In-vitro bioefficacy of fungal antagonists against root rot of Pea caused by Rhizoctonia solani (Kuhn)

2018 ◽  
Vol 3 (02) ◽  
pp. 166-170
Author(s):  
Safdar Kaiser Hasmi ◽  
R. U. Khan

In-vitro effectiveness of various antagonistic fungi namely Aspergillus niger, A. flavus, Trichoderma koningii, T. atroviride, and T. harzianum were evaluated against Rhizoctonia solani by dual culture technique on potato dextrose agar. According to the observation recorded after 5 days, all the treatments were found to be superior over control (R. solani), but among all treatments A. niger was found to the most effective antagonist, with highest radial growth inhibition of the pathogen (77.01 percent), followed by A. flavus, T. harzianum and T. koningii i.e., 66.23, 64.42 and 62.20 percent. While as, T. atroviride was found to be the least effective one with minimum growth inhibition i.e., 42.21 percent. Whereas, at the same time control (R. solani) showed 100 percent radial growth and covered the whole Petri Plate within 5 days. All the bio-control agents were significantly effective to inhibit the sclerotia formation and development, except T. atroviride in which formation of sclerotia was recorded, while in all other treatments complete inhibition of sclerotia formation was recorded after 10 days of incubation.

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
E. K. Wanjiku ◽  
J. W. Waceke ◽  
J. N. Mbaka

Demand for organic avocado fruits, together with stringent food safety standards in the global market, has made producers to use alternative, safe, and consumer-friendly strategies of controlling the postharvest fungal disease of avocado fruits. This study assessed the in vitro efficacy of Trichoderma spp. (T. atroviride, T. virens, T. asperellum, and T. harzianum) against isolated avocado stem-end rot (SER) fungal pathogens (Lasiodiplodia theobromae, Neofusicoccum parvum, Nectria pseudotrichia, and Fusarium solani) using a dual culture technique. The Trichoderma spp. were also evaluated singly on postharvest “Hass” avocado fruits. Spore suspension at 5 × 104 conidial/ml of the Trichoderma spp. was applied on the avocado fruits at three time points, twenty-four hours before the fungal pathogen (preinoculation), at the same time as the fungal pathogen (concurrent inoculation), and 24 hours after the fungal pathogen (postinoculation). In the in vitro study, T. atroviride showed the highest mycelial growth inhibition against N. parvum (48%), N. pseudotrichia (55%), and F. solani (32.95%), while T. harzianum had the highest mycelial growth inhibition against L. theobromae. Trichoderma asperellum was the least effective in inhibiting the mycelial growth of all the pathogens. Similarly, T. virens showed the highest mycelial growth inhibition against N. pseudotrichia at 45% inhibition. On postharvest “Hass” fruits, T. atroviride showed the highest efficacy against N. parvum, N. pseudotrichia, and F. solani in all the applications. Trichoderma virens and T. harzianum were most effective against all the pathogens during postinoculation, while Lasiodiplodia theobromae was best controlled by T. virens, T. harzianum, and T. asperellum during postinoculation. Both T. atroviride and T. harzianum present a potential alternative to synthetic fungicides against postharvest diseases of avocado fruits, and further tests under field conditions to be done to validate their efficacy. The possibility of using Trichoderma spp. in the management of SER on avocado fruits at a commercial level should also be explored.


2007 ◽  
Vol 53 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Naveen Kumar Arora ◽  
Min Jeong Kim ◽  
Sun Chul Kang ◽  
Dinesh Kumar Maheshwari

A study was conducted to investigate the possibility of involvement of chitinase and β-1,3-glucanase of an antagonistic fluorescent Pseudomonas in growth suppression of phytopathogenic fungi, Phytophthora capsici and Rhizoctonia solani . Fluorescent Pseudomonas isolates GRC3 and GRC4 were screened for their antifungal potential against phytopathogenic fungi by using dual culture technique both on solid and liquid media. The percent inhibition was calculated. Various parameters were monitored for optimization of enzyme activities by fluorescent Pseudomonas GRC3. The involvement of chitinases, β-1,3-glucanases, and antifungal metabolites of nonenzymatic nature was correlated with the inhibition of P. capsici and R. solani. The results provide evidence for antibiosis as a mechanism for antagonism. The study also confirms that multiple mechanisms are involved in suppressing phytopathogens as evidenced by the involvement of chitinase and β-1,3-glucanase in inhibition of R. solani but not P. capsici by isolate GRC3.


