The banana Fusarium wilt (BFW) caused by Fusarium oxysporum f. sp. cubense tropical race4 (FocTR4) is difficult to control worldwide, which causes a huge economic losse to banana industry. The purpose of this study was to screen Trichoderma strains with antagonistic activity against FocTR4, to isolate and purify the active compound from the fermentation broth, so as to provide important biocontrol strains and active compound resources. In this work, Trichoderma strains were isolated and screened from the rhizosphere soil of crops, and the strains capable of efficiently inhibiting FocTR4 were screened by plate confrontation, and further confirmed by testing inhibition for the conidial germination and mycelial growth of FocTR4. The phylogenetic tree clarified the taxonomic status of the biocontrol strains. Moreover, the active components in the fermentation broth of the strains were separated and purified by column chromatography, the structure of the most active component was analyzed by nuclear magnetic resonance spectroscopy (NMR), the BFW control effect was tested by pot experiments. We obtained a strain JSHA-CD-1003 with antagonistic activity against FocTR4, and the inhibition rate from plate confrontation was 60.6%. The fermentation broth of JSHA-CD-1003 completely inhibited the germination of FocTR4 conidia within 24 hours. The inhibition rate of FocTR4 hyphae growth was 52.6% within 7 d. A phylogenetic tree was constructed based on the ITS and tef1-α gene tandem sequences, and JSHA-CD-1003 was identified as Trichoderma brevicompactum. Purification and NMR identification showed that the single active compound was trichodermin, and the minimum inhibitory concentration (MIC) was 25 μg/mL. Pot experiments showed that the fermentation broth of strain JSHA-CD-1003 was effective against BFW. The control rate of leaf yellowing was 47.4%, and the rate of bulb browning was 52.0%. Therefore, JSHA-CD-1003 effectively inhibited FocTR4 conidial germination and mycelium growth through producing trichodermin, and showed biocontrol effect on banana wilt caused by FocTR4, thus is a potential biocontrol strain.
Fusarium ; Musa ; Phylogeny ; Trichodermin ; Hypocreales

Wilt disease is a major disease of cultivated Salvia miltiorrhiza, which is caused by Fusarium oxysporum. Since the infection process of F. oxysporum in plants is affected by environment factors, this study was conducted to reveal the relationship between disease severity and concentration of the pathogen in plants in the infection process of F. oxysporum in seedlings of S. miltiorrhiza by pot experiments and to reveal the effects of temperature and humidity on the infection process. The results showed that, after inoculation of S. miltiorrhiza seedlings with F. oxysporum, the pathogen in different parts was detected at different time, and it was first detected in substrates. With the continuous propagation of the pathogen(4-5 d), it gradually infected the roots and stems of the seedlings, and the plants had yellowing leaves and withering. The number of the pathogen reached the maximum in each part after 7-8 d, and then gradually decreased in the later stage of the disease. The concentration of the pathogen in substrates, roots and stems of S. miltiorrhiza showed a trend of decreasing after increasing with the aggravation of the disease and reached the maximum in the samples of moderate morbidity, while the concentration in the samples of severe morbidity decreased. In addition, the infection of F. oxysporum in seedlings of S. miltiorrhiza was affected by temperature and humidity. The suitable temperature was 25-30 ℃ and the suitable humidity was 80%-90%. This study could provide guidance for the experiments on pathogenicity of F. oxysporum, screening of biocontrol bacteria and controlling of wilt.
Seedlings/microbiology* ; Salvia miltiorrhiza ; Temperature ; Humidity ; Fusarium

Based on polyketide syntheses gene (PKS) and non-ribosomal peptide synthetases gene (NRPS), one strain with high anti-pathogenic activity was screened from 77 strains isolated from Arctic marine sediments and identified. By optimizing the composition of culture medium and fermentation conditions, the production of this strain's active metabolites was improved and the main metabolites were identified by HRMS, ¹H NMR and ¹³C NMR. The antibacterial spectrum of the main metabolites and the effect of the metabolites on cucumber Fusarium wilt were also determined. The results showed that the strain was Bacillus velezensis and it showed growth promoting effect on plants. When the strain was cultured in 5 g/L maltose, 10 g/L tryptone, 10 g/L sodium chloride, at 30 ℃, 150 r/min for 60 h, the diameter of the inhibition zone increased from (16.23±0.42) to (24.42±0.57) mm. The metabolites of this strain mainly contain macrolide compound macrolactin A, which has antagonistic effect on a variety of pathogenic bacteria and fungi. Cucumber seedling experiments showed that the metabolites of this strain had a protective effect on cucumber Fusarium wilt, and showed a good potential for development and application as a biocontrol agent.
Polyketides/pharmacology* ; Fungi ; Bacteria ; Fusarium/genetics* ; Anti-Bacterial Agents/pharmacology* ; Peptide Synthases/genetics*

