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1.
The bioformulation of Pseudomonas fluorescens (Pf1 and TDK1) and Beauveria bassiana (B2) strains was evaluated individually and in combinations with and without chitin for their efficacy against leafminer insect and collar rot disease and the effect of the interaction between Pseudomonas, Beauveria and groundnut leafminer insect and collar rot pathogen in the expression of defense enzymes and pathogenesis-related proteins (PR-proteins) in groundnut. Among the various bioformulations, B2 + TDK1 + Pf1 (amended with or without chitin) formulation significantly reduced the incidence of leafminer and collar rot disease when compared to untreated control. A significant increase in the enzymatic activity of phenylalanine ammonia-lyase, peroxidase, polyphenol oxidase, chitinase, β-1,3-glucanase, superoxide dismutase, catalase, lipoxygenase, and phenolics in groundnut plants treated with B2 + TDK1 + Pf1 bioformulation (amended with or without chitin) and challenge inoculated with Aproaerema modicella and Sclerotium rolfsii. Native gel electrophoresis also revealed the expression of more isoforms of pathogenesis-related proteins and other defense enzymes viz., polyphenol oxidase and superoxide dismutase in plants treated with B2 + TDK1 + Pf1 mixture challenged with A. modicella and S. rolfsii. The present study reveals that sustained and timely induction and accumulation of these defense enzymes and PR-proteins enhance the resistance in groundnut against leafminer insect and collar rot disease. 相似文献
2.
Saravanakumar D Muthumeena K Lavanya N Suresh S Rajendran L Raguchander T Samiyappan R 《Pest management science》2007,63(7):714-721
Fluorescent pseudomonad strains Pf1, TDK1 and PY15 individually and in combination were evaluated against leaffolder, Cnaphalocrocis medinalis Guen., in rice under in vitro, glasshouse and field conditions. Among the various treatments used, a combination of Pf1, TDK1 and PY15 strains effectively reduced the incidence of leaffolder pest in rice plants to an extent comparable with chlorpyrifos-methyl. In addition, morphogenesis of the insect pest in all stages, larval, pupal and adult, was greatly affected by a combination of Pseudomonas Pf1, TDK1 and PY15 strains. Further, the induction of defence-related molecules was demonstrated. An increased accumulation of defence molecules such as chitinase and proteinase inhibitors was observed with a combined Pf1, TDK1 and PY15 treatment compared with all other treatments. Western blot analysis of chitinase revealed the extra induction of 18, 28 and 35 kDa isoforms in rice plants treated with a mixture of Pf1, TDK1 and PY15 strains against leaffolder pest. The study revealed that a combination of fluorescent pseudomonad strains affects the development of leaffolder pest by inducing defence molecules in rice plants which in turn enhance resistance to leaffolder attack. 相似文献
3.
水稻病虫危害损失和防治效益评估研究初报 总被引：1，自引：0，他引：1
2005-2008年笔者在早稻、晚稻生长期间进行防治与不防治对比试验。分析试验数据得出:全程不防治平均减产51.26%,常规防治平均增产113.14%,常规防治平均收益4498.58元/hm2,比全程不防治增86.12%,平均投入产出比1:5.18。拟合出单虫或单病在定局时的发生量(或发生率)与其危害损失之间的线性回归模型:稻飞虱每丛虫量(X)与损失率(Y)之间关系式为Y=8.7654+0.0881X;稻纵卷叶螟卷叶率(X)与损失率(Y)之间关系式为Y=1.9341+0.2851X;二化螟发生率(X)与损失率(Y)之间关系式为Y=1.4182+1.0407X;稻瘟病白穗率(X)与损失率(Y)之间关系式为Y=0.3765+0.9004X;纹枯病病株率(X)与损失率(Y)之间关系式为Y=-2.4469+0.2829X,相关分析均达极显著水平。 相似文献
4.
