scholarly journals Biological Control of Fusarium Crown and Root Rot of Wheat by Streptomyces Isolates – It’s Complicated

2019 ◽  
Vol 3 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Mark Winter ◽  
Peter L. Samuels ◽  
Lindsey K. Otto-Hanson ◽  
Ruth Dill-Macky ◽  
Linda L. Kinkel
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
In Vitro Tests ◽  
Fusarium Spp ◽  
Wheat Seedlings ◽  
Genus Streptomyces ◽  
Stem Base ◽  
Crown And Root Rot ◽  
Streptomyces Isolate

The predominant causal agents of Fusarium crown and root rot (FCR) of wheat, along with Fusarium pseudograminearum, are F. graminearum and F. culmorum. Members of the Gram-positive bacterial genus Streptomyces have been shown to inhibit isolates of the genus Fusarium, and Fusarium spp. isolates are also able to inhibit Streptomyces isolates in vitro. However, little is known about these complex antagonistic interactions and the potential for inhibitory Streptomyces to reduce FCR of wheat. The aim of this study was to analyze whether inhibitory Streptomyces isolates affect FCR of wheat and reduce root and stem base colonization by Fusarium culmorum. We enriched sterilized potting soil with spore suspensions of two Streptomyces isolates, inoculated the soil with F. culmorum-colonized wheat straw, and planted pre-germinated wheat seedlings. At 4 weeks, F. culmorum-inoculated plants had significant FCR symptoms on roots and showed reduced fresh weight of roots and above-ground plant biomass compared with the non-inoculated controls. Enrichment of soil with an inhibitory Streptomyces isolate reduced F. culmorum DNA in roots and stem bases by 75% compared with inoculation with F. culmorum alone. Interestingly, co-inoculation of F. culmorum with a non-inhibitory Streptomyces isolate led to the highest levels F. culmorum DNA in stem base tissue and greatest Streptomyces densities (CFU per g of soil) in the rhizosphere. In vitro assays revealed that F. culmorum showed a strong inhibitory activity against the pathogen-inhibitory Streptomyces isolate but not against the non-inhibitory isolate. In vitro tests with a larger set of 17 Streptomyces and five Fusarium spp. isolates revealed that there was little variation among Fusarium spp. isolates in capacities to inhibit the collection of Streptomyces isolates. In contrast, the sensitivity to inhibition by pathogenic Fusarium spp. isolates varied widely among Streptomyces isolates. The results of this study suggest the potential of Streptomyces isolates for biocontrol of FCR of wheat, while highlighting the specificity of Streptomyces−Fusarium interactions. Broader understanding of the variation in susceptibility within Fusarium spp. populations to Streptomyces inhibition and vice versa are needed to advance the potential for successful biological control.

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.

scholarly journals Use of Fungicides and Biological Controls in the Suppression of Fusarium Crown and Root Rot of Asparagus Under Greenhouse and Growth Chamber Conditions

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 493-498 ◽  
Author(s):  
T. C. Reid ◽  
M. K. Hausbeck ◽  
K. Kizilkaya
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Field Experiments ◽  
Growth Chamber ◽  
Root Weight ◽  
Fusarium Spp ◽  
Crown And Root Rot ◽  
Control Disease ◽  
Disease Pressure ◽  
Commercial Field

Growth chamber, greenhouse, and field experiments were conducted with fungicides and biological control agents, including nonpathogenic isolates of Fusarium oxysporum, to test their ability to control disease caused by F. oxysporum f. sp. asparagi and F. proliferatum. In greenhouse studies with asparagus seedlings in soil, Trichoderma harzianum strain T-22, benomyl, and fludioxonil treatments increased root weight and decreased root disease compared with the infested control when a low level of F. oxysporum f. sp. asparagi and F. proliferatum was used. The fungicide fludioxonil limited plant death caused by Fusarium spp. at high inoculum levels, whereas T. harzianum strain T-22 was not effective. Nonpathogenic isolates of F. oxysporum were effective in limiting Fusarium disease on asparagus seedlings in culture tubes, although isolates differed in their ability to control disease caused by F. oxysporum f. sp. asparagi and F. proliferatum. In greenhouse studies, no significant differences in plant death were found between asparagus plants growing in media infested with F. oxysporum f. sp. asparagi and F. proliferatum and left untreated, and those treated with nonpathogenic F. oxysporum. The efficacy of fungicides and biological control products to control Fusarium crown and root rot under commercial field conditions could not be evaluated due to low disease pressure.

