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1.
尖孢镰孢菌古巴专化型(Fusarium oxysporum f.sp.cubense)是香蕉枯萎病的病原菌,该菌是一种土壤习居菌,了解香蕉根区土壤中真菌多样性及镰孢菌属(Fusarium)真菌所占比例,对如何减少土壤中的病原菌、预防香蕉枯萎病的发生有重要的指导意义。该文通过采集不同宿根年限的香蕉健康植株和枯萎病植株的根区土壤,利用高通量测序技术测定土壤样品中的真菌种群。结果表明:(1)同一宿根年限的香蕉植株中,健康植株根区土壤中所获的reads及OTUs数量均高于枯萎病植株,说明健康植株根区土壤的真菌多样性丰富于枯萎病植株。(2)除了一年生香蕉枯萎病植株以担子菌门(Basidiomycota)为主外,其他土壤样品中均以子囊菌门(Ascomycota)为主,其中的丛赤壳科最高相对丰度来自三年生健康植株的根区土壤(26.02%),其次是五年生的枯萎病植株根区土壤(15.56%)。(3)在丛赤壳科中,镰孢菌属在三年生健康植株土壤中的相对丰度最高(2.54%),在其他样品中的相对丰度在0.1%~0.65%之间;在镰孢菌属中,腐皮镰孢菌(Fusarium solani)的相对丰度(0~1.59%之间)高于尖孢镰孢菌(F.oxysporum),尖孢镰孢菌仅占很小的比例(相对丰度0~0.08%之间)。可见,在不同香蕉植株的根区土壤中,健康植株的根区土壤真菌多样性高于枯萎病植株,无论是健康植株还是枯萎病植株的根区土壤中,作为香蕉枯萎病病原菌的镰孢菌属或尖孢镰孢菌的群体均不占主导地位。  相似文献   

2.
Major cell wall-bound phenolic compounds were detected and identified in roots of tomato at different stages of growth. Alkaline hydrolysis of the cell wall material of the root tissues yielded ferulic acid as the major bulk of the phenolic compounds. Other phenolic compounds identified were 4-hydroxybenzoic acid, vanillic acid, 4-hydroxybenzaldehyde, vanillin and 4-coumaric acid. All the six phenolic acids were higher in very early stage of plant growth. Ferulic acid, 4-hydroxybenzoic acid and 4-coumaric acid exhibited a decreasing trend up to 60 days and then the content of these phenolic acids increased somewhat steadily towards the later stage of growth. Total phenolics, phenylalanine ammonia-lyase (PAL) activity and peroxidase (POD) activity were in tandem match with the occurrence pattern of the phenolic acids. Ferulic acid showed highest antifungal activity against tomato wilt pathogen Fusarium oxysporum f. sp. lycopersici. The results of this study may be interpreted to seek an explanation for high susceptibility of tomato plants at flowering stage to Fusarium wilt. It may also be concluded that greater amounts of ferulic acid in combination with other phenolics and higher level of PAL and POD activities after 60 days of growth may have a role in imparting resistance against Fusarium wilt at a late stage of plant growth.  相似文献   

3.
For this study, 21 isolates of fungi belonging to Rhizoctonia and Fusarium genera were isolated from the diseased faba bean plants, obtained from the different localities in Assiut governorate, showing root rot and wilt symptoms. The isolates proved to be pathogenic on Masr 1 faba bean cultivar under greenhouse conditions. F. oxysporum isolates caused wilt disease; however, the isolates of R. solani and other Fusarium species caused root rot. The virulence of isolates on the tested faba bean cultivar was different. The highly pathogenic isolates of these fungi were employed in this study. The effect of soil amendment with Planta Rich and Rich Composts (CMs) alone or in combination with seed coating by the antagonistic yeast Pichia guilliermondi before sowing on the severity of Rhizoctonia and Fusarium root rot and Fusarium wilt of faba bean was tested under greenhouse and field conditions. The tested isolates of yeast proved to be highly antagonistic to the pathogen in vitro. The test rates of CMs were equivalent to 2, 7, 10 and 14 ton/feddan in the greenhouse and 7 and 10 t/feddan in the field conditions. Uncomposted soil was used as a control. The results showed that the tested CMs have a suppressive effect on the severity of root rot and wilt diseases of faba bean under greenhouse and field conditions. The application of CMs (Planta Rich and Rich) alone at the rates equivalent to 2, 7, 10 and 14 t/feddan in greenhouse and 7 and 10 t/feddan in the field conditions to the soil infested with the tested pathogens reduced percentage of the tested diseases compared with uncomposted soil. Combined CMs treatments with yeast seed treatment increased the suppressive effect of CMs on the disease severity.  相似文献   

4.
Ramamoorthy  V.  Raguchander  T.  Samiyappan  R. 《Plant and Soil》2002,239(1):55-68
Pseudomonas fluorescens isolate Pf1 was found to protect tomato plants from wilt disease caused by Fusarium oxysporum f. sp. lycopersici. Induction of defense proteins and chemicals by P. fluorescens isolate Pf1 against challenge inoculation with F. oxysporum f. sp. lycopersici in tomato was studied. Phenolics were found to accumulate in bacterized tomato root tissues challenged with F. oxysporum f. sp. lycopersici at one day after pathogen challenge. The accumulation of phenolics reached maximum at the 5th day after pathogen challenge. In pathogen-inoculated plants, the accumulation started at the 2nd day and drastically decreased 4 days after the pathogen inoculation. Activities of phenylalanine ammonia-lyase (PAL), peroxidase (PO) and polyphenol oxidase (PPO) increased in bacterized tomato root tissues challenged with the pathogen at one day after pathogen challenge and activities of PAL and PO reached maximum at the 4th day while activity of PPO reached maximum at the 5th day after challenge inoculation. Isoform analysis revealed that a unique PPO1 isoform was induced and PO1 and PPO2 isoforms were expressed at higher levels in bacterized tomato root tissues challenge inoculated with the pathogen. Similarly, -1,3 glucanase, chitinase and thaumatin-like proteins (TLP) were induced to accumulate at higher levels at 3-5 days of challenge inoculation in bacterized plants. Western blot analysis showed that chitinase isoform Chi2 with a molecular weight of 46 kDa was newly induced due to P. fluorescens isolate Pf1 treatment challenged with the pathogen. TLP isoform with molecular weight of 33 kDa was induced not only in P. fluorescens isolate Pf1-treated root tissues challenged with the pathogen but also in roots treated with P. fluorescens isolate Pf1 alone and roots inoculated with the pathogen. These results suggest that induction of defense enzymes involved in phenylpropanoid pathway and accumulation of phenolics and PR-proteins might have contributed to restriction of invasion of F. oxysporum f. sp. lycopersici in tomato roots.  相似文献   

5.
Kokalis–Burelle  N.  Vavrina  C. S.  Rosskopf  E. N.  Shelby  R. A. 《Plant and Soil》2002,238(2):257-266
Field trials were performed in Florida to evaluate tomato and pepper transplants amended with formulations of several plant growth-promoting rhizobacteria (PGPR) in a production system that included soil solarization. Transplants grown in five different formulations of PGPR were planted into plots treated by soil solarization, MeBr fumigation, or untreated soil. Treatments were assessed for incidence of several naturally occurring tomato and pepper pathogens including root-knot nematode (Meloidogyne incognita) and species of Pythium, Phytophthora, and Fusarium. Highly significant increases in tomato and pepper transplant growth occurred in response to most formulations of PGPR tested. Transplant vigor and survival in the field were improved by PGPR treatments in both tomato and pepper. Diseases of tomato caused by root-knot nematodes, Fusarium, Phytophthora, and Pythium were not affected by PGPR treatments. PGPR formulation LS261 reduced numbers of root-knot nematode galls on pepper while pepper root condition was improved with formulations LS213, LS256 and LS261. Individual PGPR strains affected the number of Pythium colonies isolated from pepper roots, but did not affect isolation of Pythium from tomato roots. Greater numbers of colonies of Pythium were isolated from pepper roots in the MeBr treatment and fewest in the solarization treatment. Numbers of colony forming units of Fusarium were significantly higher in the untreated soil than in MeBr fumigated or solarized soil with no effect of PGPR on isolation of Fusarium from either crop. Incidence of wilt symptoms on tomato was significantly lower in MeBr treated plots and highest in the untreated plots. Yield of extra large tomato fruit and total yield increased with PGPR formulation LS256. Yield of pepper was increased with formulations LS255 and LS256. Solarization combined with LS256 on pepper produced yields comparable to MeBr.  相似文献   

6.
The potential of the biological control fungus Penicillium oxalicum to suppress wilt caused by Fusarium oxysporum f. sp. melonis and F. oxysporum f. sp. niveum on melon and watermelon, respectively, was tested under different growth conditions. The area under disease progress curve of F. oxysporum f. sp. melonis infected melon plants was significantly reduced in growth chamber and field experiments. In glasshouse experiments, it was necessary to apply P. oxalicum and dazomet in order to reduce Fusarium wilt severity in melons caused by F. oxysporum f. sp. melonis. For watermelons, we found that P. oxalicum alone reduced the area under the disease progress curve by 58% in the growth chamber experiments and 54% in the glasshouse experiments. From these results, we suggested that P. oxalicum may be effective for the management of Fusarium wilt in melon and watermelon plants.  相似文献   

7.
枯萎病是顽固性土传病害,称为瓜菜中的“癌症”,已成为制约我国瓜菜产业可持续健康发展的瓶颈问题。本文简要介绍瓜菜枯萎病危害,并从细胞壁降解酶、毒素、信号传导和致病基因等方面综述瓜菜枯萎病灾变机制,然后从根际微生物组自身与病原菌、土壤层面和植物层面等重点阐述了根际微生物组防治和抵御瓜菜枯萎病的机理,最后对枯萎病发生和抑制关键因子挖掘、核心微生物组构建及根际微生物组分子机制等进行了展望,期望生防微生物防治病害发生进入一个崭新且高效的阶段,为加快提升作物抗逆性机理研究提供一定思路。  相似文献   

8.
Experiments were conducted on tomato to study the potential of brown alga Sargassum johnstonii as a biofertilizer. Seaweed extract was applied as a foliar spray, soil drench, and soil drench + foliar spray to assess its effect on plant growth, yield, and concentration of lycopene and vitamin C. The main objective of the study was to enhance the biochemical constituents with neutraceutical and antioxidant values in tomato fruit. Different concentrations (0.1%, 0.4%, 0.8%, 2%, 6%, 8%, and 10%; v/v) of seaweed extract were used and growth was observed over a period of 7 months. A total of 14 sprays/drenches were applied at 15-day intervals during the entire vegetative and reproductive phase. A statistically significant increase in vegetative growth (plant height, shoot length, root length, and number of branches), reproductive parameters (flower number, fruit number, and fresh weight), and biochemical constituents (photosynthetic pigments, proteins, total soluble sugars, reducing sugars, starch, phenols, lycopene, and vitamin C) was recorded following all three methods of treatment at higher concentrations of seaweed extract. The study also reports auxin- and cytokinin-like activity, and the presence of macro- (Ca, Mg, Na, and K) and micronutrients (Fe, Cu, Zn, and Mn), in seaweed extract of S. johnstonii, which makes it a potential biofertilizer.  相似文献   

9.
植物枯萎病是影响作物生长的重要因素,利用植物内生菌拮抗病原菌生长,从而降低其危害程度是目前研究的热点。本研究从健康的番茄植株中筛选分离得到一株对番茄枯萎病病原菌有较强拮抗作用的内生细菌B-R1,通过形态学、生理生化以及分子生物学检测分析,鉴定该菌株为苏云金芽胞杆菌(Bacillus thuringiensis)。为进一步探索该菌株的生防作用,首先将菌株发酵后离心,得到发酵上清液,采用盐酸沉淀法对其活性物质进行粗提,并检测其对大肠埃希菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)以及尖孢镰刀菌(Fusarium oxysporum)的抑菌活性。通过薄层色谱法(TLC)、傅里叶红外光谱(FI-TR)、高分辨液相色谱-质谱联用仪(LC-MS)分析并鉴定活性物质的结构。结果表明,苏云金芽胞杆菌对尖胞镰刀菌有良好的抑制作用,结构分析初步鉴定抗菌物质中含有丰原素(fengycin),属于脂肽类抗生素。  相似文献   

