Elucidation of genetic relatedness of Magnaporthe grisea, an incitent of pearl millet blast disease by molecular markers associated with virulence of host differential cultivars

2020 ◽  
Vol 149 ◽  
pp. 104533
Author(s):  
Shivakantkumar Adhikari ◽  
Shreya M. Joshi ◽  
Bandenamaj K. Athoni ◽  
Prakashgouda V. Patil ◽  
Sudisha Jogaiah
Keyword(s):  
Molecular Markers ◽  
Pearl Millet ◽  
Magnaporthe Grisea ◽  
Genetic Relatedness ◽  
Blast Disease ◽  
Differential Cultivars

scholarly journals Deciphering Genotype-By-Environment Interaction for Target Environmental Delineation and Identification of Stable Resistant Sources Against Foliar Blast Disease of Pearl Millet

2021 ◽  
Vol 12 ◽  
Author(s):  
S. Mukesh Sankar ◽  
S. P. Singh ◽  
G. Prakash ◽  
C. Tara Satyavathi ◽  
S. L. Soumya ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Magnaporthe Grisea ◽  
Resistance Breeding ◽  
Genotype By Environment Interaction ◽  
Blast Disease ◽  
Environment Interaction ◽  
Breeding Programs ◽  
Genotype By Environment ◽  
Desirability Index ◽  
Resistant Genotypes

Once thought to be a minor disease, foliar blast disease of pearl millet, caused by Magnaporthe grisea, has recently emerged as an important biotic constraint for pearl millet production in India. The presence of a wider host range as well as high pathogenic heterogeneity complicates host–pathogen dynamics. Furthermore, environmental factors play a significant role in exacerbating the disease severity. An attempt was made to unravel the genotype-by-environment interactions for identification and validation of stable resistant genotypes against foliar blast disease through multi-environment testing. A diversity panel consisting of 250 accessions collected from over 20 different countries was screened under natural epiphytotic conditions in five environments. A total of 43 resistant genotypes were found to have high and stable resistance. Interestingly, most of the resistant lines were late maturing. Combined ANOVA of these 250 genotypes exhibited significant genotype-by-environment interaction and indicated the involvement of crossover interaction with a consistent genotypic response. This justifies the necessity of multi-year and multi-location testing. The first two principal components (PCs) accounted for 44.85 and 29.22% of the total variance in the environment-centered blast scoring results. Heritability-adjusted genotype plus genotype × environment interaction (HA-GGE) biplot aptly identified “IP 11353” and “IP 22423, IP 7910 and IP 7941” as “ideal” and “desirable” genotypes, respectively, having stable resistance and genetic buffering capacity against this disease. Bootstrapping at a 95% confidence interval validated the recommendations of genotypes. Therefore, these genotypes can be used in future resistance breeding programs in pearl millet. Mega-environment delineation and desirability index suggested Jaipur as the ideal environment for precise testing of material against the disease and will increase proper resource optimization in future breeding programs. Information obtained in current study will be further used for genome-wide association mapping of foliar blast disease in pearl millet.

The taxonomical identity of the perfect state of Pyricularia grisea and its allies

1978 ◽  
Vol 56 (2) ◽  
pp. 180-183 ◽  
Author(s):  
H. Yaegashi ◽  
S. Udagawa
Keyword(s):  
Magnaporthe Grisea ◽  
Single Species ◽  
Causal Agent ◽  
Blast Disease ◽  
Stem Rot ◽  
Pyricularia Grisea ◽  
Perfect State ◽  
Conidial State

Magnaporthe grisea is proposed as a comb.nov. for Ceratosphaeria grisea Hébert, the perfect state of Pyricularia grisea (Cke.) Sacc. Pyricularia grisea is very close morphologically to P. oryzae Cav., well known as the causal agent of blast disease on rice. Magnaporthe was recently established in the Diaporthales to accommodate a single species, M. salvinii (Catt.) Krause & Webster, which was described as the cause of stem rot of rice with conidial state known as Nakataea sigmoidea Hara. Based on a review of the taxonomic characters of Ceratosphaeria grisea, the desirability is discussed of its inclusion in the genus Magnaporthe.

scholarly journals First Report of Gray Leaf Spot on St. Augustinegrass in Italy

Plant Disease ◽  
2003 ◽  
Vol 87 (12) ◽  
pp. 1536-1536 ◽  
Author(s):  
G. Polizzi ◽  
I. Castello ◽  
A. M. Picco ◽  
D. Rodino
Keyword(s):  
Leaf Spot ◽  
Magnaporthe Grisea ