Purification of a chitinase from Trichoderma sp. and its action on Sclerotium rolfsii and Rhizoctonia solani cell walls.

1997 ◽  
Vol 43 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Luzia H. C. Lima ◽  
Cirano J. Ulhoa ◽  
Adrienne P. Fernandes ◽  
Carlos R. Felix
1999 ◽  
Vol 65 (3) ◽  
pp. 929-935 ◽  
Author(s):  
Carolina Carsolio ◽  
Nicole Benhamou ◽  
Shoshan Haran ◽  
Carlos Cortés ◽  
Ana Gutiérrez ◽  
...  

ABSTRACT The role of the Trichoderma harzianum endochitinase (Ech42) in mycoparasitism was studied by genetically manipulating the gene that encodes Ech42, ech42. We constructed several transgenic T. harzianum strains carrying multiple copies of ech42 and the corresponding gene disruptants. The level of extracellular endochitinase activity when T. harzianum was grown under inducing conditions increased up to 42-fold in multicopy strains as compared with the wild type, whereas gene disruptants exhibited practically no activity. The densities of chitin labeling of Rhizoctonia solani cell walls, after interactions with gene disruptants were not statistically significantly different than the density of chitin labeling after interactions with the wild type. Finally, no major differences in the efficacies of the strains generated as biocontrol agents against R. solani or Sclerotium rolfsii were observed in greenhouse experiments.


2012 ◽  
Vol 7 (9) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Paraj Shukla ◽  
Suresh Walia ◽  
Vivek Ahluwalia ◽  
Balraj S. Parmar ◽  
Muraleedharan G. Nair

Thirty known dialkanoates of ethylene, propylene and diethylene glycols were synthesized by reacting the glycols with acyl chlorides and their structures confirmed by IR, NMR and mass spectral analyses. They exhibited significant antifungal activity against two phytopathogenic fungi Rhizoctonia solani Kuehn and Sclerotium rolfsii Sacc in a dose dependent manner. Propylene glycol dipentanoate was the most active against R. solani. followed by diethylene glycol dibutanoate and ethylene glycol dibutanoate. Against S. rolfsii ethylene glycol diheptanoate was found to be most active followed by diethylene glycol diisobutanoate As compared to the standard reference benomyl (EC50 5.16 μg/mL), the potential alkanediol dialkanoates showed EC50 in the range of 33 – 60 μg/mL.


1985 ◽  
Vol 15 (3) ◽  
pp. 187-190 ◽  
Author(s):  
E. J. Maria Florence ◽  
J. K. Sharma ◽  
K. V. Sankaran ◽  
C. Mohanan

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Savita Jandaik ◽  
Preeti Thakur ◽  
Vikas Kumar

The present study was conducted to determine antifungal activity of three different concentrations (5, 10, and 15%) of cow urine against three fungal pathogens (Fusarium oxysporum, Rhizoctonia solani, andSclerotium rolfsii) isolated from infected plants of Methi and Bhindi that showed symptoms of damping off and wilting disease by poison food technique. The extent of growth of test fungi in plates poisoned with cow urine was lesser when compared with the control plates. Among these concentrations cow urine at 15% concentration was most effective. When the three fungal organisms were compared, maximum growth suppression was observed inFusarium oxysporum(78.57%) at 15% concentration of cow urine followed byRhizoctonia solani(78.37%) andSclerotium rolfsii(73.84%). Finally we concluded that the cow urine has antifungal activities and the inhibitory activity can be used in the control of fungi. The nutritional effect of cow urine on plant growth was also tested withTrigonella foenum-graecum(Methi) andAbelmoschus esculentus(Bhindi) plants and the chlorophyll and protein content was also estimated.


1989 ◽  
Vol 16 (2) ◽  
pp. 76-82
Author(s):  
Gregory B. Parker ◽  
Olin D. Smith ◽  
W. James Grichar

Abstract Colorimetry was evaluated as a method to assess pod disease in peanuts (Arachis hypogaea L.) caused primarily by Pythium myriotylum Drechs., Sclerotium rolfsii Sacc., and Rhizoctonia solani Kuhn. Data analyzed were from nineteen replicated tests conducted from 1982 to 1987, exclusive of 1985, in three South Texas locations. Each plot was scored for pod disease colorimetrically and visually. A negative linear relationship (R2>96%) was found between Hunter color values (L and b) and percent infection measured visually for samples hand selected to approximate eleven disease levels varying from 0-100%. Variability among readings was less at extremes of infection. Correlation both between visual ratings and between visual and colorimetric ratings was affected by soil differences, pathogens infecting the pods, pod genotype, and level of infection present. Correlation among visual raters was generally higher than that between color value ratings. Two-thirds of the lines in these tests classified visually as being in the best 50% for pod disease were also in the best 50% according to colorimetric scores. Use of colorimetry in conjunction with a single visual rating was estimated to increase efficiency and reduce costs of evaluation compared to multiple visual ratings.


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