Fusarium Wilt Disease Of Tomato Research Articles

Impact of biosynthesized silver nanoparticles (AgNPs) on fusarium wilt disease in tomato: In vitro and In vivo studies Hafez, M. S., Abdou, El-S., Shaat, M. M. and Abd ElGawad, T. I. Plant Pathology Department, Faculty of Agriculture, Minia Universit

Impact of biosynthesized silver nanoparticles (AgNPs) on fusarium wilt disease in tomato: In vitro and In vivo studies Hafez, M. S., Abdou, El-S., Shaat, M. M. and Abd ElGawad, T. I. Plant Pathology Department, Faculty of Agriculture, Minia Universit

Screening of some commonly cultivated tomato varieties against Fusarium wilt in Jama’are, Bauchi State, Nigeria

Fusarium wilt disease of tomato is caused by Fusarium oxysporum f.sp. lycopersici and is a limiting factor to tomato production in Nigeria. This research was conducted to assess the effect of Fusarium oxysporum on some tomato varieties cultivated in Jama’are, Bauchi state. The objectives of this research work were to isolate and identify pathogen (Fusarium oxysporum) from the soil, to determine the incidence and severity of Fusarium wilt on different varieties of Tomato grown in Jama’are, and to determine the most resistance variety among four different varieties. The experiment was laid in a Completely Randomized design (CRD) with four replications. The four tomato varieties (Roma Savanna, Rio Grande, UC82B and Tropimech) were inoculated at the root region by making shallow groove around the base of the plant in the root region and placing 3 g mycelia plug of 7 days old pure culture of F. oxysporum face-down close to the root of the seedling and covered with soil. At two weeks intervals after treatments the seedlings were then observed for symptoms of wilt infection. Data on disease incidence (%), were collected based on observation after which they were analyzed using Analysis of Variance (ANOVA) test. The Disease Incidence Percentage for Roma Savanna, Rio Grande, UC28B and Tropimech were evaluated to be 51.6%, 18.2 %,38.4 % and 43.3 % respectively while the Disease Severity Percentage were 72.1%, 24.8%, 40.9% and 62.3% respectively. The findings of this research reveals that; there is a significant effect of F. oxysporum on the tomato varieties, all the varieties were severely infected to some degree, and that of all species, Roma savanna was moderately resistant to F. oxysporum to some degree. This agrees with other findings in the literature, as Fusarium oxysporum affects different varieties of tomato at different growth stages. Also, it was observed that screening excises involving selecting of non-infected seedlings with Fusarium species and other fungi should be done prior to transplanting.

Evaluation of the Humic Acid Efficiency and the Bioagent Chaetomium globosum in Controlling Fusarium Wilt Disease in Tomato

Fusarium wilt disease presents a significant menace to tomato plants, necessitating effective preventative measures. Five isolates of Fusarium oxysporum f.sp. lycopersici from infected tomato plants from different regions in Missan province, each showing varying levels of pathogenicity. Differences in the ability of tomato seedlings to be infected by these isolates were also observed during a pot experiment, ranging from highly pathogenic to non-pathogenic. To address this issue, the efficacy of the bioagent Chaetomium globosum and humic acid in controlling the pathogenic fungus F. oxysporum f.sp. lycopersici and improving the growth indicators of tomato plants in the presence of the causative fungus. Two concentrations of humic acid (8 and 4 mL/l) were tested to determine their efficacy in reducing the growth of pathogenic fungi in vitro. We found that the growth of the pathogenic fungi decreased to 41.06% at a concentration of 8 ml/l, compared to the control, which showed no growth. Moreover, when used alone or in combination with humic acid, C. globosum significantly reduced the percentage and severity of infection. The treatment involving the interaction between the bioagent and humic acid at a concentration of 8 ml/l recorded an infection percentage of 14.4% and an infection severity of 11.87%, compared to the pathogenic fungus treatment that resulted in 53% infection and 43.80% severity, respectively. Moreover, the use of C. globosum and different concentrations of humic acid raised all growth indices in all treatments whether in the presence or absence of pathogenic funus. These improvements included increased fresh and dry weight of the shoot and root, enhanced plant height and leaf area, as well as a significant increase in the content of total phenols and total chlorophyll in the leaves. The findings of this study highlight the potential of C. globosum and humic acid as effective control measures against fusarium wilt disease in tomato plants. The results indicate their ability to suppress the pathogenic fungus and promote plant growth. These findings hold promise for the development of sustainable agricultural practices.