Mathiyazhagan Kavino Sankarasubramanian Harish Neelakandan Kumar Duraisamy Saravanakumar Ramasamy Samiyappan 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(4):353-362
Pseudomonas fluorescens strains CHA0 and Pf1 were investigated for their biocontrol efficacy against Banana bunchy top virus (BBTV) in banana (Musa spp.) alone and in combination with chitin under glasshouse and field conditions. Bioformulation of P. fluorescens strain CHA0 with chitin was effective in reducing the banana bunchy top disease (BBTD) incidence in banana under glasshouse
and field conditions. In addition to disease control, the bioformulation increased the economic yield significantly compared
to the untreated control. Increased accumulation of oxidative enzymes, peroxidase (PO), polyphenol oxidase (PPO), phenylalanine
ammonia lyase (PAL), pathogenesis-related (PR) proteins, chitinase, β-1,3-glucanase and phenolics were observed in CHA0 bioformulation
amended with chitin-treated plants challenged with BBTV under glasshouse conditions. Indirect ELISA indicated the reduction
in viral antigen concentration in P. fluorescens strain CHA0 with chitin-treated banana plants corresponding to reduced disease ratings. The present study revealed that induction
of defence enzymes by P. fluorescens with chitin amendment reduced the BBTD incidence and increased bunch yield in banana. 相似文献
5.
Serratia marcescens strain B2 is an antagonistic bacterium that produces the red-pigmented antibiotic prodigiosin and suppresses rice sheath blight caused by Rhizoctonia solani AG-1 IA. Rice sheath blight disease was suppressed when plants were inoculated with this bacterium an hour before pathogen inoculation but not when plants were treated 4 weeks before pathogen inoculation. In both cases the bacteria were detected in the rice rhizosphere 4 weeks after inoculation. Bacteria isolated from the rice plant and rhizosphere inhibited biosynthesis of prodigiosin in S. marcescens strain B2. We suggest that bacteria isolated from rice plants and rhizospheres mediate the suppression of antibiotic production of biological control agents and that such suppression is common under field conditions. 相似文献
6.
D. M. De Costa S. S. T. Samarasinghe H. R. D. Dias D. M. N. Dissanayake 《Phytoparasitica》2008,36(1):52-65
Epiphytic microorganisms on the phyllosphere of traditional and high-yielding rice varieties were isolated from different
agroecological zones of Sri Lanka and screened for theirin vitro andin vivo antagonism againstRhizoctonia solani Kühn AG-1 1A, the sheath blight pathogen of rice. Among a total of 196 bacterial and 91 fungal isolates, 12 bacterial and
two fungal isolates which showed more than 50% growth inhibition ofR. solani were tested for theirin vivo antagonism. Among the 14 antagonists tested, six bacterial and one fungal isolate substantially reduced the incidence of
sheath blight (by more than 82%) and severity (by more than 92%) of the rice varieties BG94-1 and IR8 grown in a pot experiment
under open field conditions. Using five antagonists that showed the bestin vitro antagonism, a pot experiment was conducted to determine whether the presence of indigenous microflora on the rice sheath
had any effect on the effectiveness of antagonism. Three isolates (B4, GbB5 and HMWB4) controlled sheath blight incidence
and severity equally well in the presence and absence of indigenous microflora. Two isolates (BG352B1 and BG300B1) were more
effective when they were introduced into the rice sheath without indigenous microflora. Among the effective antagonists determined
by the pot experiment, isolates B4, B16, BG94-1B5, GbB5, HMWB4 and BG379-F2 were tested under field conditions for two consecutive
growing seasons. Under field conditions, severity of rice sheath blight was significantly reduced by the application of all
the tested antagonists as a spray on rice sheath at a concentration of 108 cfu ml−1, starting 3 days after the development of symptoms and continuing for three applications at 10-day intervals. Antagonistic
performances were consistent in the two seasons under field conditions andB. megatarium A (isolate B16) andAspergillus niger (isolate BG379-F2) performed as the most effective antagonists in both seasons. When disease severity was quantified as percentage
sheath area covered by the disease lesions, the respective reductions in disease severity were greater than 50% and 61% byB. megaterium A (isolate B16) andAspergillus niger (isolate BG379-F2), respectively, in both seasons.
http://www.phytoparasitica.org posting Jan. 10, 2008. 相似文献
7.
本文对上高县2014年早稻纹枯病、稻瘟病、二化螟、稻纵卷叶螟和稻飞虱这几类水稻主要病虫害在防治与不防治条件下进行了田间试验对比,对不同处理病虫情况及产量情况进行调查,对防治效益进行了评估。结果表明,完全不防治产量损失最大,单一病虫害中纹枯病损失最大,其次是稻纵卷叶螟、稻飞虱、二化螟和稻瘟病;完全不防治的效益损失最大,单一病虫害中纹枯病损失效益最大,其次是稻纵卷叶螟、稻飞虱、二化螟和稻瘟病。2014年上半年雨水多,湿度大,造成纹枯病重发生,稻纵卷叶螟和稻飞虱中等发生,二化螟和稻瘟病轻发生。 相似文献
8.
9.
