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1.
马铃薯干腐病菌硫色镰孢的生物学特性   总被引:1,自引:0,他引:1  
从碳源、氮源、酸碱度及生长温度等方面对引起马铃薯干腐病的硫色镰孢Fusarium sulphureum的生物学特性进行了研究。结果表明,该病原菌在不同发育阶段对营养和环境条件的要求存在差异。在固体培养基上,菌落生长最佳碳源为葡萄糖、麦芽糖,最佳氮源为蛋白胨,pH8?为最佳;在液体培养基中,菌丝体生长以麦芽糖为最佳碳源,以硝酸钠为最佳氮源,pH6?为最佳;在分生孢子萌发阶段,在以羧甲基纤维素钠、蛋白胨和谷氨酸为碳、氮源的营养液中,分生孢子萌发率最高,最适pH 6–8。该病菌最适生长温度为25℃,分生孢子致死  相似文献   

2.
Isolates of non-pathogenic Fusarium moniliforme (Fu3, Fu7 and Fu24), F. oxysporum (Fu2, Fu4), F. solani (Fu25) and F. merismoides (Fu1) that were found to be effective in reducing wilt incidence in tomato were tested for their potential to elicit induced systemic resistance (ISR) in tomato. Talc formulations of these isolates derived from liquid fermentation as well as cell elicitors of these cultures were tested. Changes in the phenol and total protein contents and activities of peroxidase and polyphenol oxidase were studied. Isolate Fu3 induced more phenol and total protein contents as well as activities of peroxidase and polyphenol oxidase. Elicitors of Fu2 induced more of these compounds and enzymes. Although Fu1, Fu4 and Fu24 were found to give good control against Fusarium wilt incidence in an earlier study, they were less effective in inducing these defense related compounds. Peroxidase activity was increased when plants were treated with Fu3, Fu4, Fu7, Fu24 and Fu25, whereas polyphenol oxidase activity was increased only with the isolate Fu3 and elicitor of Fu2. It is suggested that ISR was the mode of action for the isolates Fu2 and Fu3, whereas for the other isolates, the mode of action may be root colonisation, competition for nutrition and so on. The role of ISR with non-pathogenic isolates of Fusarium spp. is discussed.  相似文献   

3.
蔓割病是我国南方薯区甘薯主要病害之一,本研究采用直接观察、显微和超微结构观测等方法,对高抗、中感和高感蔓割病的3个甘薯品种(高抗品种:金山57,中感品种:热薯1号,高感品种:新种花)接种蔓割病菌28 d植株充分发病后其茎基部细胞的侵染结构进行了观察。结果表明,在用清水作对照处理时,3个品种茎部组织的细胞形态和结构正常且完整,细胞代谢强。高抗品种金山57无论是接种组还是对照组,均未发现病原菌丝的存在,其茎下部、中部和上部细胞结构相对完整。中感品种热薯1号,蔓割病菌从其茎基部侵入后导致茎基部细胞破损坏死,而中部寄主-病原互作较为活跃和典型,造成养分运输受阻,茎基部接种后病原菌丝会沿着寄主茎部的维管束和其他组织一直向寄主的茎部末端蔓延,遭受侵染后的部位其细胞反应与高感品种新种花类似。高感品种新种花遭受蔓割病原菌侵染后,病原菌菌丝从茎基部新鲜剪口侵入后进入表皮细胞、皮层、维管束并在甘薯茎基部蔓延至中部、上部,直至寄主整株枯死,甘薯茎的木质部导管出现侵填体,质壁分离;与此同时,细胞壁的沉积物及乳突在病原菌的入侵处形成,各种无定型物质或纤丝构成的织网迅速包围入侵菌丝。  相似文献   

