scholarly journals Control of Magnaporthe oryzae and Rice Growth Promotion by Bacillus subtilis JN005

2021 ◽  
Author(s):  
Huajun Zhu ◽  
Hu Zhou ◽  
Zuohua Ren ◽  
Erming Liu
Keyword(s):  
Bacillus Subtilis ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Growth Promotion ◽  
Biological Control Agent ◽  
Disease Incidence ◽  
Control Treatment ◽  
Bacterial Suspension ◽  
Sterile Water ◽  
Rice Leaves

AbstractIt is quite important to develop the microorganism resources with biocontrol capacity for rice blast. This study evaluated Bacillus subtilis JN005 for growth promotion and biocontrol efficacy against Magnaporthe oryzae. Results showed that rice seeds treated with 1 × 107 cfu/mL suspension of B. subtilis JN005 had 16% germination energy, 14% germination rate, 15% germination index, and 270% vigor index compared to those treated with sterile water (control). In pot experiments, the JN005 strain-treated rice plants exhibited notable increase in plant height, root length, stem circumference, and fresh weight, as well as higher concentration of chlorophyll a, chlorophyll b, and total chlorophyll in rice leaves. Rice leaves inoculated with the JN005 strain resulted in increased activities of defense-related enzymes, including peroxidase (POD), phenylalanine ammonialyase (PAL), superoxide dismutase (SOD), and catalase (CAT) compared to the water and the M. oryzae-inoculated treatments. In vitro inoculated rice leaves with 1 × 107 cfu/mL bacterial suspension compared to sterile water or control treatment exhibited lower disease incidence in the curative and preventive groups by 79% and 76%, respectively. Field experiment showed that after spraying with 1 × 107 cfu/mL bacterial suspension, efficacy rates on controlling rice blast on plants were (56.82 ± 1.12)% and (58.39 ± 3.05)% at seedling and maturity stages, respectively, and that rice production yield was (524.40 ± 17.88) g/m2. Therefore, B. subtilis JN005 could be a promising biological control agent for rice blast, thereby warranting further investigation of its efficacy.

scholarly journals Bacillus subtilis ALBA01 can mitigate onion pink root symptoms caused by Setophoma terrestris

2019 ◽  
Author(s):  
P Sayago ◽  
F Juncosa ◽  
A Albarracín Orio ◽  
D.F. Luna ◽  
G Molina ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Crop Rotation ◽  
Growth Promotion ◽  
Disease Incidence ◽  
Soil Fumigation ◽  
Promotion Effect ◽  
Physiological Variables ◽  
Yield Parameters ◽  
Onion Cultivar ◽  
Setophoma Terrestris

AbstractSoil-borne pathogen Setophoma terrestris is the causal agent of pink root of onion, one of the most challenging diseases in onion production. Conventional approaches for managing the disease like solarization, soil fumigation and crop rotation have not been proven effective enough. In this work, we evaluated the biocontrol capacity of Bacillus subtilis ALBA01 (BsA01) against S. terrestris, in a highly susceptible onion cultivar, both under greenhouse and field conditions. Disease incidence and severity were evaluated together with growth, photosynthesis among other physiological variables and yield parameters. When compared with plants infected with the pathogen, those plants co-inoculated with BsA01 showed significantly less damage and levels of biocontrol above 50%. With regard to physiological parameters, plants challenged with S terrestris and inoculated with BsA01 performed as well as the control non-infected plants revealing a growth promotion effect of BsA01 on onion plants.

scholarly journals Antifungal activity of microbial nanoparticles derived from Chaetomium spp. against Magnaporthe oryzae causing rice blast

2020 ◽  
Vol 56 (No. 3) ◽  
pp. 180-190
Author(s):  
Jiaojiao Song ◽  
Kasem Soytong ◽  
Somdej Kanokmedhakul ◽  
Kwanjai Kanokmedhakul ◽  
Supattra Poeaim
Keyword(s):  
Antifungal Activity ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Spore Production ◽  
Etoac Extract ◽  
Rice Leaves ◽  
Chaetomium Elatum ◽  
Layer Chromatography

The Magnaporthe oryzae isolate PO2 was proven to cause rice blast var. PSL 2 in this study. Chaetomium elatum, Chaetomium lucknowense and Chaetomium brasiliense were antagonised to M. oryzae.  The hexane extract of C. brasiliense gave the highest inhibition of the spore production with an ED<sub>50</sub> of 35 ppm, the EtOAC extract of C. lucknowense inhibited the spore production at 57 ppm and the EtOAC extracts of C. elatum inhibited the spore production at 106 ppm. The nano-CLM (C. lucknowense) inhibited the spore production at 5.24 ppm, the nano-CBH (C. brasiliense) inhibited the spore production at 6.86 ppm and the nano-CEE (C. elatum) inhibited the spore production at 7.89 ppm. The rice leaves treated with nano-CBH from C. brasiliense produced Sakuranertin and Oryzalexin B as seen on the thin layer chromatography where the Rf value was 0.08 assumed to be Sakuranertin, and the Rf value of 0.28 supposed to be Oryzalexin B. It was found that the nanoparticles act as elicitors to induce immunity in rice plants through the production of phytoalexin.

