Search

In 2023 in Aichi Prefecture, shiso plant growth in a deep flow technique (DFT) hydroponic system was delayed from mid-March to late April with roots showing evidence of rotting. An oomycete species was isolated from the roots and identified as Phytopythium helicoides based on morphological characteristics and DNA sequence homology. Identical symptoms appeared on shiso plants after inoculating seedlings with zoospores from the strain, and the same oomycete species was reisolated from the diseased plants. This study is the first report in the world of root rot caused by P. helicoides in shiso in a DFT hydroponic system. [ABSTRACT FROM AUTHOR]

Soybean is an important protein and oil crop around the world, widely cultivated in Heilongjiang province, China. In the summer of 2021, soybean root rot samples were collected from farms in multiple regions of Heilongjiang province to isolate pathogens. Twenty‐seven fungal isolates with similar morphology were found, causing soybean root discolouration and blackness leading to root rot, but which had relatively mild pathogenicity, with an average disease index of 13.69–32.25. Morphological features and multilocus phylogenetic analyses divided these isolates into four species: Clonostachys rosea (48.2%), C. rosea f. sp. rosea (14.8%), C. chloroleuca (29.6%) and Clonostachys sp. (7.4%). Co‐inoculation of these four species with two important pathogenic Fusarium species that can cause soybean root rot, F. annulatum and Fusarium sp. 1 in the Fusarium oxysporum species complex (FOSC), showed that C. rosea and Clonostachys sp. significantly reduced the pathogenicity of F. annulatum to soybean root, while C. rosea f. sp. rosea and C. chloroleuca slightly increased the pathogenicity of F. annulatum. C. rosea, Clonostachys sp., C. chloroleuca and C. rosea f. sp. rosea slightly reduced the pathogenicity of Fusarium sp. 1 in the FOSC. Our research is the first to report Clonostachys sp., C. chloroleuca and C. rosea f. sp. rosea causing soybean root rot in Heilongjiang province, China, and that these four Clonostachys species can affect the pathogenicity of Fusarium species, alleviating or aggravating soybean root rot. The findings of this study provide new insights into exploring the interactions between pathogens and thus effectively controlling them. [ABSTRACT FROM AUTHOR]

Phytophthora cinnamomi is a hemibiotrophic oomycete causing Phytophthora root rot in over 5,000 plant species, threatening natural ecosystems, forestry, and agriculture. Genomic studies of P. cinnamomi are limited compared to other Phytophthora spp. despite the importance of this destructive and highly invasive pathogen. The genome of two genetically and phenotypically distinct P. cinnamomi isolates collected from avocado orchards in California were sequenced using PacBio and Illumina sequencing. Genome sizes were estimated by flow cytometry and assembled de novo to 140-141Mb genomes with 21,111-21,402 gene models. Genome analyses revealed that both isolates exhibited complex heterozygous genomes fitting the two-speed genomemodel. The more virulent isolate encodes a larger secretome and more RXLR effectors when compared to the less virulent isolate. Transcriptome analysis after P. cinnamomi infection in Arabidopsis thaliana, Nicotiana benthamiana, and Persea americana de Mill (avocado) showed that this pathogen deploys common gene repertoires in all hosts and host-specific subsets, especially among effectors. Overall, our results suggested that clonal P. cinnamomi isolates employ similar strategies as other Phytophthora spp. to increase phenotypic diversity (e.g., polyploidization, gene duplications, and a bipartite genome architecture) to cope with environmental changes. Our study also provides insights into common and host-specific P. cinnamomi infection strategies and may serve as a method for narrowing and selecting key candidate effectors for functional studies to determine their contributions to plant resistance or susceptibility. [ABSTRACT FROM AUTHOR]

AbstractWestern white pine (Pinus monticola) with genetic tolerance to white pine blister rust disease caused by Cronartium ribicola constitutes an invaluable resource for the mitigation of this disease as well as the restoration of the species and its utilization in managed forests. In the last several years, typical root-rot symptoms and sudden tree death have been observed in some western white pine plantations located in British Columbia (BC) in Canada, and a few Phytophthora species were found to be associated with symptomatic trees. Our objectives were to survey one of the plantations located in south-west BC on Vancouver Island to confirm the presence of these Phytophthora species and other oomycetes and test their pathogenicity on western white pine by completing Koch’s postulates. We used direct plating of root samples on PARP(H)-CMA media and by baiting for oomycetes in soil and root samples. Ten oomycetes, including four Phytophthora species (Phytophthora cinnamomi, P. cactorum-like, P. cryptogea and P. pseudocryptogea) were isolated from roots and soil samples of diseased Pi. monticola trees. The Phytophthora species were identified using ITS, β-tubulin and TEF1 gene regions. Koch’s postulates were validated with controlled inoculations of 1-year old seedlings; mortality occurred as early as 15 days after inoculation with P. cinnamomi when the seedlings were maintained in warm temperature conditions (25°C). Molecular typing of two P. cinnamomi cultures using Oxford Nanopore MinIONTM sequencing indicated that they belong to one of the two main clonal clusters of mating type A2 that have been recognized as the main drivers of the global P. cinnamomi epidemic. [ABSTRACT FROM AUTHOR]

Stalk and root rots of cultivated sorghum (Sorghum bicolor) are caused by several Fusarium species worldwide. This study evaluated Fusarium diversity, pathogenicity and population structure amongst 212 isolates obtained from 169 sorghum plants from commercial field crops in eastern Australia. Sequences of translation elongation factor‐1α (tef‐1α), RNA polymerase II largest subunit (rpb1), RNA polymerase II second largest subunit (rpb2) and calmodulin (cmdA) were used to construct multilocus phylogenies that enabled the identification of 16 Fusarium species in Fusarium chlamydosporum species complex (FCSC), Fusarium fujikuroi species complex (FFSC), Fusarium incarnatum‐equiseti species complex and Fusarium oxysporum species complex (FOSC). The majority of isolates (n = 171) belonged to FFSC. The pathogenicity of 17 selected isolates was determined by artificial inoculation of sorghum seedlings and completing Koch's postulates. Isolates of species in FFSC were significantly (p < 0.05) more aggressive as root pathogens in sorghum seedlings than isolates of other species tested and widely distributed across all sampling sites. Amongst the 35 isolates of FOSC, 26 belonged to Fusarium cili, which is only known as an endophyte from healthy roots of Rosa roxburghii in China. Fusarium sporodochiale (in FCSC) and Fusarium contaminatum (in FOSC) are reported as sorghum seedling root rot pathogens for the first time. [ABSTRACT FROM AUTHOR]

The Bacillus velezensis strain NT35, which has strong biocontrol ability, was isolated from the rhizosphere soil of Panax ginseng. The antifungal effects of the NT35 strain against the mycelium and spore growth of Ilyonectria robusta, which causes ginseng rusty root rot, were determined. The inhibitory rate of I. robusta mycelial growth was 94.12% when the concentration of the NT35 strain was 107 CFU·mL-1, and the inhibitory rates of I. robusta sporulation and spore germination reached 100 and 90.31%, respectively, when the concentration of the NT35 strain was 104 and 108 CFU·mL-1, respectively. Strain NT35 had good prevention effects against ginseng rust rot indoors and in the field with the control effect 51.99%, which was similar to that of commercial chemical and biocontrol agents. The labeled strain NT35-Rif160-Stre400 was obtained and colonized ginseng roots, leaves, stems and rhizosphere soil after 90 days. Bacillus velezensis NT35 can induce a significant increase in the expression of five defensive enzyme-encoding genes and ginsenoside biosynthesisrelated genes in ginseng. In the rhizosphere soil, the four soil enzymes and the microbial community improved during different periods of ginseng growth in response to the biocontrol strain NT35. The NT35 strain can recruit several beneficial bacteria, such as Luteimonas, Nocardioides, Sphingomonas, and Gemmatimonas, from the rhizosphere soil and reduce the relative abundance of Ilyonectria, Fusarium, Neonectria and Dactylonectria, which cause root rot and rusty root rot in ginseng plants. The disease indices were significantly negatively correlated with the abundances of Sphingomonas and Trichoderma. Additionally, Sphingomonadales, Sphingomonadaceae and actinomycetes were significantly enriched under the NT35 treatment according to LEfSe analysis. These results lay the foundation for the development of a biological agent based on strain NT35. [ABSTRACT FROM AUTHOR]

