scholarly journals Biological Control of the Root-Knot Nematode Meloidogyne javanica by Trichoderma harzianum

2001 ◽  
Vol 91 (7) ◽  
pp. 687-693 ◽  
Author(s):  
E. Sharon ◽  
M. Bar-Eyal ◽  
I. Chet ◽  
A. Herrera-Estrella ◽  
O. Kleifeld ◽  
...  
Keyword(s):  
Biological Control ◽  
Proteolytic Activity ◽  
Trichoderma Harzianum ◽  
Meloidogyne Javanica ◽  
In Vitro Assays ◽  
In Vitro Tests ◽  
Root Knot Nematode ◽  
Soil Extracts ◽  
Greenhouse Experiments

The fungal biocontrol agent, Trichoderma harzianum, was evaluated for its potential to control the root-knot nematode Meloidogyne javanica. In greenhouse experiments, root galling was reduced and top fresh weight increased in nematode-infected tomatoes following soil pretreatment with Trichoderma peat-bran preparations. The use of a proteinase Prb1-transformed line (P-2) that contains multiple copies of this gene improved biocontrol activity in the greenhouse experiments compared with the nontransformed wild-type strain (WT). All the Trichoderma strains showed the ability to colonize M. javanica-separated eggs and second-stage juveniles (J2) in sterile in vitro assays, whereas P-2 also penetrated the egg masses. This protease-transformed line presented the same nematicidal and overall proteolytic activity as the WT in in vitro tests in which concentrated soil extracts from Trichoderma-treated soils immobilized the infective J2. However, the J2 immobilization and proteolytic activities of both P-2 and the WT were higher than those obtained with strain T-203. Characterization of the activity of all Trichoderma strains soil extracts on J2 showed that it was heat resistant and restricted to the low-molecular-weight fraction (less than 3 kDa). It is suggested that improved proteolytic activity of the antagonist may be important for the biological control of the nematodes.

Biocontrol of seed-borne Alternaria raphani and A. brassicicola

1987 ◽  
Vol 33 (10) ◽  
pp. 850-856 ◽  
Author(s):  
G. Vannacci ◽  
G. E. Harman
Keyword(s):  
Biological Control ◽  
Host Range ◽  
Trichoderma Harzianum ◽  
Pythium Species ◽  
Biological Control Agents ◽  
Fusarium Sp ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Radish Seedlings

Forty-two microorganisms were tested as biological control agents against Alternaria raphani and A. brassicicola. Tests were conducted for in vitro antagonistic ability, for ability to control the pathogens on naturally infected seeds germinated on moistened blotters, and in planting mix in growth chamber studies, and for their ability to reduce pod infection. The organisms tested were obtained from cruciferous seeds or were strains already identified as being effective against soil-borne Pythium species. The blotter test indicated that six organisms increased both the number of healthy seedlings and the number of seedlings produced from A. raphani infected radish seeds. An additional seven strains improved either germination or increased the number of healthy seedlings. Twenty-nine organisms increased the number of healthy cabbage seedlings from A. brassicicola infected seeds, but total germination was not modified by any treatment. Experiments in planting mix showed that five antagonists (Chaetomium globosum, two strains of Trichoderma harzianum, T. koningii, and Fusarium sp.) increased the number of healthy plants in both radish samples tested, while four additional antagonists provided a significant increase in only one of the samples tested. The five antagonists that consistently increased numbers of healthy radish seedlings also decreased pod infection by A. raphani. None were as effective as iprodrone, however. Several effective antagonists were found to be mycoparasitic against Alternaria spp. Some strains of Trichoderma previously found to be effective against Pythium spp. were also effective against Alternaria spp., indicating that these strains have a wide host range.

scholarly journals Screening of wheat endophytes as biological control agents against Fusarium head blight using two different in vitro tests

2017 ◽  
Vol 202 ◽  
pp. 11-20 ◽  
Author(s):  
Morgane Comby ◽  
Marie Gacoin ◽  
Mathilde Robineau ◽  
Fanja Rabenoelina ◽  
Sébastien Ptas ◽  
...  
Keyword(s):  
Biological Control ◽  
Fusarium Head Blight ◽  
In Vitro Tests ◽  
Biological Control Agents ◽  
Head Blight

scholarly journals Bacillus velezensis 83 a bacterial strain from mango phyllosphere, useful for biological control and plant growth promotion

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Karina A. Balderas-Ruíz ◽  
Patricia Bustos ◽  
Rosa I. Santamaria ◽  
Víctor González ◽  
Sergio Andrés Cristiano-Fajardo ◽  
...  
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Biological Control Agent ◽  
Gene Clusters ◽  
In Vitro Assays ◽  
Shoot Biomass ◽  
Plant Growth Promoting Bacteria ◽  
Bacillus Velezensis