4.
Fusarium spp. attack potato roots causing root-rot, damping-off and wilt disease in Assuit Governorate. Forty-five Fusarium isolates were isolated from F. nygamai, F. acutatum, F. solani, F. proliferatum, F. subglutinans, and F. oxysporum. Isolates were tested for their pathogenic capability on Burn potato variety during growing season 2007/2008. Isolates infect potato plants causing either damping-off or wilt symptoms. Isolates varied in their virulence. Role of potato tuber seed in the transmission of the causal pathogen to daughter using Electrophoresis. Protein profiles of the tested isolates divided into four sub-clusters at similarity levels 93.79, 91.55 and 92.62% while isolate of Fusarium profile No. 11 formed separate sub-clusters at similarity level 69.79%. F. nygamai and F. solani were notable exception because profile No. 4 of F. nygamai from roots and profile No. 4 from sprouts were almost identical (similarity level 96.81%); similarity level between profile No. 8 from roots and profile no/8 from sprouts was 95.44%. Results prove that F. nygamai and F. solani are potato tuber seed-borne fungus. T. harzianum, T. viride, T. longibrachiatum, G. virens and E. nigrum or its filtrate inhibited the growth of F. nygamai, F. acutatum, F. solani, F. proliferatum, F. subglutinans and F. oxysporum. The formulation of T. harzianum, T. longibrachiatum and G. virens against tested pathogenic fungi reduce disease incidence under greenhouse conditions.  相似文献   

5.
Of the 390 Kabuli chickpea genotypes evaluated from 2005 to 2010 against Ascochyta blight (AB), Fusarium wilt (FW) and Dry root rot (DRR) resistance using standard screening techniques, 48 were found to be resistant to FW and DRR. Of these, four genotypes viz GLK95091, GLK95061, GLK24092 and GLK24096 showed resistance to AB with disease score less than 4.0 while another four genotypes GLK22072, GLK22098 and GLK24099 displayed AB disease score 5.0. GLK 22117 with FW percentage 6.3 and DRR 3.5 tested for seven years displayed good performance at other locations in India as well. Extra bold seeded genotypes GLK 26171, GLK26177 and GLK23001have shown good level of resistance to AB, FW and DRR and can be suggested as donors in crossing programme. It was observed that level of FW resistance was comparatively low in large-seeded and extra-large-seeded kabuli than small seeded kabuli.  相似文献   

6.
Abstract

Populations of the genus Fusarium in wheat fields were studied within the crop-growing season at Qena area (Upper Egypt) using two different types of media (DCPA and DRBA) at 25°C. Fourteen Fusarium species were isolated during this study, namely F. anthophilum, F. aquaeductuum, F. chlamdosporum, F. dimerum, F. merismoides, F. moniliforme, F. oxysporum, F. poae, F. proliferatum, F. sambucinum, F. scripi, F. solani, F. sporotrichioides and F. subglutinans. Fusarium merismoides, F. oxysporum and F. sambucinum were the most common Fusarium species isolated from different wheat plant parts (rhizosphere and rhizoplane) as well as from the wheat fields (soil and air). Fusarium spp. rarely appeared at the beginning of the season and increased sharply between January to March and decreased slightly or sharply at the end of the season according to the type of media and isolation source.  相似文献   

7.
Culture filtrates of Trichoderma viride and Trichoderma harzianum were inhibitory of Fusarium moniliforme and, to a lesser extent, Aspergillus flavus. The degree of inhibition was, however, dependent on the carbon or nitrogen source incorporated into the medium. Scanning electron microscopy revealed the development of abnormal fruiting structures on exposure to some Trichoderma culture filtrate, while macroscopically, growth restriction and, in the case of A. flavus, altered colony colouration were observed. Based on the results of inverted colony culture, it would appear that some isolates of Trichoderma produce inhibitory volatile compounds. The production of possible antibiotics was also demonstrated. The aggressive behaviour (towards A. flavus and F. moniliforme) demonstrated by Trichoderma spp. may be partly explained by the liberation of extracellular enzymes by these fungi. An isolate of T. viride exhibited amylolytic, pectinolytic, proteolytic and cellulolytic activity. Based on the results of the present investigation, Trichoderma spp. are potential candidates for biocontrol of some mycotoxin-producing fungi, but there exists some doubt as to their osmotolerance within the air-dry seed. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