Background: Soil-borne plant diseases represent a severe problem that negatively impacts the production of food crops. Actinobacteria play a vital role in biocontrolling soil-borne fungi. Aim and objectives: The target of the present study is to test the antagonistic activity of chitinase-producing Streptomyces cellulosae Actino 48 (accession number, MT573878) against Rhizoctonia solani. Subsequently, maximization of Actino 48 production using different fermentation processes in a stirred tank bioreactor. Finally, preparation of bio-friendly formulations prepared from the culture broth of Actino 48 using talc powder (TP) and bentonite in a natural as well as nano forms as carriers. Meanwhile, investigating their activities in reducing the damping-off and root rot diseases of peanut plants, infected by R. solani under greenhouse conditions. Results: Actino 48 was found to be the most significant antagonistic isolate strain at p ≤ 0.05 and showed the highest inhibition percentage of fungal mycelium growth, which reached 97%. The results of scanning electron microscope (SEM) images analysis showed a large reduction in R. solani mycelia mass. Additionally, many aberrations changes and fungal hypha damages were found. Batch fermentation No. 2, which was performed using agitation speed of 200 rpm, achieved high chitinase activity of 0.1163 U mL− 1 min− 1 with a yield coefficient of 0.004 U mL− 1 min− 1 chitinase activity/g chitin. Nano-talc formulation of Actino 48 had more a significant effect compared to the other formulations in reducing percentages of damping-off and root rot diseases that equal to 19.05% and 4.76% with reduction percentages of 60% and 80%, respectively. The healthy survival percentage of peanut plants recorded 76.19%. Furthermore, the nano-talc formulation of Actino 48 was sufficient in increasing the dry weight of the peanut plants shoot, root systems, and the total number of peanut pods with increasing percentages of 47.62%, 55.62%, and 38.07%, respectively. Conclusion: The bio-friendly formulations of actinobacteria resulting from this investigation may play an active role in managing soil-borne diseases. [ABSTRACT FROM AUTHOR]

Introduction: Fusarium oxysporum is a significant soil-borne fungal pathogen that affects over 100 plant species, including crucial crops like tomatoes, bananas, cotton, cucumbers, and watermelons, leading to wilting, yellowing, growth inhibition, and ultimately plant death. The root rot disease of A. macrocephala, caused by F. oxysporum, is one of the most serious diseases in continuous cropping, which seriously affects its sustainable development. Methods: In this study, we explored the interaction between A. macrocephala and F. oxysporum through integrated small RNA (sRNA) and degradome sequencing to uncover the microRNA (miRNA)-mediated defense mechanisms. Results: We identified colonization of F. oxysporum in A. macrocephala roots on day 6. Nine sRNA samples were sequenced to examine the dynamic changes in miRNA expression in A. macrocephala infected by F. oxysporum at 0, 6, and 12 days after inoculation. Furthermore, we using degradome sequencing and quantitative real-time PCR (qRT-PCR), validated four miRNA/target regulatory units involved in A. macrocephala-F. oxysporum interactions. Discussion: This study provides new insights into the molecular mechanisms underlying A. macrocephala's early defense against F. oxysporum infection, suggesting directions for enhancing resistance against this pathogen. [ABSTRACT FROM AUTHOR]

Soilborne fungal pathogens that cause root rot, wilting and dying are the most important problems in pistachio production. The purpose of this study was to examine, isolate, and diagnose the pathogens from diseased pistachio trees in orchards and nurseries located in southeastern Turkey. Fungi isolated from the pistachio trees were identified by morphology and the sequences of the internal transcribed spacer (ITS) region and translation elongation factor-1α (TEF-1α). Fusarium solani, Fusarium oxysporum, Fusarium brachygibbosum, Fusarium chlamydosporum and Macrophomina phaseolina were the most important fungi causing root rot, wilting and decline of pistachio trees. Pathogenicity studies showed that all of the fungi identified can colonize and damage the vascular tissues of a sapling and cause substantial lesions and vascular discolourations. This study provides the first evidence of wilting due to the root and crown rot in pistachio trees in Siirt province of Turkey caused by some Fusarium species, especially F. solani, F. oxysporum, F. chlamydosporum, F. brachygibbosum and M. phaseolina. Finally, the research enabled the identification of some fungal pathogens that are seriously harming pistachio trees in southeastern Turkey. [ABSTRACT FROM AUTHOR]

Sugarbeets are largely produced without irrigation, making drought stress inevitable when rainfall is insufficient. Whether drought stress impacts root storage, however, is currently unknown. Research was conducted to determine the effect of preharvest water stress on postharvest sugarbeet root respiration rate and susceptibility to storage rots as these traits are the primary determinants for sucrose loss and quality deterioration. Greenhouse‐grown plants were subjected to four levels of water deficit by discontinuing watering for 0, 7, 14 or 21 days prior to harvest. Plants receiving water‐restrictive treatments displayed physiological stress by leaf epinasty, reductions in net photosynthetic rate and leaf relative water content and increases in leaf temperature, whereas the water content of roots harvested from these plants progressively decreased with the severity of the preharvest water‐deficit treatment. Harvested roots from all watering treatments were stored at 10°C and 95% relative humidity for up to 12 weeks and evaluated for respiration rate and susceptibility to storage rot. Root respiration rate during storage was inversely related to root water content at harvest by second‐order equations, such that respiration was not significantly affected by minor reductions in root water content but increased exponentially for roots obtained from severely drought‐stressed plants with water contents at harvest of ≤75%. Similarly, roots with water contents ≤75% had elevated levels of electrolyte leakage, a measure of cellular membrane damage, and were more susceptible to dehydration and fungal infection during storage. In separate experiments, roots harvested from water‐stressed plants were inoculated with Botrytis cinerea or Penicillium vulpinum, two causal agents for storage rots. In these experiments, preharvest water stress quantitatively increased root rot and qualitatively altered symptoms of their infection. Overall, these results demonstrate that severe preharvest drought stress is likely to significantly increase sugarbeet root storage losses caused by root respiration and storage rots and that storage losses are likely to accelerate with time in storage. However, mild‐to‐moderate drought conditions prior to harvest are expected to have no or minimal effect on storage losses from root respiration or storage rots. [ABSTRACT FROM AUTHOR]

Root rot is a highly infectious disease in traditional Chinese medicine (TCM) that spreads quickly and significantly affects the yield and quality of TCM. Therefore, there is an urgent need for accurate and convenient early warning technology to guide root rot control. The root rot of TCM is mainly caused by Fusarium fungi infecting plants. After plants have been infected with fungi, zearalenone (ZEN), fumonisin (FB), fusarium acid (FA), and other compounds will produce duo to Fusarium infects plants to promote metabolism. And the trace expression of these compounds in plants is used as root rot early warning markers (RREWM). Herein, an electrochemical immunosensor was developed for the rapid, convenient, and sensitive detection of zearalenone (ZEN), an early warning marker for Radix isatidis root rot. The immunosensor utilizes Fe3O4@g-C3N4 composite ITO electrode. Initially, the ITO conductive films were modified with Fe3O4@g-C3N4 and gold nanoparticles (AuNPs) through droplet coating and chemical deposition, respectively. Subsequently, the AuNPs were conjugated with zearalenone antibody (ZEN-Ab) to generate high affinity sulfhydryl-bound recognition elements. Under the optimized condition, the sensor demonstrates a linear wide range of 10.00 pg mL−1 to 1.20 × 104 pg mL−1 with a LOD of 3.86 pg mL−1. Additionally, the sensor showed good reproducibility and stability. This study exhibits a convenient, accurate, and low-cost method for detecting early warning markers of root rot in TCM cultivation, which was expected to provide a reliable warning technology for the early warning and prevention of diseases in the planting process of TCM. [ABSTRACT FROM AUTHOR]

Four new modes of action, oxathiapiprolin, fluopicolide, mandipropamid, and ethaboxam, have or are pending registrations on multiple tree crops in the USA including avocado, citrus, almond (and other tree nuts), and stone fruits to be used in sustainable anti-resistance rotation and mixture programs for managing Phytophthora diseases. All four fungicides are highly toxic in vitro against species of Phytophthora from different tree crops. Efficacy of foliar applications of oxathiapiprolin and mandipropamid for the management of citrus brown rot persisted for over 10 weeks. Still, residues could be removed to non-detectable levels by postharvest washing and brushing of fresh-market fruit. The four fungicides were highly effective in reducing root rot and crown/trunk cankers on tree crops and demonstrated acropetal systemic movement through the xylem after soil application and absorption by almond, citrus, and cherry roots. This was substantiated by reduced lesion size in stem inoculations of potted trees that were treated by soil applications or by in vitro bioassays and HPLC–MS–MS analyses of root, stem, and leaf extracts. Using an adapted Bromilow model that is based on the partition coefficient logP that indicates the lipo- or hydrophilicity and the acid dissociation constant pKa, mobility of ethaboxam, fluopicolide, mandipropamid, and oxathiapiprolin in plants was predicted, and this was supported by our studies. Mandipropamid and a mandipropamid–oxathiapiprolin pre-mixture are now registered as foliar applications for managing citrus brown rot, whereas oxathiapiprolin and fluopicolide are registered, and ethaboxam is pending registration as soil applications to control citrus root rot. Oxathiapiprolin has also been registered for soil use on almond and other nut crops, as well as avocado, and soil applications of mandipropamid are planned to be restricted to nursery use of multiple crops. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Northwest A & F University - Natural Science Edition is the property of Editorial Department of Journal of Northwest A&F University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The microbial communities in rhizosphere soil play important roles in plant health and crop productivity. However, the microbial community structure of rhizosphere soil still remains unclear. In this study, the composition, diversity and function of the microbial communities in the rhizosphere soil of healthy and diseased plants were compared using Illumina MiSeq high-throughput sequencing. The Sobs (richness) and Shannon (diversity) indices of the soil microbial communities were higher in the rhizospheres of 2- and 3-year-old susceptible plants than in those of the healthy plants. With the increase in planting time, the numbers of fungi tended to decrease, while those of the bacteria tended to increase. Fungal diversity could be used as a biological indicator to measure the health of Knoxia roxburghii. The microbial composition and differential analyses revealed that the rhizosphere soil infested with fungi had a higher relative abundance at the phylum level in Ascomycota and Basidiomycota, while the bacteria had a higher relative abundance of Chloroflexi and a lower relative abundance of Actinobacteriota. At the genus level, the rhizosphere soil infested with fungi had relatively more abundant unclassified_f__Didymellaceae and Solicoccozyma and relatively less abundant Saitozyma and Penicillium. The bacterial genus norank_f__Gemmatimonadaceae was the most abundant, while Arthrobacter was less abundant. In addition, the abundance of Fusarium in the fungal community varied (p = 0.001). It tended to increase in parallel with the planting years. Therefore, it was hypothesized that the change in the community composition of Fusarium may be the primary reason for the occurrence of root rot in K. roxburghii, and the change in the abundance of Fusarium OTU1450 may be an indication of the occurrence of root rot in this species. The community function and prediction analyses showed that the pathogenic fungi increased with the increase in planting years. In general, soil fungi can be roughly divided into three types, including pathotrophs, symbiotrophs, and saprotrophs. An analysis of the differences in the prediction of different rhizosphere functions showed that D and L were significantly different in the COG enrichment pathway of the K. roxburghii rhizosphere bacteria (p < 0.05). The soil physical and chemical properties, including the pH, AK, total potassium (TK), and catalase (S_CAT), had the most significant effect on the soil fungal community, and most of the soil physical and chemical properties significantly correlated with the bacterial community. This study demonstrated that the occurrence of root rot had an important effect on the diversity, structure and composition of microbial communities. In addition, the results will provide a theoretical basis to prevent and control root rot in K. roxburghii. [ABSTRACT FROM AUTHOR]

