scholarly journals In Vitro Evaluation of Herbicides on Beneficial and Pathogenic Microorganisms

Author(s):  
Thumu Venkateswara Reddy ◽  
Meera V. Menon ◽  
Anita Cherian K. ◽  
Sindhu P.V. ◽  
Karthika Mohan ◽  
...  

Abstract An experiment was conducted in the laboratory to evaluate the effect of herbicides on beneficial and pathogenic microorganisms. Eighteen treatments included six herbicides at three different doses viz., cyhalofop-butyl (80, 160 and 240 ppm), cyhalofop-butyl + penoxsulam (150, 300 and 450 ppm), bispyribac-sodium (25, 50 and 75 ppm), fenoxaprop-p-ethyl (60, 12 and 180 ppm), carfentrazone-ethyl (20, 40 and 60 ppm) and chlorimuron-ethyl + metsulfuron-methyl (4, 8 and 12 ppm) evaluated on beneficial microbial bioagents (Trichoderma viride and Pseudomonas fluorescens) and pathogenic microorganisms (Rhizoctonia solani, Pyricularia oryzae and Xanthomonas oryzae pv. oryzae). Results revealed that bispyribac-sodium and cyhalofop-butyl + penoxsulam had greatest inhibitory effect on pathogenic microorganisms Rhizoctonia solani (47.76 and 54.40%) and Pyricularia oryzae (49.07 and 61.12%), but showed no effect on Xanthomonasoryzaepv. oryzae, and were less harmful to biocontrol agents Trichoderma viride and Pseudomonas fluorescens at recommended doses, which were effective in control of broad spectrum of weed flora in rice ecosystem.

Author(s):  
Akhilesh Kumar Kulmitra ◽  
Neha Sahu ◽  
V.B. Sanath Kumar ◽  
Thejesha A. G. ◽  
Amlan Ghosh ◽  
...  

The five different bio-agents viz., Trichoderma viride, T. harzianum, T. virens, Pseudomonas fluorescens and Bacillus subtilis were evaluated against Pyricularia oryzae at four and eight days after incubation through dual culture technique. Among the five different bio-agents, highest per cent inhibition of mycelial growth of fungus was recorded in T. virens i.e. 67 per cent and 70 percent after four and eight days after incubation respectively with mean of 68.5 per cent followed by Trichoderma viride with the inhibition of 61 and 63 per cent respectively with mean of 62 per cent. The Pseudomonas fluorescens did not show any inhibition of mycelial growth of P. oryzae as the pathogen over grew the bio-agents.


Author(s):  
Mezeal Ali Intesar, Ibraheem Jameel Liqaa ,Mizil Nghamish Sh

In vitro testing, antagonistic capability of Trichoderma spp. obtained from the rhizosphere of tomato showed inhibitory effect against growth of   R. solani ,  few biological control agents have achieved success under field conditions. Among the hundreds of organisms identified as potential biological disease control agent, only few have resulted in proving commercially acceptable control of these diseases. Rhizoctonia solani were  isolate from a naturally occurring epidemic of damping-off tomato plants grown in Kut governorate, Iraq,In vitro, of  9 isolates belonging to the fungus Trichoderma spp.  5 isolates belonging to the fungus T. viride while diagnosed 4 isolates belong to the fungus T. harzianum  isolated from the rhizosphere of tomato plants. Both T. viride and T. harzianum had antagonistic effect on R.solani isolates . Results showed that ability of six isolates of the pathogenic fungus to damping   of the tomato plant seedlings under greenhouse conditions ,   isolates R.solani-M  and R.solani-H showed the largest percentage of the disease compared with other isolates( 30.2 and 32.1%) respectively, while the effect of isolate R.solani-A was daming  of  21.9% from tomato seedlings Pre-emergence.  


2020 ◽  
Vol 16 (1) ◽  
pp. 37-48
Author(s):  
Ratna Sari Dewi ◽  
Giyanto Giyanto ◽  
Meity Suradji Sinaga ◽  
Dadang Dadang ◽  
Bambang Nuryanto

Saat ini teknologi pengendalian hayati penyakit utama padi terus berkembang. Dalam pengembangan teknologi pengendalian hayati, mekanisme penghambatan patogen dalam perkembangan penyakit pada suatu populasi tumbuhan dalam area tertentu menjadi hal yang penting. Penelitian bertujuan mendapatkan bakteri agens hayati potensial dalam pengendalian penyakit penting padi di antaranya yang disebabkan Pyricularia oryzae, Xanthomnas oryzae pv. oryzae, Rhizoctonia solani, Burkholderia glumae, dan Drechlera oryzae, berdasarkan mekanisme antagonisme, kemampuan menginduksi ketahanan dan mendukung kebugaran tanaman, serta kompatibilitas antaragens hayati. Ralstonia pickettii TT47, Pseudomonas fluorescens P12, Chromobacterium sp. T51118, Bacillus subtilis 451 dan 154, serta Streptomyces sp. T51105 dibuktikan memiliki mekanisme antibiosis dengan menghasilkan metabolit sekunder dan senyawa volatil. Berdasarkan uji produksi enzim kitinolitik Chromobacterium sp. dan Streptomyces sp. memiliki mekanisme lisis. Aktivitas antibiotik R. pickettii dan P. fluorescens tergolong kuat terhadap P. oryzae dengan penekanan secara berurutan sebesar 79.68% dan 77.59% pada uji biakan ganda. Penekanan pertumbuhan miselium P. oryzae dan R. solani pada uji volatil mencapai 100% oleh Chromobacterium sp. Semua agens hayati umumnya mampu menginduksi ketahanan dan mendukung kebugaran tanaman. Uji kompatibilitas menunjukan R. pickettii, P. fluorescens, dan Chromobacterium sp. bersifat kompatibel. Dari hasil penelitian diperoleh tiga bakteri agens hayati dengan kategori unggul, yaitu P. fluorescens P12, R. pickettii TT47, dan Chromobacterium sp. T51118. Ketiganya mampu menekan pertumbuhan patogen, menginduksi ketahanan dan mendukung kebugaran tanaman, memiliki patogen sasaran yang lebih beragam, serta bersifat kompatibel.