scholarly journals Genetic Differentiation of Magnaporthe oryzae Populations from Scouting Plots and Commercial Rice Fields in Korea

2008 ◽  
Vol 98 (4) ◽  
pp. 436-442 ◽  
Author(s):  
S.-Y. Park ◽  
M. G. Milgroom ◽  
S. S. Han ◽  
S. Kang ◽  
Y.-H. Lee
Keyword(s):  
Genetic Differentiation ◽  
Mating Type ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Disease Incidence ◽  
Rice Fields ◽  
Dna Fingerprint ◽  
Group I ◽  
Group Ii ◽  
Set Up

A previous study of the diversity and population structure of the rice blast fungus, Magnaporthe oryzae, over a 20-year period in Korea, found novel fingerprint haplotypes each year, and the authors hypothesized that populations might experience annual bottlenecks. Based on this model, we predicted that M. oryzae populations would have little or no genetic differentiation among geographic regions because rice blast is commonly found throughout Korea each year and M. oryzae would have to disperse from small populations surviving annually between rice crops. To test this hypothesis, we sampled M. oryzae from rice fields in eight provinces in Korea in a single year (1999). In four provinces, we sampled from a set of rice cultivars commonly grown in commercial fields (group I); because of low disease incidence in four other provinces, we could not sample from commercial fields and instead sampled from scouting plots of different cultivars set up for detecting new pathotypes of M. oryzae (group II). All isolates were genotyped with DNA fingerprint probes MGR586 and MAGGY, a telomere-linked gene family member TLH1, the PWL2 host specificity gene and mating type. Fingerprint haplotypes clustered into two distinct lineages corresponding to the two sets of cultivars (groups I and II), with haplotype similarities of 71% between lineages and >76% within lineages. Isolates from the same cultivar within group I were genetically differentiated among locations, and isolates within the same location were differentiated among cultivars. Differentiation for TLH1 and PWL2 was significant (P < 0.03), but not as strong as for fingerprint markers. Similar analyses were not possible among group II isolates because too few isolates were available from any one cultivar. All isolates were in the same mating type, Mat1-1, ruling out sexual reproduction as a source of novel haplotypes. When the 1999 samples were compared with the historical samples from the previous study, haplotypes of group I formed a separate cluster, while those of group II clustered with haplotypes from the historical sample. Altogether, geographic subdivision, monomorphism of mating type, and correlation of haplotypes to sets of cultivars are not consistent with the hypothesis of repeated turnover of haplotypes. Instead, the previous correlations of haplotypes to year might have been caused by inadequate sampling of haplotypes each year, highlighting the need for studies of population genetics to be conducted with systematic samples collected to address specific questions.

scholarly journals SCREENING OF SALT TOLERANT BACTERIA FOR PLANT GROWTH PROMOTION ACTIVITIES AND BIOLOGICAL CONTROL OF RICE BLAST AND SHEATH BLIGHT DISEASE ON MANGROVE RICE

2018 ◽  
Vol 55 (1A) ◽  
pp. 54
Author(s):  
Nguyen Van Minh
Keyword(s):  
Antifungal Activity ◽  
Plant Growth ◽  
Fungal Pathogen ◽  
Rice Blast ◽  
Root Zone ◽  
Growth Promotion ◽  
Sheath Blight ◽  
Control Treatment ◽  
Rice Soil ◽  
Model Combination