ANTAGONISTIC POTENTIAL OF Trichoderma harzianum AGAINST F. oxysporum f. sp. lycopersici ISOLATES CAUSING FUSARIUM WILT DISEASE OF TOMATO (Solanum lycopersicum L.)

Antagonistic effect of T. harzianum was carried out on F. oxysporum f. sp. lycopersici. isolates of tomato variety (UC 82B) in a screen house located at the Teaching and Research Farm of Federal University of Agriculture, Makurdi during 2015 cropping season to determine the ability of the antagonistic in controlling Fusarium wilt diseases of tomato. The F. oxysporum isolates tested were coded as: FoAs1, FoAs2, FoAg, FoNb, FoSb, FoAm, FoAk, FoOr, FoAd and FoUAM together with an uninoculated control. The experiment was a 2 x 11 factorial laid out in Completely Randomized Design (CRD) and replicated three times. T. harzianum was introduced at three different times (Two days before, same time and two days after the inoculation of F. oxysporum). In vitro tests results revealed antagonistic effects of T. harzianum on F. oxysporum isolates. Growth inhibition was significantly higher (P≤0.05) when T. harzianum was introduced two days before inoculation of F. oxysporum. Interaction shows that T. harzianum introduced two days before inoculation of F. oxysporum gave better inhibition of all the Fusarium isolates tested except isolates FoAd and FoAg compared with when the antagonist was introduced at the same time and when it was introduced two days after inoculation of F. oxysporum. Also, T. harzianum (P≤0.05) totally inhibited the growth of isolates FoAg, FoAs1, FoNb, FoOr and FoUAM but not those of FoAd, FoAk, FoAm, FoAs2 and FoSb. It is therefore recommended that T. harzianum be used in the management of fusarium wilt disease of tomato

Management of Fusarium wilt of tomato (Pusa Ruby) by plant extracts and fungicides

Fusarium wilt disease of tomato caused by Fusarium oxysporum f. sp. lycopersici is one of the most important and widespread disease of the cultivated tomato.The yield loss in tomato in temperate region of India due to this disease is 10 to 90 percent. Investigation was undertaken to screen out the fungicides viz., Azoxystrobin(T1), Propineb(T2), Thiophanate Methyl (T3), Difenoconazole(T4), Mancozeb(T5), Mancozeb + Thiophanate Methyl(T6), Boscolid+Pyraclostrobin(T7) and control (T8) and plant extracts viz, onion bulb(T9), ,ginger rhizome(T10), garlic clove(T11), neem leaf (T12), ashwagandha leaf(T13), sarpgandha leaf(T14), ashok leaf(T15) and control (T16) , against wilt of tomato under in vivo and in vivo conditions. Ginger rhizome extract (T10) was found very promising as it produced 82.2 % growth inhibition of F. oxysporumf.sp. lycopersiciat @t 15 % concentration followed by garlic clove(T11) (76.1%). Two soil drenching withgarlic clove(T11), @ 15 percent showed minimum disease incidence of (16.6%) with maximum yield (435.3 q/ha) followed by ginger rhizome(T10) extract (18.4% and 428.2 q/ha). Mancozeb + Thiophanate Methyl(T6), Difenoconazole(T4) and Thiophanate Methyl(T6) completely inhibited the radial growth and sporulation of Fusarium oxysporumf.sp. lycopersici after 144 hrs of incubation. Two soil drenching of Mancozeb +Thiophanate Methyl(T6), @ 15 per cent was also found the best for managing the disease as minimum disease incidence (5.3%) and highest yield (470.9 q/ha) was recorded.

