scholarly journals In vitro Efficacy of Native Trichoderma Isolates against Pythium spp. and Rhizoctonia solani (Kuhn.) causing Damping-off Disease in Tomato (Solanum lycopersicum Miller)

2019 ◽  
Vol 8 (02) ◽  
pp. 566-579 ◽  
Author(s):  
Markidahun Biam ◽  
Dipali Majumder ◽  
Heipormi Papang
Keyword(s):  
Rhizoctonia Solani ◽  
Solanum Lycopersicum ◽  
Damping Off ◽  
Trichoderma Isolates

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 Rapid Screening of Rhizobacteria for Suppression of Rhizoctonia Damping-off

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 468B-468
Author(s):  
J.O Becker ◽  
U.K. Schuch
Keyword(s):  
Rhizoctonia Solani ◽  
Raphanus Sativus ◽  
Soil Samples ◽  
Rapid Screening ◽  
Agricultural Crops ◽  
Screening System ◽  
Damping Off ◽  
Bacterial Strains ◽  
Second Tier

A rapid screening system was developed to identify plant-beneficial rhizobacteria useful in protecting nursery seedlings against damping-off caused by Rhizoctonia solani. Ornamental and agricultural crops were planted into 100 soil samples that were collected from various fields throughout California. More than 7000 bacterial strains from the rhizosphere of these crops were isolated and tested in vitro for antibiosis against R. solani AG4. In a second tier, 600 active strains were tested in planting trays seeded with radish (Raphanus sativus `Cherry Belle'). Each planting cell filled with commercial potting mix contained millet-grown R. solani inoculum in the center and eight radish seeds at the periphery. Bacteria were cultured for 24 hr at 25°C in 10% tryptic soy broth and were applied as a drench at 1 × 107 cfu/cc to each cell. Trays were incubated in a growth chamber at 21°C and a 10-hr photoperiod. Post-emergence damping-off occurred within 8 to 9 days after planting, and no further losses were observed after 14 days. Approximately 0.5% of the original 7000 bacterial strains tested reduced damping-off significantly. Fifteen bacterial strains controlled Rhizoctonia damping-off by 30% to 60% compared to the non-treated control.

scholarly journals Isolation of antagonistic fungi from rhizospheres and its biocontrol activity against different isolates of soil borne fungal pathogens infected legumes

2019 ◽  
Vol 20 (7) ◽  
Author(s):  
ERIYANTO YUSNAWAN ◽  
ALFI INAYATI ◽  
YULIANTORO BALIADI
Keyword(s):  
Rhizoctonia Solani ◽  
Fungal Pathogens ◽  
In Vitro Study ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Antagonistic Fungi ◽  
Biocontrol Activity ◽  
Fusarium Sp ◽  
Trichoderma Isolates

Abstract. Yusnawan E, Inayati A, Baliadi Y. 2019. Isolation of antagonistic fungi from rhizospheres and its biocontrol activity against different isolates of soil borne fungal pathogens infected legumes. Biodiversitas 20: 2048-2054. Soilborne diseases caused by Rhizoctonia solani and Fusarium sp. are biotic limits for legume production. Biological controls offer environmental friendly control for these pathogens. This study aimed to isolate and screen Trichoderma from different rhizospheres and to obtain effective Trichoderma isolates to suppress in vitro growth of the soil borne pathogens. The antagonistic inhibitory activity was performed by dual culture method. Seven out of forty indigenous Trichoderma isolates collected from East Java, Indonesia effectively suppressed the growth of different fungal isolates, namely Rhizoctonia solani (R.s1), R. solani (R.s2) as well as Fusarium sp. which infected soybean and mung bean. In vitro study showed different suppression of the pathogens on dual culture tests. The seven isolates inhibited the growth of R. solani (R.s1), R.solani (R.s2) and Fusarium sp. ranging from 90.0 to 99.6%, 72.8 to 82.4%, and 67.9 to 90.8%, respectively. Isolate origin and genetic variability of Trichoderma played an important role in the antagonistic activity. The fast-growing of selected Trichoderma showed their abilities for space occupation and nutrition competition, which involved in the antagonistic activity. The mycelial growth of Trichoderma over pathogens showed hyperparasitism mechanism. In addition, coiling of Trichoderma over hyphal pathogens was observed during microscopic observation. The seven Trichoderma isolates, therefore, are promising as biological control agents against the soil borne fungi infected legumes.