Plant Growth Promoting Bacteria have proven themselves in agricultural applications not only as biofertilizers but also as biocontrol agents against different phytopathogens. In this study, we focused on investigating the ability of Enterobacter cloacae to induce the immune response of Zea mays against Fusarium oxysporum infection. The bacterium was transformed with a plasmid to express Green Fluorescence Protein and used in a greenhouse experiment in combination with Fusarium infection in different treatments. E. cloacae successfully colonized the root, resulting in enhanced physical growth with great investment in leaf area, photosynthetic pigment production, and reduced anthocyanin content. E. cloacae left a considerable resistance to root rot caused by Fusarium, as the disease severity was reduced from 74.2% (in the case of Fusarium infection alone) to about 35.8% (in the case of E. cloacae addition 14 days before fungal infection). The amount of salicylic acid (SA) was markedly elevated, and Pathogen-Related Protein showed up to an eightfold increase in the expression level. From these results, we suppose that E. cloacae induces SA-dependent systemic acquired resistance, which allows pre-colonized plants to resist Fusarium infection. [ABSTRACT FROM AUTHOR]

Background: The soil-borne fungi, Rhizoctonia solani and Sclerotium rolfsii, are major pathogens of Brassicae crops. This study was performed to clarify the relationship between the accumulation pattern of the genus Trichoderma and disease suppression in frequently inoculated soils with binucleate Rhizoctonia (BNR), Rhizoctonia solani and Sclerotium rolfsii. Results: As compared to the control group, five Trichoderma virens strains isolated from soil inoculated with R. solani or BNR significantly reduced the severity of S. rolfsii (85.6–100% covering percentage) and R. solani (95.7–100% covering percentage). Similarly, five T. hamatum strains obtained from soil inoculated with R. solani were shown to be highly suppressive against S. rolfsii (83.9–97.1% covering percentages) and R. solani (60.2–96.2% covering percentages). Four out of five T. hamatum strains obtained from soil infected with S. rolfsii exhibited considerable suppression against S. rolfsii (63.7–91.2% covering percentages), while the SM5 strain did not. The phylogenetic analysis of the TEF and ITS regions of Trichoderma hamatum revealed that most isolates were classified into the same cluster with homology of 99–100%. Five strains of each T. virens and T. hamatum were isolated from the suppressive soil with high antagonistic potentials against R. solani and S. rolfsii. Suppression and antagonistic activity of T. hamatum isolated from soil frequently inoculated with sterile barley grains were negligible, whereas T. hamatum isolated from frequently inoculated soil with BNR and R. solani demonstrated considerable suppression of the pathogens and antagonistic activity. Accumulation and quantification of T. virens and T. hamatum were confirmed using loop-mediated isothermal amplification (LAMP). Conclusion: In conclusion, disease suppression in frequently inoculated soil with BNR, R. solani and S. rolfsii was due to Trichoderma spp. accumulated selectively in each replicate of soil inoculation. [ABSTRACT FROM AUTHOR]

Purpose: Rot disease caused by Fusarium poses a formidable threat to the growth of saffron (Crocus sativus L.), resulting in substantial damage to both yield and quality. It is paramount to delve into the root causes of rot disease in saffron to optimize both yield and quality. Existing preventive and treatment modalities have exerted deleterious effects on corms and the natural environment. Consequently, the quest for efficacious and eco-friendly methods such as biological control agents has become an urgent imperative. Methods: The disparate distribution of microbial communities between rhizospheric microorganisms and saffron serves as the foundational exploration for uncovering the underlying causes of rot disease. Samples from various saffron organs and rhizosphere soil were gathered, and the sequencing data from the microbial communities were interpreted using 16S rRNA and ITS gene sequencing methods. This facilitated an in-depth examination of the composition and changes of microorganisms in both healthy and diseased saffron plants. Results: The findings indicated rot disease reduced the abundance and diversity of microorganisms in saffron, and the fungal co-occurrence networks were less stable and their communities were more sensitive to rot disease than the bacterial community. Fusarium was the predominant genus in diseased samples, accounting for 99.19% and 89.77% of the communities in diseased leaves and corms. With corms and leaves displaying heightened susceptibility to infection compared to other plant organs. Some of the beneficial bacterial taxa enriched in the diseased plants were also identified in networks, they showed an antagonistic relationship with Fusarium, suggesting a potential for these bacteria to be used in biologically based control strategies against rot disease. These insights could prove invaluable for the development of biocontrol agents aimed at combating this plant ailment. Conclusion: These findings significantly advance our understanding of saffron-microbiome interactions and could provide fundamental and important data for improving saffron yield and quality in the process of sustainable development. [ABSTRACT FROM AUTHOR]

Ginsengs, widely acknowledged for their health-promoting properties, are predominantly grown for their roots, necessitating an extended cultivation period of a minimum of 4 to 6 years for maturation. The prolonged growth duration in a specific location makes ginseng plants susceptible to soil-borne ailments, such as root rot, leading to significant detrimental effects. Focusing on the crucial role of the plant microbial community in maintaining ginseng health, the study reveals that repeated and continuous cultivation leads to the collapse of the initial disease-suppressive rhizosphere community, resulting in severe root rot. The dominance of Pseudomonadaceae in the rhizosphere subsequently reinstates disease suppression, aligning with suppressive soil generation phenomena. The research investigates the applicability of identified patterns to field conditions and demonstrates that rhizosphere samples from the field closely resemble conditions observed in pot-based NH4Cl treatment experiments. These findings emphasize the critical role of the rhizosphere microbial community in ginseng health maintenance during extended cultivation, offering insights into disease prevention strategies. The study also suggests the potential of pot-based experiments in simulating field conditions and informs future approaches for sustainable ginseng cultivation. [ABSTRACT FROM AUTHOR]

Common bean (Phaseolus vulgaris L.) is an essential food staple and source of income for small-holder farmers across Africa. However, yields are greatly threatened by fungal diseases like root rot induced by Rhizoctonia solani. This study aimed to evaluate an integrated approach utilizing vermicompost tea (VCT) and antagonistic microbes for effective and sustainable management of R. solani root rot in common beans. Fourteen fungal strains were first isolated from infected common bean plants collected across three Egyptian governorates, with R. solani being the most virulent isolate with 50% dominance. Subsequently, the antagonistic potential of vermicompost tea (VCT), Serratia sp., and Trichoderma sp. was assessed against this destructive pathogen. Combinations of 10% VCT and the biocontrol agent isolates displayed potent inhibition of R. solani growth in vitro, prompting in planta testing. Under greenhouse conditions, integrated applications of 5 or 10% VCT with Serratia marcescens, Trichoderma harzianum, or effective microorganisms (EM1) afforded up to 95% protection against pre- and post-emergence damping-off induced by R. solani in common bean cv. Giza 6. Similarly, under field conditions, combining VCT with EM1 (VCT + EM1) or Trichoderma harzianum (VCT + Trichoderma harzianum) substantially suppressed disease severity by 65.6% and 64.34%, respectively, relative to untreated plants. These treatments also elicited defense enzyme activity and distinctly improved growth parameters including 136.68% and 132.49% increases in pod weight per plant over control plants. GC–MS profiling of Trichoderma harzianum, Serratia marcescens, and vermicompost tea (VCT) extracts revealed unique compounds dominated by cyclic pregnane, fatty acid methyl esters, linoleic acid derivatives, and free fatty acids like oleic, palmitic, and stearic acids with confirmed biocontrol and plant growth-promoting activities. The results verify VCT-mediated delivery of synergistic microbial consortia as a sustainable platform for integrated management of debilitating soil-borne diseases, enhancing productivity and incomes for smallholder bean farmers through regeneration of soil health. Further large-scale validation can pave the adoption of this climate-resilient approach for securing food and nutrition security. [ABSTRACT FROM AUTHOR]

