Search Results (727)

Fusarium oxysporum f. sp. lycopersici (Fol) is a destructive soil-borne pathogen responsible for major global losses in tomato production, within a context of increasingly constrained fungicide use in intensive farming systems. Sustainable alternatives to chemical fungicides are urgently needed, and microbial secondary metabolites represent a promising source of antifungal compounds. This study explores the antifungal potential of secondary metabolites produced by a natural isolate of Beauveria bassiana (Bb758) previously reported to exhibit strong biocontrol activity against Fol. LC-HRMS metabolomic profiling revealed a chemically diverse metabolite profile dominated by amino acid-derived compounds, peptides and alkaloids. Purification of the crude extract by column chromatography and reverse-phase HPLC yielded beauvericin and several 2,5-diketopiperazines as the main bioactive constituents. These compounds were identified by NMR and LC-HRMS analyses. The antifungal activity of beauvericin (BEA), cyclo(l-Phe-l-Pro) (CFP) and fractions was evaluated against spore germination and germ tube development of Fol. BEA exhibited dose-dependent but limited activity, showing significant inhibition only at high concentrations (100 μg mL⁻¹). In contrast, CFP showed significantly higher antifungal activity than BEA, inhibiting both germination and germ tube formation at concentrations as low as 10 μg mL⁻¹. These results identify CFP as a promising antifungal compound targeting the early infection stages of Fol and highlight fungal-derived diketopiperazines as candidate molecules for sustainable disease management strategies. Full article

Apple (Malus domestica Borkh.) is a major fruit crop of global economic importance, and China ranks first worldwide in both apple cultivation area and total production. With the large-scale renewal of aging orchards, apple replant disease (ARD) has become increasingly prevalent in major apple-producing regions. ARD is typically characterized by severe growth suppression, impaired root development, increased incidence of soil-borne diseases, and, in severe cases, seedling mortality. These symptoms substantially constrain orchard renewal, limit improvements in fruit yield and quality, and threaten the sustainable development of the apple industry. The etiology of ARD is complex and involves the synergistic interaction of three factors: soil microbial dysbiosis characterized by pathogen enrichment and the depletion of beneficial microorganisms; allelopathic autotoxicity caused by the accumulation of phenolic acids, especially phloridzin; and degraded soil physicochemical properties, including acidification, compaction, and nutrient imbalance. Current management strategies mainly include the use of ARD-tolerant rootstocks, microbial regulation, chemical and physical soil disinfection, and agronomic practices such as crop rotation and organic amendment application. Among these approaches, biological regulation mediated by beneficial rhizosphere and endophytic microorganisms has attracted increasing attention because of its environmental compatibility and sustainability. This review summarizes the occurrence patterns, regional characteristics, core pathogenic mechanisms, and integrated management strategies of ARD, with particular emphasis on the functional roles of rhizosphere and endophytic microbiomes in disease alleviation. The review provides a theoretical basis and practical reference for the development of green, efficient, and sustainable strategies for ARD control and apple orchard management. Full article

Rusty root rot of ginseng (Panax ginseng) caused by Ilyonectria spp. infection is a devastating soil-borne disease restricting the sustainable production of garden-cultivated ginseng (GCG) in Northeast China and causes severe yield and economic losses; GCG is far more susceptible to this pathogen than forest-cultivated ginseng (Lin-Xia-Shan-Shen, LXSS). Ginsenosides, the signature triterpenoid saponin defensive metabolites of ginseng, are characteristic dammarane-type triterpenoid defensive saponins represented by Re, Rg₂, Rb₁, Rd, and Rg₁. These compounds are continuously secreted into the rhizosphere and widely participate in plant–microbe interactions, yet their functional roles in mediating Ilyonectria infection remain poorly clarified. This study aimed to clarify how rhizospheric ginsenosides regulate the infection process of pathogenic Ilyonectria strains. Two pathogenic strains, Ilyonectria sp. SYM-1 and Ilyonectria sp. SYM-2, were found isolated from diseased GCG roots and verified as causal agents via morphological observation, molecular ITS identification and artificial inoculation infection experiments. Interestingly, the concentrations of five ginsenosides, Re, Rg₂, Rb₁, Rd, and Rg₁, in the rhizospheric soil of GCG with rusty root rot were significantly higher than those in the rhizospheric soil of healthy LXSS plants. In addition, the concentrations of ginsenosides in the LXSS rhizospheric soils decreased with increasing age of plants. Non-nutritive suspension co-culture assays showed that high concentrations of the ginsenosides Rg₁ and Rd significantly promoted spore germination of the strains SYM-1 and SYM-2. However, Rb₁ had a certain inhibitory effect on the growth of Ilyonectria sp. SYM-2. Host inoculation experiments further indicated that infection with either fungus significantly reduced the concentrations of ginsenosides produced in ginseng roots. These results demonstrate that the pathogenic fungi SYM-1 and SYM-2 of Ilyonectria can adapt to and utilize ginsenosides. Collectively, these findings prove that the two pathogenic Ilyonectria strains have evolved the capacity to adapt to and exploit rhizospheric ginsenosides to facilitate their infectivity. From an application perspective, reducing rhizospheric ginsenoside release may represent a promising theoretical strategy for ginseng cultivation and germplasm improvement, which warrants further verification by field or greenhouse experiments for validation. Full article