8.
The biological efficacy of Trichoderma species may differ due to variations in ecosystems. This study was conducted to assess the biocontrol efficacy of some native Trichoderma isolates against Fusarium solani, an important causal agent of potato wilt disease under laboratory and greenhouse conditions at Shahrood Agricultural Research Centre, Shahrood, Iran, during 2006–2007. Fourteen isolates were collected among which eight showed promising ability in inhibiting the growth of the pathogen through dual culture and production of volatile and non-volatile inhibitors but T. brevicompactum (T1), T. longibrachiatum (T5) and T. asperellum (T2) were almost better than other isolates in inhibiting the mycelial growth of the pathogen in comparison to control in the above three tests (p ≤ 0.01). Isolates performing mycoparasitism under in vitro condition were evaluated against the disease in pot culture under greenhouse condition. In all treatments in which Trichoderma isolates + F. solani were involved lower disease incidence was noticed in comparison to Fusarium-infested control (p ≤ 0.05). Best disease control was observed in potted plants treated with F. solani + T. longibrachiatum (T5) with 6.25% disease incidence in comparison to Fusarium-infested control, in which disease incidence was observed to be 75%. Interaction of T. brevicompactum (T1) and F. solani also indicated good control of the disease by 12.50% of disease incidence.  相似文献   

9.
Fusarium species and fumonisin production by toxigenic strains were investigated. During 1996–1998, 158 samples of poultry feeds were collected from a factory located in the department of Río Cuarto Córdoba province, Argentina. The most common species of Fusarium were F. moniliforme (60.7%) and F. nygamai (35.4%) followed by F. semitectum, F. subglutinans, F. proliferatum, F. dlamini, F. solani, F. oxysporum and F. napiforme. Fungal counts ranged from 1 × 103 to 8 × 105 CFU/g with mean values from 1.5 × 103 to 2.3 × 105 CFU/g. The highest counts were for F. dlamini, F. subglutinans, F. moniliforme and F. nygamai. Strains of F. moniliforme, F. nygamai, and F. proliferatum were screened for their potential to produce fumonisin B1 (FB1), fumonisin B2 (FB2) and fumonisin B3 (FB3) in corn grain. The samples were analysed using a modified high performance liquid chromatography method. The strains assayed, 43 strains, produced three fumonisins. There was a high degree of variability in the quantities of FB1, FB2, and FB3 produced. The toxin produced in highest levels by the majority of the strains was FB1. The range of concentration varied from 5.4 to 3,991, 1.01 to 189 and 0.4 to 765 ppm per gram of corn for FB1, FB2 and FB3 respectively. The toxigenic pattern of strains was normal, although two strains of F. moniliforme produced exceptionally high concentrations of FB3 and minor concentrations of FB2 and FB1. This is the first report from Argentina on Fusarium species in poultry feeds and fumonisin production by these strains.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

10.
Dryopteris crassirhizoma dryocrassin ABBA treatment was tested for its effectiveness in controlling Fusarium solani var. coeruleum growth in vitro and for prevention of postharvest dry rot of potato tubers and slices. Dryocrassin ABBA strongly inhibited mycelial growth, resulting in reductions in both mycelium dry weight and per cent spore germination of F. solani var. coeruleum at concentrations of 2.0, 0.5 and 0.1 mg/ml. Scanning electron microscopy (SEM) observations showed that treatment induced abnormal, tightly twisted morphological changes in hyphae. Moreover, in vivo experiments demonstrated that dryocrassin ABBA treatment at 2 mg/ml effectively controlled dry rot of potato tubers inoculated with mycelial discs of F. solani var. coeruleum. After dryocrassin ABBA treatment, the content of soluble proteins, peroxidase (POD) and superoxide dismutase (SOD) activity increased, and malondialdehyde (MDA) content remained the stable situation. In addition, the expression level of plant lipid‐transfer proteins (LTPs) genes – StLTPa1, StLTPa7, StLTPb1 and StLTPb3 – was upregulated. These results collectively demonstrate that dryocrassin ABBA can inhibit growth of Fusarium pathogens to induce disease resistance. On the other side, dryocrassin ABBA maybe induce potato defence responses.  相似文献   