Evaluation of Soil Streptomyces spp. for the Biological Control of Fusarium Wilt Disease and Growth Promotion in Tomato and Banana

Fusarium oxysporum f. sp. lycopersici (Fol) and Fusarium oxysporum f. sp. cubense (Foc), are the causal agent of Fusarium wilt disease of tomato and banana, respectively, and cause significant yield losses worldwide. A cost-effective measure, such as biological control agents, was used as an alternative method to control these pathogens. Therefore, in this study, six isolates of the Streptomyces-like colony were isolated from soils and their antagonistic activity against phytopathogenic fungi and plant growth-promoting (PGP) activity were assessed. The results showed that these isolates could inhibit the mycelial growth of Fol and Foc. Among them, isolate STRM304 showed the highest percentage of mycelial growth reduction and broad-spectrum antagonistic activity against all tested fungi. In the pot experiment study, the culture filtrate of isolates STRM103 and STRM104 significantly decreased disease severity and symptoms in Fol inoculated plants. Similarly, the culture filtrate of the STRM304 isolate significantly reduced the severity of the disease and symptoms of the disease in Foc inoculated plants. The PGP activity test presents PGP activities, such as indole acetic acid production, phosphate solubilization, starch hydrolysis, lignin hydrolysis, and cellulase activity. Interestingly, the application of the culture filtrate from all isolates increased the percentage of tomato seed germination and stimulated the growth of tomato plants and banana seedlings, increasing the elongation of the shoot and the root and shoot and root weight compared to the control treatment. Therefore, the isolate STRM103 and STRM104, and STRM304 could be used as biocontrol and PGP agents for tomato and banana, respectively, in sustainable agriculture.

Botanicals, as a Sustainable Agroecological Alternative to Synthetic Pesticide for Controlling Leaf Miner (Pinworm) and Fusarium Wilt Disease of Tomato

Botanicals, as a Sustainable Agroecological Alternative to Synthetic Pesticide for Controlling Leaf Miner (Pinworm) and Fusarium Wilt Disease of Tomato

GCMS analysis and antifungal activity of leaf extracts of Ailanthus excelsa (Roxb), against Fusarium oxysporum causal agent of Fusarium wilt disease in tomato

GCMS analysis and antifungal activity of leaf extracts of Ailanthus excelsa (Roxb), against Fusarium oxysporum causal agent of Fusarium wilt disease in tomato

Uji Kemampuan Trichokompos Dalam Menekan Penyakit Layu Fusarium Pada Tanaman Tomat

Fusarium wilt is one of the deadly diseases on tomato plants that need to be controlled.Trichocompost is compost containing the antagonistic fungus Trichoderma sp., which increasessoil fertility and controls plant pathogens. This study aimed to examine the effect of trichocompostdoses on: (1) the growth and yield of tomato plants, (2) the incidence of fusarium wilt, and (3) theseverity of fusarium wilt disease in tomato plants.This research was conducted at the Laboratoryof Plant Diseases and Greenhouses of Faperta Undana from March 2021 to August 2021. Thisstudy used a Randomized Block Design consisting of seven treatments repeated three times, sothere were 21 experimental units. The treatments tried were Trichocompost 25 g/polybag twoweeks before F. oxysporum inoculation, Trichocompost 50 g/polybag two weeks before F.oxysporum inoculation, Trichocompost 75 g/polybag two weeks before F. oxysporum inoculation,Trichocompost 25 g/polybag two weeks after F. oxysporum inoculation, Trichocompost 50g/polybag two weeks after inoculation of F. oxysporum, Trichocompost 75 g/polybag two weeksafter inoculation of F. oxysporum, andInoculation of F. oxysporum at planting withouttrichocompost application. The results showed that: (1) Trichocompost 75 g/polybag applied twoweeks before Fusarium oxysporum inoculation was able to increase plant height, the number ofleaves, and the number of tomato fruits, (2) Trichocompost applied two weeks before and afterinoculation of Fusarium oxysporum was able to reduce the incidence of fusarium wilt, (3)Trichocompost 75 g/polybag, applied two weeks before Fusarium oxysporum inoculation, reducedthe severity of fusarium wilt and was included in the category of high control effectiveness.