Background: Since the 1980s, soils in a 22-km2 area near Lake Neuchâtel in Switzerland have been recognized for their innate ability to suppress the black root rot plant disease caused by the fungal pathogen Thielaviopsis basicola. However, the efficacy of natural disease suppressive soils against insect pests has not been studied. Results: We demonstrate that natural soil suppressiveness also protects plants from the leaf-feeding pest insect Oulema melanopus. Plants grown in the most suppressive soil have a reduced stress response to Oulema feeding, reflected by dampened levels of herbivore defense-related phytohormones and benzoxazinoids. Enhanced salicylate levels in insect-free plants indicate defense-priming operating in this soil. The rhizosphere microbiome of suppressive soils contained a higher proportion of plant-beneficial bacteria, coinciding with their microbiome networks being highly tolerant to the destabilizing impact of insect exposure observed in the rhizosphere of plants grown in the conducive soils. We suggest that presence of plant-beneficial bacteria in the suppressive soils along with priming, conferred plant resistance to the insect pest, manifesting also in the onset of insect microbiome dysbiosis by the displacement of the insect endosymbionts. Conclusions: Our results show that an intricate soil–plant-insect feedback, relying on a stress tolerant microbiome network with the presence of plant-beneficial bacteria and plant priming, extends natural soil suppressiveness from soilborne diseases to insect pests. 4oEYADM9UCsv5obDEsLZQ_ Video Abstract [ABSTRACT FROM AUTHOR]

Hemp, a member of the Cannabis sativa L. species, has a rich history and is a versatile crop with industrial, nutritional, medical, and environmental potential. It has been used for centuries in textiles, paper, ropes, and construction materials. Hemp seeds and hemp-derived products are gaining popularity as nutritious and functional foods. Hemp also contains cannabinoids, such as cannabidiol (CBD), which have potential therapeutic effects and are the subject of extensive research. Additionally, hemp cultivation offers environmental benefits, including soil remediation and carbon sequestration. The regulatory landscape surrounding hemp is evolving, with changes in laws and regulations opening up new opportunities for research and commercialization. The future of the hemp industry looks promising, with opportunities for innovation and sustainable development across various sectors. This special issue of the Journal of Cannabis Research includes manuscripts on hemp plant science, genetics, chemistry, regulation, and medical and industrial uses, providing a comprehensive overview of the field. [Extracted from the article]

For soybean, novel single dominant Resistance to Phytophthora sojae (Rps) genes are sought to manage Phytophthora root and stem rot. In this study, resistance to P. sojae was mapped individually in four recombinant inbred line (RIL) populations derived from crosses of the susceptible cultivar Williams with PI 407985, PI 408029, PI 408097, and PI424477 previously identified as putative novel sources of disease resistance. Each population was screened for resistance with five to seven isolates of P. sojae separately over multiple F7-F10 generations. Additionally, three of the populations were screened with inoculum from the combination of three P. sojae isolates (PPR), which comprised virulence to 14 Rps genes. Over 2,300 single-nucleotide polymorphism markers were used to construct genetic maps in each population to identify chromosomal regions associated with resistance to P. sojae. Resistance segregated as one or two genes to the individual isolates and one gene toward PPR in each population and mapped to chromosomes 3, 13, or 18 in one or more of the four RIL populations. Resistance to five isolates mapped to the same chromosome 3 region are as follows: OH7 (PI 424477 and PI408029), OH12168, OH7/8, PPR (PI 407985), and 1.S.1.1 (PI408029). The resistance regions on chromosome 13 also overlapped for OH1, OH25, OH-MIA (PI424477), PPR (PI 424477, PI 407985, and PI 408097), PPR and OH0217 (PI 408097), and OH4 (PI 408029), but were distinct for each population suggesting multiple genes confer resistance. Two regions were identified on chromosome 18 but all appear to map to known loci; notably, resistance to the combined inoculum (PPR) did not map at this locus. However, there are putative new alleles in three of four populations, three on chromosome 3 and two on chromosome 13 based on mapping location but also known virulence in the isolate used. This characterization of all the Rps genes segregating in these populations to these isolates will be informative for breeding, but the combined inoculum was able to map a novel loci. Furthermore, within each of these P. sojae isolates, there was virulence to more than the described Rps genes, and the effectiveness of the novel genes requires testing in larger populations. [ABSTRACT FROM AUTHOR]

Mentha haplocalyx essential oil (MEO) has demonstrated inhibitory effects on Fusarium oxysporum. Despite its environmentally friendly properties as a natural product, the limited water solubility of MEO restricts its practical application in the field. The use of nanoemulsion can improve bioavailability and provide an eco-friendly approach to prevent and control Panax notoginseng root rot. In this study, Tween 80 and anhydrous ethanol (at a mass ratio of 3) were selected as carriers, and the ultrasonic method was utilized to produce a nanoemulsion of MEO (MNEO) with an average particle size of 26.07 nm. Compared to MTEO (MEO dissolved in an aqueous solution of 2% DMSO and 0.1% Tween 80), MNEO exhibited superior inhibition against F. oxysporum in terms of spore germination and hyphal growth. Transcriptomics and metabolomics results revealed that after MNEO treatment, the expression levels of certain genes related to glycolysis/gluconeogenesis, starch and sucrose metabolism were significantly suppressed along with the accumulation of metabolites, leading to energy metabolism disorder and growth stagnation in F. oxysporum. In contrast, the inhibitory effect from MTEO treatment was less pronounced. Furthermore, MNEO also demonstrated inhibition on meiosis, ribosome function, and ribosome biogenesis in F. oxysporum growth process. These findings suggest that MNEO possesses enhanced stability and antifungal activity, which effectively hinders F. oxysporum through inducing energy metabolism disorder, meiotic stagnation, as well as ribosome dysfunction, thus indicating its potential for development as a green pesticide for prevention and control P. notoginseng root rot caused by F.oxyosporum. [ABSTRACT FROM AUTHOR]

Wheat leaf disease prevention and treatment requires an accurate and rapid classification of wheat leaf diseases and their extent. Using healthy wheat, leaf rust, crown, root rot, and wheat loose smut as research objects, this study proposes a deep learning-based technique for classifying wheat leaf diseases. A collaborative generative adversarial network is used as an image imputation in the proposed methodology, allowing a generator and discriminator network to properly estimate the missing data in the dataset using the residual method. It is used to improve feature extraction in wheat leaf images. The major contribution of this study is to use a pre-trained deep learning convolutional neural network architecture as a foundation to improve and construct an automated tool for wheat leaf disease image categorization. To classify wheat leaf diseases, a modification to the Residual Network with 50 layers (ResNet50) is being suggested. The ′Conv′, ′Batch Normaliz′, and ′Activation Leaky Relu′ layers were added as part of this modification. These layers are inserted into the ResNet50 architecture for accurate feature extraction and discrimination. Extensive tests are carried out to evaluate the proposed model's performance on photos from a large wheat disease classification dataset. The suggested approach outperforms ResNet50, InceptionV3, and DenseNet, according to the experimental findings. The suggested method achieves the greatest identification accuracy of 98.44%. These discoveries might aid in the accurate detection and categorization of wheat leaf diseases. [ABSTRACT FROM AUTHOR]

Fusarium incarnatum‐equiseti species complex infects a wide variety of food crops. Six fungal isolates were isolated from rotted roots of Dolichos lablab (hyacinth bean), Trichosanthes dioica (pointed gourd), Momordica dioica (spiny gourd), Capsicum frutescens (chilli) and Pisum sativum (garden pea), and identified as Fusarium spp., belonging to Fusarium incarnatum‐equiseti species complex (FIESC), through conidial morphology, sporodochia on carnation leaf agar medium and sequencing of nuclear ITS‐rRNA and transcription elongation factor 1α gene. Multilocus phylogenetic analysis demonstrated their inclusion within the Incarnatum clade of FIESC. All of them were self‐incompatible and failed to pair with other isolates. Vegetative incompatibility affected their pathogenicity and host specificity. The isolates secreted extracellular cell wall degrading enzymes cellulase (0.033 ± 0.002–0.403 ± 0.020 U.mL−1), polygalacturonase (0.005 ± 0.0001–0.392 ± 0.010 U.mL−1) and pectin‐lyase (0.015 ± 0.001–0.407 ± 0.012 U.mL−1) for direct penetration to root tissue. They also secreted toxic metabolites that inhibited germination of Cicer arietium (chickpea) and Pisum sativum (garden pea) seeds. The isolates exhibited complete pathogenicity on their original hosts (death due to root rotting, Disease Severity Index‐ 100%) but less pathogenicity in other non‐host plants (yellowing of lower leaves without sign of root rot, Disease Severity Index‐ <20%). This study reported the production of plant cell wall degrading enzymes and toxic metabolites by some pathogens belonging to FIESC and three new hosts of the pathogen such as hyacinth bean, spiny gourd and garden pea, from the Indian subcontinent. [ABSTRACT FROM AUTHOR]

