scholarly journals Bacillus-based biological control of cotton seedling disease complex

2014 ◽  
Vol 54 (4) ◽  
pp. 340-348
Author(s):  
Mohammad Ahmed Khiyami ◽  
Moawad Ragab Omar ◽  
Kamel Ahmed Abd-Elsalam ◽  
Aly Abd El-Hady Aly
Keyword(s):  
Dry Weight ◽  
Damping Off ◽  
Single Strain ◽  
Seedling Disease ◽  
Cotton Seedling ◽  
Disease Complex ◽  
Fungal Isolates ◽  
Greenhouse Evaluation ◽  
Bacillus Spp ◽  
Bacillus Strains

Abstract To formulate an efficient and eco-friendly strategy for the management of cotton seedling disease complex, pot experiments were conducted and the efficiency of eight Bacillus strains against seven fungi involved in the disease were determined. A greenhouse evaluation of the interaction between fungal isolates and Bacillus strains was carried out. The evaluation revealed a very highly significant Bacillus strains x fungal isolates interaction for all the following parameters: preemergence damping-off, postemergence damping-off, survival, plant height, and dry weight. This interaction implies that a single strain of the Bacillus sp. can be highly effective against a fungal isolate, but may have only minimal effects on other fungal isolates. The results of the present study demonstrated that Bacillus circulans and B. coagulans were the most effective strains in controlling cotton seedling disease. Therefore, strains of Bacillus spp. should be tested against as many fungal isolates as possible. The testing will improve the chance of identifying Bacillus strains effective against several fungal isolates.

A Fungicide Application Decision (FAD) Support System for Postbloom Fruit Drop of Citrus (PFD)

2002 ◽  
Vol 3 (1) ◽  
pp. 16 ◽  
Author(s):  
Natália A. R. Peres ◽  
Soonho Kim ◽  
Howard W. Beck ◽  
Nilton L. Souza ◽  
Lavern W. Timmer
Keyword(s):  
Rhizoctonia Solani ◽  
Support System ◽  
Thielaviopsis Basicola ◽  
Seedling Disease ◽  
Cotton Seedling ◽  
Fungicide Application ◽  
Disease Complex ◽  
Fruit Drop ◽  
Application Decision ◽  
Seedling Diseases

Surveys were conducted to identify fungi associated with postemergence cotton seedling disease in Missouri. Samples consisted of 10 cotton seedlings, 2 to 3 weeks after emergence, with symptoms of seedling diseases collected from a 0.25 ha area in each of 60 fields in 1997 and 1998. Four genera of fungi were cultured from the roots (Fusarium, Pythium, Rhizoctonia, and Thielaviopsis) and three species were identified: Rhizoctonia solani, Thielaviopsis basicola, and Pythiumultimum. Rhizoctonia solani, T. basicola, and P. ultimum were cultured from seedlings in 70%, 47%, and 15% of fields sampled in 1997, respectively, and 55%, 17%, and 5% of fields sampled in 1998, respectively. Repeated tests of pathogenicity confirmed that R. solani AG-4, T. basicola, and P. ultimum were major causal agents of postemergence cotton seedling disease in Missouri. This study provides the first documentation on the distribution and frequency of fungi associated with postemergence seedling disease complex of cotton based on a survey of randomly selected fields. Accepted for publication 10 July 2002. Published 31 July 2002.

Fungi Associated With Postemergence Cotton Seedling Disease in Missouri

2002 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
J. A. Wrather ◽  
B. Phipps ◽  
C. S. Rothrock
Keyword(s):  
Rhizoctonia Solani ◽  
Thielaviopsis Basicola ◽  
Seedling Disease ◽  
Cotton Seedling ◽  
Disease Complex ◽  
Seedling Diseases

Surveys were conducted to identify fungi associated with postemergence cotton seedling disease in Missouri. Samples consisted of 10 cotton seedlings, 2 to 3 weeks after emergence, with symptoms of seedling diseases collected from a 0.25 ha area in each of 60 fields in 1997 and 1998. Four genera of fungi were cultured from the roots (Fusarium, Pythium, Rhizoctonia, and Thielaviopsis) and three species were identified: Rhizoctonia solani, Thielaviopsis basicola, and Pythiumultimum. Rhizoctonia solani, T. basicola, and P. ultimum were cultured from seedlings in 70%, 47%, and 15% of fields sampled in 1997, respectively, and 55%, 17%, and 5% of fields sampled in 1998, respectively. Repeated tests of pathogenicity confirmed that R. solani AG-4, T. basicola, and P. ultimum were major causal agents of postemergence cotton seedling disease in Missouri. This study provides the first documentation on the distribution and frequency of fungi associated with postemergence seedling disease complex of cotton based on a survey of randomly selected fields. Accepted for publication 9 July 2002. Published 22 July 2002.