Abstract Bacillus velezensis 83 was isolated from mango tree phyllosphere of orchards located in El Rosario, Sinaloa, México. The assessment of this strain as BCA (biological control agent), as well as PGPB (plant growth-promoting bacteria), were demonstrated through in vivo and in vitro assays. In vivo assays showed that B. velezensis 83 was able to control anthracnose (Kent mangoes) as efficiently as chemical treatment with Captan 50 PH™ or Cupravit hidro™. The inoculation of B. velezensis 83 to the roots of maize seedlings yielded an increase of 12% in height and 45% of root biomass, as compared with uninoculated seedlings. In vitro co-culture assays showed that B. velezensis 83 promoted Arabidopsis thaliana growth (root and shoot biomass) while, under the same experimental conditions, B. velezensis FZB42 (reference strain) had a suppressive effect on plant growth. In order to characterize the isolated strain, the complete genome sequence of B. velezensis 83 is reported. Its circular genome consists of 3,997,902 bp coding to 3949 predicted genes. The assembly and annotation of this genome revealed gene clusters related with plant-bacteria interaction and sporulation, as well as ten secondary metabolites biosynthetic gene clusters implicated in the biological control of phytopathogens. Despite the high genomic identity (> 98%) between B. velezensis 83 and B. velezensis FZB42, they are phenotypically different. Indeed, in vitro production of compounds such as surfactin and bacillomycin D (biocontrol activity) and γ-PGA (biofilm component) is significantly different between both strains.

Suppressive effects of composts against the root-knot nematode Meloidogyne javanica on tomato

Nematology ◽  
2002 ◽  
Vol 4 (8) ◽  
pp. 891-898 ◽  
Author(s):  
Yuji Oka ◽  
Uri Yermiyahu
Keyword(s):  
Water Extract ◽  
Meloidogyne Javanica ◽  
Suppressive Effect ◽  
Cattle Manure ◽  
Nematicidal Activity ◽  
Root Knot Nematode ◽  
Grape Marc ◽  
Manure Compost ◽  
Cattle Manure Compost

AbstractSuppressive effects of two composts, from cattle manure and grape marc, on the root-knot nematode Meloidogyne javanica were tested in pot and in vitro experiments. No root galls were found on tomato roots grown in soils containing 10 or 25% (v/v) cattle manure compost, and very few on those grown in 50% grape marc compost. Significant reductions in galling index were also found on tomato plants grown in soils containing lower concentrations of this compost. Chemical analysis of the composts and leachates from the soils showed that the cattle manure compost had higher electrical conductivity (EC) and higher concentrations of nitrogen, especially N–NH4, than the grape marc compost. Water extract of the cattle manure compost showed high nematicidal activity to the nematode juveniles and less activity toward the eggs in vitro. Water extract of the grape marc compost showed weaker nematicidal activity to the juveniles and eggs. Washing composted soils with excess water before nematode inoculation and tomato planting led to better plant growth, but the nematode-suppressive effect was decreased. These results suggest that high nitrogen concentrations, especially N–NH4, and high EC values contribute to the nematode suppressiveness of the composts.

scholarly journals The Application of Manure (Poultry Wests) and Bio-Formulations of Trichoderma harzianum and T. viride and Their Interaction to Control Root-knot Disease on Radish and Chard

2019 ◽  
Vol 32 (1) ◽  
pp. 88-98
Author(s):  
Nuha A. Al-Zehebawi ◽  
Dhia S. Al-Waily ◽  
Labeed A. Al-Saad
Keyword(s):  
Plant Height ◽  
Molecular Identification ◽  
Contaminated Soil ◽  
Trichoderma Harzianum ◽  
Control Treatment ◽  
Root Knot Nematode ◽  
Green House ◽  
Control Root ◽  
Positive Treatment

The study was designed to examine the effect of manure (poultry wastes) and bio-formulations of Trichoderma harzianum and T. viride separately or with some, to control root-knot disease on radish (Raphanus sativus L.) and chard (Beta vulagaris var.cicla (L.)). The study included the isolation of pathogenic nematode of both plant roots, morphological and molecular identification, examination of the pathogenicity in vitro and in vivo and green house experiments involved application of manure and fungal bio-formulations treatments. The morphological and molecular identification confirmed the identity of root-knot nematode, as Meloidogyne javanica, which was pathogenic to radish and chard. The recorded infection severity was 89 and 95% respectively. The green house experiment results revealed that MThTv treatment was significantly reduced infection severity to 0% for radish and chard in contaminated soil (CS) compared with control positive treatment (55.17 and 40%) respectively. MThTv treatment also showed a highest plant height for Radish in non-nematode-contaminated soil (NCS) and CS treatment (17.85 and 16.50 cm) respectively compared with control positive treatment (5.00 cm), while the highest plant height of Chard was 24.5 cm in MThTv-NCS. The wet weight index in Radish showed a superiority of MThTv and MTh in NC on other treatments (201.75 and 189.5 g.plant-1) respectively followed by MThTv-NCS treatment (184.5 g.plant-1) compared with 19.25 gm.plant-1 in control treatment. In Chard the results showed similar pattern represented by superiority of MThTv-NC treatment (255.25 gm.plant-1) followed by MThTv-NCS (190.75 gm.plant-1) compared with 37.50 gm/plant for positive control.