10.
Biocontrol agents, viz., Rhizobium meliloti, Pseudomonas aeruginosa, Aspergillus niger and Trichoderma harzianum, are used as seed dressing and soil is amended with Prsosopis juliflora (Swartz) DC. plant parts like stem, leaves and flower at 1% w/w for the control of root-rot fungi. All antagonists suppressed the infection of root-rot fungi viz., Fusarium spp., Rhizoctonia solani and Macrophomina phaseolina whereas the infection of R. solani and M. phaseolina was controlled when cowpea (Vigna unguiculata L.) and mungbean (Vigna radiata L.) seeds were treated with P. aeruginosa and T. harzianum and the soil was amended with P. juliflora leaves’ powder at 1% w/w. However, germination of both the crops was observed in all treatments. Growth parameters like shoot and root length, shoot and root weight, and leaf area significantly increased in all the treatments as compared to the control parameters. P. aeruginosa and T. harzianum in combination with soil amendment with P. juliflora plant parts at 1% w/w were the most effective for the control of root-rot fungi of leguminous plants.  相似文献   

11.
Three hundred and seventy two isolates belonging to the genusStreptomyces were isolated and screened for chitinase production.Streptomyces plicatus was found to be the best producer. The highest chitinase production were incubated for 3 d at 30 °C on buffered culture medium (pH 8.0) containing chitin plus sucrose and calcium nitrate as carbon and nitrogen sources.S. plicatus chitinase had a highly significant inhibitory effect on spore germination, germ tube elongation and radial growth ofFusarium oxysporum f.sp.lycopersict., Altrernaria alternata andVerticillium albo-atrum, the causal organisms ofFusarium wilt, stem canker andVerticillium wilt diseases of tomato. Application ofS. plicatus to the root system of tomato plants before transplantation markedly protected tomato plants against the tested phytopathogenic fungiin vivo.  相似文献   

12.
Abstract

Five isolates of Ralstonia solanacearum were isolated from a naturally wilted root of tomato plants grown in Assiut governorate. The antibacterial activity of extract of Datura, Garlic and Nerium were tested in controlling R. solanacearum in vitro and in vivo. Garlic exhibited the strongest antibacterial activity against bacterial wilt in vitro and in vivo followed by Datura and then Nerium. Cold water extracts of these plant species were more effective than hot water extract in the development of the disease in vivo. In greenhouse experiments, the application of the tested plant extract to soil at the time of inoculation, two days before inoculation and two days after inoculation the pathogen, significantly reduced the disease index of wilt on Super Marmande tomato cultivars. The application of plant extracts at the same time as inoculation resulted in the highest reduction of disease index.  相似文献   

13.
【背景】利迪链霉菌(Streptomyces lydicus)对多种作物均有较好的促生效果,且对病原真菌具有广谱抑制作用,但该菌对细菌性青枯病的防控研究较少。【目的】探究利迪链霉菌M01能否促进番茄生长并抑制番茄青枯病,以及M01对番茄生长的影响是否通过影响根际细菌群落结构实现。【方法】采用温室盆栽试验和扩增子高通量测序技术研究M01对番茄生长、青枯病发病率及根际细菌群落组成的影响。【结果】施用利迪链霉菌M01的番茄植株鲜重、干重、株高、用土壤与作物分析开发(soil and plant analyzer develotrnent, SPAD)方法测量的叶绿素浓度、根系活力和植株P含量比对照分别提高了22.7%、12.5%、16.0%、28.1%、18.4%和17.9%,其中对株高、SPAD值和植株磷含量影响显著(P<0.05)。M01处理延缓了番茄青枯病的发病时间,接种9周后发病率比对照降低了41.8%。此外,M01对番茄根际细菌群落无显著影响(门水平群落组成,P=0.4;属水平群落组成,P=0.4)。【结论】利迪链霉菌M01可促进番茄植株生长并抑制番茄青枯病,利迪链霉菌M01对番茄生长的影响并非通过调控根际细菌群落实现。  相似文献   