Weed Science ◽  
2012 ◽  
Vol 60 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Kelly A. Barnett ◽  
Christy L. Sprague ◽  
William W. Kirk ◽  
Linda E. Hanson

Previous greenhouse studies with a noncommercial glyphosate-resistant sugarbeet variety indicated that susceptibility to Rhizoctonia crown and root rot could increase after glyphosate was applied. Greenhouse and field experiments were conducted in 2008 and 2009 to determine if glyphosate influenced disease severity in potential commercially available varieties of glyphosate-resistant sugarbeet. In the first greenhouse experiment in 2008, Hilleshög 9027RR, the most tolerant variety to Rhizoctonia crown and root rot, exhibited an increase in disease severity when glyphosate was applied. There were no significant differences between herbicide treatments in Hilleshög 9028RR, and glyphosate decreased disease severity in Hilleshög 9032RR when compared with the no-herbicide treatment. Experiments conducted to determine if glyphosate influenced Rhizoctonia solani growth in vitro indicated that glyphosate did not increase the radial growth of R. solani, except at 10× (190 µg ae ml−1) the normal rate of glyphosate plus ammonium sulfate (AMS). Field and additional greenhouse experiments were conducted using four commercial varieties. Differences in disease severity were observed when comparing varieties, but glyphosate did not significantly influence the severity of Rhizoctonia crown and root rot when compared with the no-herbicide control. Choosing a glyphosate-resistant sugarbeet variety with the best demonstrated tolerance to Rhizoctonia crown and root rot is an important factor in reducing disease severity and maintaining sugarbeet yield.


2019 ◽  
Vol 5 (01) ◽  
pp. 133-137
Author(s):  
Rashmi S. Nigam ◽  
R. U. Khan ◽  
Reshu Singh ◽  
Joginder Singh

Pea (Pisum sativum) is an important leguminous crop in many countries including India. Wilt and root rot of pea is an important and widespread disease that often causes significant reduction in the yield and quality of harvested peas throughout the production areas. It is the most important and widespread disease of pea grown in relatively dry and warm area. In-vitro effectiveness of various antagonistic fungal isolates namely T. harzianum (Th1, Th2, Th3, Th4 and Th5) was evaluated against Fusarium oxysporum f. sp. pisi, Rhizoctonia solani and Pythium ultimum by dual culture technique on potato dextrose agar. According to the observation recorded after 5 days, all the rhizospheric fungal isolates evaluated for their antagonistic potential against wilt and root-rot pathogens, exhibited significant effect on radial growth inhibition of pathogens in comparison to control. Among the fungal isolates, Th3 and Th5 of T. harzianum proved to be most effective in reducing the growth of F. oxysporum f. sp. pisi, R. solani and P. ultimum. It was worthy to note that all rhizospheric fungal isolates visualized an increase in their antagonistic potential over the period of time in subsequent hours of inoculation.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1162
Author(s):  
Ahmed A. Heflish ◽  
Ahmed Abdelkhalek ◽  
Abdulaziz A. Al-Askar ◽  
Said I. Behiry

Two molecularly identified tomato isolates, Trichoderma asperelloides Ta41 and Rhizoctonia solani Rs33, were characterized and antagonistically evaluated. The dual culture technique showed that Ta41 had a high antagonistic activity of 83.33%, while a light microscope bioassay demonstrated that the Ta41 isolate over-parasitized the pathogen completely. Under greenhouse conditions, the application of Ta41 was able to promote tomato plant growth and had a significant increase in plant height, root length, and shoot fresh, shoot dry, root fresh, and root dry weight. It also improved chlorophyll content and total phenol content significantly, both in protective and in curative treatments. The protective treatment assay exhibited the lowest disease index (16.00%), while the curative treatment showed a disease index of 33.33%. At 20 days post-inoculation, significant increases in the relative expression levels of four defense-related genes (PR-1, PR-2, PR-3, and CHS) were observed in all Ta41-treated plants when compared with the non-treated plants. Interestingly, the plants treated with Ta41 alone showed the highest expression, with relative transcriptional levels of CHS, PR-3, PR-1, and PR-2 that were, compared with the control, 3.91-, 3.13-, 2.94-, and 2.69-fold higher, respectively, and the protective treatment showed relative transcriptional levels that were 3.50-, 3.63-, 2.39-, and 2.27-fold higher, respectively. Consequently, the ability of Ta41 to promote tomato growth, suppress Rs33 growth, and induce systemic resistance supports the incorporation of Ta41 as a potential bioagent for controlling root rot disease and increasing the productivity of crops, including tomatoes.