Antagonistic Effect of Plant Growth-Promoting Fungi Against Fusarium Wilt Disease in Tomato: In vitro and In vivo Study

Fusarium wilt is considered one of the most destructive diseases for tomato plants. The novelty of this work was to investigate the antifungal and plant growth-promoting capabilities of some plant growth-promoting fungi (PGPF). Plant growth-promoting fungi (PGPF) improved the plant health and control plant infections. In this study, two fungal strains as PGPF were isolated and identified as Aspergillus fumigatus and Rhizopus oryzae using molecular method. The extracts of A. fumigatus and R. oryzae exhibited promising antifungal activity against F. oxysporum in vitro. Moreover, antagonistic effect of A. fumigatus and R. oryzae against F. oxysporum causing tomato wilt disease was evaluated in vivo. Disease severity and growth markers were recorded and in vitro antagonistic activity assay of the isolated A. fumigatus and R. oryzae against Fusarium oxysporum was measured. Physiological markers of defense in plant as response to stimulate systemic resistance (SR) were recorded. Our results indicated that A. fumigatus and R. oryzae decreased the percentage of disease severity by 12.5 and 37.5%, respectively. In addition, they exhibited relatively high protection percentage of 86.35 and 59.06% respectively. Fusarium wilt was declined the growth parameters, photosynthetic pigments, total soluble carbohydrate, and total soluble protein, whereas content of free proline, total phenols, and the activity of antioxidant enzymes activity increased under infection. Moreover, application of A. fumigatus and R. oryzae on infected plants successfully recovered the loss of morphological traits, photosynthetic pigment total carbohydrates, and total soluble proteins in comparison to infected control plants. PGPF strains in both non-infected and infected plants showed several responses in number and density of peroxidase (POD) and polyphenol oxidase (PPO) isozymes.

Xylaria feejeensis, SRNE2BP a Fungal Endophyte with Biocontrol Properties to Control Early Blight and Fusarium Wilt Disease in Tomato and Plant Growth Promotion Activity.

Over the past decade endophytic fungi have been known as a source of secondary metabolites with the ability to act as a biocontrol agents. Xylaria feejeensis, SRNE2BP a fungal endophyte isolated from a mangrove tree exhibited antagonistic activity against two fungal pathogens of tomato. Crude extract of X. feejeensis SRNE2BP significantly inhibited Fusarium oxysporum MFLUCC 19-0157 growth as shown approximately 60-75% in in vitro and in situ assays. Both assays showed that the endophyte also inhibited mycelium formation of Alternaria solani MFLUCC 19-0093 by 56% and 87%, respectively. The half maximal inhibitory concentration of X. feejeensis SRNE2BP crude extract against A. solani and F. oxysporum was approximately 7mg/l. Crude extract and mycelium of X. feejeensis SRNE2BP showed potential in controlling early blight and fusarium wilt disease in tomato, respectively. Seedlings from seeds coated with crude extract of X. feejeensis SRNE2BP had lower disease severity (31.71%) of early blight disease compared to un-treated seeds (57.13%). Soil treated with 10% endophytic mycelium not only reduced fusarium wilt in tomato plant (55.55% severity compared with 91.66% in un-treated soil) but also promoted seed emergence and growth of tomato. Structure analysis revealed that 12 secondary metabolites, especially mellein derivatives, are major components of the crude extract of X. feejeensis SRNE2BP. These compounds could be responsible for antifungal activities; however, further study is required. Our findings strongly suggest that colonization with this fungal endophyte can be beneficial to the host plant especially with regards to plant growth promotion and broad antagonistic activity.