From 22 rice, soil and water samples collected in the field of Long An and Tien Giang provinces, we isolated and screened 87 strains of bacteria around the root zone and endophytic bacteria. Through testing the ability of plant growth stimulation, the result showed 16 strains were capable of nitrogen fixation, 13 strains were capable of phosphate solubilization, 27 strains were capable of IAA production and 2 strains had all 3 activities. By the dual testing method and the percentage of inhibition method between bacterial and fungal pathogen, LD5 and LS6 strains had the highest antifungal activity against Rhizotocnia sp. CR1 at 94.02 %. TS3 and TĐ13 strains had the highest antifungal activity against Magnaporthe sp. BP3 at 81.74 ± 0.88 % and 80 ± 0.60 %, respectively. Furthermore, there were 6 strains inhibiting both Rhizotocnia sp. CR1 and Magnaporthe sp. BP3 (LĐ5, LS4, LS6, LN1, LN6, TS3). The strains were identified by biochemical methods. The results showed that LD5, LS6 and TS3 were 70.37 % similar to Bacillus thurigiensis, TD13 strain was 70.37 % similar to Bacillus pantothenticus, TD9 strain was 72.72 % similar to Azotobacter vinelandii and TD6 strain was 70.37 % similar to Bacillus subtilis. Regarding the test of activity to stimulate growth in net house model, combination of 4-strain (TD6, TD9, TD13, TS3) had the effect of increasing the length of roots, trunk and weight of rice compared with control treatment. For evaluation of biocontrol of fungal pathogen in net house model, the abilities to control sheath blight in N-2C1 and N-LĐ5 treatment were the highest (40.59 % and 39.06 %, respectively). The ability to control rice blast in N-2C2 treatment was the highest (41.26 %). The ability to biocontrol both sheath blight and rice blast in N-4C treatment was 37.89 %.

scholarly journals Carolina Foxtail (Alopecurus carolinianus): Susceptibility and Suitability as an Alternative Host to Rice Blast Disease (Magnaporthe oryzae [formerly M. grisea])

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 504-507 ◽  
Author(s):  
Y. Jia ◽  
D. Gealy ◽  
M. J. Lin ◽  
L. Wu ◽  
H. Black
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Artificial Inoculation ◽  
Rice Cultivars ◽  
Alternative Host ◽  
Lesion Development ◽  
Disease Symptoms ◽  
Rice Leaves

Carolina foxtail (Alopecurus carolinianus) has not been reported to host Magnaporthe oryzae. A collection of Carolina foxtail obtained from several Arkansas locations over a 4-year period was inoculated with four races of the fungus under greenhouse conditions and, in all cases, inoculation resulted in the formation of irregular, yellow and brown lesions without obvious gray centers that are characteristic for blast on rice. Differences in these lesions were not observed among our collection. These lesions appeared to differ from typical blast lesions on inoculated rice leaves but were evident following artificial inoculation of Carolina foxtail in the greenhouse. M. oryzae races that differed in pathogenicity toward rice cultivars also displayed differences in lesion development on Carolina foxtail. The most virulent race on rice cultivars also produced lesions most rapidly on Carolina foxtail. These lesions developed more quickly on Carolina foxtail than on the most susceptible rice cultivars tested, including a susceptible California cultivar, M202. M. oryzae isolates cultured from these lesions in the infected Carolina foxtail caused typical disease symptoms of blast on inoculated rice cultivars. We suggest that Carolina foxtail is a new and previously unrecognized host for the blast pathogen.

scholarly journals Genetic and nutritional diversity of Bacillus subtilis isolates demonstrating different aspects related to plant growth promotion

2020 ◽  
pp. 880-888
Author(s):  
Bianca de Melo Silveira dos Santos ◽  
Maura Santos dos Reis de Andrade Silva ◽  
Davy William Hidalgo Chávez ◽  
Everlon Cid Rigobelo
Keyword(s):  
Bacillus Subtilis ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Agricultural Practices ◽  
Production Costs ◽  
Control Treatment ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Promote Plant Growth

Currently, agricultural practices have been undergoing intense transformations, imposing major challenges such as maintaining productivity with lower production costs and environmental impacts. One of the alternatives to meet these requirements is the use of plant growth promoting bacteria, including Bacillus subtilis. However, different isolates may express different aspects and levels of plant growth promotion. The present study aimed to verify the genetic and nutritional diversity of eight B. subtilis isolates, demonstrating different aspects and levels of plant growth promotion. Eight B. subtilis isolates were analyzed as to their nutritional diversity by BiologEcoPlate TM kit, genetic diversity by Box-PCR, and a trial in greenhouse conditions. The experimental design in greenhouse trial was completely randomized with 9 treatments and five replicates, resulting in 45 pots. Treatments were eight Bacillus subtilis strains, and a control treatment using plants without bacterial inoculation. Isolates 290 and 287 are genetically similar, while isolates 248 and 263 also showed similarity. Genetic and substrate consumption (carbon) analyses showed differences and similarities among isolates, allowing the distribution of isolates into different groups. It was observed that the isolate with the highest ability to promote plant growth was the only isolate that consumed glycyl-L- glutamic acid. These results open the way for further investigations in an attempt to clarify what are the conditions and / or characteristics required by isolates for the plant growth promotion to be more effective.

scholarly journals Bacillus subtilis GB519 Promotes Rice Growth and Reduces the Damages Caused by Rice Blast Fungus Magnaporthe oryzae

