scholarly journals Survey on Rice Blast and Morphological Characterization of Magnaporthe oryzae oryzae

2021 ◽  
pp. 8-21
Author(s):  
Z. Nazifa ◽  
F. M. Aminuzzaman ◽  
K. Akhter ◽  
M. K. Rehena ◽  
L. Laila
Keyword(s):  
Surface Structure ◽  
Magnaporthe Oryzae ◽  
Severity Score ◽  
Rice Blast ◽  
Disease Incidence ◽  
Morphological Diversity ◽  
Rice Flour ◽  
Morphological Characterization ◽  
Growth Media

Aims: To survey and study morphological characterization of rice blast caused by Magnaporthe oryzae oryzae (MoO) that has become a major factor limiting rice yield throughout the world. Study Design: Complete Randomized Design (CRD). Place and Duration of Study: Mycology Laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka from June 2018 to December 2019. Methodology: A survey was done in three northern districts of Bangladesh namely Gaibandha (Gobindogonj and Mohimagonj), Dinajpur (Birampur) and Bogura (Dupchanchia), disease incidence and severity was recorded and samples were collected. Five different media including Water Agar (WA), Potato Dextrose Agar (PDA), Potato Sucrose Agar (PSA), Rice flour Yeast Agar (RfYA) and Oat Meal Agar (OMA) were used to culture MoO. Colony characters like growth character, color, surface structure and shape of 28 MoO isolates were recorded in PDA. Results: Among the three surveyed districts, the highest incidence (84.26%) of blast was recorded from Gobindogonj with a severity score of 7. The highest severity score 9.00 (65%) of blast was recorded in Mohimagonj where blast incidence was only 29.12%. Among the five different growth media highest mycelia growth was observed in Oat Meal Agar (20 mm) and lowest in Water Agar (10mm) at 7 DAI. Colony color of all the isolates was whitish grey to blackish with sufficient growth and the average colony diameter was 50 mm. Conclusion: The results of the present study demonstrate that there is a certain level of morphological diversity such as mycelial growth rate and colony characters like color, surface structure and shape exists among isolates of MoO.

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.

Morphological and molecular characterization of Magnaporthe oryzae causing rice blast disease in Odisha

2018 ◽  
Vol 55 (3) ◽  
pp. 467 ◽  
Author(s):  
Chinmayee Sahu ◽  
Manoj Kumar Yadav ◽  
Gayatree Panda ◽  
S Aravindan ◽  
Ngangkham Umakanta ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Morphological And Molecular Characterization

Characterization of T-DNA insertion patterns in the genome of rice blast fungus Magnaporthe oryzae

2007 ◽  
Vol 51 (4) ◽  
pp. 233-243 ◽  
Author(s):  
Guihua Li ◽  
Zhuangzhi Zhou ◽  
Guifu Liu ◽  
Fucong Zheng ◽  
Chaozu He
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Blast Fungus ◽  
Blast Fungus ◽  
Dna Insertion

scholarly journals CHARACTERIZATION OF BACTERIAL ISOLATES FOR SUSTAINABLE RICE BLAST CONTROL

2020 ◽  
Vol 33 (3) ◽  
pp. 702-712
Author(s):  
BÁRBARA ESTEVAM DE MELO MARTINS ◽  
AMANDA ABDALLAH CHAIBUB ◽  
MARCIO VINICIUS DE CARVALHO BARROS CORTÊS ◽  
VALÁCIA LEMES DA SILVA LOBO ◽  
MARTA CRISTINA CORSI DE FILIPPI
Keyword(s):  
Rice Blast ◽  
Pcr Amplification ◽  
Morphological Characterization ◽  
Bacterial Isolates ◽  
Specific Primers ◽  
Leaf Blast ◽  
Fluorescent Pigment ◽  
Gram Staining ◽  
Bacillus Spp