The sunn pest, Eurygaster integriceps Puton, is a major pest of wheat in West and Central Asia. Studies were conducted to investigate the effect of Beauveria bassiana (teleomorph; Cordyceps bassiana) isolates on the sunn pest. Bioassays were done with adult insects collected from overwintering sites at three different times. The effect of sublethal doses of fungi on the insects’ feeding and fecundity was determined. When the sunn pest adults were treated with 2 × 107 conidia mL?1, all isolates caused significant sunn pest mortality varying between 24 and 100% 12 days after inoculation. There were significant differences between mortality, depending on the date of fungal application. Adult sunn pests treated with B. bassiana at sublethal concentrations caused significantly less damage to wheat leaves than sunn pests in the control. The number of eggs laid by the sunn pest was significantly fewer when wheat plots in plastic greenhouse and field cages were infested with adult sunn pests treated at sublethal concentrations, compared with sunn pests in control plots. Results show that sublethal dosages of B. bassiana reduced sunn pest feeding and fecundity. Applying B. bassiana in sunn pest overwintering sites minimizes the pest populations, which would move to wheat fields in spring. 相似文献
10.
Artificial infestation methods were employed to generate damage function graphs for guilds of three rice insect pests. In the vegetative stage, infestation of whorl maggot (Hydrellia philippina Ferino) and defoliators (a mixed population of Naranga aenescens Moore and Rivula atimeta [Swinhoe]) was applied as a combined or single pest attack. Infestation of yellow stemborer (Scirpophaga incertulas [Walker]) and leaffolder (Cnaphalocrocis medinalis [Guenée]) each were infested in one or two crop growth stages. Combinations of three stresses (four N application rates, solar radiation from the wet or dry season, and/or the presence or absence of weeds) were applied to each guild to develop more holistic economic injury levels (EILs). Slopes on the linear portion of damage curves of each pest guild became steeper with each additional stress applied, whether from multiple insect pest attack, low N, low solar radiation, or weeds. EILs can be developed by pest managers from the graphs of the damage functions for the variables quantified in this study. 相似文献
11.
Willocquet L Elazegui FA Castilla N Fernandez L Fischer KS Peng S Teng PS Srivastava RK Singh HM Zhu D Savary S 《Phytopathology》2004,94(7):672-682
ABSTRACT A simulation study was conducted to assess the current and prospective efficiency of rice pest management and develop research priorities for lowland production situations in tropical Asia. Simulation modeling with the RICEPEST model provided the flexibility required to address varying production situations and diverse pest profiles (bacterial leaf blight, sheath blight, brown spot, leaf blast, neck blast, sheath rot, white heads, dead hearts, brown plant-hoppers, insect defoliators, and weeds). Operational definitions for management efficacy (injury reduction) and management efficiency (yield gain) were developed. This approach enabled the modeling of scenarios pertaining to different pest management strategies within the agroecological contexts of rice production and their associated pest injuries. Rice pests could be classified into two broad research priority-setting categories with respect to simulated yield losses and management efficiencies. One group, including weeds, sheath blight, and brown spot, consists of pests for which effective pest management tools need to be developed. The second group consists of leaf blast, neck blast, bacterial leaf blight, and brown plant-hoppers, for which the efficiency of current management methods is to be maintained. Simulated yield losses in future production situations indicated that a new type of rice plant with high-harvest index and high-biomass production ("New Plant Type") was more vulnerable to pests than hybrid rice. Simulations also indicated that the impact of deployment of host resistance (e.g., through genetic engineering) was much larger when targeted against sheath blight than when targeted against stem borers. Simulated yield losses for combinations of production situations and injury profiles that dominate current lowland rice production in tropical Asia ranged from 140 to 230 g m(-2). For these combinations, the simulated efficiency of current pest management methods, expressed in terms of relative yield gains, ranged from 0.38 to 0.74. Overall, the analyses indicated that 120 to 200 x 10(6) tons of grain yield are lost yearly to pests over the 87 x 10(6) ha of lowland rice in tropical Asia. This also amounts to the potential gain that future pest management strategies could achieve, if deployed. 相似文献
12.