11.
通过抑菌及细胞壁降解酶活性试验,研究向日葵花盘(sunflower disc,SFD)水提物对引起马铃薯干腐病主要病原菌——硫色镰刀菌(Fusarium sulphureum)生长及其侵染不同马铃薯品种时分泌的多聚半乳糖醛酸酶(polygalacturonase,PG)、果胶甲基半乳糖醛酸酶(polymethyl-ga...  相似文献   

12.
Abstract

A total of 106 Fusarium spp. were isolated from infected roots and soil samples of wheat and rice. Of the 106 isolates, 32 from wheat, and 74 from rice, were isolated. Six Fusarium spp. (F. oxysporum, F. moniliforme, F. poae, F. graminearum, F. tricinctum and F. equiseti) were identified at specie level. In aggressiveness tests Fusarium spp. root rot causing fungi were screened out into different aggressiveness classes according to disease severity scales. The aggressiveness of Fusarium spp. was studied on wheat varieties (Inqalab-91 and chakwal-86) and on rice varieties (Basmati-385 and IRRI-6) under controlled conditions. The overall total number of aggressive isolates was higher in rice than in wheat. However, the percentage of severely aggressive isolates was high in wheat, whereas the percentage of moderately and slightly aggressiveness isolates was high in rice. In rice, five isolates were non-aggressive and on wheat 17 were non-aggressive. Random Amplified Polymorphism DNAs (RAPDs) were used to study the polymorphism and genetic variations within the population of Fusarium spp. that established to study correlation between taxonomical and genetical characters of fungi. Five random primers were used P1 (5′-AGGAGGACCC-3′), P2 (5′-ACGAGGGACT-3′), PE7 (5′-AGATGCAGCC-3′), P14 (5′-CCACAGCACG-3′) and PE20 (5′-AACGGTGACC-3′). Each of the 10-mer primers produced results based on the respective banding patterns they generated in present investigations. Primers distinguished the F. oxysporum, F. moniliforme, F. graminearum, F. tricinctum, F. poa and F. equiseti. All the tested primers yielded amplification products, and that were reproducible. Although there was some intraspecific variation with primers, some strains were similar and some were different in banding pattern. In F. oxysporum, F. moniliforme, F. graminearum, F. tricinctum, F. poa and F. equiseti were seen clustered close to one another but each primer separated them unambiguously. All primer (P1, P2, P14, PE7 and PE20) combination produced 62 bands. All primers have shown interspecific and intraspecific variations in banding patterns.  相似文献   

13.
A study was carried out to test direct and indirect antagonistic effect against Fusarium wilt, caused by Fusarium oxysporum f. sp. ciceri (FOC), and plant growth-promoting (PGP) traits of bacteria isolated from rhizosphere soils of chickpea (Cicer arietinum L.). A total of 40 bacterial isolates were tested for their antagonistic activity against FOC and of which 10 were found to have strong antagonistic potential. These were found to be Streptomyces spp. (five isolates) and Bacillus spp. (five isolates) in the morphological and biochemical characterisation and 16S rDNA analysis. Under both greenhouse and wilt sick field conditions, the selected Streptomyces and Bacillus isolates reduced disease incidence and delayed expression of symptoms of disease, over the non-inoculated control. The PGP ability of the isolates such as nodule number, nodule weight, shoot weight, root weight, grain yield and stover yield were also demonstrated under greenhouse and field conditions over the non-inoculated control. Among the ten isolates, Streptomyces sp. AC-19 and Bacillus sp. BS-20 were found to have more potential for biocontrol of FOC and PGP in chickpea. This investigation indicates that the selected Streptomyces and Bacillus isolates have the potential to control Fusarium wilt disease and to promote plant growth in chickpea.  相似文献   