Management Fusarium Wilt Disease in Tomato by Combinations of Bacillus amyloliquefaciens and Peppermint Oil

The most important disease of tomato is Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL). To control this disease, this study examined the combined use of bacterial bioagents and peppermint oil (PO). Seven bacterial isolates were collected from tomato plant rhizospheres and tested in vitro against FOL. The highest growth inhibition against FOL was shown by isolate No.3. This isolate was identified using 16S rRNA sequencing gene as Bacillus amyloliquefaciens (BA). Peppermint oil tested at different concentrations (1, 2, and 3%) against FOL mycelial growth in vitro showed the highest inhibition at 3%. The effects of BA, PO, and BA + PO in vitro on the seed germination and seedling vigor index of the tomato cv. ‘Tala F1’ was also tested. All “BA, PO, and BA + PO” treatments increased the percentage of germinated seeds and seedlings’ main shoots and root length compared to control treated seeds. The BA, PO, and BA + PO treatments were further tested under greenhouse and field conditions with pre-treated seedlings in FOL-contaminated soil. Under greenhouse conditions, each treatment decreased disease severity compared to untreated seedlings. Under field conditions, pre-treatment of tomato seedlings with BA and PO treatments reduced disease severity greater than BA + PO in combination and the mock-treated plants (66.6% for BA, 66.6% for PO and 55.3% for BA + PO, respectively). These findings support the use of BA or PO as bio-control agents against F. oxysporum in tomato. The interplay between peppermint oil, B. amyloliquefaciens, F. oxysporum, and the host plant requires further study to identify the causative mechanism for this increased disease resistance.

Effect of soil drenching with humic acid, L-methionine and phosphoric acid on Fusarium wilt and induction of enzymes related to oxidative stress and defense in tomato plants

The main objective of the present study was to evaluate the efficacy of humic acid, L-methionine and phosphoric acid as a soil application for controlling Fusarium wilt disease of tomato and their effect on gene expression alterations using protein and isozyme profiling. Two isolates from each of Fusarium oxysporum f. sp. lycopersici (FOL) and F. solani (FS) were obtained from diseased tomato plants. According to pathogenicity tests, all tested isolates were able to infect tomato cultivars; cv. Super Jackal and cv. 745 under greenhouse conditions. In in vitro studies, the addition of humic acid, L-methionine and phosphoric acid to the medium at different concentrations reduced the growth of the tested isolates of the pathogens. Under greenhouse conditions, the addition of humic acid at 2%, 2 g/L of L-methionine and 0.6% of phosphoric acid to infested soil after sowing significantly decreased percentage disease severity of Fusarium wilt at both seasons (2016/17 and 2017/18). Protein bands at molecular weight 47.2 KD, 38.2 KD, 16.3 KD and 15.6 KD appeared only in treated plants. New esterase, peroxidase, chitinase and superoxide dismutase isozyme bands were detected in all treatments while not appear in the control. This results revealed that these treatments were able to induced new protein which increases resistance in tomato plants to Fusarium wilt disease.

Evaluation potential of PGPR to protect tomato against Fusarium wilt and promote plant growth.

Soilborne fungal diseases are most common among vegetable crops and have major implications for crop yield and productivity. Eco-friendly sustainable agriculture practices that can overcome biotic and abiotic stresses are of prime importance. In this study, we evaluated the ability of plant growth-promoting rhizobacterium (PGPR) Bacillus aryabhattai strain SRB02 to control the effects of tomato wilt disease caused by Fusarium oxysporum f. sp. lycopersici (strain KACC40032) and promote plant growth. In vitro bioassays showed significant inhibition of fungal growth by SRB02. Inoculation of susceptible and tolerant tomato cultivars in the presence of SRB02 showed significant protection of the cultivar that was susceptible to infection and promotion of plant growth and biomass production in both of the cultivars. Further analysis of SRB02-treated plants revealed a significantly higher production of amino acids following infection by F. oxysporum. Analysis of plant defense hormones after inoculation by the pathogen revealed a significantly higher accumulation of salicylic acid (SA), with a concomitant reduction in jasmonic acid (JA). These results indicate that B. aryabhattai strain SRB02 reduces the effects of Fusarium wilt disease in tomato by modulating endogenous phytohormones and amino acid levels.