ABSTRACT Rice blast (Magnaporthe oryzae) limits rice (Oryza sativa) grain yields worldwide. The objective of this investigation was to morphologically, biochemically, and molecularly characterize six bacterial isolates, BRM 32109, BRM 32110, BRM 32111, BRM 32112, BRM 32113, and BRM 32114, and to determine their potential as antagonists to M. oryzae. Morphological characterization was based on colony formation and color, Gram staining, and fluorescent pigment production. Biochemical studies were based on cellulase, chitinase, phosphatase, indoleacetic acid, and siderophore production, as well as biofilm formation. The molecular identification used specific primers for PCR amplification of the 16S rRNA region, followed by sequencing. The antagonism studies involved three experiments, which had randomized designs. Two of them were conducted in laboratory conditions, pairing bacterial colonies and M. oryzae, using bacterial filtrates, and the third was conducted in greenhouse conditions. BRM 32111 and BRM 32112 were identified as Pseudomonas sp., BRM 32113 as Burkholderia sp., BRM 32114 as Serratia sp., and BRM 32110 and BRM 32109 as Bacillus spp. BRM 32112, BRM 32111, and BRM 32113 inhibited the colony of M. oryzae by 68%, 65%, and 48%, respectively. The bacterial suspensions of the BRM 32111, BRM 32112, and BRM 3212 filtrates suppressed leaf blast by 81.0, 79.2, and 66.3%, respectively. BRM 32111 and BRM 32112 were determined to be antagonists of M. oryzae and were found to solubilize phosphate, produce siderophores and cellulose, form biofilms, and suppress leaf blast. These isolates should be further investigated as potential biological control agents for leaf blast control.

scholarly journals System-Wide Characterization of MoArf GTPase Family Proteins and Adaptor Protein MoGga1 Involved in the Development and Pathogenicity of Magnaporthe oryzae

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Shengpei Zhang ◽  
Lina Yang ◽  
Lianwei Li ◽  
Kaili Zhong ◽  
Wenhao Wang ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Vesicle Trafficking ◽  
Family Members ◽  
Adaptor Protein ◽  
Small Gtpase ◽  
Content Type ◽  
Blast Fungus ◽  
Adp Ribosylation Factor

ABSTRACT ADP ribosylation factor (Arf) small GTPase family members are involved in vesicle trafficking and organelle maintenance in organisms ranging from Saccharomyces cerevisiae to humans. A previous study identified Magnaporthe oryzae Arf6 (MoArf6) as one of the Arf proteins that regulates growth and conidiation in the rice blast fungus M. oryzae, but the remaining family proteins remain unknown. Here, we identified six additional Arf proteins, including MoArf1, MoArl1, MoArl3, MoArl8, MoCin4, and MoSar1, as well as their sole adaptor protein, MoGga1, and determined their shared and specific functions. We showed that the majority of these proteins exhibit positive regulatory functions, most notably, in growth. Importantly, MoArl1, MoCin4, and MoGga1 are involved in pathogenicity through the regulation of host penetration and invasive hyphal growth. MoArl1 and MoCin4 also regulate normal vesicle trafficking, and MoCin4 further controls the formation of the biotrophic interfacial complex (BIC). Moreover, we showed that Golgi-cytoplasm cycling of MoArl1 is required for its function. Finally, we demonstrated that interactions between MoArf1 and MoArl1 with MoGga1 are important for Golgi localization and pathogenicity. Collectively, our findings revealed the shared and specific functions of Arf family members in M. oryzae and shed light on how these proteins function through conserved mechanisms to govern growth, transport, and virulence of the blast fungus. IMPORTANCE Magnaporthe oryzae is the causal agent of rice blast, representing the most devastating diseases of rice worldwide, which results in losses of amounts of rice that could feed more than 60 million people each year. Arf (ADP ribosylation factor) small GTPase family proteins are involved in vesicle trafficking and organelle maintenance in eukaryotic cells. To investigate the function of Arf family proteins in M. oryzae, we systematically characterized all seven Arf proteins and found that they have shared and specific functions in governing the growth, development, and pathogenicity of the blast fungus. We have also identified the pathogenicity-related protein MoGga1 as the common adaptor of MoArf1 and MoArl1. Our findings are important because they provide the first comprehensive characterization of the Arf GTPase family proteins and their adaptor protein MoGga1 functioning in a plant-pathogenic fungus, which could help to reveal new fungicide targets to control this devastating disease.

scholarly journals Genome-wide characterization of methylguanosine-capped and polyadenylated small RNAs in the rice blast fungus Magnaporthe oryzae