The influence of temperature on the exudation of nutrients from cotton seeds and on preemergence damping-off by Rhizoctonia solani

1969 ◽  
Vol 47 (11) ◽  
pp. 1663-1669 ◽  
Author(s):  
D. S. Hayman
Keyword(s):  
Amino Acids ◽  
Rhizoctonia Solani ◽  
Physiological Age ◽  
Inoculum Potential ◽  
Damping Off ◽  
Seed Exudate ◽  
Influence Of Temperature On ◽  
Cotton Seeds ◽  
Total Amino Acids

Evidence is presented suggesting that increased seed exudation is a major factor contributing to increased preemergence damping-off of cotton seedlings by Rhizoctonia solani at low temperatures.About seven and three times as much total amino acids and sugars were exuded at 18 and 24 °C, respectively, as at 30 °C, by germinating cotton seeds of equivalent physiological age. Sixteen amino acids and five sugars were exuded. Seed exudation is not related to rate of germination or to respiration.Accumulation of seed exudate at low temperatures was related to increased pathogenesis in vitro and in soil. This appeared to be because R. solani competitively used this exudate to increase its inoculum potential near the germinating seed, thereby becoming more virulent on the susceptible juvenile tissues of the seedling.

scholarly journals Maple Bark Biochar Affects Rhizoctonia solani Metabolism and Increases Damping-Off Severity

2015 ◽  
Vol 105 (10) ◽  
pp. 1334-1346 ◽  
Author(s):  
Tanya R. Copley ◽  
Konstantinos A. Aliferis ◽  
Suha Jabaji
Keyword(s):  
Rhizoctonia Solani ◽  
Plant Species ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Primary Metabolism ◽  
Damping Off ◽  
Biochar Amendment

Many studies have investigated the effect of biochar on plant yield, nutrient uptake, and soil microbial populations; however, little work has been done on its effect on soilborne plant diseases. To determine the effect of maple bark biochar on Rhizoctonia damping-off, 11 plant species were grown in a soilless potting substrate amended with different concentrations of biochar and inoculated or not with Rhizoctonia solani anastomosis group 4. Additionally, the effect of biochar amendment on R. solani growth and metabolism in vitro was evaluated. Increasing concentrations of maple bark biochar increased Rhizoctonia damping-off of all 11 plant species. Using multivariate analyses, we observed positive correlations between biochar amendments, disease severity and incidence, abundance of culturable bacterial communities, and physicochemical parameters. Additionally, biochar amendment significantly increased R. solani growth and hyphal extension in vitro, and altered its primary metabolism, notably the mannitol and tricarboxylic acid cycles and the glycolysis pathway. One or several organic compounds present in the biochar, as identified by gas chromatography-mass spectrometry analysis, may be metabolized by R. solani. Taken together, these results indicate that future studies on biochar should focus on the effect of its use as an amendment on soilborne plant pathogens before applying it to soils.

scholarly journals INIBIÇÃO MICELIAL in vitro DE Rhizoctonia solani CAUSADOR Damping-off EM ALFACE COM USO DE Trichoderma asperellum

2017 ◽  
Author(s):  
WALDINEY Xavier Ferreira ◽  
ALINE Figueiredo Cardoso ◽  
CASSIA Cristina Chaves Pinheiro ◽  
TELMA Fatima Vieira Batista ◽  
GISELE Barata da Silva
Keyword(s):  
Rhizoctonia Solani ◽  
Trichoderma Asperellum ◽  
Damping Off