14.
Fusarial wilt of tomato (Lycopersicon esculentum Mill.) is a very common and severe disease occurring in most of the vegetable fields in West Bengal, India. Potenciation and formulation of different fungicidal chemicals and phytoextracts were evaluated against the growth of the pathogen wherein carbendazim (bavistin) and leaf extracts of Azadirachta indica (neem) were recorded to be most effective. Combined treatment with 4 ml neem leaf extract and 1 ml captan (0.01%) or with 4 ml garlic bulb extract and 1 ml captan (0.01%) exhibited 100% growth inhibition of the pathogen. Integrated control of the pathogen with phytoextracts, fungicide and biocontrol agents was carried out. Among the treatments, a combination with extracts of neem, captan (0.01%) and metabolites of Trichoderma harzianum was proved to be superior over the other. Field experiment with three fungicides at 0.5% concentration was carried out in randomised block design where application of bavistin showed up to 62.27% reduction of wilt infection in tomato plants. Soil solarisation of tomato field showed 62.50 and 66.69% reduction of infection during the trial years. However, integration of soil solarisation with the applications of T. harzianum, captan (0.01%) and neem resulted in 100% reduction of infection and thus it was recorded as the most effective treatment in reducing the incidence of the disease.  相似文献   

15.
The Fusarium wilt caused by Fusarium oxysporum strains is the most devastating disease of cucumber, banana, and tomato. The biological control of this disease has become an attractive alternative to the chemical fungicides and other conventional control methods. In this review, the research trends and biological control efficiencies (BCE) of different microbial strains since 2000 are reviewed in detail, considering types of microbial genera, inoculum application methods, plant growth medium and conditions, inoculum application with amendments, and co-inoculation of different microbial strains and how those affect the BCE of Fusarium wilt. The data evaluation showed that the BCE of biocontrol agents was higher against the Fusarium wilt of cucumber compared to the Fusarium wilts of banana and tomato. Several biocontrol agents mainly Bacillus, Trichoderma, Pseudomonas, nonpathogenic Fusarium, and Penicillium strains were evaluated to control Fusarium wilt, but still this lethal disease could not be controlled completely. We have discussed different reasons of inconsistent results and recommendations for the betterment of BCE in the future. This review provides knowledge of the biotechnology of biological control of Fusarium wilt of cucumber, banana, and tomato in a nut shell that will provide researchers a beginning line to start and to organize and plan research for the future studies.  相似文献   

16.
In autoclaved greenhouse soil without Fusarium oxysporum f. sp. vasinfectum, Meloidogyne incognita did not cause leaf or vascular discoloration of 59-day-old cotton plants. Plants had root galls with as few as 50 Meloidogyne larvae per plant. Root galling was directly proportional to the initial nematode population level. Fusarium wilt symptoms occurred without nematodes with 77,000 fungus propagules or more per gram of soil. As few as 50 Meloidogyne larvae accompanying 650 fungus propagules caused Fusarium wilt. With few exceptions, leaf symptoms appeared sooner as numbers of either or both organisms increased. In soils infested with both organisms, the extent of fungal invasion and colonization was well correlated with the extent of nematode galling and other indications of the Fusarium wilt syndrome.  相似文献   

17.
采用涂布计数及荧光定量PCR和PCR-DGGE技术,研究了氨水熏蒸对土壤微生物区系的影响,并研究氨水熏蒸对高发枯萎病香蕉园枯萎病的防控效果和对香蕉产量的影响。结果表明:与熏蒸前相比,高发枯萎病香蕉园土壤施用130 L/667 m2的氨水熏蒸后,尖孢镰刀菌的数量下降了1个log单位;与对照处理相比,下降了0.5个log单位。氨水熏蒸后土壤可培养细菌数量与对照相比没有显著差异,但显著低于熏蒸前,可培养真菌的数量显著低于熏蒸前和对照;可培养细菌真菌的比值与熏蒸前相比没有显著差异,但显著高于对照。与对照及熏蒸前相比,氨水熏蒸后土壤中总细菌及总真菌的数量显著下降;熏蒸前后及对照处理总细菌真菌的比值没有明显差异。各土壤样品总细菌及真菌群落结构的PCR-DGGE分析结果表明,氨水熏蒸后土壤微生物在聚类上和条带组成上均与熏蒸前及对照有显著性差异。与对照相比,氨水熏蒸处理使香蕉枯萎病的发病率降低了20%,每666.7m2增产1.25t。以上结果表明,利用合适浓度的氨水对高发枯萎病香蕉园的土壤熏蒸,能够有效改良土壤微生物区系和降低枯萎病的发生。  相似文献   