2010 ◽  
Vol 38 (21) ◽  
pp. 7558-7569 ◽  
Author(s):  
Malali Gowda ◽  
Cristiano C. Nunes ◽  
Joshua Sailsbery ◽  
Minfeng Xue ◽  
Feng Chen ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Small Rnas ◽  
Rice Blast ◽  
Rice Blast Fungus ◽  
Blast Fungus ◽  
Genome Wide

scholarly journals Morphological characterization of seeds in Portulacaceae

Phytotaxa ◽  
2013 ◽  
Vol 141 (1) ◽  
pp. 1 ◽  
Author(s):  
Gilberto Ocampo
Keyword(s):  
Cell Walls ◽  
Individual Cell ◽  
Morphological Diversity ◽  
Morphological Characterization ◽  
Seed Morphology ◽  
Important Variation ◽  
Species Complexes ◽  
Multiple Samples

Portulacaceae is a monogeneric family with around 100 species distributed around the world. Seed morphology is diverse in this group, and its variation has been used for taxonomic and identification purposes. However, documentation of seed morphology has focused on a few species complexes or has been limited to specific countries and geographic areas. Moreover, the terminology employed in different investigations is heterogeneous, thus complicating analyses of seed morphological diversity in Portulacaceae. In this study, the seed morphology of 58 samples representing 49 species, 9 subspecies, and 2 cultivars of Portulaca was documented with the use of scanning electron microscopy (SEM). Based on the examination of the resulting images, a set of morphological features for describing the general shape of the seeds and their individual cell features is proposed; in addition, morphological descriptions for all taxa included in this study are provided. The results indicate that the shape of the seeds was constant within species, contrary to the characters that describe individual cell features, which showed important variation even within the same seed sample. In particular, the outline of the cells and the curvature of the anticlinal cell walls (ACW) were very variable, so a combination of character states was needed to describe the overall diversity of a sample. Conversely, the relief of the periclinal cell walls (PCW) was relatively constant throughout the seeds of the same species, but the relief of the cells of the lateral and peripheral faces was dissimilar in a number of taxa. In addition, other studies provide evidence that the relief of the PCW may vary in widely distributed species. Increased taxon sampling and multiple samples of species with wide geographical ranges will facilitate the study of patterns of variation, and may provide insights into the role of environmental variables on seed diversity of Portulacaceae.

scholarly journals Isolation and Characterization of Avirulence Genes in Magnaporthe oryzae

2017 ◽  
Vol 7 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Mui Sie Jee ◽  
Leonard Whye Kit Lim ◽  
Martina Azelin Dirum ◽  
Sara Ilia Che Hashim ◽  
Muhammad Shafiq Masri ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Fungal Pathogen ◽  
Rice Blast ◽  
Avirulence Gene ◽  
Avirulence Genes ◽  
Isolation And Characterization ◽  
Molecular Pattern ◽  
Avr Gene ◽  
Avr Genes

Magnaporthe oryzae is a fungal pathogen contributing to rice blast diseases globally via their Avr (avirulence) gene. Although the occurrence of M. oryzae has been reported in Sarawak since several decades ago, however, none has focused specifically on Avr genes, which confer resistance against pathogen associated molecular pattern-triggered immunity (PTI) in host. The objective of this study is to isolate Avr genes from M. oryzae 7’ (a Sarawak isolate) that may contribute to susceptibility of rice towards diseases. In this study, AvrPiz-t, AVR-Pik, Avr-Pi54, and AVR-Pita1 genes were isolated via PCR and cloning approaches. The genes were then compared with set of similar genes from related isolates derived from NCBI. Results revealed that all eight Avr genes (including four other global isolates) shared similar N-myristoylation site and a novel motif. 3D modeling revealed similar β-sandwich structure in AvrPiz-t and AVR-Pik despite sequence dissimilarities. In conclusion, it is confirmed of the presence of these genes in the Sarawak (M. oryzae) isolate. This study implies that Sarawak isolate may confer similar avirulence properties as their counterparts worldwide. Further R/Avr gene-for-gene relationship studies may aid in strategic control of rice blast diseases in future.

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.

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