Relationship between in vitro growth inhibition of pathogens and suppression of preemergence damping-off and postemergence root rot of white bean seedlings in the greenhouse by bacteria

1994 ◽  
Vol 40 (2) ◽  
pp. 113-119 ◽  
Author(s):  
M. S. Reddy ◽  
R. K. Hynes ◽  
G. Lazarovits
Keyword(s):  
Rhizoctonia Solani ◽  
Disease Severity ◽  
Fusarium Solani ◽  
Root Rot ◽  
Culture Media ◽  
Pythium Ultimum ◽  
Damping Off ◽  
Bacterial Strains ◽  
White Bean

One hundred and twenty diverse bacterial strains were screened under greenhouse conditions for their ability to protect white bean seedlings from preemergence damping-off caused by Pythium ultimum and Rhizoctonia solani and postemergence root rot by Fusarium solani f.sp. phaseoli. Preemergence mortality or root rot increased with an increase in the inoculum concentration of fungal isolates. For further testing, 200 propagules/g soil of P. ultimum, 3 propagules/g soil of R. solani, and log 3 conidia/g vermiculite of F. solani f.sp. phaseoli were used, as these rates provided an optimal level (approximately 50%) of disease severity. Bacterial strains suspended in sterile distilled water were added to pathogen-amended soil or vermiculite at log 7 colony-forming units/g soil or vermiculite prior to seeding. Final healthy stand and root rot were recorded 4 weeks after planting. Nine bacterial strains on P. ultimum, five on R. solani, and nine on F. solani f.sp. phaseoli provided significant (P = 0.05) suppression of disease severity compared with the nonbacterized control. Bacterial strains were also tested in vitro against the mycelial growth of the fungi on solid and liquid media. There was no relationship between the ability of bacterial strains to inhibit fungal vegetative growth on solid culture media and their ability to suppress pathogen activity in the greenhouse, but, for a few strains, the reduction in disease was linked to reduced growth of the pathogens in liquid media.Key words: White bean, damping-off, root rot, Pythium ultimum, Rhizoctonia solani, Fusarium solani f.sp. phaseoli.

scholarly journals Effect of soil fungi communities on the growth of damping-off pathogens in relation to incubation temperature and medium pH

2014 ◽  
Vol 35 (2) ◽  
pp. 275-290 ◽  
Author(s):  
Małgorzata Kacprzak ◽  
Małgorzata Mańka
Keyword(s):  
Rhizoctonia Solani ◽  
Soil Fungi ◽  
Incubation Temperature ◽  
Fusarium Avenaceum ◽  
Trichoderma Atroviride ◽  
Forest Nursery ◽  
Damping Off ◽  
Medium Ph ◽  
Saprotrophic Fungi

Four communities of saprotrophic fungi from a forest nursery soil were tested for their effect on the <i>in vitro</i> growth of damping-off pathogens: <i>Rhizoctonia solani, Fusarium avenaceum, F. culmorum, F. oxysporum</i> and <i>F. solani</i> in relation to incubation temperature (5, 10, 15, 20 or 25°C) and medium pH (4.3; 5.6 or 7.5). The soil fungi communities weakly suppressed the growth of pathogens studied only at the lower temperatures (5 or 10°C). At the higher temperatures the communities tested supported the growth of all pathogens. The supporting effct was increasing with the increase of temperature, independently of pH. The effect was highly dependent on incubation temperature and not dependent on medium pH (P<0.05, analysis of variance). Duncan's multiple range tests indicate no significant differences (in the majority of combinations) in the effect of soil fungi communities on the <i>in vitro</i> growth of tested pathogens between temperatures 15, 20 and 25°C, independently of medium pH. The growth of the pathogens studied was suppressed mainly by: <i>Gliocladium catenulatum, Trichoderma atroviride, T. koningii, T. viride, Truncalella truncata<i> and <i>Zygorrhynchus moelleri</i>

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