14.
马铃薯晚疫病生防木霉菌的筛选及鉴定   总被引:1,自引:0,他引:1  
曲远航  王琦  姚彦坡  黄振霖  李燕 《菌物学报》2014,33(6):1231-1241
采用马铃薯活体筛选法从268株木霉菌中筛选获得两株对致病疫霉有较强抑菌活性的木霉菌株R-5和T-15。这两株木霉菌代谢液可抑制病原菌生长及孢子囊萌发。温室防病试验发现,接种两株木霉菌可以减轻晚疫病的发生。田间试验进一步证明,两株木霉菌对晚疫病具有良好的田间防治效果,防效分别达到了72.4%和70.0%。经分子生物学方法鉴定,两株木霉菌分别为拟康氏木霉和棘孢木霉。实验构建的以活体筛选为基础的生防木霉菌筛选方法是一种可行高效的生防木霉菌筛选方式。  相似文献   

15.
为探究外源褪黑素对棉花抗枯萎病的影响及作用机理,以海岛棉新海14号为材料,于叶面喷施不同浓度褪黑素(0、10、25、50、75、100 μmol/L)后接种棉花枯萎病菌,对枯萎病菌侵染后棉花幼苗进行抗病性鉴定、抗病相关酶活性及基因表达分析。结果表明,外源褪黑素对棉花枯萎病菌的生长无抑制作用,10-100 μmol/L褪黑素均能在一定程度上提高棉花对枯萎病的抗性,其中50 μmol/L褪黑素处理效果最好。与对照相比,50 μmol/L褪黑素预处理能有效减少接菌后棉花叶片中的过氧化氢(H2O2)含量和超氧阴离子(O2·-)的产生速率,增强过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、几丁质酶(CHT)、β-1,3葡聚糖酶(GLU)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)活性,并显著提高木质素代谢途径相关基因(GbPALGb4CLGbCAD)和类黄酮代谢途径关键基因(GbCHIGbDFRGbTT7)的表达量。表明50 μmol/L 的褪黑素处理能提高接菌后棉花抗氧化能力,增强防御酶活性,调控木质素、类黄酮代谢途径相关基因的表达,从而提高棉花对枯萎病的抗性。  相似文献   

16.
Pineapple (Ananas comosus) is one the important fruit crops planted in Malaysia, and this study was conducted to determine Fusarium spp. associated with diseases of the fruit crop as Fusarium is prevalent in tropical countries. Our objective was to identify and characterize Fusarium spp. associated with pineapple fruit rot and leaf spot mainly found on the fruits and leaves in Peninsular Malaysia. Fusarium isolates (n = 108) associated with pineapple fruit rot and leaf spot were characterized by morphological, molecular and phylogenetic analyses, a mating study and pathogenicity testing. TEF‐1α sequence analysis identified Fusarium proliferatum, Fusarium verticillioides, Fusarium sacchari and Fusarium sp. Mating was successful only between tester strains of F. proliferatum and F. verticillioides. Sexual crosses with standard tester strains showed that 82 isolates of F. proliferatum produced fertile crosses with mating population D (Gibberella intermedia) and three isolates of F. verticillioides were fertile with the tester strain of mating population A (Gibberella moniliformis). All isolates were pathogenic, causing pineapple fruit rot and leaf spot, thus fulfilling Koch's postulates.  相似文献   

17.
In order to build integrated strains with superior growth-promoting and disease-suppression effects, the biological control efficacy of Fo47 solid agents combined with actinomycetes strains toward Fusarium oxysporum and Verticillium dahliae were investigated in experiments on watermelon, cotton and eggplant. Five actinomycetes strains were prepared by solid fermentation. The count of viable solid agents, initially with propagules at 107–1011 CFU/g, slowly decreased after being stored one year at room temperature. After being inoculated into sterile soil for 50 days, the viable count of strain Fo47 remained at a stable level. The suppressive effects of Fo47 combined with strain QLP12 on Fusarium wilt on watermelon and cotton, and Verticillium wilt on eggplant, reaching 58.47%, 50.73% and 58.82%, respectively. This was significantly better than the single strain Fo47 alone, and growth of these treated plants and the colonisation rate of Fo47 were increased substantially as well. These results indicate that solid integrated agents with a high viability count and superior stability in soil could increase disease suppression and promote plant growth by synergy with different strains. The increased suppression obtained by Fo47 combined with actinomycete strains was not due to a simple addition of different mechanisms of biocontrol agents. By being intelligently integrated, these combinations increase disease suppression and provide the best biocontrol effect.  相似文献   