Salvia miltiorrhiza is a commonly used bulk medicinal material in China. Due to the increasing demand in recent years, the planting area is expanding. In the artificial cultivation of S. miltiorrhiza, continuous cropping obstacles are prominent, which has seriously restrained the growth of S. miltiorrhiza, resulted in serious root diseases, and affected the yield and quality of medicinal materials. The pathogen infection can induce plant resistance. Previously, this research group isolated Fusarium oxysporum and Verticillium dahlia from the roots of diseased S. miltiorrhiza. In this study, 7 days after inoculation of S. miltiorrhiza with F. oxysporum(Foc group) and V. dahlia(Vd group), the incidence rates in S. miltiorrhiza were 48% and 26%, respectively. Both the two pathogens significantly reduced the aboveground biomass of S. miltiorrhiza. Five days after inoculation, the activities of defensive enzymes, such as peroxidase(POD), phenylalanine ammonia-lyase(PAL), superoxide dismutase(SOD), and polyphenol oxidase(PPO) reached the peak. The enzyme activity of the Foc group was significantly higher than that of the Vd group. Three days after inoculation, the expression of defense genes SmPDF2.1 and SmPR10 peaked and then decreased. The results showed that F. oxysporum and V. dahlia showed pathogenicity to S. miltiorrhiza and could strongly induce systemic resistance. In terms of the above indexes, F. oxysporum was superior to V. dahlia.
Salvia miltiorrhiza ; Verticillium ; Dahlia ; Virulence ; Fusarium

Zearalenone(ZEN) is a mycotoxin produced by Fusarium, possessing estrogen-like effects, carcinogenicity, and multiple toxicities. To seek more efficient and practical agents for biological detoxification and broaden their application, this study isolated 194 bacterial strains from the moldy tuberous root of Pseudostellaria heterophylla, which were co-cultured with ZEN. An efficient ZEN-degrading strain H4-3-C1 was screened out by HPLC and identified as Acinetobacter calcoaceticus by morphological observation and molecular identification. The effects of culture medium, inoculation dose, culture time, pH, and temperature on the degradation of ZEN by H4-3-C1 strain were investigated. The mechanism of ZEN degradation and the degrading effect in Coicis Semen were discussed. The degradation rate of 5 μg·mL~(-1) ZEN by H4-3-C1 strain was 85.77% in the LB medium(pH 6) at 28 ℃/180 r·min~(-1) for 24 h with the inoculation dose of 1%. The degradation rate of ZEN in the supernatant of strain culture was higher than that in the intracellular fluid and thalli. The strain was inferred to secret extracellular enzymes to degrade ZEN. In addition, the H4-3-C1 strain could also degrade ZEN in Coicis Semen. If the initial content of ZEN in Coicis Semen was reduced from 90 μg·g~(-1) to 40.68 μg·g~(-1), the degradation rate could reach 54.80%. This study is expected to provide a new strain and application technology for the biological detoxification of ZEN in food processing products and Chinese medicinal materials.
Bacteria ; Fusarium ; Mycotoxins ; Temperature ; Zearalenone

Fusarium is the major pathogen of root rot of Pseudostellaria heterophylla. This study aims to explain the possible distribution of Fusarium species and the contamination of its toxin-chemotypes in tuberous root of P. heterophylla. A total of 89 strains of fungi were isolated from the tuberous root of P. heterophylla. Among them, 29 strains were identified as Fusarium by ITS2 sequence, accounting for 32.5%. They were identified as five species of F. avenaceum, F. tricinctum, F. fujikuroi, F. oxysporum, and F. graminearum based on β-Tubulin and EF-1α genes. LC-MS/MS detected 18, 1, and 5 strains able to produce ZEN, DON, and T2, which accounted for 62.1%, 3.4%, and 17.2%, respectively. Strain JK3-3 can produce ZEN, DON, and T2, while strains BH1-4-1, BH6-5, and BH16-2 can produce ZEN and T2. PCR detected six key synthase genes of Tri1, Tri7, Tri8, Tri13, PKS14, and PKS13 in strain JK3-3, which synthesized three toxins of ZEN, DON, and T2. Four key synthase genes of Tri8, Tri13, PKS14, and PKS13 were detected in strains BH1-4-1, BH6-5, and BH16-2, which were responsible for the synthesis of ZEN and T2. The results showed that the key genes of toxin biosynthesis were highly correlated with the toxins produced by Fusarium, and the biosynthesis of toxin was strictly controlled by the genetic information of the strain. This study provides a data basis for the targeted prevention and control of exo-genous mycotoxins in P. heterophylla and a possibility for the development of PCR for rapid detection of toxin contamination.
Caryophyllaceae ; Chromatography, Liquid ; Fusarium/genetics* ; Mycotoxins ; Tandem Mass Spectrometry