The sustainable management of chemical fumigants in intensive horticulture represents one of the most complex challenges in European agricultural policy, requiring the integration of agronomic knowledge, regulatory frameworks, economic viability, and stakeholder perspectives. This study proposes and tests a multi-phase consultation methodology designed to bridge the gap between individual expert knowledge and collective, evidence-based consensus, moving from qualitative field-based elicitation to structured multidisciplinary engagement and incorporating both scientific data and practical experience. A total of 72 experts were involved across two phases. In phase 1, in-depth face-to-face interviews (n = 18) captured field-level knowledge on integrated pest management strategies, risk perception, and decision-making criteria, including the economic sustainability of production systems, a dimension prioritized in the European Commission’s Vision for Agriculture and Food. Phase 2 consisted of a one-day multistakeholder event (n = 54)—bringing together researchers, regulators, industry representatives, and farmers—to confront qualitative findings with experimental data on operator safety, groundwater protection, and consumer residues. This deliberate transition from individual perception to informed, shared consensus represents the methodological core of the approach and its most distinctive contribution. The phase 1 results showed that the majority of experts considered chemical fumigants currently indispensable, while recognizing complementary strategies—particularly solarization and natural substances—as valuable supporting tools. The phase 2 experimental data confirmed operator exposure below regulatory thresholds, no groundwater contamination under professional application conditions, and the absence of detectable residues in treated crops. The results demonstrate that this structured consultation can generate actionable knowledge for integrated nematode and soil-borne disease management, with a methodology replicable across other complex regulatory and agronomic contexts within the European framework. Full article

Fusarium oxysporum f. sp. lycopersici threatens tomato production globally, resulting in severe yield losses. Nanotechnology and organic amendments are emerging as sustainable disease management practices to combat the drawbacks of chemical fungicides. This study evaluated the efficacy of nano Zn-Cu micronutrient solution and canola biofumigant on disease incidence, severity, and disease progression under field and greenhouse conditions. Tomato plants showing wilt symptoms were collected from two distinct agroecological locations of the Limpopo Province, South Africa. Morphological and molecular identification confirmed the presence of the virulent isolate. Under greenhouse conditions, weekly application of nano Zn-Cu significantly reduced wilt severity on two tomato cultivars, with 43–86% disease suppression, while canola biofumigant recorded disease suppression of 66–86%. The field experiment showed fewer disease incidences (0–40%) and severity (4–35%) on tomato plants sprayed weekly with nano Zn-Cu. This treatment maintained lower values of Area Under Disease Progress Curve (AUDPC), suggesting slower disease development. Similarly, canola biofumigant reduced disease development relative to the untreated control. Under both greenhouse and field experiments, untreated plants were severely infected, recording approximately 70% disease severity. This study demonstrated the potential of nano Zn-Cu micronutrients and canola biofumigant as sustainable solutions for managing Fusarium wilt of tomato, thereby contributing to integrated disease management. Full article

Zoonotic diseases represent an increasing public health concern worldwide, particularly in endemic regions of northwestern Mexico. This study aimed to evaluate household-level environmental and behavioral risk factors associated with Ehrlichia spp. infection in dogs living in areas with documented human rickettsiosis cases in Culiacán, Sinaloa, Mexico. A cross-sectional study was conducted, including 105 canine blood samples collected from urban and rural areas, with previous human rickettsiosis cases reported between 2021 and 2023. Microscopic examination and PCR amplification targeting the 16S rRNA gene of Ehrlichia spp. were performed. Morphological detection revealed a prevalence of 33.33%, while molecular analysis showed a prevalence of 43.83%. Risk factors significantly associated with infection included household waste, soil-type environments, free-roaming behavior identified through epidemiological analysis, and limited knowledge of tick-borne diseases among dog owners. These findings provide evidence of Ehrlichia spp. infection in dogs from areas with documented human rickettsiosis cases and highlight the value of dogs as indicators of household-level exposure to tick-borne pathogens in endemic communities. Full article

