scholarly journals Control of lettuce bottom rot by isolates of Trichoderma spp

2014 ◽  
Vol 40 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Zayame Vegette Pinto ◽  
Matheus Aparecido Pereira Cipriano ◽  
Amaury da Silva dos Santos ◽  
Ludwig Heinrich Pfenning ◽  
Flávia Rodrigues Alves Patrício

Bottom rot, caused by Rhizoctonia solani AG 1-IB, is an important disease affecting lettuce in Brazil, where its biological control with Trichoderma was not developed yet. The present study was carried out with the aim of selecting Trichoderma isolates to be used in the control of lettuce bottom rot. Forty-six Trichoderma isolates, obtained with baits containing mycelia of the pathogen, were evaluated in experiments carried out in vitro and in vivo in a greenhouse in two steps. In the laboratory, the isolates were evaluated for their capabilities of parasitizing and producing toxic metabolic substances that could inhibit the pathogen mycelial growth. In the first step of the in vivo experiments, the number and the dry weight of lettuce seedlings of the cultivar White Boston were evaluated. In the second step, 12 isolates that were efficient in the first step and showed rapid growth and abundant sporulation in the laboratory were tested for their capability of controlling bottom rot in two repeated experiments, and had their species identified. The majority of the isolates of Trichoderma spp. (76%) showed high capacity for parasitism and 50% of them produced toxic metabolites capable of inhibiting 60-100% of R. solani AG1-IB mycelial growth. Twenty-four isolates increased the number and 23 isolates increased the dry weight of lettuce seedlings inoculated with the pathogen in the first step of the in vivo experiments.In both experiments of the second step, two isolates of T. virens, IBLF 04 and IBLF 50, reduced the severity of bottom rot and increased the number and the dry weight of lettuce seedlings inoculated with R. solani AG1-IB. These isolates had shown a high capacity for parasitism and production of toxic metabolic substances, indicating that the in vitro and in vivo steps employed in the present study were efficient in selecting antagonists to be used for the control of lettuce bottom rot.

2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.


2018 ◽  
Vol 10 (9) ◽  
pp. 373
Author(s):  
Jose R. M. Campos Neto ◽  
Leonardo de J. M. G. de Oliveira ◽  
Nathalia B. Diniz ◽  
Ivaneide de O. Nascimento ◽  
Antonia Alice C. Rodrigues

To study the effects of resistance inducers used to control fusarium wilt in tomatoes due to the fungus Fusarium oxysporum Schlecht f. sp. lycopersici, we evaluated the effects of ASM (acibenzolar-S-methyl), Agro-Mos, chitosan, Biopirol and neem oil on F. oxysporum f. sp. lycopersici mycelial growth and sporulation and systemic resistance in tomatoes. In vitro experiments comprised evaluations of the products’ effects on the mycelial growth and sporulation of the PDA (potato dextrose agar) growth medium-cultured pathogen. In vivo experiments included product application to tomato plants of the Santa Cruz cultivar that were grown for 25 days on autoclaved soil, followed by determinations of disease severity and peroxidase, polyphenol oxidase and Beta-1,3-glucanase enzyme activity levels, which are related to the process of resistance induction. Pathogen inoculation occurred after 5 days at a concentration of 106 conidia/mL. We evaluated the disease according to a rating scale. Enzymatic activity was determined according to specific protocols. Neem oil controlled pathogen mycelial growth and sporulation, while ASM influenced sporulation. The products reduced the severity of wilt in the plants. We highlight neem oil, Agro-Mos and Biopirol due to their ability to induce significant peroxidase, polyphenol oxidase and Beta-1,3-glucanase expression, respectively.