Fusarium root rot is usually classified as an extremely destructive soilborne disease. From 2020 to 2021, Fusarium root rot was observed in production areas and seriously affected the yield and quality of Scutellaria baicalensis in Shanxi Province, China. Based on morphological characteristics and combined analysis of the internal transcribed spacer region of ribosomal DNA and translation elongation factor 1 -alpha sequences. 68 Fusarium isolates obtained in this work were identified as E oxysporum (52.94%), F. acuminatum (20.59%), F. solani (16.17%). F. proliferatum (5.88%), F. incarnation (2.94%), and F. brachygibbosum (1.47%). In the pathogenicity tests, all Fusarium isolates could infect S. baicalensis roots, presenting different pathogenic ability. Among these isolates, F. oxysporum was found to have the highest virulence on S. baicalensis roots, followed by F. acuminatum, F. solani, F. proliferatum. F. brachygibbosum, and F. incarnation. According to fungicide sensitivity tests, Fusarium isolates were more sensitive to fludioxonil and difenoconazole, followed by carbendazim, thiophanate-methyl, and hymexazol. In brief, this is the first report of Fusarium species (F. oxysporum, F. acuminatum, F. solani, F. proliferatum, F. incamarum, and F. brachygibbosum) as causal agents of root rot of S', baicalensis in Shanxi Province, China. The fungicide sensitivity results will be helpful for formulating management strategies of baicalensis root rot. [ABSTRACT FROM AUTHOR]

Fusarium species are agriculturally important fungi with a broad host range and can be found as endophytic, pathogenic, or opportunistic parasites in many crop plants. This study aimed to identify Fusarium species in bare-rooted, dormant plants in Turkish grapevine nurseries using molecular identification methods and assess their pathogenicity. Asymptomatic dormant plants were sampled from grapevine nurseries (43) in different regions of the country, and fungi were isolated from plant roots and internal basal tissues. The Fusarium strains were identified by performing gene sequencing (TEF1-α, RPB2) and phylogenetic analyses. Pathogenicity tests were carried out by inoculating mycelial agar pieces of strains onto the stem or conidial suspensions into the rhizosphere of vines (1103 Paulsen rootstock). Laboratory tests revealed that Fusarium species were highly prevalent in Turkish grapevine nurseries (41 out of 43). Gene sequencing and phylogenetic analyses unraveled that 12 Fusarium species (F. annulatum, F. brachygibbosum, F. clavum, F. curvatum, F. falciforme, F. fredkrugeri, F. glycines, F. nanum, F. nematophilum, F. nirenbergiae, F. solani, and Fusarium spp.) existed in the ready-to-sale plants. Some of these species (F. annulatum, F. curvatum and F. nirenbergiae) consistently caused wood necrosis of seedling stems, rotting of the basal zone and roots, and reduced root biomass. Although the other nine species also caused some root rot and root reduction, their virulence was not as severe as the pathogenic ones, and they were considered opportunistic parasites or endophytic species. This study suggests that Fusarium species might play an important role in root-basal rot, wood canker symptoms, and young vine decline in Turkish grapevine nurseries and that these species need to be considered for healthy seedling production. [ABSTRACT FROM AUTHOR]

Rhizoctonia solani is a soil-borne fungal species with worldwide distribution and poses serious threats to a wide range of economically important crops such as grain and forage crops. This pathogen has survival capabilities within plants and soil, giving rise to sclerotia and persisting for several months or years. Alfalfa (Medicago sativa) is the most widely grown and important forage crop in China and worldwide. The unique characteristics of alfalfa, such as excellent forage quality, ruminant desirability, and substantial biomass output, distinguish it from other fodder crops, and it is also known as the "Queen of Forages". However, the production of alfalfa is seriously affected by R. solani, with yield losses of 20% to 60% globally. This review firstly summarizes diseases such as seedling damping-off, root rot, crown rot, root cankers, stem cankers, blight, and stem rot caused by R. solani in alfalfa and the survival mechanism of this pathogen. The techniques for R. solani detection and quantification from plants and soils, as well as management through host resistance, cultural practices, fungicides, and biological control, were then overviewed. This review provides scientific knowledge to enable researchers to efficiently manage R. solani in alfalfa production. [ABSTRACT FROM AUTHOR]

Agave tequilana stems store fructan polymers, the main carbon source for tequila production. This crop takes six or more years for industrial maturity. In conducive conditions, agave wilt disease increases the incidence of dead plants after the fourth year. Plant susceptibility induced for limited photosynthates for defense is recognized in many crops and is known as "sink-induced loss of resistance". To establish whether A. tequilana is more prone to agave wilt as it ages, because the reduction of water-soluble carbohydrates in roots, as a consequence of greater assembly of highly polymerized fructans, were quantified roots sucrose, fructose, and glucose, as well as fructans in stems of agave plants of different ages. The damage induced by inoculation with Fusarium solani or F. oxysporum in the roots or xylem bundles, respectively, was recorded. As the agave plant accumulated fructans in the stem as the main sink, the amount of these hexoses diminished in the roots of older plants, and root rot severity increased when plants were inoculated with F. solani, as evidence of more susceptibility. This knowledge could help to structure disease management that reduces the dispersion of agave wilt, dead plants, and economic losses at the end of agave's long crop cycle. [ABSTRACT FROM AUTHOR]

In Europe, two fastidious phloem-limited pathogens, 'Candidatus Phytoplasma solani' (16SrXII-A) and 'Candidatus Arsenophonus phytopathogenicus', are associated with rubbery taproot disease (RTD) and syndrome basses richesses (SBR) of sugar beet, respectively. Both diseases can significantly reduce yield, especially when accompanied by root rot fungi. This study investigates the presence, geographic distribution and genetic traits of fastidious pathogens and the accompanying fungus, Macrophomina phaseolina, found on sugar beet across four geographically separated plains spanning seven countries in Central Europe. The survey revealed variable incidences of symptoms linked to these fastidious pathogens in the Pannonian and Wallachian Plains, sporadic occurrence in the North European Plain, and no symptomatic sugar beet in the Bohemian Plain. Molecular analyses unveiled the occurrence of both 'Ca. P. solani' and 'Ca. A. phytopathogenicus' throughout Central Europe, with a predominance of the phytoplasma. These fastidious pathogens were detected in all six countries surveyed within the Pannonian and Wallachian Plains, with only a limited presence of various phytoplasmas was found in the North European Plain, while no fastidious pathogens were detected in Bohemia, aligning with observed symptoms. While 16S rDNA sequences of 'Ca. P. solani' remained highly conserved, multi-locus characterization of two more variable loci (tuf and stamp) unveiled distinct variability patterns across the plains. Notably, the surprising lack of variability of tuf and stamp loci within Central Europe, particularly the Pannonian Plain, contrasted their high variability in Eastern and Western Europe, corresponding to epidemic and sporadic occurrence, respectively. The current study provides valuable insights into the genetic dynamics of 'Ca. P. solani' in Central Europe, and novel findings of the presence of 'Ca. A. phytopathogenicus' in five countries (Slovakia, Czech Republic, Austria, Serbia, and Romania) and M. phaseolina in sugar beet in Slovakia. These findings emphasize the need for further investigation of vector–pathogen(s)–plant host interactions and ecological drivers of disease outbreaks. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Adapting agriculture to climate change requires an understanding of the long‐term relationship between climate, disease dynamics, and yield. While some countries have monitored major crop diseases for decades or centuries, comparable data is scarce or non‐existent for many countries that are most vulnerable to climate change. For this, a novel approach was developed to reconstruct climate‐mediated changes in disease dynamics and yield. Here, a case study on Arabica coffee in its area of origin demonstrates how to combine local knowledge, climate data, and spatial field surveys to reconstruct disease and yield time series and to postulate and test hypotheses for climate–disease–yield relationships. Summary: While some countries have monitored crop diseases for several decades or centuries, other countries have very limited historical time series. In such areas, we lack data on long‐term patterns and drivers of disease dynamics, which is important for developing climate‐resilient disease management strategies.We adopted a novel approach, combining local knowledge, climate data, and spatial field surveys to understand long‐term climate‐mediated changes in disease dynamics in coffee agroforestry systems. For this, we worked with 58 smallholder farmers in southwestern Ethiopia, the area of origin of Arabica coffee.The majority of farmers perceived an increase in coffee leaf rust and a decrease in coffee berry disease, whereas perceptions of changes in coffee wilt disease and Armillaria root rot were highly variable among farmers. Climate data supported farmers' understanding of the climatic drivers (increased temperature, less rainy days) of these changes. Temporal disease‐climate relationships were matched by spatial disease‐climate relationships, as expected with space‐for‐time substitution.Understanding long‐term disease dynamics and yield is crucial to adapt disease management to climate change. Our study demonstrates how to combine local knowledge, climate data and spatial field surveys to reconstruct disease time series and postulate hypotheses for disease‐climate relationships in areas where few long‐term time series exist. [ABSTRACT FROM AUTHOR]