Biofumigation is increasingly recognized as an effective strategy for managing soilborne diseases. However, the understanding of the mechanisms of biofumigation has mostly focused on its direct inhibitory effects on plant pathogens, while the rhizosphere microbe-mediated effects induced by biofumigation remain unclear. Here, we investigated the effects of broccoli (Brassica oleracea var. italica) biofumigation on potato Fusarium wilt caused by Fusarium oxysporum and elucidated the changes in rhizosphere bacterial assemblage under biofumigation. Results showed that biofumigation significantly reduced disease incidence and increased tuber yield. In vitro assays revealed a strong direct inhibition of F. oxysporum by broccoli biofumigation, but the inhibition rate decreased from 99.78% on the first day to 76.27% on the seventh day. High-throughput sequencing and culture-based analyses demonstrated that biofumigation significantly shifted bacterial community assemblage in potato rhizosphere, enriching antagonistic taxa against F. oxysporum. Functional prediction suggested that biofumigation enriched bacteria associated with nitrogen consumption and methylotrophy. The changes in the rhizosphere bacterial community showed significant correlations with the incidence and severity of Fusarium wilt, indicating that biofumigation indirectly enhanced crop resistance to plant pathogens by altering the rhizosphere microbial community. These findings extend the current understanding of biofumigation beyond direct chemical toxicity and classical antibiosis and highlight its potential as an ecological strategy that harnesses the plant-associated microbiome for disease management. Full article

Astragalus root rot is a soil-borne disease primarily caused by Fusarium spp., which severely hampers the sustainable development of the Astragalus industry. F. acuminatum is a predominant pathogen causing this disease. To elucidate the genetic variation and adaptive evolutionary characteristics of F. acuminatum from different geographical origins, this study conducted whole-genome resequencing analysis on 28 isolates of F. acuminatum collected from four major Astragalus production regions. Approximately 124.9 Gb of high-quality sequencing data were obtained, and a large number of single-nucleotide polymorphisms (SNPs) were detected. Population genetic analysis revealed that strains from different regions did not form strictly geographically specific clusters, exhibiting a complex mixed distribution pattern. Nucleotide polymorphism analysis indicated that the Dingxi, Gansu (GD) population possessed the highest nucleotide diversity (π) value, reflecting the richest genetic diversity. Fixation index (Fst) analysis revealed significant genetic differentiation (Fst > 0.15) among populations from different provinces, suggesting that geographic isolation may be a contributing factor to restricted gene flow between pathogenic isolates in these regions. Tajima’s D positive values suggest a deviation from neutrality, consistent with balancing selection or population contraction. Ka/Ks analysis further revealed that the majority of genes exhibited Ka/Ks > 1, differing from the typical pattern of purifying selection dominance. This study revealed the genetic variation and selection signals of F. acuminatum isolates from different geographical origins, observed significant genetic differentiation between the Gansu and Ningxia populations, and identified a large number of genes that may be subject to positive selection. Full article

Root rot and vine decline (RRVD) is one of the main root diseases of melon, causing significant production losses due to the isolated or combined action of different phytopathogenic fungi. The absence of registered chemical control methods in Brazil reinforces the need for alternative integrated management strategies. This study aims to evaluate the enzymatic responses of Jack Beans plants inoculated with M. pseudophaseolina (Experiment I) and the effectiveness of crop rotation cycles between melon (ME) and Jack Bean (JB) on RRVD and soil-borne pathogens (Experiment II). In Experiment I, the activity of chitinase (CT), β-1,3-glucanase (BG), and phenylalanine ammonia-lyase (PAL) were assessed at five evaluation periods. In Experiment II, nine rotation cycles involving JB and ME, grown in naturally infested soil, were evaluated for disease incidence, severity, and fungal isolation frequency. In Experiment I, inoculated plants showed increased CT, BG, and PAL expression compared to non-inoculated plants. In Experiment II, the control treatment showed no disease incidence or severity, whereas all other rotation cycles exhibited 100% incidence and severity ranging from 4.5 to 4.9. The incorporation of JB demonstrated a suppressive effect on important pathogens associated with branch decline, reducing the frequency of Macrophomina spp. isolation (0–4% compared to 16% in the treatment without JB) and delaying the root penetration of Monosporascus spp. after two consecutive cycles. However, this management also favored the multiplication of Fusarium spp. in all treatments with JB incorporation. Full article

