scholarly journals Expression of FUB-1 and FUB-11 as Toxic genes responsible for virulence during pathogenesis and combination of biocontrol agents in inhibition of Fusaric acid of Fusarium oxysporum causing Fusarium wilt of Arachis hypogaea L.

Author(s):  
Rajeswari Pilli
2017 ◽  
Vol 14 (3) ◽  
pp. 1169-1176
Author(s):  
P. Rajeswari ◽  
Rupam Kapoor

ABSTRACT: Fusarium oxysporum causes Fusarium wilt of crop plants leads to considerable yield loss. The study was conducted to determine the beneficial effects of combining Trichoderma species and Pseudomonas fluorescens i.e Trichodema viride+ Pseudomonas fluorescens (Tv+Pf) (1+2%), Trichoderma harzianum+Pseudomonas fluorescens (Th+Pf) (1.5+2%), Trichoderma viride +Trichoderma harzianum (Tv+Th) (1+1.5%) on the activity of cellulolytic enzymes of Fusarium oxysporum to control Fusarium wilt of Arachis hypogaea. L wilt in vitro. The activity of 1,4 -β – Endoglucanase, 1,4 -β – Exoglucanase, Cellobiases produced by Fusarium oxysporum (Control) was higher. Maximum inhibition of Cellulolytic enzymes was shown by culture filtrate of Trichoderma viride + Pseudomonas fluorescens (Tv+Pf) (1+2%), followed by Trichoderma harzianum + Pseudomonas fluorescens, (Th +Pf) (1.5+2%) and Trichoderma viride + Trichoderma harzianum (Tv+Th) (1+1.5%). However, disease suppression of Fusarium wilt of Arachis hypogaea. L by the compatible combination of Trichodema viride + Pseudomonas fluorescens (1+2%) was considerably better as compared to other two strains. At the same time the other two combinations resulted in enhanced disease suppression as compared to single strains. This indicates that the potential benefits of using combination treatments to suppress Fusarium wilt. The study suggests the significance of interactive effects of Trichoderma and Pseudomonas in biocontrol of wilt disease.


2015 ◽  
Vol 3 (1) ◽  
pp. 106-110
Author(s):  
P. Rajeswari

In an attempt to develop biocontrol system for management of Fusarium wilt in groundnut, Trichoderma viride, Trichoderma harzianum,and Pseudomonas fluorescens were evaluated for their antagonistic activity against Fusarium oxysporum in vitro. .Fusarium wilt diseasescaused by the fungus Fusarium oxysporum lead to significant yield losses of crops. Experiments were conducted on the effect of culture filtratesof T.viride (1%), T. harzianum (1.5%), and P. fluorescens (2%) on the in vitro inhibition of cellulolytic enzymes of Fusarium oxysporum. Theactivity of 1,4 endoglucanases, 1,4exoglucanase Cellobiase produced by Fusariumoxysporum was higher, when compared to control.Maximum inhibition of above Cellulolytic enzymes (1, 4 endoglucanases, 1,4exoglucanase, Cellobiase) was shown by T. viride treatment wasfollowed by T. harzianum and P. fluorescens. Of all the treatments, T. viride treatment showed higher rate of inhibition of Cellulolytic enzymesof Fusarium oxysporum followed by that of T. harzianum and P. fluorescens.This present study indicates that culture filtrate of T.viride(1%)is the best biocontrol agent in the inhibition of Fusarium oxysporum causing Fusarium wilt of Arachis hypogaea .LDOI: http://dx.doi.org/10.3126/ijasbt.v3i1.12138    Int J Appl Sci Biotechnol, Vol. 3(1): 106-110 


2016 ◽  
Vol 19 (1) ◽  
pp. 40
Author(s):  
Christanti Sumardiyono ◽  
Suharyanto Suharyanto ◽  
Suryanti Suryanti ◽  
Putri Rositasari ◽  
Yufita Dwi Chinta

Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is the most destructive disease of banana. Until today this disease has not been successfully controlled. Fusaric acid is a toxin produced by Foc. Tyloses produced inxylem that caused wilting and yellowing of banana plants, inhibit soil nutrition and water stream. The study carried out previously showed that enriched fusaric acid in banana culture induced the resistance of banana seedlings against Foc. The signal of induced resistance increased the phenolic compounds. One of the phenolic compounds is salicylic acid. The aim of this study was to detect induced resistance of banana plant from tissue cultured enriched with fusaric acid. The experiment was done in the field highly infected with Foc. Observation of resistance was done by measuring disease percentage of yellowing and wilting leaves.Tyloses produced in xylem was observed microscopically from cross section of root. Root damage intensity was counted using tyloses score. Salicylic acid content of root was analyzed with phenolic compounds method using HPLC. The results showed that banana plants from enriched tissues culture with 1.165 ppm of fusaric acid increased the resistance against Foc, but salicylic acid was not detected. Salicylic acid was only detected at low concentration (2 ppb) in moderate resistant banana roots from induced plants with 9.32 ppm of fusaric acid. The chromatogram showed three peaks of unknown phenolic compounds. Tyloses intensity was not related with induced resistance of banana against fusarium wilt. Advanced research is needed with more plants samples. It was suggested to identify the phenolic compounds which were detected in induced resistant plant.Keywords: banana, fusaric acid, fusarium wilt, induced resistance, salicylic acidLayu fusarium yang disebabkan oleh Fusarium oxysporum f. sp. cubense (Foc) adalah penyakit yang sangat merusak pada pisang dan belum dapat dikendalikan secara tuntas. Gejala berupa kelayuan daun karena tersumbatnya xilem karenapembentukan tilosis yaitu pertumbuhan sel dalam jaringan xilem. Pengimbasan ketahanan diharapkan dapat menjadi salah satu cara pengendalian penyakit layu fusarium. Penelitian sebelumnya menunjukkan penambahan asam fusaratdalam kultur jaringan dapat mengimbas ketahanan bibit pisang terhadap penyakit layu fusarium. Asam salisilat adalah salah satu signal ketahanan yang akan meningkat kandungannya bila terjadi peningkatan ketahanan akibat pengimbasan. Penelitian ini bertujuan untuk mendeteksi hasil pengimbasan ketahanan pisang dengan asam fusarat dalam kultur jaringan. Tanaman telah ditanam di lapangan yang terinfeksi berat oleh Foc. Intensitas penyakit di lapang diamati dengan menghitung persentase daun menguning dan atau layu. Intensitas kerusakan akar diamati dengan pembuatan irisan tipis dan pengamatan tilosis dengan cara skoring. Analisis asam salisilat dalam akar dilakukan dengan metode analisis senyawa fenol menggunakan HPLC. Hasil penelitian tanaman dari bibit yang diimbas dengan 1,165 ppm asam fusarat dalam kultur jaringan menunjukkan peningkatan ketahanan di lapang. Intensitas tilosis lebih rendah pada tanaman yang diimbas ketahanannya dibandingkan yang tidak diimbas. Asam salisilat dalam tanaman yang diimbas ketahannnya denganasam fusarat 9,32 ppm terdeteksi pada konsentrasi yang sangat rendah yaitu 2 ppb, dengan ketahanan moderat. Pada tanaman hasil pengimbasan yang menunjukkan kriteria tahan asam salisilat tidak terdeteksi, namun terdeteksi tigapuncak senyawa fenol yang belum teridentifikasi. Intensitas tilosis pada tanaman yang diimbas ketahanannya tidak menunjukkan penurunan dibandingkan dengan tanaman yang tidak diperlakukan. Penelitian ini perlu dilanjutkan dengan sampel yang lebih banyak. Identifikasi jenis senyawa fenol perlu dilakukan dalam penelitian lanjutan.Kata kunci: asam fusarat, asam salisilat, layu fusarium, pengimbasan ketahanan, pisang


2016 ◽  
Vol 56 (3) ◽  
pp. 257-264 ◽  
Author(s):  
Jahanshir Amini ◽  
Zahra Agapoor ◽  
Morahem Ashengroph