Evaluation of Trichoderma asperellum for inhibiting growth of Fusarium oxysporum f. sp. lycopersici and enhancing growth of tomato and fruit quality

Fusarium wilt is a soil borne disease causing severe losses in tomato plants. The pathogen perseverance in the soil makes the disease difficult to control. Therefore, this study was conducted to examine the efficacy of the biocontrol agent Trichoderma asperellum against Fusarium oxysporum f. sp. lycopersici, causal agent of Fusarium wilt disease of tomato based on in vitro and in vivo conditions. Trichoderma asperellum B1092 inhibited mycelial growth of the pathogen under in vitro condition using poison agar method. As in vivo, formulation of Trichoderma asperellum-enriched oil palm empty fruit bunch was significantly enhanced the growth parameters of tomato seedlings as compared to the control and it also significantly reduced the wilt disease severity. As a conclusion, T. asperellum B1902 may offer the potential for biologically controlling Fusarium wilt of tomato, inducing the growth of tomato seedlings and improve its quality.

In vitro evaluation of the chemical fungicides against Fusarium oxysporum f. sp. lycopersici causal organism of fusarium wilt of tomato

Tomato is the third important vegetable crop grown in India, after potato and onion with an area of 0.78 M ha and production and productivity of 19,759 Mt and 25.04 Mt ha-1 respectively. Tomato crop is very often affected by several diseases incited by pathogens such as fungi, bacteria, viruses and nematodes. Among all the fungal diseases that infect tomato, Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici (Fol), is one of the most serious and destructive diseases across the world causing severe economic losses, wherever tomato is grown. Due to prolonged survival of Fol in the soil as saprophyte and overcoming the challenging conditions by producing resistant structures, it has become very difficult to manage the disease. The most feasible method for managing Fusarium wilt disease of tomato is by usage of effective fungicides. Ten fungicides viz., Copper oxychloride 50%WP, Mancozeb 75% WP, Carbendazim 12% + Mancozeb 63% WP, Metalaxyl 4% + Mancozeb 64% WP, Hexaconzole 5% + Captan 70% WP, Thiophanate Methyl 70% WP, Thiophanate Methyl 45% + Pyraclostrobin 5% FS, Tebuconazole 250 E.C, Tebuconazole 50% + Trifloxystrobin 25% WP and Azoxystrobin 23% SC were evaluated against Fol under in vitro conditions at three concentrations i.e. 500, 1000 and 1500 ppm. Three replications were maintained for each treatment with control. Tebuconazole 50% + Trifloxystrobin 25% WP was found to be the most effective fungicide followed by Tebuconazole 250 E.C with high fungitoxicity against Fol. Azoxystrobin 23% SC was the least effective. The results of this present investigation will be helpful for future research on fungicide management for Fusarium wilt of tomato.

Secretome-Wide Analysis of Lysine Acetylation in Fusarium oxysporum f. sp. lycopersici Provides Novel Insights Into Infection-Related Proteins.

Fusarium oxysporum f. sp. lycopersici (Fol) is the causal agent of Fusarium wilt disease in tomato. Proteins secreted by this pathogen during initial host colonization largely determine the outcome of pathogen-host interactions. Lysine acetylation (Kac) plays a vital role in the functions of many proteins, but little is known about Kac in Fol secreted proteins. In this study, we analyzed lysine acetylation of the entire Fol secretome. Using high affinity enrichment of Kac peptides and LC-MS/MS analysis, 50 potentially secreted Fol proteins were identified and acetylation sites determined. Bioinformatics analysis revealed 32 proteins with canonical N-terminal signal peptide leaders, and most of them were predicted to be enzymes involved in a variety of biological processes and metabolic pathways. Remarkably, all 32 predicted secreted proteins were novel and encoded on the core chromosomes rather than on the previously identified LS pathogenicity chromosomes. Homolog scanning of the secreted proteins among 40 different species revealed 4 proteins that were species specific, 3 proteins that were class-specific in the Ascomycota phylum, and 25 proteins that were more widely conserved genes. These secreted proteins provide a starting resource for investigating putative novel pathogenic genes, with 26 up-regulated genes encoding Kac proteins that may play an important role during initial symptomless infection stages.

Endophyte-Mediated Resistance in Tomato to Fusarium oxysporum Is Independent of ET, JA, and SA.