18.
During the summer season of 2003 and 2004, wilt syndromes of grapevine leaves (Cv. crimson) and vascular discolouration of roots have been observed in 2-year-old grapevine plants in the field at two sides in Gharbeia Governorate, Egypt. First, symptoms of wilt began on bottom leaves borderline as chlorosis and then these turned to necrotic spots and the leaves died. Wilt symptoms were spread to apical associated with vascular discolouration of roots and stem basal. Routine isolations of discoloured root tissue from diseased plant yielded eight isolates of Fusarium oxysporum Schlechtend only where no other fungi were developed. Microscopic examination revealed the presence of three shapes of microconidia, first is avoid shape non-septate measuring 2.5–3.0 μm × 6–10 μm, second is cylindrical with one septa measuring 2.6 μm × 17.0 μm and third shape also cylindrical with two septate measuring 3.0 μm × 20.0 μm. Macroconidia was rarely with three septate measuring 3.5– 4.0 μm × 35.0–38.0 μm, and chlamydospores were found singly or in pairs or chains. F. oxysporum isolates attacked grapevine plants (Cv. crimson) causing vascular wilt (66.7%) and root-rot syndrome (33.3%). In vitro isolates of F. oxysporum causing wilt of grapevine (Cv. crimson) varied for producing lytic enzymes, i.e. polygalacturonase (PG) and cellulase. The reactions of several grapevines (Cvs.) with a virulent isolate of F. oxysporum indicated the presence of two different symptoms, i.e. vascular wilt only on grapevine plants (Cv. crimson) and root-rot on the other grapevine (Cvs.), i.e. superior, Thompson, King robi and flame seedless. All F. oxysporum isolates caused vascular wilt of grapevine Cv. crimson, successfully reisolated from symptomatic vascular infected tissue and complete identification on the basis of colony, conidia morphology and host range at formae speciales level as F. oxysporum f. sp. herbemontis (Tochetto) Gordan. This is the first report of Fusarium wilt on grapevine in Egypt.  相似文献   

19.
A survey was conducted from June 2012 to May 2013 in the Institute for Agricultural Research Jatropha plantation along Shika road to determine the progress of incidence and severity of Jatropha dieback caused by Fusarium sp. over a year. The disease incidence did not significantly differ among the months under review while disease severity was highest in August and lowest in March 2013.  相似文献   

20.
Fusarium-infected wheat seed decreases germination, seedling emergence, and causes post emergence seedling death, and can contribute to wheat scab and ear rot of maize, with consequent production of mycotoxins such as deoxynivalenol and zearalenone. Current seed treatments have proved ineffective in controlling seedling blight and scab. A patented endophytic bacterial strain, Bacillus mojavensis RRC 101, and several other strains of this species were studied to determine in vitro antagonism to some Fusarium species and to assess the potential of this bacterium to serve as an endophytic biocontrol for seedling blight of wheat produced by species within the F. graminearum complex, as well as other species of Fusarium. Seedling emergence and seed germination were two tests used as indicators of seedling blight. These tests were conducted in growth rooms with two wheat cultivars highly susceptible to scab, Norm and Pioneer 2552, and other cultivars with varying resistance to scab. The results indicated that all strains of this bacterium were antagonistic in vitro to the strains of F. graminearum and its seven related species, as well as four strains of F. pseudograminearum and the two strains of F. verticillioides. Germination of the highly scab susceptible cultivar 2552 was increased from 77 to 97% when planted in soil containing a mixed inoculum of F. graminearum and related species. Seedling emergence in the very susceptible wheat cultivar Norm increased from 20 to 82% when treated with the bacterium. The data indicated that inoculating wheat kernels with B. mojavensis reduced seedling blight of wheat produced by F. graminearum and related Fusarium species indicating the potential for this bacterium as a biocontrol under field condition.  相似文献   

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