2021 ◽  
Author(s):  
Feng Zhu ◽  
JICHUN WANG ◽  
Yulin Jia ◽  
Chengli Tian ◽  
Xian Wu ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Field Experiments ◽  
Blast Disease ◽  
Plant Production ◽  
Subtilis Strain ◽  
Fresh Weight ◽  
Gyra Gene ◽  
Ustilaginoidea Virens

Rice blast disease caused by fungus Magnaporthe oryzae (syn. Pyricularia oryzae) is one of the most damaged diseases of rice reducing plant production worldwide. In the present study, Bacillus subtilis strain GB519 was identified from the rhizosphere based on predicted signatures of 16S rDNA and gyrA gene and morphological, biochemical and physiological characteristics. Treated with B. subtilis GB519, rice plant exhibited increased germination rate, vigor index, shoot length, shoot fresh weight, root fresh weight coupled with more production of Indole Acetic Acid (IAA), organic (Porg) and inorganic phosphorus (Phos). In culture GB519 inhibited growth of following rice fungal pathogens (in order from most effective to least effective): M. oryzae, Ustilaginoidea virens, Fusarium graminearum, F. moniliforme, F. oxysporum and Rhizoctonia solani. Three years studies showed that when rice was sprayed with GB519, there were significant reductions in rice blast incidence both in greenhouse and fields: 70.3% and 62.1% in 2017, and 69.9% and 71.6% in 2018, 75.1% and 75.6% in 2019. Such reductions were correlated with accumulated hydrolytic enzymes including amylases, proteases, chitinase and lipases, and the defense enzyme activity of the total antioxidant capacity (TAOC), catalase (CAT) and superoxide dismutase (SOD) in rice. Field experiments showed that the biocontrol efficacy of GB519 was similar to that of other biological and chemical fungicides. Our results that B. subtilis strain GB519 promoted plant growth and reduced blast disease suggest that this strain has potential to be used as a biological control agent against rice blast.

scholarly journals Rice Blast Disease (Magnaporthe oryzae): A Menace to Rice Production and Humanity

2020 ◽  
pp. 32-39
Author(s):  
G. O. Agbowuro ◽  
M. S. Afolabi ◽  
E. F. Olamiriki ◽  
S. O. Awoyemi
Keyword(s):  
Food Security ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Disease Incidence ◽  
Rice Production ◽  
Rice Blast Disease ◽  
Control Measures ◽  
Blast Disease ◽  
Economic Losses ◽  
Rice Grain

Rice blast disease is one of the major constraints to rice production, threatening food security globally. Rice grain production losses due to the disease leads economic losses to the farmers, and to an increase in global rice price as a result of the supply that is far below the consumer demand. The losses from the disease annually was estimated to feed over 60 million individual. The disease has been studied comprehensively by researchers due to the importance attached to rice and its vast spread and destructiveness across the globe. A good understanding of the pathogen causing the disease, its life cycle and development, epidemiology, symptoms, management strategy will offer a good insight into the disease incidence and give an appropriate and effective decision-making in its management. Different control measures have been adopted managing the disease, including the use of resistant varieties. Integrated disease management strategies coupled with good agronomy practices are required for successful control of rice blast for food security. This review, therefore, examined the fundamentals of rice blast disease (Magnaporthe oryzae) and offered strategies to minimize the disease activities to ensure proper production and increase the supply of rice grains.

scholarly journals Mating Types Analysis of Magnaporthe oryzae Populations by Molecular Methods

2014 ◽  
Vol 8 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Soma Samanta ◽  
Urmila Dhua ◽  
Shubhransu Nayak ◽  
L. Behera ◽  
A. K. Mukherjee
Keyword(s):  
Mating Type ◽  
Ribosomal Rna ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Population Diversity ◽  
Disease Spread ◽  
Mating Types ◽  
Type Analysis ◽  
Sexual Recombination ◽  
Rice Leaves

Rice blast is a devastating disease which is caused by the heterothallic fungus Magnaporthe oryzae. Compatible sexual recombination which occurs between two M. oryzae strains of different mating types, can enhance genetic variability. Assessment of mating type alleles is used as a marker to measure population diversity. Forty six isolates of M. oryzae were collected from infected rice leaves from various ecosystems of coastal Odisha, India, and the mating type analysis using molecular markers was carried out. MAT1-1 mating type was dominating in all the ecosystems and MAT1-2 was found to be present in uplands as well as in irrigated fields. Both mating types could be found in the same field in irrigated ecosystem. The disease spread was very fast vertically as well as horizontally in those fields resulting in blast lesions looking as ‘green islands (gi) produced in senescence leaves’, and MAT1-2 was found to be associated with all gi lesions. Consequently, the management of the disease in those plots was very difficult. Interestingly, ribosomal RNA IGS region could not be amplified in MAT1-2 isolates but consistent amplification was obtained in MAT1-1 mating type isolates.

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