. The purpose of this work was to retest the seedling and adult resistance to powdery mildew in spring bread wheat accessions selected over a period of more than twenty years and redefine the effectiveness of disease resistance sources at the present time.Materials and methods. Since 2000, VIR has conducted a search for powdery mildew resistance among 1283 spring bread wheat accessions. The identified 36 sources of adult and seedling powdery mildew resistance were reevaluated in 2022. Field and laboratory studies into the resistance to the pathogen were performed according to VIR’s guidelines.Results and discussion. In 2022, field and laboratory studies of spring bread wheat cultivars revealed accessions with resistance to the pathogen in all phases of plant development. Six sources remained resistant to powdery mildew for 13–22 years, another six showed resistance for 7–12 years, and 8 cultivars were immune for 6 years. Resistance of 9 accessions identified for this trait in 2020 was confirmed.Conclusion. Field and laboratory research into the resistance of spring bread wheat accessions to the pathogen identified sources retaining seedling and adult resistance to the Leningrad population of powdery mildew for 7 years or more. These accessions are recommended for use in wheat breeding programs.

Evaluation of Inoculation Methods for Determination of Winter Wheat Resistance to Fusarium Head Blight

One of the most severe winter wheat (Triticum aestivum L.) diseases is Fusarium head blight (FHB). It is believed that selection for resistance to FHB is better in high disease pressure environments, for which various methods of artificial inoculation are used. The standard spray method of artificial inoculation is believed to be technically demanding and labour intensive. Therefore, scattering Fusarium-infected maize stalks onto trial plots after wheat emergence is suggested as a suitable alternative. The aim of this study was to compare the mean values and heritability of the visual rating index (VRI) and the percentage of Fusarium-damaged kernels (FDK) between the two abovementioned methods of artificial inoculation and natural infection, and to determine the phenotypic correlations between the three methods for the studied traits. The achieved levels of VRI and FDK were comparable for the two methods of artificial inoculation and considerably lower under natural conditions. Heritability for VRI ranged over four years from 0.68 to 0.91 for the spray method, from 0.73 to 0.95 for the infected maize stalks, and from 0.26 to 0.65 for natural infection, whereas for FDK it ranged from 0.56 to 0.85, 0.38 to 0.83, and 0.11 to 0.44 for the three inoculation methods, respectively. The strong positive correlation between the two applied methods of artificial inoculation for studied traits suggests that scattering infected maize stalks could serve as a reliable supplement for the technically and labor-intensive spray method of artificial inoculation.

Comparative transcriptomics identifies the key in planta-expressed genes of Fusarium graminearum during infection of wheat varieties.

Fusarium head blight (FHB), caused mainly by the fungus Fusarium graminearum, is one of the most devastating diseases in wheat, which reduces the yield and quality of grain. Fusarium graminearum infection of wheat cells triggers dynamic changes of gene expression in both F. graminearum and wheat, leading to molecular interactions between pathogen and host. The wheat plant in turn activates immune signaling or host defense pathways against FHB. However, the mechanisms by which F. graminearum infects wheat varieties with different levels of host resistance are largely limited. In this study, we conducted a comparative analysis of the F. graminearum transcriptome in planta during the infection of susceptible and resistant wheat varieties at three timepoints. A total of 6,106F. graminearum genes including those functioning in cell wall degradation, synthesis of secondary metabolites, virulence, and pathogenicity were identified during the infection of different hosts, which were regulated by hosts with different genetic backgrounds. Genes enriched with metabolism of host cell wall components and defense response processes were specifically dynamic during the infection with different hosts. Our study also identified F. graminearum genes that were specifically suppressed by signals derived from the resistant plant host. These genes may represent direct targets of the plant defense against infection by this fungus. Briefly, we generated databases of in planta-expressed genes of F. graminearum during infection of two different FHB resistance level wheat varieties, highlighted their dynamic expression patterns and functions of virulence, invasion, defense response, metabolism, and effector signaling, providing valuable insight into the interactions between F. graminearum and susceptible/resistant wheat varieties.