2018 ◽  
Vol 12 (1) ◽  
pp. 131-147 ◽  
Author(s):  
Gedyon Tamiru ◽  
Diriba Muleta

Objective:Evaluate for potential biocontrol agent by assessing isolates forin vitroinhibitory efficacy, probable mechanisms to inhibit fungal pathogen and effect on growth of Faba bean infected withF. solani.Methods:The effect of Rhizobium isolates on the development of radial mycelium ofF. solaniin PDA medium were testedin vitro. The experiments were carried out using the dual culture technique. Isolates that showed inhibitory effect againstF. solaniin vitrowere tested to assess hydrolytic enzymes and growth promoting traits. Subsequently, the three Rhizobium isolates that showed the greatest inhibitions and their combinations were tested in the greenhouse againstF. solaniroot rot on seedlings by applying cell suspensions at three different times of exposure to the pathogen.Results:In dual culture, 27 rhizobium isolates inhibited the radial growth ofF. solanimycelium more than 25%. Isolates JU26(1), JU15(2) and Ho-1WG, inhibited fungal radial growth by 70.5 %, 64.7% and 63.7%, respectively. Among the 27 Rhizobium isolates tested for hydrolytic enzymes 26.1%, 44.4%, 14.8% were positive for chitinase, protease and lipase production, respectively. Chitinase, protease and lipase positive isolates showed significant fungal mycelia inhibition. Eight (29.6%) were positive for hydrogen cyanide production. Also, 24(88.8%) were positive for IAA production and over 50% formed visible dissolution haloes on PA. Concurrent production of protease, lipases, chitinase, IAA and phosphate solubilization coupled with anti-fungal activity suggests potential plant growth promotion and broad-spectrum bio control of these isolates. Furthermore, combination and Ho-1WG consistently reduced disease incidence and severity; and increased growth parameters on seedling in greenhouse at all times of application compared to diseased (control). Maximum disease severity (73.3%) reduction was observed with application of combination before the pathogen. The combination formulation provided the highest (48 cm/plant) shoot height when applied before the pathogen.Conclusion:Beneficial traits strongly assist the efficiency of candidate antagonists for desired biocontrol, emphasizing the value of concerted mechanisms of action. The result indicated the possible use of Rhizobial isolates as an alternative means of BRR management but further study is needed to verify actual use in agricultural production.


2020 ◽  
Vol 73 (4) ◽  
pp. 787-792
Author(s):  
Alyssa Swehla ◽  
Abhay K. Pandey ◽  
Ramakrishnan M. Nair

AbstractIn the rice-fallow system, dry root rot (DRR) is an emerging disease of mungbean (Vigna radiata (L.) R. Wilczek var. radiata) caused by the necrotrophic fungus Macrophomina phaseolina. The pathogen causes extensive production losses. In this study, the bioactivity of four Trichoderma harzianum isolates, namely Th-Dharwad, Th-Raichur, Th-Niphm, and Th-Udaipur procured from the Indian research institutes were evaluated against M. phaseolina of mungbean by the dual culture technique. The efficacy of these T. harzianum isolates were also compared with the effective fungicides such as thiram and carbendazim by the poison food method. Results showed that among the T. harzianum isolates, isolate of Th-Raichur was most effective, exhibiting 76.96% mycelial growth inhibition of the test pathogen. As compared to the thiram, carbendazim was more effective, and exhibited 100% mycelial growth inhibition of the test pathogen. In addition, carbendazim was also more effective than the isolate of Th-Raichur. In the sick pot experiment, mungbean seeds treated with Th-Raichur isolate showed a lower percent incidence of DRR (20%) than the untreated seeds (86.6%). The biological spectrum of Th-Raichur isolate was examined against M. phaseolina isolated from the different hosts such as urdbean and vegetable soybean, alongwith two other root pathogens, namely Fusarium solani of mungbean, and Sclerotium rolfsii of urdbean. The isolate of Th-Raichur showed maximum antagonistic activity against the pathogens M. phaseolina and F. solani of mungbean. Thus, Th-Raichur isolate can be used as a potential fungal biocontrol agent for the reduction of DRR in mungbean.