Root endophytes can confer resistance against plant pathogens by direct antagonism or via the host by triggering induced resistance. The latter response typically relies on jasmonic acid (JA)/ethylene (ET)-depended signaling pathways, but can also be triggered via salicylic acid (SA)-dependent signaling pathways. Here, we set out to determine if endophyte-mediated resistance (EMR), conferred by the Fusarium endophyte Fo47, against Fusarium wilt disease in tomato is mediated via SA, ET or JA. To test the contribution of SA, ET, and JA in EMR we performed bioassays with Fo47 and Fusarium oxysporum f. sp. lycopersici in tomato plants impaired in SA accumulation (NahG), JA biosynthesis (def1) or ET-production (ACD) and -sensing (Nr). We observed that the colonization pattern of Fo47 in stems of wildtype plants was indistinguishable from that of the hormone mutants. Surprisingly, EMR was not compromised in the lines affected in JA, ET, or SA signaling. The independence of EMR on SA, JA, and ET implies that this induced resistance-response against Fusarium wilt disease is distinct from the classical Induced Systemic Resistance (ISR) response, providing exciting possibilities for control of wilt diseases independent of conventional defense pathways.

Effect of Trichoderma spp. on Fusarium wilt disease of tomato.

Seven isolates of Trichoderma spp. (T1 to T7) from Egypt were evaluated in vitroby bioassay for their potential to antagonize Fusarium oxysporum f.sp. lycopersici (FOL, the causal pathogen of tomato wilt disease). The highest percentage of inhibition against the tested pathogenic isolate were obtained with Trichoderma isolate (T7) followed by Trichoderma isolate (T3). In greenhouse experiments, the application of the highly antagonistic isolates of Trichoderma spp. (T3 and T7) led to a significant decrease of disease severity compared to the untreated control treatment. The lowest severity was achieved with the T3 isolate (24.8%) followed by isolate T7 (34.6%) compared with the other tested isolates. To understand the ability of Trichoderma isolates to protect against wilt disease, itsinduced systemic resistancein tomato plants has been studied. The expression of a defense-related gene (β-1,3-glucanase gene) was assessed by real-time RT-PCR in tomato plants to test the accumulation kinetics of transcripts encoding PR proteins in the roots of tomato in control (only with the pathogen), T3&FOL, and T7&FOL treatments. The highest degree of gene expression was found in tomato plants which were treated with T3&FOL compared with control (pathogen only). Two species of antagonistic Trichoderma (T3& T7) were characterized based on molecular tools using internal transcribed spacers (ITS1 and ITS4). The results of genetic characterization identified two different species of Trichoderma (T. atroviride and T. longibrachiatum).

Nanofibrillation enhances the protective effect of crab shells against Fusarium wilt disease in tomato.

Chitin, a polymer of N‑acetyl‑d‑glucosamine, is a beneficial material for agriculture because it enhances plant growth and disease control. Although chitin utilization is limited by handling difficulties, chitin nanofiber (CNF) can be more feasibly used since it behaves as a water-soluble material. To broaden the utilization of chitin, protein/CaCO3/chitin nanofiber (P/Ca/CNF) and protein/chitin nanofiber (P/CNF) complexes were prepared from crab shells without using environmentally hazardous chemical in chitin purification processes. Chitin was disintegrated into nanofibers by grinder pretreatment and the subsequent use of a high-pressure water jet system. The nanofibrillation degree depended on the number of mechanical treatments applied. The addition of CNFs to soil slightly enhanced tomato growth relative to that of CNF-untreated or crushed crab shell-treated plants. Furthermore, CNFs treatment reduced the incidence of Fusarium wilt disease in tomato plants. Disease inhibition by P/Ca/CNF and P/CNF was more effective than that by crushed crab shells, and comparable to that by pure CNF. There was no significant relationship between disease reduction level and nanofibrillation degree. In conclusion, P/Ca/CNF prepared with the minimal number of steps was sufficiently able to inhibit Fusarium wilt disease in tomato, and could thus be an eco-friendly material to control plant diseases in sustainable agriculture.