Enhancing Resistance of Tomato and Hot Pepper to Pythium Diseases by Seed Treatment with Fluorescent Pseudomonads 总被引：1，自引：0，他引：1
V. Ramamoorthy T. Raguchander R. Samiyappan 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(5):429-441
Twenty isolates of fluorescent pseudomonads were evaluated for their ability to control damping-off in tomato (Lycopersicon esculentum) and hot pepper (Capsicum annuum). These isolates were characterized as Pseudomonas fluorescens and Pseudomonas putida. Two isolates, PFATR and KKM 1 belonged to P. putida and the remaining 18 isolates belonged to P. fluorescens. Among these isolates, P. fluorescens isolate Pf1 showed the maximum inhibition of mycelial growth of Pythium aphanidermatum and increased plant growth promotion in tomato and hot pepper. P. fluorescens isolate Pf1 was effective in reducing the damping-off incidence in tomato and hot pepper in greenhouse and field conditions. Isolate Pf1 was further tested for its ability to induce production of defense-related enzymes and chemicals in plants. Earlier and increased activities of phenylalanine ammonia lyase (PAL), peroxidase (PO) and polyphenol oxidase (PPO) were observed in P. fluorescens Pf1 pretreated tomato and hot pepper plants challenged with Pythium aphanidermatum. Moreover, higher accumulation of phenolics was noticed in plants pretreated with P. fluorescens isolate Pf1 challenged with Pythium aphanidermatum. Thus, the present study shows that in addition to direct antagonism and plant growth-promotion, induction of defense-related enzymes involved in the phenyl propanoid pathway collectively contributed to enhance resistance against invasion of Pythium in tomato and hot pepper. 相似文献
13.
14.
秸秆还田对水稻根际微生物多样性和水稻纹枯病发生的影响 总被引：1，自引：0，他引：1
为探究稻麦轮作模式下秸秆还田对水稻根际微生物多样性与水稻纹枯病发生的影响,本研究采用Illumina测序技术结合生物信息学比较分析了秸秆还田与不还田处理的水稻根际微生物群落多样性差异,并采用实时荧光定量PCR （real-time fluorescent quantitative PCR,RT-qPCR）对这2种稻田土壤中水稻纹枯病菌Rhizoctonia solani含量进行测定,并采用随机五点取样法调查稻田中水稻纹枯病发病率和病情指数。结果表明,秸秆还田后水稻根际细菌群落Chao1丰富度指数和Shannon多样性指数均有所增加,分别增加14.42%和4.39%,其中前者增幅显著;根际真菌群落Chao1丰富度指数降低29.60%,而Shannon多样性指数略有增加,增加5.96%;在门水平上,秸秆还田和不还田处理的水稻根际土壤优势细菌门均为变形菌门、放线菌门、绿弯菌门和酸杆菌门,优势真菌门均为子囊菌门、接合菌门和担子菌门;在属水平上,秸秆还田处理的硝化螺旋菌属和芽胞杆菌属相对丰度分别比不还田处理的显著增加96.11%和106.19%;在水稻孕穗期秸秆还田土壤中水稻纹枯病菌含量比不还田处理的显著增加120.20%;秸秆还田后水稻纹枯病发生加重,病情指数比不还田处理的增加18.10%~45.41%。 相似文献
15.
16.
P. Vidhyasekaran N. Kamala A. Ramanathan K. Rajappan V. Paranidharan R. Velazhahan 《Phytoparasitica》2001,29(2):155-166
When lower leaves of rice plants were inoculated with powder formulation of a saprophytic strain ofPseudomonas fluorescens, Pfl, upper leaves, in addition to the inoculated lower leaves, showed resistance to the rice bacterial blight pathogenXanthomonas oryzae pv.oryzae. When the leaves were challenge-inoculated withX. oryzae pv.oryzae 4 days afterP. fluorescens application on lower leaves, the disease intensity in upper leaves decreased from 6.7 to 1.1. When rice seeds were treated
with the formulation ofP. fluorescens Pfl and sown, 30-day-old seedlings showed resistance toX. oryzae pv.oryzae and the disease intensity decreased from 6.8 to 1.2. The induced resistance was transient; leaves sprayed withP. fluorescens Pfl at 30 days after treatment and leaves of 60-day-old seedlings fromP. fluorescens-treated seeds did not show resistance to the pathogen. In field trials, seed treatment followed by foliar application of the powder
formulation ofP. fluorescens Pfl effectively controlled rice bacterial blight and increased the yield. In the induced resistant leaves a sharp increase
in lignification and activities of peroxidase, phenylalanine ammonia-lyase and 4-coumarate: CoA ligase was observed when the
leaves were challenge-inoculated withX. oryzae pv.oryzae. An approximately threefold increase in lignin content, peroxidase activity and phenylalanine ammonia-lyase activity and a
fivefold increase in 4-coumarate: CoA ligase activity were observed 5 days after challenge inoculation withX. oryzae pv.oryzae in rice leaves pretreated withP. fluorescens for 5 days. A similar increase in defense-related activities was not observed in susceptible interactions or inP. fluorescens-treated plants at later stages of interactions when no resistance to the pathogen was observed. 相似文献
17.