The root rot mainly caused by Fusarium solani is a bottleneck in the cultivation of Panax notoginseng. In this study, we reported a gene encoding a plant cell wall structural protein, P. notoginseng proline‐rich protein (PnPRPL1), whose transcription was upregulated by F. solani and induced by some hormone signals. The PnPRPL1 recombinant protein significantly inhibited the growth and conidial germination of the root rot pathogens. Downregulation of PnPRPL1 by RNA interference (RNAi) in P. notoginseng leaves increased the susceptibility to F. solani, whereas overexpression of PnPRPL1 in tobacco (Nicotiana tabacum) enhanced the resistance to F. solani. Compared with wild‐type tobacco, the PnPRPL1‐overexpressing transgenic tobacco had higher reactive oxygen species (ROS)‐scavenging enzyme activities, lower ROS levels, and more lignin and callose deposition. The opposite results were obtained for the P. notoginseng expressing PnPRPL1 RNAi fragments. Furthermore, the PnPRPL1 promoter transcription activity was induced by several plant hormones and multiple stress stimuli. In addition, the transcription factor PnWRKY27 activated the expression of PnPRPL1 by directly binding to the promoter region. Thus, PnPRPL1, which is positively regulated by a WRKY transcription factor, encodes an antimicrobial protein that also mediates ROS homoeostasis and callose/lignin deposition during the response to F. solani infection. Summary Statement: Root rot severely reduces the yield and quality of Panax notoginseng herbs. A P. notoginseng proline‐rich protein gene is activated by WRKY transcription factor, and it functions as an antimicrobial protein and regulator of reactive oxygen species homoeostasis, leading to increased protection against root rot. [ABSTRACT FROM AUTHOR]

Fusarium spp., a necrotrophic soil‐borne pathogen, causes root rot disease on many crops. CERK1, as a typical pattern recognition receptor, has been widely studied. However, the function of CERK1 during plant–Fusarium interaction has not been well described. We determined that MdCERK1 is a susceptibility gene in the apple‐Fusarium solani (Fs) interaction, and jasmonic acid (JA) plays a crucial role in this process. MdCERK1 directly targets and phosphorylates the lipoxygenase MdLOX2.1, an enzyme initiating the JA biosynthesis, at positions Ser326 and Thr327. These phosphorylations inhibit its translocation from the cytosol to the chloroplasts, leading to a compromised JA biosynthesis. Fs upregulates MdCERK1 expression during infection. In turn, when the JA level is low, the apple MdWRKY71, a transcriptional repressor of MdCERK1, is markedly upregulated and phosphorylated at Thr99 and Thr102 residues by the MAP kinase MdMMK2. The phosphorylation of MdWRKY71 enhances its transcription inhibition on MdCERK1. Taken together, MdCERK1 plays a novel role in limiting JA biosynthesis. There seems to be an arms race between apple and Fs, in which Fs activates MdCERK1 expression to reduce the JA level, while apple senses the low JA level and activates the MdMMK2‐MdWRKY71 module to elevate JA level by inhibiting MdCERK1 expression. Summary Statement: Chitin Elicitor Receptor Kinase 1, CERK1 plays a well‐known role in plants to initiate the primary defence upon pathogens infection. In addition to this, this study discovered that apple CERK1 interacts with and phosphorylates the lipoxygenase MdLOX2.1 to block the JA biosynthesis. Moreover, the apple MMK2‐WRKY71 module negatively regulates MdCERK1 expression to maintain the JA level. [ABSTRACT FROM AUTHOR]

Root rot caused by Fusarium spp. is a significant issue in the chickpea-growing regions of Montana. The specific Fusarium species responsible for the disease and their prevalence remain uncertain. A survey was conducted in 2020 and 2021 to identify Montana's Fusarium species associated with chickpea. Four hundred and twenty-six Fusarium isolates were recovered from symptomatic chickpea roots across ten counties in the state. Isolates were identified by comparing translation elongation factor 1-α (TEF1-α) sequences in the FUSARIUM-ID database. Among the recovered isolates, Fusarium oxysporum was the most prevalent species (33%), followed by F. acuminatum (21%), F. avenaceum (15%), F. redolens (14%), F. culmorum (6%), F. sporotrichioides (6%), Neocosmospora solani (6%), F. equiseti (2%), F. torulosum (0.9%), F. gamsii (0.8%), F. proliferatum (0.2%), F. pseudograminearum (0.2%), and F. brachygibbosum (0.1%). The aggressiveness of a subset of 51 isolates representing various Fusarium spp. was tested on chickpea cv. 'CDC Frontier'. A non-parametric variance analysis conducted on disease severity ranks indicated that F. avenaceum isolates were highly aggressive. This study reports for the first time that F. gamsii, F. proliferatum and F. brachygibbosum are causal agents of root rot in chickpea in the United States. This knowledge is invaluable for making informed decisions regarding crop rotation, disease management, and developing resistant chickpea varieties against economically significant Fusarium pathogens. [ABSTRACT FROM AUTHOR]

Strawberry red core root rot disease affects the growth and yield of strawberry (Fragaria ananassa Duch), which leads to economic losses in China. The study employed a tissue separation method to isolate and identify the causal agent responsible for strawberry red core root rot. This was achieved by the observation of its morphological characteristics, sequencing analyses, and pathogenicity tests. The sensitivity of five chemical fungicides against the two species of Fusarium was determined using the mycelial growth rate method, and the biological characteristics of the two species were examined. The pathogens were identified as Fusarium solani and Fusarium oxysporum. The optimal conditions for the mycelial growth of F. solani and F. oxysporum were determined to be potato sucrose agar at 25 °C and pH 6, and potato dextrose agar at 30 °C and pH 8, respectively, with a 24:24 light cycle. The most suitable carbon and nitrogen sources for the mycelial growth of F. solani were sucrose and sodium nitrate (NaNO3), while for F. oxysporum, they were glucose and peptone. A fungicide sensitivity test indicated that Prochloraz had a good inhibitory effect on the growth of F. solani and F. oxysporum with EC50 values of 0.088 mg L−1 and 0.162 mg. The growth inhibition effect of Azoxystrobin to F. solani and Carbendazim to F. oxysporum was not obvious. This study provides a theoretical basis for further research on strawberry red core root disease and its prevention. [ABSTRACT FROM AUTHOR]

Because of their tolerance to root rot and many abiotic stresses, rootstocks are generally required for commercial avocado production. However, cutting and air-layering, which are popular methods of vegetative propagation for producing large numbers of uniform and genetically identical plants, have been unsuccessful for years. To develop a practical and efficient rooting procedure for selected avocado clonal rootstocks, the present research investigated the effects of various factors on rooting cutting. Shoots were divided into three groups (air layering, direct cutting, and stem-buried etiolation) and treated with different combinations (plant growth regulators, PGRs; soaking time; and culture media), in which orthogonal or randomized-block designs were used. The rooting rate, average root length, average root number, average root dry weight, and rooting quality (Q value) were used as evaluation indicators. The results show that etiolation treatment of the mother shoot is the requisite condition for avocado shoot rooting. In addition, the rooting effect of etiolated cuttings was strongly impacted by PGR type, concentration, and soaking time, whereas no significant differences were detected among the culture media. Among these factors, the roots and the survival rates of etiolated cuttings of two hard-to-root varieties were optimal under the following conditions: indolebutyric acid concentration of 2500 mg/L, dipping duration for 5 s, and perlite:vermiculite culture at 1:1. The rooting rate of 'Dusa' was generally greater than that of 'Duke 7' and reached 82%. [ABSTRACT FROM AUTHOR]

THE SUPPRESSION effect of four biocontrol agents (i.e., cyanobacteria extracts: Nostoc linckia, Anabaena variabilis, Oscillatoria agardhii, and Spirulina sp.), in combination with Rhizobium leguminosarum biovar viceae (TAL–1148), against Rhizoctonia solani in faba bean plants was investigated through laboratory and pot experiments. After testing five R. solani isolates for pathogenicity, all of the identified fungi were found to be pathogenic and to have induced symptoms of root rot and pre- and post-damping-off. Comparing the results of in vitro experiments to the untreated control, algal extracts dramatically suppressed the pathogen's ability to develop mycelially. In comparison to the control (0%), O. agardhii showed the highest reduction (59.63%), followed by N. linckia (51.85%), A. variabilis (48.52%), and Spirulina sp. (40.37%). When compared to the other studied cyanobacteria and the control treatment, the combined effect of Rhizobium and cyanobacteria extracts (O. agardhii and N. linckia) produced the highest reduction in pre- and post-emergence damping-off, measuring 13.33 and 6.67%, respectively, in pot studies. Furthermore, in comparison to the control, these treatments enhanced the number and dry weight of nodules, shoot height, dry weight of shoots, N2%, and N content. Similar results were obtained using the fungicide Rizolex-T50%, which decreased the incidence and severity of the disease but had negative effects on Rhizobium and the symbiotic N2–fixing characteristics. Plants cultivated from treated faba bean seeds showed notable increases in the activity of the oxidative reductive enzymes (i.e., peroxidase and polyphenol oxidase). Thus, it could be concluded that using algal extracts in conjunction with R. leguminosarum was thought to be a practical, secure, and economical way to manage this type of soil-borne disease. More further studies are needed to emphasize this sustainable and eco-friendly approach using different phytopathogens. [ABSTRACT FROM AUTHOR]