Pathogenic function of the natural variation of CP in WYMV and CWMV

The soil-borne viral disease, caused by wheat yellow mosaic virus (WYMV) and Chinese wheat mosaic virus (CWMV), is one of the most destructive wheat diseases in China. Considering the large wheat growing area in China, the genetic diversity of WYMV and CWMV could be high in the country. However, studies on genetic diversity of WYMV and CWMV in China are limited, making it difficult to prevent and control viral diseases on wheat. During 2021–2022, the wheat leaves with typical yellow mosaic virus symptoms were randomly collected from wheat fields in seven provinces. Nine WYMV and one CWMV isolates were identified in the samples using small RNA sequencing and RACE technology. Sequence alignment showed that several amino acid substitutions were occurred in the coat protein (CP) from these isolates. Moreover, we replaced the CP of WYMV and CWMV infectious clones with CP of newly identified isolates and found that natural variation of CP is involved in the pathogenicity of WYMV. Moreover, the WYMV infectious clones containing CP of the WYMV isolates from Junan at Shandong Province or Yangzhou at Jiangsu Province have enhanced WYMV infection in several local wheat resistance cultivars. Taken together, our findings suggest that the distribution of WYMV and CWMV in wheat growing areas has expanded in these years and the natural variation of viral genome is involved in pathogenicity of WYMV. Our results also provide a theoretical basis to explain the real distribution of wheat viral resistance varieties in China.

A method for reducing the concentrations of Fusarium graminearum trichothecenes in durum wheat grain with the use of Debaryomyces hansenii

Fusarium head blight (FHB), caused mainly by Fusarium graminearum, is one of the most dangerous diseases of durum wheat. This hemibiotrophic pathogen transitions from the biotrophic phase, during which it penetrates host tissues and secretes trichothecenes, to the necrotrophic phase which leads to the destruction of host tissues. Yeasts applied to spikes often reduce mycotoxin concentrations, but the underlying mechanisms have not been fully elucidated. Therefore, the aim of this study was to analyze the concentrations trichothecenes in durum wheat grain and changes in the F. graminearum transcriptome under the influence the Debaryomyces hansenii antagonistic yeast strain. Debaryomyces hansenii cells adhered to and formed cell aggregates/biofilm on the surface of spikes and pathogenic hyphae. Biological control suppressed the spread of F. graminearum by 90 % and decreased the content of deoxynivalenol (DON) in spikes by 31.2 %. Yeasts significantly reduced the expression of pathogen's genes encoding the rpaI subunit of RNA polymerase I and the activator of Hsp90 ATPase, but they had no effect on mRNA transcript levels of genes encoding the enzymes involved in the biosynthesis of trichothecenes. The yeast treatment reduced the number of F. graminearum operational taxonomic units (OTUs) nearly five-fold and increased the number of D. hansenii OTUs more than six-fold in the spike mycobiome. The mechanisms that suppress infections should be explored to develop effective biological methods for reducing the concentrations mycotoxins in wheat grain.

The influence of environmentally safe preparations on the yield and infection by winter wheat diseases in the conditions of the Right-Bank Forest Steppe

Goal. To assess the impact of seed and crop treatment with biopreparations, as well as the introduction of a biodestructor into the soil, on the productivity of winter wheat and its damage by diseases. Methods. Field — for registration of diseases of winter wheat; quantity and weight — for determination of the crop structure; mathematical-statistical — for finding out the reliability of the results obtained. Results. It was established that pre-sowing treatment of seeds with ecologically safe preparations (Vympel-K, Organic-balance, MikoHelp) helps to increase the yield of winter wheat by 2.6–8.8% in the case of seed treatment with the Organic-balance preparation and introduction of the Organic-balance biodestructer into the soil. Foliar treatment with Organic-balance helped to increase yield by 5.9–9.2%, and application of the biodestructor Organic-balance to the soil increased by 2.9–6.3%. In addition, seed treatment with biopreparations and a biodestructor reduced the spread of root rot to 6.9–9.6% compared to 14.2% in the control variant. The treatment of crops with the drug Organic-balance restrained the spread of powdery mildew of wheat to 60–64% compared to 77–80% in the control. Conclusions. Application of biologically safe preparations (Organic-balance biodestructor — in the amount of 1.5 l/ha, Vympel-K — 0.5 l/t, Organic-balance — 1.5 l/t, MikoHelp — 3.0 l/t), treatment per leaf (Organic-balance — 0.5 l/ha) contributed to a significant (2.9–9.2%) increase in the productivity of winter wheat and a reduction in its damage by diseases. Preparations for seed treatment showed a higher percentage efficiency — an increase in yield by 5.7–8.8% in areas where the destructor was not applied and foliar treatment was not carried out compared to the background (2.6–4.1%), where these measures did not conduct. Treatment with the biological preparation MikoHelp gives the greatest effect. Its use contributes to an increase in yield by 4.1–8.8%, or 0.24–0.45 t/ha. The specified ecologically safe elements of agricultural technology are recommended to be used to improve ecologically safe technologies for growing winter wheat in agro-formations of various forms of ownership of the Right-Bank Forest Steppe of Ukraine.

Profiling the Pyrenophora tritici-repentis secretome: The Pf2 transcription factor regulates the secretion of the effector proteins ToxA and ToxB.