Author(s):  
Divya Bhandhari ◽  
Amar Singh ◽  
J.V. Patel ◽  
D.K. Banyal

Background: Colocasia is cultivated globally for its edible corm and leaves. Leaf blight incited by Phytophthora colocasiae is the most destructive disease of colocasia. The current study aims at biological management of the disease. Methods: Nine Trichoderma isolates from the colocasia rhizosphere soil along with five designated isolates of Trichoderma spp. already available in the Department of Plant Pathology, CSK HPKV, Palampur were tested in vitro for antagonistic activity against P. colocasiae. Similarly, six unidentified bacterial strains isolated from colocasia phylloplane and available Pseudomonas fluorescens were evaluated for antagonistic activity against P. colocasiae under in vitro conditions. The bioagents found best under in vitro conditions were evaluated in vivo. Result: Trichoderma isolate Ti-6 was found significantly superior bioagent as it resulted in 72.9 per cent mycelial growth inhibition of P. colocasiae followed by Ti-5 (63.2%), Ti-4 (60.1%) and Ti-1 (54.5%). Amongst bacterial antagonists, Pseudomonas fluorescens gave maximum mycelial growth inhibition of 50.5 per cent followed by Pb-3 (31.4%) and Pb-6 (30.5%). The efficacy of five Trichoderma spp isolates viz., Ti-6, Ti-5, Ti-4, Ti-1, T. viride and one bacterial isolate of P. fluorescens found effective under in vitro were also evaluated in vivo using three delivery systems under net house condition. Corm treatment with bioagents was found superior for management of colocasia blight. Corm treatment with Ti-6 was found to be significantly superior to other treatments as 93.74 per cent of disease control was observed. For drenching, bioagent Ti-6 was proved best in managing blight disease (88.91%) followed by Ti-5 (88.90%). However, Ti-5 isolate of Trichoderma sp. as soil application was found superior with 90.02 per cent disease control.


2020 ◽  
Vol 21 (1) ◽  
pp. 8-19
Author(s):  
Sutarman Sutarman ◽  
Ahmad Khafidh Jalaluddin ◽  
Arrohmatus Syafaqoh Li’aini ◽  
Andriani Eko Prihatiningrum

This study aims to determine the molecular-based characteristics of Trichoderma sp. Tc-Jjr-02 and its effect as a biocontrol agent in protecting tobacco seedlings against bacterial wilt caused by R. solanacearum. The characterization of biocontrol agents was based on morphological and molecular data’s observation using microscope and the key of determination. The in vivo experiments was consist of five treatments: (1) inoculation of Trichoderma isolates at six hours before R. solanacearum inoculation, (2) inoculation of Trichoderma isolates at six hours after R. solanacearum inoculation (3) simultaneous inoculation of Trichoderma isolates and R. solanacearum, (4) inoculated only with R. solanacearum, and (5) without any inoculation. The experiment was repeated six times. Based on BLAST’s analysis, the Tc-Jjr-02 sequence is in accordance with T. asperellum with 100% Query Cover. Inoculation of T. asperellum Tc-Jjr-02 at six hours before and after and simultaneously with pathogens providing protection for young tobacco plants by slowing down the time for the  onset of blight by 100–162%, reducing the symptom index by 56–63%, and increasing the dry weight of plant biomass by 39–53% compared to tobacco seeds which were only inoculated with R. solanacearum.


Plant Disease ◽  
2021 ◽  
Author(s):  
Uriel Acosta-González ◽  
Hilda Victoria Silva-Rojas ◽  
Dionicio Fuentes-Aragón ◽  
Jesus Hernández-Castrejón ◽  
Alejandro Romero-Bautista ◽  
...  

Fusarium wilt of blackberry (FWB) is an emerging disease caused by a Fusarium oxysporum species complex. More than 3000 ha of blackberry (Rubus spp.) crops have been lost in Mexico since 2011. The objectives of this research were: (i) to evaluate the sensitivity of pathogenic F. oxysporum isolates recovered from symptomatic blackberry plants to fungicides with different modes of action, (ii) to assess the potential of these fungicides and plant resistance inducers against FWB in the greenhouse, and (iii) to determine the effects of commercial biofungicides and two indigenous strains of Trichoderma spp. on the incidence of FWB. The EC50 values of the fungicides prochloraz, thiabendazole, azoxystrobin, thiophanate-methyl, difenoconazole, triflumizole, and potassium phosphite for six pathogenic F. oxysporum isolates were determined. In a separate experiment, the fungicides acibenzolar-S-methyl (ASM), potassium phosphite, and commercial biofungicides, as well as two soil microbial inoculants and two indigenous Trichoderma strains, were tested for protection against wilt development in blackberry plants in the greenhouse. Prochloraz showed an average sensitivity for EC50 of 0.01 μg ml−1 for the tested F. oxysporum isolates, followed by difenoconazole and thiabendazole. Prochloraz and ASM proved to be the most effective treatments in the greenhouse. In contrast, potassium phosphite was ineffective in both the in vitro and in vivo experiments. The soil bioinoculants MicroSoil®, Baktillis®, T. koningiopsis, and T. asperellum significantly reduced the incidence of disease in the greenhouse. These results provide evidence for the potential of the various tools as useful components of integrated FWB management in the field.