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 Antagonistic Strain Bacillus amyloliquefaciens XZ34-1 for Controlling Bipolaris sorokiniana and Promoting Growth in Wheat

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1526
Author(s):  
Yanjie Yi ◽  
Youtian Shan ◽  
Shifei Liu ◽  
Yanhui Yang ◽  
Yang Liu ◽  
...  
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Bacillus Amyloliquefaciens ◽  
Biological Control Agent ◽  
Wheat Yield ◽  
Bipolaris Sorokiniana ◽  
Common Root ◽  
Bioactive Substances ◽  
Wheat Seedlings ◽  
Common Root Rot

Common root rot, caused by Bipolaris sorokiniana, is one of the most prevalent diseases of wheat and has led to major declines in wheat yield and quality worldwide. Here, strain XZ34-1 was isolated from soil and identified as Bacillus amyloliquefaciens based on the morphological, physiological, biochemical characteristics and 16S rDNA sequence. Culture filtrate (CF) of strain XZ34-1 showed a high inhibition rate against B.sorokiniana and had a broad antifungal spectrum. It also remarkably inhibited the mycelial growth and spore germination of B. sorokiniana. In pot control experiments, the incidence and disease index of common root rot in wheat seedlings were decreased after treatment with CF, and the biological control efficacy was significant, up to 78.24%. Further studies showed XZ34-1 could produce antifungal bioactive substances and had the potential of promoting plant growth. Lipopeptide genes detection with PCR indicated that strain XZ34-1 may produce lipopeptides. Furthermore, activities of defense-related enzymes were enhanced in wheat seedlings after inoculation with B.sorokiniana and treatment with CF, which showed induced resistance could be produced in wheat to resist pathogens. These results reveal that strain XZ34-1 is a promising candidate for application as a biological control agent against B.sorokiniana.

scholarly journals Pathogenicity of Fusarium species associated with crown and root rot of wheat (Triticum aestivum) under different condition

2019 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Bareen Sidqi Shareef Al-Tovi ◽  
Raed Abduljabbar Haleem
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Field Experiments ◽  
Fusarium Species ◽  
Test Tube ◽  
Spore Suspension ◽  
Wheat Crop ◽  
Pathogenicity Test ◽  
Crown And Root Rot

This study was conducted to test the pathogenicity of Fusarium species, the causes of crown and root rot disease of wheat crop, under three different conditions (Laboratory, Greenhouse and Field) and to show the best method for pathogenicity among different conditions. Pathogenicity test of six isolates of Fusarium species (F. graminearum, F. oxysporum, F. avenaceum, F. nivale, F. solani and F. udum) was tested on durum (Simeto) cultivar of wheat by test tube method in the laboratory, the tested fungi had substantial effect on seed germination. F. oxysporum showed the highest germination failure (44.44%) which significantly differed with other species. In the greenhouse, seedlings were inoculated by spore suspension at the base of each plant stem. The most virulent fungus after 35 days of inoculation was F. oxysporum (0.78) followed by F. solani (0.70) and F. graminearum (0.66), while the lowest disease severity was recorded by F. udum (0.16). Also in the field pathogenicity experiments of three Fusarium species (F. graminearum, F. oxysporum and F. solani) were performed on a durum (Simeto) and soft (Cham6) cultivars. Spore suspension was applied at the 2- to 3-leaf Zadoks’s growth stage. Disease severity was calculated at two stages of wheat growth (Booting and Ripening).The most virulent fungus was F. graminearum (0.42) that was significantly different from  other fungi. This work indicated that F. graminearum, F. oxysporum and F. solani showed higher infection than remaining tested species under threeconditions. Pathogenicity test in laboratory by test tube method (In-vitro) appeared more effective than greenhouse and field experiments