Forest ecosystems play an important role in upholding life on our planet. However, the onslaught of fungal pathogens like Ganoderma lucidum, poses a threat by decimating numerous tree species. G. lucidum identified as a root pathogen, causing root rot in numerous tree species of horticulture and forestry importance. The fungus initiates infection through basidiospores, which germinate and penetrate within roots and start to degrade lignocellulosic components of plant cells. Early‐stage detection of G. lucidum, is challenging, while in advance stages, the wood undergoes softening and a loss of tensile strength, rendering the disease incurable. Hence, effective management of G. lucidum necessitates a pivotal role of disease diagnostic techniques, which are currently underutilized or inadequately accessible. Subsequent implementation of suitable control measures becomes imperative to thwart disease occurrence and mitigate its impact in early stages, thus preserving the vitality of forest ecosystems. This study provides comprehensive overview of G. lucidum, covering taxonomy, pathogenicity, disease cycle, diagnosis and effective control measures, which will be helpful in formulating effective diagnostic techniques for early management of root rot disease. [ABSTRACT FROM AUTHOR]

Anthracnose, white mold, powdery mildew, and root rot caused by Colletotrichum lindemuthianum, Scletorinia sclerotiorum, Erysiphe spp., and Pythium ultimum, respectively, are among the most frequent diseases that cause significant production losses worldwide in common bean (Phaseolus vulgaris L.). Reactions against these four fungal diseases were investigated under controlled conditions using a diversity panel of 311 bean lines for snap consumption (Snap bean Panel). The genomic regions involved in these resistance responses were identified based on a genome-wide association study conducted with 16,242 SNP markers. The highest number of resistant lines was observed against the three C. lindemuthianum isolates evaluated: 156 lines were resistant to CL124 isolate, 146 lines resistant to CL18, and 109 lines were resistant to C531 isolate. Two well-known anthracnose resistance clusters were identified, the Co-2 on chromosome Pv11 for isolates CL124 and CL18, and the Co-3 on chromosome Pv04 for isolates CL124 and C531. In addition, other lesser-known regions of anthracnose resistance were identified on chromosomes Pv02, Pv06, Pv08, and Pv10. For the white mold isolate tested, 24 resistant lines were identified and the resistance was localized to three different positions on chromosome Pv08. For the powdery mildew local isolate, only 12 resistant lines were identified, and along with the two previous resistance genes on chromosomes Pv04 and Pv11, a new region on chromosome Pv06 was also identified. For root rot caused by Pythium, 31 resistant lines were identified and two main regions were located on chromosomes Pv04 and Pv05. Relevant information for snap bean breeding programs was provided in this work. A total of 20 lines showed resistant or intermediate responses against four or five isolates, which can be suitable for sustainable farm production and could be used as resistance donors. Potential genes and genomic regions to be considered for targeted improvement were provided, including new or less characterized regions that should be validated in future works. Powdery mildew disease was identified as a potential risk for snap bean production and should be considered a main goal in breeding programs. [ABSTRACT FROM AUTHOR]

Phytophthora sojae is a devastating plant pathogen that causes soybean Phytophthora root rot worldwide. Early on-site and accurate detection of the causal pathogen is critical for successful management. In this study, we have developed a novel and specific one-pot RPA/PCR-CRISPR/Cas12 assay for onsite detection (Cas-OPRAD) of Phytophthora root rot (P. sojae). Compared to the traditional RPA/PCR detection methods, the Cas-OPRAD assay has significant detection performance. The Cas-OPRAD platform has excellent specificity to distinguish 33 P. sojae from closely related oomycetes or fungal species. The PCR-Cas12a assay had a consistent detection limit of 100 pg. µL-1, while the RPA-Cas12a assay achieved a detection limit of 10 pg. µL-1. Furthermore, the Cas-OPRAD assay was equipped with a lateral flow assay for on-site diagnosis and enabled the visual detection of P. sojae on the infected field soybean samples. This assay provides a simple, efficient, rapid (<1 h), and visual detection platform for diagnosing Phytophthora root rot based on the one-pot CRISPR/Cas12a assay. Our work provides important methods for early and accurate onsite detection of Phytophthora root rot in the field or customs fields. [ABSTRACT FROM AUTHOR]

Bletilla striata is an endangered traditional medicinal herb in China. In May 2020, the emergence of white root rot severely impacted the quality and yield of B. striata, affecting about 5% of the plants at plant nurseries of the Chengdu Academy of Agricultural and Forestry Sciences. Through a series of experiments and evaluations, the pathogen was identified as Fusarium solani. This is the first report of B. striata white root rot caused by F. solani in Sichuan, China. To better understand this disease and provide data support for its control, a combination of morphological, molecular characterisation and pathogenicity determination was used in this study for assessment. Meanwhile, the effects of different carbon and nitrogen sources, culture medium, temperature, photoperiod and pH on mycelial growth and spore production of F. solani were investigated. In addition, effective fungicides were screened and the concentration ratios of fungicides were optimized using response surface methodology (RSM). The experimental results showed that sucrose was the optimum carbon source for the pathogen, and the optimum temperature and pH were 25°C and pH 7, respectively, while light did no significant effect. Effective fungicides were screened, among which difenoconazole showed the strongest inhibition with EC50 of 142.773 µg/mL. The optimum fungicide concentration scheme (difenoconazole, pyraclostrobin, and thiophanatemethyl at 395.42, 781.03, and 561.11 µg/mL, respectively) was obtained using response surface methodology (RSM) to improve the inhibition rate of 92.24 ± 0.34%. This study provides basic data for the pathogen characterization of B. striata white root rot and its potential fungicides in Sichuan, China. In addition, the optimal fungicide concentration ratios were obtained through response surface methodology (RSM) optimization, which significantly enhanced the fungicidal effect and provided a scientific basis for the future control of B. striata white root rot. [ABSTRACT FROM AUTHOR]

Soybean production is significantly impacted by Phytophthora root rot (PRR), which is caused by Phytophthora sojae. The nucleotide-binding leucine-rich repeat (NLR) gene family plays a crucial role in plant disease resistance. However, current understanding of the function of soybean NLR genes in resistance to PRR is limited. To address this knowledge gap, transgenic soybean plants overexpressing the NLR gene (Glyma.18g283200) were generated to elucidate the molecular mechanism of resistance. Here, transcript changes and metabolic differences were investigated at three time points (12, 24, and 36 h) after P. sojae infection in hypocotyls of two soybean lines, Dongnong 50 (susceptible line, WT) and Glyma.18g283200 overexpression line (resistant line, OE). Based on the changes in differentially expressed genes (DEGs) in response to P. sojae infection in different lines and at different time points, it was speculated that HOPZ-ACTIVATED RESISTANCE 1 (ZAR1), valine, leucine, and isoleucine degradation, and phytohormone signaling may be involved in the defense response of soybean to P. sojae at the transcriptome level by GO term and KEGG pathway enrichment analysis. Differentially accumulated metabolites (DAMs) analysis revealed that a total of 223 and 210 differential metabolites were identified in the positive ion (POS) and negative ion (NEG) modes, respectively. An integrated pathway-level analysis of transcriptomics (obtained by RNA-seq) and metabolomics data revealed that isoflavone biosynthesis was associated with disease resistance. This work provides valuable insights that can be used in breeding programs aiming to enhance soybean resistance against PRR. [ABSTRACT FROM AUTHOR]

Fusarium crown rot (FCR) is one of the most important soilborne diseases affecting wheat production. To investigate the diversity of the pathogens causing this disease, 199 diseased wheat samples were collected from 13 cities in Shandong province. In total, 468 isolates were obtained, and from these isolates, 11 Fusarium species were identified based on phylogenetic analyses with the translation elongation factor-1a (TEF-1a), RNA polymerase II largest subunit (RPB1), and RNA polymerase II second largest subunit (RPB2) gene sequences. Of these Fusarium isolates, 283 were identified as Fusarium pseudograminearum and the remaining isolates were identified as Fusarium graminearum (n = 113), Fusarium sinensis (n = 28), Fusarium acuminatum (n = 18), Fusarium incarnatum (n = 13), Fusarium ipomoeae (n = 5), Fusarium flocciferum (n = 3), Fusarium proliferatum (n = 2), Fusarium asiaticum (n = 1), Fusarium culmorum (n = 1), and Fusarium oxysporum (n = 1), suggesting that F. pseudograminearum is the dominant pathogen of FCR of wheat in Shandong province. Pathogenicity tests demonstrated that all 11 Fusarium species could cause typical symptoms of FCR on wheat seedlings. The results of the study indicate that a greater diversity of Fusarium species can cause FCR of wheat in Shandong province than that has been previously reported. This is the first report in the world of Fusarium incarnatum, Fusarium ipomoeae, and Fusarium flocciferum as pathogens causing FCR in wheat. [ABSTRACT FROM AUTHOR]