1989 ◽  
Vol 257 (3) ◽  
pp. F336-F340
Author(s):  
R. J. Bolterman ◽  
M. D. Bentley ◽  
S. M. Sandberg ◽  
M. J. Fiksen-Olsen ◽  
J. C. Romero

Like arachidonic acid (AA) and bradykinin (BK), the intrarenal administration of atrial natriuretic peptide (ANP) has been shown to increase the urinary excretion of prostaglandin E2 (PGE2). In the present study, the direct in vitro effects of ANP on PGE2 production were compared with those of AA and BK. Canine renal inner medullary slices were preincubated for 30 min and washed in aerated Krebs-Ringer buffer (37 degrees C). During the final incubation period, with the use of varied concentrations of AA, BK, or ANP in Krebs-Ringer buffer, samples were obtained at 0 and 30 min to be used for radioimmunoassay of PGE2. Although the rate of PGE2 production was significantly increased 11-fold with AA and threefold with BK, it was unaffected by four different doses of ANP (10(-5) to 10(-11) M). Furthermore, the production of PGE2 during basal and stimulated (BK or AA) conditions was significantly blocked by indomethacin but not by ANP. These results indicate that ANP had no direct stimulatory or inhibitory effect on the medullary production of PGE2.


2011 ◽  
Vol 6 (4) ◽  
pp. 583-586 ◽  
Author(s):  
Milica Grbić ◽  
Miloš Stupar ◽  
Jelena Vukojević ◽  
Dragoljub Grubišić

AbstractThe ability of Nepeta rtanjensis essential oil to inhibit conidia germination of fungi was evaluated in vitro. Tested fungi included in research were Cladosporium cladosporioides, Trichoderma viride and two Alternaria species originally isolated from N. rtanjensis. The conidia of Cladosporium cladosporioides were most susceptible to the N. rtanjensis essential oil treatment, and the oil concentration of 0.1 µg ml−1 caused the maximum of conidia germination inhibition. The highest concentration used in experiment that caused the maximum of conidia germination inhibition was 0.6 µg ml−1 for Alternaria isolated from leaf surface of N. rtanjensis. The germ tube elongation of Alternaria isolates significantly decreased in response of different concentrations of oil used in experiment.


Author(s):  
P Rajeswari ◽  
R Kapoor

Fusarium oxysporum, the soil borne pathogen causes vascular wilt, on majority of crop plants. It has been demonstrated that two different species of Trichoderma and Pseudomonas fluorescens suppress disease by different mechanisms. Therefore, application of a mixture of these biocontrol agents, and thus of several suppressive mechanisms, may represent a viable control strategy. A necessity for biocontrol by combinations of biocontrol agents can be the compatibility of the co-inoculated micro-organisms. Hence, compatibility between Trichoderma spp. and Pseudomonas fluorescens that have the ability to suppress Fusarium oxysporum in vitro on the activity of pectinolytic enzymes of Fusarium oxysporum. The activity of pectinolytic enzymes, i.e. pectin methyl esterase, endo and exo polymethylgalacturonases and exo and endo pectin trans eliminases produced by Fusarium oxysporum (Control) was higher. Maximum inhibition of pectin methylesterase, exo and endo polymethylgalacturonase and exo and endopectin trans eliminase 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, pathogenecity suppression of Fusarium oxysporum, a causative of Arachis hypogaea. L by the compatible combination of Trichodema viride + Pseudomonas fluorescens (1+2%) was significantly better as compared to the single bio-agent. This indicates that specific interactions between biocontrol agents influence suppression of pathogenicity factors directly by combinations of these compatible bio-agents.Int. J. Agril. Res. Innov. & Tech. 7 (2): 36-42, December, 2017


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 


2013 ◽  
Vol 54 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Alicja Saniewska ◽  
Marian Jurzysta ◽  
Zbigniew Biały

The total saponins isolated from aerial parts and roots of alfalfa (<i>Medicago sativa</i> L.) at the concentration of 0,01%, 0,05% and 0,1% showed differential influence on the mycelium growth of <i>Alternaria zinniae, Botrytis cinerea, Botrytis tulipae, Phoma narcissi, Phoma poolensis</i> and <i>Rhizoctonia solani</i>. A higher inhibitory effect on in vitro growth of mycelium of all tested pathogens indicated saponins from roots of alfalfa than from aerial parts. Tested saponins from roots at lhe concentration of 0,1% totally inhibited linear growth of Phoma narcissi, and linear growth of <i>Alternaria zinniae</i> was limited about 67%, Botrytis cinerea about 74%, Botrytis tulipae about 68%, Phoma poolensis about 38%, and <i>Rhizoctonia solani</i> about 74% in comparison to the control. The saponins of alfalfa from roots at the concentration of 0,1% and 0,2% applied as preinoculation sprays evidently inhibited the development of <i>Phoma narcissi</i> on <i>Hippeastrum</i> leaves. This dose of aerial saponins of alfalfa did not effect the development of necrotic spots on the leaves.


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