The global wheat disease tan spot is caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr) which secretes necrotrophic effectors to facilitate host plant colonization. We previously reported a role of the Zn2 Cys6 binuclear cluster transcription factor Pf2 in the regulation of the Ptr effector ToxA. Here, we show that Pf2 is also a positive regulator of ToxB, via targeted deletion of PtrPf2 which resulted in reduced ToxB expression and defects in conidiation and pathogenicity. To further investigate the function of Ptr Pf2 in regulating protein secretion, the secretome profiles of two Δptrpf2 mutants of two Ptr races (races 1 and 5) were evaluated using a SWATH-mass spectrometry (MS) quantitative approach. Analysis of the secretomes of the Δptrpf2 mutants from in vitro culture filtrate identified more than 500 secreted proteins, with 25% unique to each race. Of the identified proteins, less than 6% were significantly differentially regulated by Ptr Pf2. Among the downregulated proteins were ToxA and ToxB, specific to race 1 and race 5 respectively, demonstrating the role of Ptr Pf2 as a positive regulator of both effectors. Significant motif sequences identified in both ToxA and ToxB putative promoter regions were further explored via GFP reporter assays.

A small cysteine-rich fungal effector, BsCE66 is essential for the virulence of Bipolaris sorokiniana on wheat plants

The Spot Blotch (SB) caused by hemibiotrophic fungal pathogen Bipolaris sorokiniana is one of the most devastating wheat diseases leading to 15–100% crop loss. However, the biology of Triticum-Bipolaris interactions and host immunity modulation by secreted effector proteins remain underexplored. Here, we identified a total of 692 secretory proteins including 186 predicted effectors encoded by B. sorokiniana genome. Gene Ontology categorization showed that these proteins belong to cellular, metabolic and signaling processes, and exhibit catalytic and binding activities. Further, we functionally characterized a cysteine-rich, B. sorokiniana Candidate Effector 66 (BsCE66) that was induced at 24–96 hpi during host colonization. The Δbsce66 mutant did not show vegetative growth defects or stress sensitivity compared to wild-type, but developed drastically reduced necrotic lesions upon infection in wheat plants. The loss-of-virulence phenotype was rescued upon complementing the Δbsce66 mutant with BsCE66 gene. Moreover, BsCE66 does not form homodimer and conserved cysteine residues form intra-molecular disulphide bonds. BsCE66 localizes to the host nucleus and cytosol, and triggers a strong oxidative burst and cell death in Nicotiana benthamiana. Overall, our findings demonstrate that BsCE66 is a key virulence factor that is necessary for host immunity modulation and SB disease progression. These findings would significantly improve our understanding of Triticum-Bipolaris interactions and assist in the development of SB resistant wheat varieties.

Wheat disease’s global spread concerns researchers

Wheat disease’s global spread concerns researchers

Dynamic Analysis of Regional Wheat Stripe Rust Environmental Suitability in China

Stripe rust is one of the most destructive wheat diseases in China, negatively affecting the production safety and causing yield losses of wheat. Thus, it is important to analyze the environmental suitability and dynamic changes of wheat stripe rust in China. The occurrence of stripe rust is affected by multiple factors. Therefore, this study combined data from various disciplinary fields such as remote sensing, meteorology, biology, and plant protection to evaluate the environmental suitability of stripe rust in China using species distribution models. The study also discusses the importance and effect of various variables. Results revealed that meteorological factors had the greatest impact on the occurrence of stripe rust, especially temperature and precipitation. Wheat growth factors have a greater impact from April to August. Elevation has a greater impact in summer. The ensemble model results were better than the single model, with TSS and AUC greater than 0.851 and 0.971, respectively. Overlapping analysis showed that the winter stripe rust suitable areas were mainly in the Sichuan Basin, Northwestern Hubei, Southern Shaanxi, and Southern Henan wheat areas. In spring, the suitable areas of stripe rust increased in Huang-Huai-Hai and the middle and lower reaches of the Yangtze River and Guanzhong Plain, and the development of northwestern wheat areas such as Xinjiang and Gansu slightly lagged behind. In summer, wheat threatened by stripe rust is mainly in late-ripening spring wheat areas in Gansu, Ningxia, Qinghai, and Xinjiang. This study can provide a scientific basis for optimizing and improving the comprehensive management strategy of stripe rust.