Background: Rhizosphere and endophytic fungi play important roles in plant health and crop productivity. However, their community dynamics during the continuous cropping of Knoxia valerianoides have rarely been reported. K. valerianoides is a perennial herb of the family Rubiaceae and has been used in herbal medicines for ages. Here, we used high-throughput sequencing technology Illumina MiSeq to study the structural and functional dynamics of the rhizosphere and endophytic fungi of K. valerianoides. Results: The findings indicate that continuous planting has led to an increase in the richness and diversity of rhizosphere fungi, while concomitantly resulting in a decrease in the richness and diversity of root fungi. The diversity of endophytic fungal communities in roots was lower than that of the rhizosphere fungi. Ascomycota and Basidiomycota were the dominant phyla detected during the continuous cropping of K. valerianoides. In addition, we found that root rot directly affected the structure and diversity of fungal communities in the rhizosphere and the roots of K. valerianoides. Consequently, both the rhizosphere and endophyte fungal communities of root rot-infected plants showed higher richness than the healthy plants. The relative abundance of Fusarium in two and three years old root rot-infected plants was significantly higher than the control, indicating that continuous planting negatively affected the health of K. valerianoides plants. Decision Curve Analysis showed that soil pH, organic matter (OM), available K, total K, soil sucrase (S_SC), soil catalase (S_CAT), and soil cellulase (S_CL) were significantly related (p < 0.05) to the fungal community dynamics. Conclusions: The diversity of fungal species in the rhizosphere and root of K. valerianoides was reported for the first time. The fungal diversity of rhizosphere soil was higher than that of root endophytic fungi. The fungal diversity of root rot plants was higher than that of healthy plants. Soil pH, OM, available K, total K, S_CAT, S_SC, and S_CL were significantly related to the fungal diversity. The occurrence of root rot had an effect on the community structure and diversity of rhizosphere and root endophytic fungi. [ABSTRACT FROM AUTHOR]

Phytophthora cactorum is a plant pathogenic oomycete that causes crown rot in strawberry leading to significant economic losses every year. To invade the host, P. cactorum secretes an arsenal of effectors that can manipulate host physiology and impair its defense system promoting infection. A transcriptome analysis was conducted on a susceptible wild strawberry genotype (Fragaria vesca) 48 hours post inoculation with P. cactorum to identify effectors expressed during the early infection stage. The analysis revealed 4,668 P. cactorum genes expressed during infection of F. vesca. A total of 539 secreted proteins encoded by transcripts were identified, including 120 carbohydrate-active enzymes, 40 RXLRs, 23 proteolytic enzymes, nine elicitins, seven cysteine rich proteins, seven necrosis inducing proteins and 216 hypothetical proteins with unknown function. Twenty of the 40 RXLR effector candidates were transiently expressed in Nicotiana benthamiana using agroinfiltration and five previously unreported RXLR effector genes (Pc741, Pc8318, Pc10890, Pc20813, and Pc22290) triggered cell death when transiently expressed. The identified cell death inducing RXLR effectors showed 31-66% identity to known RXLR effectors in different Phytophthora species having roles in pathogenicity including both activation and suppression of defense response in the host. Furthermore, homology analysis revealed that these cell death inducing RXLR effectors were highly conserved (82 - 100% identity) across 23 different strains of P. cactorum originating from apple or strawberry. [ABSTRACT FROM AUTHOR]

Background: Dry root rot of chickpea caused by Macrophomina phaseolina (Tassi) Goid is a serious biotic constraint for chickpea production in Rajasthan. For the management of soil borne disease like dry root rot of chickpea, by using fungicides alone is not feasible due to environmental and health hazards. Hence integrated management of the disease by using bio-agents and fungicides is the best alternative. Therefore, in the present investigation, our main emphasis was to identify best fungicide and bio-agent for management of dry root rot in chickpea. Methods: Eight fungicides and four bio-agents were evaluated against dry root rot pathogen (M. phaseolina) in lab as well as in field condition. The experiment was conducted at instructional farm, COA, SKRAU, Bikaner during Rabi-2019 on most popular cv. GNG-1581 in RBD design with the application of seed treatment and soil application of different bio-agents and fungicides at different concentrations against dry root rot disease and compared with an untreated control. Result: Among all the fungicides used in the present investigation, tebuconazole 50% + trifloxystrobin 25% was found most effective in inhibiting the mycelial growth of the pathogen. Among all the bio-agents, T. harzianum was found most effective in inhibiting the mycelial growth of the pathogen. Under field condition, tebuconazole 50%+ trifloxystrobin 25% WG as seed treatment @ 1.5 g/kg along with T. harzianum @ 10 kg/ha as soil application gave maximum (83.76 %) disease control with highest pod yield (19.5 q/ha) and net return (Rs 39,826/ha). These treatments can provide an effective and economical management of dry root rot disease for chickpea cultivators. [ABSTRACT FROM AUTHOR]

Strawberry root rot caused by Fusarium solani is one of the main diseases of strawberries and significantly impacts the yield and quality of strawberry fruit. Biological control is becoming an alternative method for the control of plant diseases to replace or decrease the application of traditional chemical fungicides. To obtain antagonistic bacteria with a high biocontrol effect on strawberry root rot, over 72 rhizosphere bacteria were isolated from the strawberry rhizosphere soil and screened for their antifungal activity against F. solani by dual culture assay. Among them, strains CMS5 and CMR12 showed the strongest inhibitory activity against F. solani (inhibition rate 57.78% and 65.93%, respectively) and exhibited broad-spectrum antifungal activity. According to the phylogenetic tree based on 16S rDNA and gyrB genes, CMS5 and CMR12 were identified as Bacillus amyloliquefaciens. Lipopeptide genes involved in surfactin, iturin, and fengycin biosynthesis were detected in the DNA genomes of CMS5 and CMR12 by PCR amplification. The genes related to the three major lipopeptide metabolites existed in the DNA genome of strains CMS5 and CMR12, and the lipopeptides could inhibit the mycelial growth of F. solani and resulted in distorted hyphae. The inhibitory rates of lipopeptides of CMS5 and CMR12 on the spore germination of F. solani were 61.00% and 42.67%, respectively. The plant-growth-promoting (PGP) traits in vitro screening showed that CMS5 and CMR12 have the ability to fix nitrogen and secreted indoleacetic acid (IAA). In the potting test, the control efficiency of CMS5, CMR12 and CMS5+CMR12 against strawberry root rot were 65.3%, 67.94% and 88.00%, respectively. Furthermore, CMS5 and CMR12 enhanced the resistance of strawberry to F. solani by increasing the activities of defense enzymes MDA, CAT and SOD. Moreover, CMS5 and CMR12 significantly promoted the growth of strawberry seedlings such as root length, seedling length and seedling fresh weight. This study revealed that B. amyloliquefaciens CMS5 and CMR12 have high potential to be used as biocontrol agents to control strawberry root rot. [ABSTRACT FROM AUTHOR]

An investigation into oomycete diversity in rice paddies of Fars Province in Iran led to the identification of two new Pythium sensu lato (s.l.) species as Globisporangium izadpanahii sp. nov. and Pythium banihashemianum sp. nov. The identification was based on morphological and physiological features as well as on the phylogenetic analysis of nuclear (ITS and βtub) and mitochondrial (cox1 and cox2) loci using Bayesian inference and Maximum Likelihood. The present paper formally describes these two new species and defines their phylogenetic relationships with other congeneric species. According to multiple gene genealogy analysis, G. izadpanahii sp. nov. was grouped with other species of Globisporangium (formerly, clade G of Pythium s.l.) and was closely related to both G. nagaii and the recently described G. coniferarum. The second species, designated P. banihashemianum sp. nov., was grouped with other species of Pythium sensu stricto (formerly, clade B of Pythium s.l.) and, according to the phylogenetic analysis, shared an ancestor with P. plurisporium. The production of globose hyphal swellings was a major characteristic of G. izadpanahii sp. nov., which did not produce vesicles and zoospores. In pathogenicity tests on rice seedlings, P. banihashemianum sp. nov. isolates were highly pathogenic and caused severe root and crown rot, while G. izadpanahii sp. nov. isolates were not pathogenic. [ABSTRACT FROM AUTHOR]

Phytophthora pathogens possess hundreds of effector genes that exhibit diverse expression patterns during infection, yet how the expression of effector genes is precisely regulated remains largely elusive. Previous studies have identified a few potential conserved transcription factor binding sites (TFBSs) in the promoters of Phytophthora effector genes. Here, we report a MYB‐related protein, PsMyb37, in Phytophthora sojae, the major causal agent of root and stem rot in soybean. Yeast one‐hybrid and electrophoretic mobility shift assays showed that PsMyb37 binds to the TACATGTA motif, the most prevalent TFBS in effector gene promoters. The knockout mutant of PsMyb37 exhibited significantly reduced virulence on soybean and was more sensitive to oxidative stress. Consistently, transcriptome analysis showed that numerous effector genes associated with suppressing plant immunity or scavenging reactive oxygen species were down‐regulated in the PsMyb37 knockout mutant during infection compared to the wild‐type P. sojae. Several promoters of effector genes were confirmed to drive the expression of luciferase in a reporter assay. These results demonstrate that a MYB‐related transcription factor contributes to the expression of effector genes in P. sojae. [ABSTRACT FROM AUTHOR]