scholarly journals The Role of Salicylic Acid and Pseudomonas fluorescens in Systemic Resistance Against Rhizoctonia solani kühn in Guar (Cyamopsis tetragonoloba (l.) Taub.)

2017 ◽  
Vol 6 (1) ◽  
pp. 01-15
Author(s):  
Montaser F. Abdel-Monaim
Keyword(s):  
Salicylic Acid ◽  
Rhizoctonia Solani ◽  
Pseudomonas Fluorescens ◽  
Root Rot ◽  
Yield Components ◽  
Growth Parameters ◽  
Field Conditions ◽  
Systemic Resistance ◽  
Cyamopsis Tetragonoloba ◽  
Damping Off

Rhizoctonia solani was found to be associated with root rot symptoms of guar plants collected from different fields in New Valley governorate, Egypt. All the obtained isolates were able to attack guar plants (cv. Local) causing damping-off and root rot diseases. R. solani isolates No. 8 (RG8) was the more virulent ones in the pathogenicity tests. Salicylic acid (SA) and Pseudomonas fluorescens (PF) individually or in combination were examined for their potential in suppression damping-off and root rot and growth promotion of guar plants in vitro and in vivo. Both SA and P. fluorescens either individually or in combination inhibited the growth of the tested pathogenic fungi.SA combined with P. fluorescens recorded the highest inhibited growth followed by P. fluorescens alone. Under greenhouse and field conditions, all treatments significantly reduced damping-off and root rot severity. The combination of SA and P. fluorescens was more effective than using them individually.  Under field conditions, all these treatments significantly increased growth parameters (plant height and No. of branches plant-1) and yield components (No. of pods plant-1, weight of 100 seeds and total yield fed.-1 and Guaran content (gm plant-1) in both locations (El-Kharga and Mallawy Agric. Res. Stations) during growing season 2014.The combination of SA and P. fluorescens were recorded the highest growth parameters and yield components. Generally, the combination of SA and P. fluorescens recorded the best results for controlling damping-off and root rot diseases in greenhouse and field with addition improved plant growth and increased yield components in the field. In physiological studies, activity of defense-related enzymes, including peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), pathogenesis related (PR) protein (chitinase and β 1,3 gluconase), were increased in inoculated and non-inoculated plants treated with the SA and P. fluorescens either individually or in combination, during the experimental period. The combination of SA and P. fluorescens recorded the highest increase in activity of all enzymes.  In general, the activity of these enzymes begins to accumulate after two days of treatment and reached maximum levels at 6 to 10 days, then the activities of these enzymes were decreased progressively. On the other hand, total phenols and lignin increased in guar plants inoculated with R. solani and treated with SA and P. fluorescens individually or in combination. The highest accumulation of phenols was recorded 8th days from application, while lignin recorded the highest level at 10th days from application. In the end, these results suggested that SA and P. fluorescens either individually or in combination may play an important role in controlling the guar damping-off and root rot diseases, though they have induction of systemic resistance in guar plants.

scholarly journals Improvment Biocontrol of Damping-Off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide

2013 ◽  
Vol 2 (1) ◽  
pp. 14-24
Author(s):  
Montaser F. Abdel-Monaim
Keyword(s):  
Hydrogen Peroxide ◽  
Salicylic Acid ◽  
Faba Bean ◽  
Root Rot ◽  
Yield Components ◽  
Growth Parameters ◽  
Biocontrol Agents ◽  
Damping Off ◽  
Chemical Inducers ◽  
Bean Plants

Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina were found to be associated with root rot and wilt symptoms of faba bean plants collected from different fields in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride, Bacillus megaterium) and chemical inducers (salicylic acid and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promotion of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi.Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA+ B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/ wilt severity and increased survival of plants. Also, these treatments increased fresh and dry weights of the survived plants in pots compared with control.  The combination of biocontrol agents and chemical inducers were more effective than using them individually and SA+ T. viride was the best treatment in this respect. Under field conditions, all these treatments significantly increased growth parameters (plant height and No. of branches plant-1) and yield components (No. of pods and seedsplant-1, weight of 100 seeds and total yield feddan-1 and protein content in both seasons (2010-2011 and 2011-2012). Faba bean seeds soaked in SA+ T. viride and SA+ B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination of biocontrol agents and chemical inducers recoded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in the field. 

scholarly journals Sensitivity of Rhizoctonia solani AG-2-2 from Sugar Beet to Fungicides

Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
Sahar Arabiat ◽  
Mohamed F. R. Khan
Keyword(s):  
Sugar Beet ◽  
Rhizoctonia Solani ◽  
Root Rot ◽  
The United States ◽  
Damping Off ◽  
Growth Assay ◽  
The Mean ◽  
Crown And Root Rot ◽  
Mean Concentration

Rhizoctonia damping-off and crown and root rot caused by Rhizoctonia solani are major diseases of sugar beet (Beta vulgaris L.) worldwide, and growers in the United States rely on fungicides for disease management. Sensitivity of R. solani to fungicides was evaluated in vitro using a mycelial radial growth assay and by evaluating disease severity on R. solani AG 2-2 inoculated plants treated with fungicides in the greenhouse. The mean concentration that caused 50% mycelial growth inhibition (EC50) values for baseline isolates (collected before the fungicides were registered for sugar beet) were 49.7, 97.1, 0.3, 0.2, and 0.9 μg ml−1 and for nonbaseline isolates (collected after registration and use of fungicides) were 296.1, 341.7, 0.9, 0.2, and 0.6 μg ml−1 for azoxystrobin, trifloxystrobin, pyraclostrobin, penthiopyrad, and prothioconazole, respectively. The mean EC50 values of azoxystrobin, trifloxystrobin, and pyraclostrobin significantly increased in the nonbaseline isolates compared with baseline isolates, with a resistant factor of 6.0, 3.5, and 3.0, respectively. Frequency of isolates with EC50 values >10 μg ml−1 for azoxystrobin and trifloxystrobin increased from 25% in baseline isolates to 80% in nonbaseline isolates. Although sensitivity of nonbaseline isolates of R. solani to quinone outside inhibitors decreased, these fungicides at labeled rates were still effective at controlling the pathogen under greenhouse conditions.

scholarly journals Plant growth-promoting rhizobacteria induced resistance in Jatropha curcas through phenyl propanoid metabolism against Rhizoctoniabataticola

2017 ◽  
Vol 9 (1) ◽  
pp. 121-128
Author(s):  
S. Kumar ◽  
M. Singh ◽  
Sushil Sharma
Keyword(s):  
Plant Growth ◽  
Pseudomonas Fluorescens ◽  
Jatropha Curcas ◽  
Root Rot ◽  
Plant Growth Promoting Rhizobacteria ◽  
Systemic Resistance ◽  
Total Phenols ◽  
Phenyl Propanoid ◽  
Plant Growth Promoting ◽  
Growth Promoting

The root rot disease in Jatropha curcas L. caused by Rhizoctonia. bataticola (Taub.) Butler has been recorded in causing 10-12 per cent mortality of 20-30 days old seedlings of Jatropha curcasin southern Haryana. The incidence of this disease has also been observed from other parts of Haryana too. Induction of systemic resistance in host plants through microbes and their bioactive metabolites are attaining popularity in modern agricultural practices. Studies on the plant growth-promoting rhizobacteria induced resistance in Jatropha curcas through phenyl propanoid metabolism against Rhizoctoniabataticola were undertaken at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Three plant growth-promoting rhizobacteria (PGPRs) viz., Pseudomonas maltophila, Pseudomonas fluorescens and Bacillus subtilis were evaluated for their potential to induce systemic resistance in Jatropha against root rot. The maximum increase of 97 per cent in total phenols, 120 per cent in peroxidase, 123 per cent in polyphenol oxidase, 101 per cent in phenylalanine ammonia lyase and 298 per cent in tyrosine ammonia lyase was detected in plants raised with Pseudomonas fluorescens+ Rhizoctoniaba-taticola inoculation in Jatropha curcas at 10 days post inoculation against control except total phenols where it was maximum (99%) at 30 DPI. There was slight or sharp decline in these parameters with age irrespective of inoculations. The pathogen challenged plants showed lower levels of total phenols and enzymes. The observations revealed that seed bacterization with Pseudomonas fluorescens results in accumulation of phenolics and battery of enzymes in response to pathogen infection and thereby induce resistance systemically.

scholarly journals Potential of Pseudomonas putida, Bacillus subtilis, and their mixture on the management of Meloidogyne incognita, Pectobacterium betavasculorum, and Rhizoctonia solani disease complex of beetroot (Beta vulgaris L.)