Aims: This study aimed to isolate and identify fungi involved in causing diseases to Vanilla planifolia as well as to study their pathogenicity level in causing disease. Methodology and results: The diseased parts of vanilla plants were collected from vanilla farms located in Pahang and Sabah, Malaysia from May 2015 to May 2016. Diseases tissue transplantation was adopted to isolate the fungi for morphology identification prior to the polymerase chain reaction (PCR) amplification of internal transcribed spacer (ITS) regions using universal primers for fungi, ITS1 and ITS4. After being isolated, the fungi pathogenicity was tested on detached fresh and mature vanilla leaves. A total of 22 fungal isolates were identified, Fusarium fujikuroi and F. oxysporum were the two most recovered species, followed by Colletotrichum gloeosporioides, Fusarium sp., F. proliferatum and F. solani. Pathogenicity test revealed a significantly high pathogenicity of F. oxysporum and C. gloeosporiodes (p<0.01) on detached vanilla leaf, with high level of damage. Conclusion, significance and impact of study This study provides valuable information on fungi-associated diseases on vanilla plants grown in Malaysia and can be used for future development in disease management.
Vanilla--microbiology ; Fusarium--isolation & ; purification ; Colletotrichum--isolation & ; purification

Aims: Piper nigrum L. (black pepper) is an economically important commodity plant in Malaysia, which generated RM 200.95 million from pepper export in the year of 2018. However, the increase in pepper production is restricted by diseases. Fusarium wilt is one of the major diseases of P. nigrum L. The objectives for this study were to isolate Fusarium spp. associated with Fusarium wilt of P. nigrum L. from selected pepper farms in the northwestern region of Sarawak and to characterize the Fusarium spp. isolated morphologically and molecularly. Methodology and results: Fusarium spp. were isolated from diseased root samples. The pathogen was grown on potato dextrose agar (PDA) under dark condition at circa (ca.) 25 °C for morphological characterisation. Molecular characterisation was done by using internal transcribed spacer (ITS). Phylogenetic tree was constructed to study the genetic relationship of the isolates. Fusarium solani, F. oxysporum, F. proliferatum were the three Fusarium species identified. There were variations in morphological characters observed between and among the species, including the colony form, margin, elevation, surface appearance and pigmentation. No distinctive morphological characteristic was specific to a location. In addition, growth rate, macroconidia sporulation rate, and microconidia sporulation rate of the isolates were not correlated. In molecular phylogeny, the three Fusarium species were separated into three distinct clades representing the three identified species. The genetic relatedness between isolates within each species was depicted in the tree. Conclusion, significance and impact of study Variations were observed among isolates in this study based on morphological and molecular characterization. This study would contribute information on the variations of Fusarium spp. associated with Fusarium wilt of P. nigrum L. from the northwestern region of Sarawak.
Fusarium ; Fusariosis ; Piper nigrum

Trichoderma spp. is a kind of filamentous fungi with important biocontrol value. Twelve strains of Trichoderma spp. were isolated from the soils of different types of crops in Shaoxing, Zhejiang and Foshan, Guangdong. The antagonistic resistance to Fusarium oxysporum was compared by plate confrontation test. The further analysis of volatile secondary metabolites for two strains were carried out using HS-SPME-GC-MS analysis. The results showed that T. asperellum ZJSX5003 and GDFS1009 had fast growth ability, and the inhibition effects on F. oxysporum were 73% and 74% respectively. Six identical volatile metabolites were detected as follows 2-Methyl-1-propanol, 3-Methyl-1-butanol, 3-Methyl-3-buten-1-ol, Acetyl methyl carbinol, Butane-2,3-diol and 6-n-pentyl-2H-pyran-2-one (6-PAP). Among them, 6-PAP was validated to have a higher inhibitory effect on F. oxysporum in vitro. This study will provide basis for the development of biocontrol agents with metabolites of Trichoderma, such as 6-PAP.
Antibiosis ; Antifungal Agents ; pharmacology ; Fusarium ; drug effects ; physiology ; Gas Chromatography-Mass Spectrometry ; Trichoderma ; chemistry ; metabolism

Root rot disease is vital disease of Coptis chinensis, it has bursted in most producing area in recent years, and has caused severe damage. To identify the pathogenic fungi, Fusarium spp. fungi were isolated from rot root, of which the pathogenic fungi were screened with inoculation on C. chinensis root and plant, and identified with molecular and morphological method. The 20 Fusarium spp. fungi were obtained, of which 5 displayed high pathogenicity. It was deduced that F. oxysporum, F. solani and F. tricinctum were the pathogen, possibly pioneer pathogen of C. chinensis root rot disease. Among which F. oxysporum was dominant and deserved to pay more attention. High temperature and high humidity can increase pathogenicity of Fusarium spp. So the global climate warming may lead to temperature rising of C. chinensis producing area and favor the pathogen fungi, which may be one of the main factors leading to bursting of C. chinensis root rot disease. To control the root rot, beside developing and using pesticide, producing base should be moved to a high altitude area.
Coptis/microbiology* ; Fusarium/pathogenicity* ; Plant Diseases/microbiology* ; Plant Roots/microbiology*