AbstractIn this study, about 112 isolates ofStreptomyceswere isolated from chickpea rhizospheric soils. Among the isolated strains, five showed strong inhibitory effects against chickpea Fusarium wilt caused byFusarium oxysporumf. sp.ciceris in vitrousing plate assay and selected for further studies. The selected strains were identified asStreptomycesspp. based on morphological and biochemical characterization as well as 16S rDNA sequences analysis. Our results assigned them to strains related to genus ofStreptomyces.In vitro, antagonistic effects ofStreptomycesstrains against the disease were evaluated through the dual-culture method, volatile and non-volatile metabolites, siderophore, protease and chitinase production. All bacterial strains inhibited mycelial growth of the pathogen ranging from 26 to 44.2% in dual culture assay. The non-volatile extract of five of theStreptomycesstrains inhibited more than 50% growth of the pathogen, whereas volatile compounds were less effective on mycelial growth inhibition (20.2 to 33.4%). The ability of the biocontrol agents to produce siderophore and protease were varied, whereas, production of chitinase was detected for all strains. Results of the greenhouse assay indicated that all biocontrol agents reduced disease severity (ranging from 38.7 to 54.8%). Accordingly, strain KS62 showed higher control efficacy (54.8%). In addition, the biomass of chickpea plants (plant height and dry weight) significantly increased in plants treated withStreptomycesstrains compared to non-bacterized control. The results of this study showed that it may be possible to manage chickpea Fusarium wilt disease effectively by usingStreptomycesspecies, as biocontrol agents. Therefore, evaluating their efficiency under field conditions is needed.


2000 ◽  
Vol 35 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Raquel Ghini ◽  
Monica Mezzalama ◽  
Roberto Ambrosoli ◽  
Elisabetta Barberis ◽  
Angelo Garibaldi ◽  
...  

Before planning the large-scale use of nonpathogenic strains of Fusarium oxysporum as biocontrol agents of Fusarium wilt, their behaviour and potential impact on soil ecosystems should be carefully studied as part of risk assessment. The aim of this work was to evaluate the effects of antagonistic F. oxysporum strains, genetically manipulated (T26/6) or not (233/1), on soil microbial biomass and activity. The effects were evaluated, in North-western Italy, in two soils from different sites at Albenga, one natural and the other previously solarized, and in a third soil obtained from a 10-year-old poplar stand (Popolus sp.), near Carignano. There were no detectable effects on ATP, fluorescein diacetate hydrolysis, and biomass P that could be attributed to the introduction of the antagonists. A transient increase of carbon dioxide evolution and biomass C was observed in response to the added inoculum. Although the results showed only some transient alterations, further studies are required to evaluate effects on specific microorganism populations.


2019 ◽  
Vol 11 (1) ◽  
pp. 138-143 ◽  
Author(s):  
P. Rajeswari

Fusarium wilt caused by Fusarium oxysporum is a devastating disease of peanut. The fungus causes severe yield loss in groundnut. Combinations of biocontrol agents that are compatible with each other is a viable approach to control the plant disease. The study was conducted to determine the beneficiary aspects of  combining different species of Trichoderma and Pseudomonasfluorescens i.e Trichoderma viride+Pseudomonas fluorescens (Tv+Pf), Trichoderma harzianum+Pseudomonas fluorescens (Th+Pf) and Trichoderma viride +Trichoderma harzianum (Tv+Th) to control the Fusarium wilt  in  biochemicalparameters such as DNA, RNA, Amino nitrogen, phenols, dihydroxy and   proline  contents of Arachis hypogaea.L. Among the three combinations tested, Trichoderma viride + Pseudomonas fluorescens (1+2%) sprayed leaves provided greater suppression of Fusariumoxysporum by increasing the levels of DNA,RNA,Amino nitrogen contents resulting  in the suppression of  Fusarium wilt  disease of Arachis hypogaea L.Maximum  reduction of  DNA, RNA, Amino nitrogen was observed in the infected Fusariumoxysporumleaves Phenol, Dihydroxy phenols and proline contents increase sharply in the treated plants treated with (Tv+Pf) as compared to the control plants. At the same time the other two combinations resulted in  enhanced control  in  comparison with  individual ones. This present study indicates that specific combination of Trichoderma viride and Pseudomonas fluorescens could have the greater efficacy in the inhibition of pathogen  in the biocontrol of Fusarium wilt  disease  as   compared   with   individual strains.


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