Moringa oleifera seed cake is the byproduct of moringa oil extraction and the most valuable source of 4-(α-L-rhamnosyloxy)benzyl glucosinolate (glucomoringin; GMG), the precursor of 4-(α-L-rhamnosyloxy)benzyl isothiocyanate (moringin; GMG+M). The vascular fungus Fusarium oxysporum f. sp. lycopersici (FOL) is an important soil-borne pathogen of tomato in cultivated areas worldwide. Coating seeds with phytochemicals has been reported to prevent seed transmission and control seedling infection. In this work, GMG was extracted and purified from moringa seed cake on the multigram scale, and GMG+M solutions obtained through controlled hydrolysis of the precursor with commercial myrosinase were evaluated against the pathogen both in vitro and in planta. FOL conidia germination and mycelial growth were significantly inhibited by GMG+M solutions in the range 1–1000 µM, in a dose-dependent manner, compared to GMG and control treatments, which did not differ significantly. Interestingly, the coating of tomato var. crovarese seeds with GMG or GMG+M (100 µM) resulted in equally effective reduction (70%) of the disease severity in post-emergence, suggesting a plant-mediated mechanism underlying the efficacy of the intact glucosinolate. Seed coating with both phytochemicals triggered polyphenol oxidase (PPO) activity in five-day-old tomato sprouted rootlets. This study highlighted the potential biotechnological value of M. oleifera seedcake for the development of a sustainable biopesticide. Full article

Soybean root rot, a destructive soilborne disease complex caused by a consortium of pathogenic fungi, poses a persistent threat to global soybean productivity. During 2022–2023, a total of 990 fungal isolates were recovered from symptomatic soybean roots across Heilongjiang Province, Northeast China. Of these, 279 isolates were identified as Fusarium equiseti through integrated morphological characterization and multilocus phylogenetic analysis. Notably, F. equiseti exhibited markedly elevated isolation frequencies (5.6–58.9%) across surveyed regions, confirming its status as the emerging dominant causal agent of root rot in this agroecological zone. Pathogenicity evaluations revealed that 76.67% of isolates displayed moderate virulence, with one strain classified as highly virulent (3.33%). In vitro fungicide sensitivity assays indicated that F. equiseti was most susceptible to prochloraz (mean EC₅₀ = 0.0010 µg·mL⁻¹) and fludioxonil (mean EC₅₀ = 0.0042 µg·mL⁻¹). When deployed as seed treatments, these two fungicides achieved 53.61% and 47.32% control efficacy against root rot, respectively, while significantly enhancing soybean seedling emergence, root length, and fresh weight. Collectively, these findings provide a scientific foundation for the precise, sustainable management of F. equiseti-mediated root rot in cold-region soybean production systems. Full article

Organic vegetable cultivation requires soil management strategies that improve carbon balance and suppress soilborne diseases. This study evaluated the efficacy of acidified microbial biochar pellets (ABPM) in enhancing net ecosystem carbon balance (NECB) and suppressing clubroot disease (Plasmodiophora brassicae) during organic Chinese cabbage (Brassica rapa ssp. pekinensis) cultivation. In a field-scale evaluation, three treatments were compared: guano fertilizer (control), ABPM 27 (inoculated with Pseudomonas fluorescens 22BCO027), and ABPM 86 (inoculated with Bacillus megaterium 22BCO086). Soil incorporation of ABPM 27 and ABPM 86 significantly increased soil carbon sequestration by 29.1% and 22.4%, respectively, while simultaneously reducing cumulative greenhouse gas emissions under the experimental conditions. This resulted in positive NECB values of 2.63 and 2.94 t CO₂-eq ha⁻¹, suggesting enhanced carbon retention potential within the studied cultivation system. Beyond its impact on carbon dynamics, ABPM 27 increased marketable yield by 8.6% (77.4 t ha⁻¹) and reduced clubroot incidence by 46.2%. Rhizosphere microbial analysis revealed that ABPM 27 promoted late-season microbial diversity and the persistence of beneficial Bacillus spp. and Pseudomonas spp. populations. These findings suggest the potential multifunctional role of microbially engineered biochar pellets in improving crop production, carbon retention, and pathogen suppression under organic cultivation conditions. However, these findings are based on a single-season field experiment and NECB-based carbon balance estimates, and therefore require validation across multiple growing seasons and cultivation environments. Full article