scholarly journals Use of Lentinan and Fluopimomide to Control Cotton Seedling Damping-Off Disease Caused by Rhizoctonia solani

Agriculture ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 75
Author(s):  
Shoumin Sun ◽  
Haohao Yan ◽  
Gang Chen ◽  
Shuai Yang ◽  
Jie Wang ◽  
...  
Keyword(s):  
Plant Growth ◽  
Rhizoctonia Solani ◽  
Plant Disease Resistance ◽  
Field Trials ◽  
Cotton Production ◽  
Damping Off ◽  
Seedling Disease ◽  
Cotton Seedling ◽  
Cotton Seeds ◽  
Acid Pathway

Lentinan (LNT) is a natural and functional polysaccharide isolated from Lentinus edodes fruiting bodies, which functions in stimulating the plant immune response, improving plant disease resistance and regulating plant growth. This study explores the use of LNT as a plant growth regulator and attractant in cotton production. After treatment with LNT, the content of malondialdehyde (MDA) in cotton seeds decreased, whereas the activities of polyphenol oxidase (PPO), superoxide dismutase (SOD) and peroxidase (POD) in leaves increased significantly. LNT also promoted the growth and development of cotton plants and significantly reduced the incidence of cotton damping-off disease. The relative expression of salicylic acid pathway-related genes in cotton also increased significantly. The prevention mechanism of fluopimomide was also evaluated, and the result showed lower EC50 values and was effective in controlling cotton seedling disease caused by Rhizoctonia solani in both greenhouse experiments and field trials. The use of LNT and fluopimomide in controlling cotton seedling damping-off disease showed a synergistic effect in field trials. These results will provide a new insight into the agricultural application of LNT as a biological fungicide in the field of biological controls.

scholarly journals Annulment of antagonism shifts properties that are beneficial to plants in two-member consortia of Bacillus velezensis

2021 ◽  
Author(s):  
Jiahui Shao ◽  
Yan Liu ◽  
Jiyu Xie ◽  
Polonca Štefanič ◽  
Yu Lv ◽  
...  
Keyword(s):  
Social Interactions ◽  
Influencing Factor ◽  
Microbial Consortia ◽  
Single Strain ◽  
Combined Use ◽  
Level Function ◽  
Bacillus Spp ◽  
And Function ◽  
Synthetic Microbial Consortia ◽  
Bacillus Strains

Bacillus spp. strains that are beneficial to plants are widely used in commercial biofertilizers and biocontrol agents for sustainable agriculture. Generally, functional Bacillus strains are applied as single strain communities since the principles of synthetic microbial consortia constructed with Bacillus strains remain largely unclear. Here, we demonstrated that the mutual compatibility directly affects the survival and function of two-member consortia composed of B. velezensis SQR9 and FZB42 in the rhizosphere. A mutation in the global regulator Spo0A of SQR9 markedly reduced the boundary phenotype with wild-type FZB42, and the combined use of the SQR9Δspo0A mutant and FZB42 improved biofilm formation, root colonization and the production of secondary metabolites that are beneficial to plants. We further confirmed the correlation between the swarm discrimination phenotype between the two consortia members and the effects that are beneficial to plants in a greenhouse experiment. Our results provide evidence that social interactions among bacteria could be an influencing factor in achieving a desired community-level function.

QUALITATIVE AND QUANTITATIVE ESTIMATION OF SEEDS MYCOFLORA AND THEIR INFLUENCE ON COTTON SEEDLING DAMPING –OFF DISEASE.

2011 ◽  
Vol 2 (6) ◽  
pp. 583-595
Author(s):  
A. El-Samawaty ◽  
M. Omar ◽  
D. El-Wakil ◽  
Naglaa mohamed
Keyword(s):  
Quantitative Estimation ◽  
Damping Off ◽  
Cotton Seedling ◽  
Qualitative And Quantitative

scholarly journals A Novel Microbial Zearalenone Transformation through Phosphorylation

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 294
Author(s):  
Yan Zhu ◽  
Pascal Drouin ◽  
Dion Lepp ◽  
Xiu-Zhen Li ◽  
Honghui Zhu ◽  
...  
Keyword(s):  
Microbial Transformation ◽  
Acid Tolerance ◽  
Transformation Product ◽  
The United States ◽  
Corn Silage ◽  
Rrna Gene ◽  
Bacillus Spp ◽  
High Concentrations ◽  
The 16S Rrna Gene ◽  
Bacillus Strains