scholarly journals Biological Efficacy of Trichoderma spp. and Bacillus spp. in the Management of Plant Diseases

2020 ◽  
Author(s):  
Francisco Daniel Hernández-Castillo ◽  
Francisco Castillo-Reyes ◽  
Marco Antonio Tucuch-Pérez ◽  
Roberto Arredondo-Valdes
Keyword(s):  
Biological Control ◽  
Fruit Trees ◽  
Plant Diseases ◽  
In Vitro Tests ◽  
Taxonomic Identification ◽  
Trichoderma Spp ◽  
Antifungal Effect ◽  
Bacillus Spp ◽  
Microbial Strain

This chapter will cover topics about the microbial antagonists Trichoderma spp. and Bacillus spp. from the perspective of use as potential biological control agents on plant diseases. Results obtained in the laboratory about from their isolation, microbial strain collections for both genera, taxonomic identification, antifungal activity in in vitro tests, obtained evaluation of the antifungal effect of secondary metabolites from microbial antagonists will be shown. Besides, results obtained from bioassays in the greenhouse and field are used as biopesticides in the control of diseases in fruit trees and vegetables and their effects on the promotion of plant growth and increased crop yield.

scholarly journals Control of root rot (Phytophthora cinnamomi) in avocado (Persea Americana) with bioagents

2020 ◽  
Vol 46 (3) ◽  
pp. 205-211
Author(s):  
Ciro Hideki Sumida ◽  
Lucas Henrique Fantin ◽  
Karla Braga ◽  
Marcelo Giovanetti Canteri ◽  
Martin Homechin
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Persea Americana ◽  
Field Conditions ◽  
In Vitro Tests ◽  
Trichoderma Spp ◽  
Maize Cultivation ◽  
Antagonistic Potential

ABSTRACT Despite the favorable edaphoclimatic conditions for avocado production in Brazil, diseases such as root rot caused by the pathogen Phytophthora cinnamomi compromise the crop. With the aim of managing root rot in avocado, the present study aimed to evaluate chemical and biological control with isolates of Trichoderma spp. and Pseudomonas fluorescens. Thus, three assays were conducted to assess: (i) mycelial inhibition of P. cinnamomi by isolates of Trichoderma spp. and P. fluorescens from different crop systems; (ii) effect of autoclaved and non-autoclaved metabolites of P. fluorescens, and (iii) chemical or biological treatment of avocado seedlings on the control of root rot under field conditions. The isolates of Trichoderma spp. from maize cultivation soil and the commercial products formulated with Trichoderma presented greater antagonism (p <0.05) to the pathogen P. cinnamomi in the in vitro tests. Similarly, non-autoclaved metabolites of P. fluorescens presented antagonistic potential to control P. cinnamomi. Under field conditions, the fungicide metalaxyl and the bioagents showed effectiveness in controlling P. cinnamomi, as well as greater root length and mass. Results demonstrated potential for the biological control of avocado root rot with Trichoderma spp. and P. fluorescens.

Reversible Nematostatic Effect of Peganum harmala L (Nitrariaceae) on Meloidogyne javanica

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
EL HASSAN MAYAD ◽  
KHADIJA BASAID ◽  
JAMES NICHOLAS FURZE ◽  
NIAMA HEIMEUR ◽  
BTISSAM SENHAJI ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Total Content ◽  
Meloidogyne Javanica ◽  
Aqueous Extracts ◽  
In Vitro Experiments ◽  
Peganum Harmala ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Methanolic Extracts

Meloidogyne javanica is considered as the most damaging nematode of vegetables in Morocco. Eco-friendly bionematicides are urgently required for its control. In vitro experiments were carried out to assess the direct effect of bioproducts of Peganum harmala against M. javanica. The bioassay showed extracts to be nematotoxic. Aqueous extracts of P. harmala exhibited reversible nematostatic activity. The estimated ID50 of the most active product in methanolic extracts was 368ppm. HPLC-MS of the methanolic extract revealed that total content of major alkaloids of P. harmala was approximately 12.162±0.637mg/g. Harmine (8.514±0.521mg/g) is the dominant alkaloid. In conclusion, Peganum harmala has a reversible nematostatic activity on second stage juveniles of M. javanica. The effect of P. harmala is due to its possession of a high content of β-carboline alkaloids, which warrant further experimentation. Bioproducts from P. harmala should be exploited through formulations for management of the root knot nematode.

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