Fungal entomopathogens like Beauveria bassiana (Ascomycota: Hypocreales) are known as antagonists of insects with multiple functional and ecological roles, and have attracted increased attention as biocontrol agents in integrated pest management programmes. For some crop plants, it has been proven that endophytic B. bassiana, besides its entomopathogenic habit, can provide protection against plant pathogens or limit their damaging effects. However, for grapevine, limited knowledge is available on the influence of endophytic B. bassiana on fungal pathogens and about the mechanisms underlying putative protection effects. This study assessed the protective potential of endophytic B. bassiana against grapevine downy mildew Plasmopara viticola in greenhouse experiments. Three and seven days after a B. bassiana treatment, potted grapevine plants were inoculated with P. viticola and the evolving disease severity was assessed. Disease severity was significantly reduced in B. bassiana-treated plants compared to control plants, depending on the age of leaves. Furthermore, a microarray and an RT-qPCR analysis were performed to work out fundamental aspects of genes involved in the interaction between grapevine and B. bassiana. The results indicate an up-regulation of diverse defence-related genes in grapevine as a response to endophytic establishment of B. bassiana. Thus, endophytic establishment of an entomopathogenic fungus such as B. bassiana in grapevine plants would represent an alternative and sustainable plant protection strategy, with the potential for reducing pesticide applications in viticulture. 相似文献
18.
采取田间小区和网室盆栽试验,研究稻飞虱和纹枯病混合发生的化控策略及复合防治指标。结果表明,水稻孕穗期(7月上中旬)用高效、长效、安全药剂扑虱灵和粉锈灵混合防治的“治前控后”化防策略保产效果最佳。试验证明,稻飞虱和纹枯病对水稻有明显的交互作用。组建了稻飞虱(白背飞虱、褐飞虱)虫量(X_(1-2))、纹枯病病株率(X_3)的复合为害损失及动态经济阈值模型。经田间小区、大田应用检验,不仅防效高,保产效果好,而且减少施药次数,保护了天敌,三大效益显著。 相似文献
19.
Bioassays were conducted in stored grains to evaluate the combined use of the entomopathogenic fungus Beauveria bassiana, diatomaceous earth (DE) and fenitrothion against adults of Rhyzopertha dominica and Tribolium castaneum. The insecticide agents were applied to wheat as follows: the fungus at 1 × 108 conidia/kg of wheat, DE at 3 g/kg of wheat and fenitrothion at a rate of 0.15 ml/kg of wheat (25% of field dose rate). Surviving insects and progeny production were monitored at thirty-day intervals until four months. For both insect species, significantly less progeny was produced on wheat treated with fenitrothion and DE + B. bassiana formulations in comparison with controls. The effect of insecticides on the grain damage, germination power of wheat and bulk density was also evaluated. After four months, B. bassiana mixed with DE reduced the damaged insect grains by 50% in comparison with both fenitrothion and control treatments. Trials using DE caused a reduction in bulk density while there were no significant differences for germination testing between treatments. 相似文献
20.
Sheath blight, caused by anastomosis group 1-IA of Rhizoctonia solani Kühn (teleomorph Thanatephorus cucumeris (Frank) Donk), is one of the most destructive rice diseases worldwide. The pathogen is able to infect plants belonging to
more than 27 families, including many economically important monocots and dicots such as rice, wheat, alfalfa, bean, peanut,
soybean, cucumber, papaya, corn, potato, tomato and sugar beet. It is a soil borne necrotrophic fungus that survives in plant
debris as sclerotia, which are small brown-to-black, rocklike reproductive structures. The sclerotia can survive in the soil
for several years and infect rice plants at the water-plant interface in the flooded field by producing mycelia. Management
of rice sheath blight requires an integrated approach based on the knowledge of each stage of the disease and cytomolecular
aspects of rice defence responses against R. solani. This review summarizes current knowledge on molecular aspects of R. solani pathogenicity, genetic structure of the pathogen populations, and the rice-R. solani interaction with emphasis on cellular and molecular defence components such as signal transduction pathways, various plant
hormones, host defence genes and production of defence-related proteins involved in basal and induced resistance in rice against
sheath blight disease. 相似文献