The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

1999 ◽  
Vol 50 (8) ◽  
pp. 1469 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden ◽  
G. M. Murray
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Rhizobium Trifolii ◽  
Biological Control Agents ◽  
Control Activity ◽  
Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

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 Effect of Biochar Amendments on Mycorrhizal Associations and Fusarium Crown and Root Rot of Asparagus in Replant Soils

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 960-966 ◽  
Author(s):  
Wade H. Elmer ◽  
Joseph J. Pignatello
Keyword(s):  
Root Rot ◽  
Root Colonization ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
First Year ◽  
Root Weight ◽  
Fusarium Spp ◽  
Biomass Waste ◽  
Mycorrhizal Associations ◽  
Crown And Root Rot

Pyrolyzed biomass waste, commonly called biochar, has attracted interest as a soil amendment. A commercial prototype biochar produced by fast pyrolysis of hardwood dust was examined in soils to determine if it could reduce the damaging effect of allelopathy on arbuscular mycorrhizal (AM) root colonization and on Fusarium crown and root rot of asparagus. In greenhouse studies, biochar added at 1.5 and 3.0% (wt/wt) to asparagus field soil caused proportional increases in root weights and linear reductions in the percentage of root lesions caused by Fusarium oxysporum f. sp. asparagi and F. proliferatum compared with a control. Concomitant with these effects was a 100% increase in root colonization by AM fungi at the 3.0% rate. Addition of aromatic acids (cinnamic, coumaric, and ferulic) that are known allelopathic agents affecting asparagus reduced AM colonization but the deleterious effects were not observed following the application of biochar at the higher rate. When dried, ground, asparagus root and crown tissues infested with Fusarium spp. were added to soilless potting mix at 0, 1, or 5 g/liter of potting mix and then planted with asparagus, there was a decrease in asparagus root weight and increase in disease at 1 g/liter of potting mix but results were inconsistent at the higher residue rate. However, when biochar was added at 35 g/liter of potting mix (roughly 10%, vol/vol), these adverse effects on root weight and disease were equal to the nontreated controls. A small demonstration was conducted in field microplots. Those plots amended with biochar (3.5% [wt/wt] soil) produced asparagus plants with more AM colonization in the first year of growth but, in the subsequent year, biochar-treated plants were reduced in size, possibly due to greater than average precipitation and the ability of biochar to retain moisture that, in turn, may have created conditions conducive to root rot. These studies provide evidence that biochar may be useful in overcoming the deleterious effects of allelopathic residues in replant soils on asparagus.

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.

Interaction of Rhizobium leguminosarum and Fusarium solani f.sp. pisi on pea affecting disease development and phytoalexin production

1989 ◽  
Vol 67 (6) ◽  
pp. 1698-1701 ◽  
Author(s):  
Usha Chakraborty ◽  
B. N. Chakraborty
Keyword(s):  
Fusarium Solani ◽  
Root Rot ◽  
Rhizobium Leguminosarum ◽  
Solid Medium ◽  
In Vitro Tests ◽  
Dual Culture ◽  
Disease Development ◽  
Antagonistic Effects ◽  
Pisum Sativum L

Pathogenicity of Fusarium solani f.sp. pisi (F. R. Jones) Snyd. & Hans was tested on five cultivars of pea (Pisum sativum L.) under identical conditions; the fungus was more virulent on cv. Arkel and less virulent on cv. Sweet Stringless. Bacterization of seeds with Rhizobium leguminosarum biovar vicieae was highly effective in reducing the severity of root rot of pea. In vitro tests with F. solani f.sp. pisi and R. leguminosarum biovar vicieae showed no antagonistic effects on solid medium. However, growth of both microorganisms was retarded in dual culture. Phytoalexins (pisatin and 4-hydroxy-2,3,9-trimethoxypterocarpan) were isolated from both Fusarium- and Rhizobium–Fusarium-infected pea epicotyls; 4-hydroxy-2,3,9-trimethoxypterocarpan was present in a greater amount in the latter than in the former, while pisatin concentration was similar in samples from both treatments.

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