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Manzoor R. Khan ◽  
Zaki A. Siddiqui
Keyword(s):  
Bacillus Subtilis ◽  
Rhizoctonia Solani ◽  
Pseudomonas Putida ◽  
Beta Vulgaris ◽  
Meloidogyne Incognita ◽  
Root Rot ◽  
Growth Parameters ◽  
Principal Component ◽  
Soft Rot ◽  
Disease Complex

AbstractEffects of Pseudomonas putida and Bacillus subtilis alone, and in combinations for the management of Meloidogyne incognita, Pectobacterium betavasculorum, and Rhizoctonia solani disease complex of beetroot (Beta vulgaris L.), were studied. Application of P. putida or B. subtilis to plants with M. incognita or P. betavasculorum or R. solani singly or in combinations caused a significant increase in plant growth parameters and the activities of defense enzymes. A significant increase in chlorophyll fluorescence attributes, viz., Fv/Fm, ɸPSII, qP, NPQ, and ETR were recorded in plants treated with P. putida or B. subtilis over pathogen-inoculated plants. Inoculation of P. putida results in a higher reduction in galling and nematode multiplication than B. subtilis. Maximum reduction in nematode multiplication and galling occurred when a mixture of P. putida and B. subtilis was used. Soft rot and root rot indices were 3 when Pectobacterium betavasculorum and Rhizoctonia solani were inoculated alone. The disease indices were rated 5 when these pathogens and M. incognita were inoculated in combinations. Inoculation of P. putida/B. subtilis with P. betavasculorum or R. solani reduced soft rot and root rot indices to 2 out of 3, while the use of P. putida + B. subtilis reduced indices to 1. Disease indices were reduced to 2–3 out of 5, when P. putida + B. subtilis were used to plants inoculated with two or three pathogens. The principal component analysis showed significant correlations among the various studied attributes. Two principal components explained a total of 86.1 and 93.4% of the overall data variability. Therefore, the use of P. putida together with B. subtilis had the potential for successful management of disease complex of beetroot.

scholarly journals Biology and control of Rhizoctonia solani on rapeseed : A Review

2005 ◽  
Vol 77 (3) ◽  
pp. 99-111 ◽  
Author(s):  
P.R. Verma
Keyword(s):  
Rhizoctonia Solani ◽  
Root Rot ◽  
Plant Root ◽  
The United States ◽  
Damping Off ◽  
High Soil Moisture ◽  
Breeding Programmes ◽  
Phosphorus And Potassium ◽  
Moderate Resistance ◽  
And Control

Rhizoctonia solani AG2-1 is the principal pathogen causing damping-off and seedling and mature plant root rot (brown girdling root rot) in oilseed rape and canola (Brassica napus and B. rapa) in western Canada and the United States; AG4 isolates mainly attack adult plants and cause basai stem rot. Seedling infection by AG2-1 is favoured by cool weather atthe time of planting, whereas warm weather late in the growing season is more conducive for infection of mature plants by AG4 isolates. Survey data show that disease development is favoured by high soil moisture, low levels of nitrogen, phosphorus and potassium and high levels of copper in fine-textured soils. Moderate resistance in condiment mustard (Sinapis alba) and some other species appears to be genetically controlled and should be utilised in breeding programmes. Carboxin and iprodione in mixtures with insecticide gamma-HCH are recommended in Canada as seed treatments to control damping-off and seedling root rot, but do not control brown girdling root rot.

scholarly journals Induction of Systematic Resistance in Soybean Plants against Fusarium Wilt Disease by Seed Treatment with Benzothiadiazole and Humic Acid

2011 ◽  
Vol 3 (2) ◽  
pp. 80-89 ◽  
Author(s):  
Montaser Fawzy ABDEL-MONAIM ◽  
Mamdoh Ewis ISMAIL ◽  
Kadry Mohamed MORSY
Keyword(s):  
Humic Acid ◽  
Growth Parameters ◽  
Soybean Seed ◽  
Total Phenol ◽  
Oxidative Enzymes ◽  
Systemic Resistance ◽  
Damping Off ◽  
Seed Soaking ◽  
Soybean Cultivars ◽  
Soybean Plants

The ability of benzothiadiazole (BTH), humic acid (HA) and their combination when used as seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Both inducers and their combination were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations i. e Minia and New Valley governorates. The tested treatments significantly reduced damping-off and wilt diseases and increased growth parameters, except number of branches plant-1, and seed yield. Application of BTH (0.25) + HA (4 g/l) was the most potent in this respect treatment. Soybean seed soaking in BTH+ HA recorded the highest activities of the testes of oxidative enzymes followed by BTH in the four soybean cultivars. Whereas, HA treatment was recorded the lowest increased of these oxidative enzymes. Also, similar results were obtained in case of total phenol but HA increased the total phenol more than BTH in all tested cultivars.

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