Rhizoctonia solani is a necrotrophic phytopathogenic fungus that causes disease in various crops. In agriculture, many crops suffer from root or seedling rot caused by this soil-borne pathogen, whereas cabbage and rice develop lesion-like symptoms on aboveground tissues. Diseases caused by R. solani are generally controlled using chemical fungicides; however, environmentally friendly alternatives are needed for sustainable agriculture. In this study, we evaluated the efficacy of lecithin, a mixture of phospholipids previously registered in Japan as an agrochemical for controlling cucumber powdery mildew, against Rhizoctonia diseases. In cabbage, foliar spraying of 0.2–1.0% soybean lecithin effectively suppressed leaf symptoms caused by R. solani isolate RhiCa-2, which was identified as AG-1 IB. In rice and Brachypodium distachyon, 0.2–1.0% lecithin significantly suppressed leaf symptoms induced by R. solani AG-1 IA. Hyphal staining of inoculated leaves revealed reduced hyphal density on lecithin-treated leaves. Consistently, hyphal growth of R. solani on cellophane placed on water agar was retarded by lecithin treatment. However, 5.0% lecithin induced phytotoxicity in B. distachyon. Egg yolk-derived lecithin also exhibited disease-suppressive activity in cabbage and B. distachyon, with efficacy comparable to that of soybean lecithin under the conditions tested. These results suggest that lecithin suppresses foliar infection by R. solani, at least in part, through direct inhibitory effects on fungal hyphae, and may serve as a potential alternative material for disease control in sustainable crop production. Full article

Damping-off disease represents a major constraint in greenhouse tomato (Solanum lycopersicum) production, being primarily caused by soil-borne fungi and oomycetes whose persistence is intensified by intensive cultivation practices. This review synthesizes current knowledge on integrated disease management strategies targeting these pathogens in protected cropping systems. Cultural practices (e.g., substrate sanitation and irrigation control), physical and chemical soil disinfestation, deployment of resistant cultivars, and biological control agents (e.g., Trichoderma, Bacillus, and Pseudomonas) are critically evaluated. Available evidence indicates that integrated approaches consistently reduce pathogen inoculum, limit infection processes, and enhance seedling establishment and vigor, thereby outperforming single-method interventions. Synergistic interactions among practices strengthen rhizosphere resilience and contribute to sustained soil health. Overall, integrated disease management offers an effective and environmentally sound framework to mitigate damping-off, reduce reliance on chemical inputs, and ensure stable tomato production in protected cultivation systems. Full article

Potato (Solanum tuberosum L.) is an important staple and food security crop to many communities in the world. However, potato production and quality is greatly constrained by bacterial wilt, a disease caused by a soil-borne pathogen, Ralstonia solanacearum. Ralstonia solanacearum can be managed through clean seed systems and therefore laboratory testing is a pre-requisite for seed certification to confirm the absence of the pathogen in potato seeds before planting. Molecular diagnostics is the gold standard for detection of R. solanacearum in potato seeds. However, the extraction of genomic DNA from R. solanacearum for molecular diagnostics is complex, tedious, lengthy and/or costly procedure. A simple, rapid and reliable DNA extraction protocol is required for use in routine molecular diagnosis of R. solanacearum, a high-risk quarantine pathogen. In this study, we developed a simple and rapid protocol for extracting genomic DNA from symptomatic and asymptomatic potato tubers infected with R. solanacearum and verified its efficiency for the detection and molecular characterization of the pathogen. The protocol was developed from the evaluation of distilled water, Tris-EDTA (TE) and Tris buffer as a base solution for tissue maceration. The DNA quantity and integrity was determined using the NanoDrop 2000C spectrophotometer and agarose gel electrophoresis, respectively. Both hot and cold solutions produced intact high molecular weight genomic DNA of sufficient yield and purity for molecular-based applications. The detection and determination of phylotypes of R. solanacearum, based on conventional and multiplex polymerase chain reaction (PCR), amplified the expected 280 and 372 bp amplicons, respectively, confirming that the quantity and quality of the extracted pathogen genomic DNA was sufficient for molecular diagnostic applications. The sequencing of the amplified products of the endoglucanase gene produced good quality sequences, which confirmed the R. solanacearum isolates to be members of phylotype II sequevar 1. This protocol is a simple, fast and reliable tool for the extraction of sufficient genomic DNA with high quality, directly from R. solancearum-infected potato tubers for PCR and sequencing applications. Its simplicity and throughput make it valuable for use in routine diagnostics and can be adopted by certification programs to ensure distribution of clean potato seeds to farmers. Full article