2020 ◽  
Vol 21 (1) ◽  
pp. 8-19
Author(s):  
Sutarman Sutarman ◽  
Ahmad Khafidh Jalaluddin ◽  
Arrohmatus Syafaqoh Li’aini ◽  
Andriani Eko Prihatiningrum

Characterizations of Trichoderma sp. and its effect on Ralstonia solanacearum of tobacco seedlings. This study aims todetermine the molecular-based characteristics of Trichoderma sp. Tc-Jjr-02 and its effect as a biocontrol agent in protecting tobaccoseedlings against bacterial wilt caused by R. solanacearum. The characterization of biocontrol agents was based on morphologicaland molecular data’s observation using microscope and the key of determination. The in vivo experiments was consist of fivetreatments: (1) inoculation of Trichoderma isolates at six hours before R. solanacearum inoculation, (2) inoculation of Trichodermaisolates at six hours after R. solanacearum inoculation (3) simultaneous inoculation of Trichoderma isolates and R. solanacearum,(4) inoculated only with R. solanacearum, and (5) without any inoculation. The experiment was repeated six times. Based onBLAST’s analysis, the Tc-Jjr-02 sequence is in accordance with T. asperellum with 100% Query Cover. Inoculation of T. asperellumTc-Jjr-02 at six hours before and after and simultaneously with pathogens providing protection for young tobacco plants by slowingdown the time for the onset of blight by 100–162%, reducing the symptom index by 56–63%, and increasing the dry weight of plantbiomass by 39–53% compared to tobacco seeds which were only inoculated with R. solanacearum.


2021 ◽  
Vol 22 (12) ◽  
pp. 6356
Author(s):  
Karolina Oszust ◽  
Michał Pylak ◽  
Magdalena Frąc

The number of raspberry plants dying from a sudden outbreak of gray mold, verticillium wilt, anthracnosis, and phytophthora infection has increased in recent times, leading to crop failure. The plants suffer tissue collapse and black roots, symptoms similar to a Botrytis–Verticillium–Colletotrichum–Phytophthora disease complex. A sizeable number of fungal isolates were acquired from the root and rhizosphere samples of wild raspberries from different locations. Subsequent in vitro tests revealed that a core consortium of 11 isolates of selected Trichoderma spp. was the most essential element for reducing in phytopathogen expansion. For this purpose, isolates were characterized by the efficiency of their antagonistic properties against Botrytis, Verticillium, Colletotrichum and Phytophthora isolates and with hydrolytic properties accelerating the decomposition of organic matter in the soil and thus making nutrients available to plants. Prebiotic additive supplementation with a mixture of adonitol, arabitol, erythritol, mannitol, sorbitol, and adenosine was proven in a laboratory experiment to be efficient in stimulating the growth of Trichoderma isolates. Through an in vivo pathosystem experiment, different raspberry naturalization-protection strategies (root inoculations and watering with native Trichoderma isolates, applied separately or simultaneously) were tested under controlled phytotron conditions. The experimental application of phytopathogens attenuated raspberry plant and soil properties, while Trichoderma consortium incorporation exhibited a certain trend of improving these features in terms of a short-term response, depending on the pathosystem and naturalization strategy. What is more, a laboratory-scale development of a biopreparation for the naturalization of the raspberry rhizosphere based on the Trichoderma consortium was proposed in the context of two application scenarios. The first was a ready-to-use formulation to be introduced while planting (pellets, gel). The second was a variant to be applied with naturalizing watering (soluble powder).


2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.


Sign in / Sign up

Export Citation Format

Share Document