Author(s):  
Ma. Ángeles Valencia de Ita ◽  
Jiménez Huerta Fátima ◽  
Conrado Parraguirre Lezama ◽  
Alfredo Báez Simón ◽  
Gerardo Landeta Cortés ◽  
...  

Diversity of the different types of chilies in Mexico has been scarcely studied, and a large variety have been found to be, such as Manzano chili. Root rot caused by oomycete Phytophthora capsici is a severe disease that affects Manzano chili production in Mexico, detracted from its production and quality. The use of biological control agents such as Trichodermanative’s species, represents an efficient alternative to reduce losses and control the disease. For this reason, the objective of the present investigation was to evaluate the antagonistic effect in vitro and in vivo of four native strains of Trichoderma spp., on Phytophthora capsici in seedlings of Manzano chili from Puebla-Mexico was evaluated. Dual culture technique was used to determine the percentage of inhibition of radial growth (PICR) of the PC-A strain of P. capsici. Analysis of the percentage of germination was also carried out, as well as the incidence of root rot at 20 days after inoculation with the pathogen (dai) in the nursery. T. harzianum strain presented the highest PICR (42.86%) of antagonistic level in vitro and class I in the Bell scale, in addition, it obtained 88% germination in the nursery and 10% mortality at 20 dai, higher than the other native strains of Trichoderma. The bio-controlling effect of strains of Trichoderma spp., offers an effective alternative for root necrosis caused by P. capsici in the cultivation of Manzano chili in Puebla-Mexico.


2010 ◽  
Vol 50 (3) ◽  
pp. 239-243 ◽  
Author(s):  
Abdulaziz Al-Askar ◽  
Younes Rashad

Efficacy of Some Plant Extracts AgainstRhizoctonia Solanion PeaAntifungal activity of ethanol-water extracts of four medicinal plants, cinnamon (Cinnamomum verumPresl.), anise (Pimpinella anisumL.), black seed (Nigella sativaL.) and clove (Syzygium aromaticumL. Merr. & Perry.) was investigated against pea (Pisum sativumL.) root-rot fungusRhizoctonia solani. In vitroantifungal activity test shown a high growth inhibition at concentration (4%) of each plant extract. The highest antifungal activity was recorded for clove extract which causes complete growth inhibition at concentration of 1%. Efficacy of clove extract on disease incidence ofRhizoctoniaroot-rot of pea was investigated in the greenhouse pot experiment. Clove extract at concentration 4% as well as the chemical fungicide recorded highly significant increase in the percentage of survived plants (40 and 48%, respectively) and highly significant decrease in disease incidence.


Author(s):  
V. I. Gwa ◽  
A. O. Nwankiti ◽  
E. J. Ekefan

In vitro antagonistic study using dual culture technique was carried out at Advanced Plant Pathology Laboratory, Federal University of Agriculture, Makurdi, Nigeria to assess the potential capability of Trichoderma harzianum as a biocontrol agent against Aspergillus niger isolated from rotten yam tubers. The test antagonist (T. harzianum) was introduced at three different times (same time with pathogen, two days before the inoculation of the pathogen and two days after the inoculation of the pathogen). The plates were incubated for 192 hours and measurements of mycelial radial growths were recorded at intervals of 24 hours beginning from the third day. The results of in vitro interactions between T. harzianum and A. niger revealed that T. harzianum was able to significantly (P ≤ 0.05) inhibit the growth of A. niger at the three different times of introduction of T. harzianum and this increased with the time of incubation. T. harzianum grew faster than A. niger and produced inhibition zones which completely stopped the growth of A. niger. Mean percentage growth inhibition was found to be highest (77.79%) when T. harzianum was introduced 2 days before inoculation of A. niger followed by  introduction of T. harzianum same with A. niger (45.96%). The least percentage growth inhibition (28.47%) was recorded when T. harzianum was introduced 2 days after inoculation of A. niger. In all cases, T. harzianum was observed to be effective at checking the growth of A. niger in vitro and therefore showed the capability for the biological control of the pathogen. It is therefore recommended that for effective in-vitro control of A. niger, T. harzianum should be introduced 2 days before the arrival of A. niger.


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