18.
Effects of treatment with phenylthiosemicarbazide (PTS) and its 4′-chloro-derivative (4′-chloro-PTS) on Fusarium wilt of pea and tomato plants were investigated. Depending on pH and availability of oxygen, PTS and 4′-chloro-PTS are converted to their corresponding phenylazothioformamides and phenylazothioformamide-S-oxides, which are the actual fungitoxic compounds. PTS and 4′-chloro-PTS were shown to inhibit growth of Fusarium oxysporum f. pisi and F. oxysporum f. lycopersici in liquid media as well as on agar plates at concentrations of 50–100 mg/1. Inhibition was greater at pH 7 than at pH 5. When administered to pea and tomato plants, both compounds caused severe phytotoxic effects, especially at temperatures favouring Fusarium wilt, thus almost entirely obscuring any protective activity against the diseases. All compounds were strongly adsorbed to loam, but readily released from sand. Neither in pea nor in tomato plants were PTS and 4′-chloro-PTS converted to any fungitoxic substance, not already present in the aqueous solutions administered.  相似文献   

19.
Fusarium wilt is caused by F. oxysporum Schlecht end. Fr. f. sp. ciceris (FOC) is a devastating disease of chickpea in Algeria. In this study, antagonistic effects of B. subtilis MF352017 (Bs1) and Trichoderma harzianum KX523899 (T5) isolated from the rhizosphere of chickpea were investigated separately and in combination for their efficacy in controlling the disease in vivo. The efficacy of the antagonistic biocontrol agents on Fusarium wilt was evaluated based on vegetative and root growth parameters of chickpea. Seed bacterisation with B. subtilis MF352017 (Bs1) and seed treatment with T. harzianum (T5) significantly protected chickpea seedlings from FOC as compared to untreated plants. Plant protection was more pronounced in T. harzianum-treated plants than in bacterised plants. The application of both antagonists effectively suppressed 93.67% of the disease and also enhanced plant growth leading to increased plant height, root length, fresh and dry weights of shoot and root. The mixture of antagonists increased the effectiveness of B. subtilis MF352017 (Bs1) isolate on Fusarium wilt and improved chickpea growth.  相似文献   

20.
The present study was conducted to investigate the effect of the residue of Chenopodium murale L. on growth, nodulation and macromolecule content of two legume crops, viz., Cicer arietinum L. (chickpea) and Pisum sativum L. (pea). A significant reduction in root and shoot length as well as dry matter accumulation occurred when both the legumes were grown in the soil amended with 5, 10, 20 and 40 g residue kg−1 soil. In general, a gradual decline in growth was associated with an increasing amount of residues in the soil. There was also a significant reduction in total chlorophyll content and the amounts of protein and carbohydrates (macromolecules) in plants growing in the residue-amended soil. The nodulation was completely absent in chickpea and pea when the plants were grown in the soil amended with 10 and 20 g residue kg−1 soil, respectively. At a lower rate of residue amendment (5 g kg−1 soil), a significant decline in nodule number and weight, and leghaemoglobin content was recorded. Root oxidizability, an indirect measure of tissue viability and cellular respiration, was adversely affected in both the legumes under various treatments of residue amendment. The observed growth reduction concomitant with increased proline accumulation indicated the presence of some inhibitory compounds in the residue-amended soil. It was rich in phenolics identified as protocatechuic, ferulic, p-coumaric and syringic acid with 12.8, 30.4, 20.2 and 33.6% relative content, respectively. The results suggest that the residue of C. murale releases phenolic allelochemicals, which deleteriously affect the growth, nodulation and macromolecule content of chickpea and pea.  相似文献   

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