Virulence of Puccinia triticina and Puccinia tritici-duri on durum wheat in southern Spain, from 2020 to 2022

Leaf rust is a major wheat disease in southern Spain, where durum wheat is an important crop. Until the 2019/2020 season, this disease was effectively managed, as the most widely planted cultivars in southern Spain had effective resistance genes. A problem arose in the spring of 2020, when every farm field and durum wheat trial examined displayed leaf rust symptoms. Leaves had few but large uredinial pustules, different from those of the normal leaf rust caused by Puccinia triticina, and telia developed rapidly after only a few days. The symptoms clearly fitted with P. tritici-duri, another wheat leaf rust species already reported in the western Mediterranean Basin. This species is not new in southern Spain but has never been observed at such high severity on almost every durum wheat cultivar grown in that region. Leaf rust severity was assessed in durum wheat field trials in the 2020, 2021 and 2022 growing seasons in four provinces of southern Spain. During 2020 and 2021, 13 single pustule isolates of leaf rust were also collected from different cultivars of durum wheat. Inoculation of the isolates on a differential host set showed that four different races were present, two being of P. tritici-duri. Only cultivar Calero showed consistent resistance to the races of P. tritici-duri employed in this study.

Synthesis, characterization and antifungal potential of titanium dioxide nanoparticles against fungal disease (Ustilago tritici) of wheat (Triticum aestivum L.)

Nanoparticles (NPs) preparation using a green as well as environmentally acceptable processes has achieved a lot of attention in recent decade. The current study compared the synthesis of titania (TiO2) nanoparticles synthesized from leaf extracts of two plant species (Trianthema portulacastrum, Chenopodium quinoa) and traditional approach by chemical preparation. The effects of no calcination on the physical characteristics of TiO2 NPs as well as their antifungal effects were examined and compared with the already reported calcinated TiO2 NPs. The produced TiO2 NPs were evaluated using high-tech techniques such as X-ray diffraction (XRD), scanning electron microscope, energy dispersive spectroscopy (EDX), and elemental mapping. TiO2 NPs prepared by sol-gel technique (T1) and prepared from extractions from leaves of T. portulacastrum (T2), and C. quinoa (T3) were either calcinated or non calcinated and tested against fungal disease (Ustilago tritici) of wheat for antifungal efficacy. The -peak (2θ) at 25.3 was confirmed by XRD to be connected with the anatase (101) form in both cases but before calcination, NPs were lacking the rutile and brookite peaks. The results showed that all types of TiO2 NPs examined had good antifungal activity against U. tritici, but those made from C. quinoa plant extract have good antifungal activity against disease. TiO2 NPs which are produced by the green methods (T2, T3) have the highest antifungal activity (58%, 57% respectively), while minimal activity (19%) was recorded when NPs were synthesized using the sol-gel method (T1) with 25 μl/mL. Non calcinated TiO2 NPs have less antifungal potential than calcined TiO2 NPs. It can be concluded that calcination may be preferred for efficient antifungal activity when using titania nanoparticles. The green technology may be used on a larger scale with less damaging TiO2 NP production and can be utilized against fungal disease on wheat crop to reduce crop losses worldwide.

Biological control of Fusarium crown rot of wheat with Chaetomium globosum 12XP1-2-3 and its effects on rhizosphere microorganisms.

Chaetomium globosum is a common plant endophytic fungi that exhibits great biocontrol potential in plant disease. Fusarium crown rot (FCR) is an important disease in wheat that seriously threatens wheat production worldwide. The control effect of C. globosum against wheat FCR remains unclear. In this study, we introduced an identified C. globosum 12XP1-2-3 and tested its biological control potential against wheat FCR. The hypha and fermentation broth exhibited an antagonistic effect against Fusarium pseudograminearum. Results from indoor experiments showed that C. globosum 12XP1-2-3 might delay the onset of symptoms of brown stem base and significantly reduced the disease index (37.3%). Field trials showed that wheat seeds coated with a spore suspension of 12XP1-2-3 grew better than the control seeds, had control effects of 25.9-73.1% on FCR disease, and increased wheat yield by 3.2-11.9%. Analysis of rhizosphere microorganisms revealed that seeds coated with C. globosum ('Cg' treatment) had a greater effect on fungal rather than on bacterial alpha diversity and may improve the health state of rhizosphere microorganisms, as reflected by the significantly increased fungal Shannon index at Feekes 11 and the increased complexity of the bacterial co-occurrence network but decreased complexity of the fungal network. Moreover, the accumulation of beneficial bacteria such as Bacillus and Rhizobium at Feekes 3, and Sphingomonas at Feekes 7 in the 'Cg' treatment may be the important contributions to healthier wheat growth state, significantly reduced relative abundance of Fusarium at Feekes 11, and reduced occurrence of FCR disease. These results provide a basis for further research on the mechanism of action of C. globosum and its application in the biological control of FCR in the field.