Zearalenone (ZEA) is a mycotoxin widely occurring in many agricultural commodities. In this study, a purified bacterial isolate, Bacillus sp. S62-W, obtained from one of 104 corn silage samples from various silos located in the United States, exhibited activity to transform the mycotoxin ZEA. A novel microbial transformation product, ZEA-14-phosphate, was detected, purified, and identified by HPLC, LC-MS, and NMR analyses. The isolate has been identified as belonging to the genus Bacillus according to phylogenetic analysis of the 16S rRNA gene and whole genome alignments. The isolate showed high efficacy in transforming ZEA to ZEA-14-phosphate (100% transformation within 24 h) and possessed advantages of acid tolerance (work at pH = 4.0), working under a broad range of temperatures (22–42 °C), and a capability of transforming ZEA at high concentrations (up to 200 µg/mL). In addition, 23 Bacillus strains of various species were tested for their ZEA phosphorylation activity. Thirteen of the Bacillus strains showed phosphorylation functionality at an efficacy of between 20.3% and 99.4% after 24 h incubation, suggesting the metabolism pathway is widely conserved in Bacillus spp. This study established a new transformation system for potential application of controlling ZEA although the metabolism and toxicity of ZEA-14-phosphate requires further investigation.

scholarly journals Myco-Suppression Analysis of Soybean (Glycine max) Damping-Off Caused by Pythium aphanidermatum

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 788
Author(s):  
Shaban R. M. Sayed ◽  
Shaimaa A. M. Abdelmohsen ◽  
Hani M. A. Abdelzaher ◽  
Mohammed A. Elnaghy ◽  
Ashraf A. Mostafa ◽  
...  
Keyword(s):  
Glycine Max ◽  
Biocontrol Agent ◽  
Lateral Roots ◽  
Dry Weight ◽  
Pythium Aphanidermatum ◽  
Damping Off ◽  
Pythium Oligandrum ◽  
Rdna Its ◽  
Half Strength

The role of Pythium oligandrum as a biocontrol agent against Pythium aphanidermatum was investigated to avoid the harmful impacts of fungicides. Three isolates of P. oligandrum (MS15, MS19, and MS31) were assessed facing the plant pathogenic P. aphanidermatum the causal agent of Glycine max damping-off. The tested Pythium species were recognized according to their cultural and microscopic characterizations. The identification was confirmed through sequencing of rDNA-ITS regions including the 5.8 S rDNA. The biocontrol agent, P. oligandrum, isolates decreased the mycelial growth of the pathogenic P. aphanidermatum with 71.3%, 67.1%, and 68.7% through mycoparasitism on CMA plates. While the half-strength millipore sterilized filtrates of P. oligandrum isolates degrade the pathogenic mycelial linear growth by 34.1%, 32.5%, and 31.7%, and reduce the mycelial dry weight of the pathogenic P. aphanidermatum by 40.1%, 37.4%, and 36.8%, respectively. Scanning electron microscopy (SEM) of the most effective antagonistic P. oligandrum isolate (MS15) interaction showed coiling, haustorial parts of P. oligandrum to P. aphanidermatum hyphae. Furthermore, P. oligandrum isolates were proven to enhance the germination of Glycine max seedling to 93.3% in damping-off infection using agar pots and promote germination of up to 80% during soil pot assay. On the other hand, P. oligandrum isolates increase the shoot, root lengths, and the number of lateral roots.

scholarly journals Application of Bio-Friendly Formulations of Chitinase-Producing Streptomyces cellulosae Actino 48 for Controlling Peanut Soil-Borne Diseases Caused by Sclerotium rolfsii

2021 ◽  
Vol 7 (3) ◽  
pp. 167
Author(s):  
Gaber Abo-Zaid ◽  
Ahmed Abdelkhalek ◽  
Saleh Matar ◽  
Mai Darwish ◽  
Muhammad Abdel-Gayed
Keyword(s):  
Open Field ◽  
Biocontrol Agent ◽  
Sclerotium Rolfsii ◽  
Dry Weight ◽  
Culture Broth ◽  
Field Conditions ◽  
Damping Off ◽  
Mycelium Growth ◽  
Particle Size Analyzer ◽  
Cell Pellet

Of ten actinobacterial isolates, Streptomyces cellulosae Actino 48 exhibited the strongest suppression of Sclerotium rolfsii mycelium growth and the highest chitinase enzyme production (49.2 U L−1 min−1). The interaction between Actino 48 and S. rolfsii was studied by scanning electron microscope (SEM), which revealed many abnormalities, malformations, and injuries of the hypha, with large loss of S. rolfsii mycelia density and mass. Three talc-based formulations with culture broth, cell-free supernatant, and cell pellet suspension of chitinase-producing Actino 48 were characterized using SEM, Fourier transform infrared spectroscopy (FTIR), and a particle size analyzer. All formulations were evaluated as biocontrol agents for reducing damping-off, root rot, and pods rot diseases of peanut caused by S. rolfsii under greenhouse and open-field conditions. The talc-based culture broth formulation was the most effective soil treatment, which decreased the percentage of peanut diseases under greenhouse and open-field conditions during two successive seasons. The culture broth formulation showed the highest increase in the dry weight of peanut shoots, root systems, and yielded pods. The transcriptional levels of three defense-related genes (PR-1, PR-3, and POD) were elevated in the culture broth formulation treatment compared with other formulations. Subsequently, the bio-friendly talc-based culture broth formulation of chitinase-producing Actino 48 could potentially be used as a biocontrol agent for controlling peanut soil-borne diseases caused by S. rolfsii.

Gliovirin, a new antibiotic from Gliocladium virens, and its role in the biological control of Pythium ultimum

1983 ◽  
Vol 29 (3) ◽  
pp. 321-324 ◽  
Author(s):  
Charles R. Howell ◽  
Robert D. Stipanovic
Keyword(s):  
Pythium Ultimum ◽  
Similar Efficacy ◽  
Antibiotic Activity ◽  
Infested Soil ◽  
Damping Off ◽  
Potato Dextrose Broth ◽  
Seedling Disease ◽  
X Ray ◽  
Gliocladium Virens ◽  
Induced Mutant

A compound with antibiotic activity toward Pythium ultimum was isolated from potato dextrose broth shake cultures of Gliocladium virens, a common soil mycoparasite known to inhibit but not parasitize P. ultimum. The mass spectrum and an X-ray crystallograph of the purified antibiotic indicated that it was a new diketopiperazine, and we have given it the trivial name gliovirin. Gliovirin is highly toxic to P. ultimum but is inactive against other fungi associated with cotton seedling disease. The antibiotic does not persist in nonsterile soil where it is apparently inactivated by the soil microflora.An ultraviolet light induced mutant of G. virens deficient for gliovirin production was overgrown by P. ultimum in culture and did not protect cotton seedlings from damping-off in P. ultimum infested soil. A mutant with enhanced gliovirin production was more inhibitory to P. ultimum in culture than the parent isolate and showed similar efficacy as a seedling disease suppressant, even though its growth rate was reduced when compared to the parent isolate. These results indicate that gliovirin may be important to the antagonist–pathogen interaction.

Influence of spatial planting arrangement of winter rye cover crop on corn seedling disease and corn productivity

Plant Disease ◽  
2021 ◽  
Author(s):  
Sarah Maria Kurtz ◽  
Jyotsna Acharya ◽  
Thomas C. Kaspar ◽  
Alison E Robertson
Keyword(s):  
Cover Crop ◽  
Dry Weight ◽  
Winter Rye ◽  
Field Plot ◽  
Seedling Disease ◽  
Shoot Dry Weight ◽  
No Till ◽  
Clade B ◽  
Corn Seedling ◽  
On Farm

Despite numerous environmental benefits associated with cover crop (CC) use, some farmers are reluctant to include CCs in their production systems because of reported yield declines in corn. There are numerous potential reasons for this yield decline, including seedling disease. A winter rye CC can serve as a ‘green bridge’ for corn seedling pathogens. We hypothesized that proximity of corn seedling roots to decaying rye CC roots contributes to corn seeding disease. An experimental field plot and an on-farm study were conducted over two years to evaluate growth, development, and disease severity of corn seedlings planted at various distances from decaying winter rye CC plants. The experimental field plot study was conducted in a no-till corn-soybean rotation with five replications of a winter rye CC treatments seeded as (i) no CC control, (ii) broadcast, (iii) 19-cm drilled rows, and (iv) 76-cm drilled rows. The on-farm study was no-till corn-soybean rotation with four replications of a winter rye cover crop seeded as 38-cm drilled rows, 76-cm drilled rows, and no CC control. The corn was planted on 76-cm rows shortly after rye was terminated. With multiple seeding arrangements of winter rye, corn was planted at different distances from winter rye. Corn radicle root rot severity and incidence, shoot height, shoot dry weight, corn height and chlorophyll at VT, ear parameters, and yield were collected. Soil samples were taken in the corn row and the interrow at winter rye termination, corn planting, and corn growth stage V3 to estimate the abundance of Pythium clade B members present in soil samples. Our results showed that increased distance between winter rye residue and corn reduced seedling disease and Pythium clade B populations in the radicles and soil, and increased shoot dry weight, leaf chlorophyll, plant height, and yield. This suggests that physically distancing the corn crop from the winter rye CC is one way to reduce the negative effects of a winter rye CC on corn.

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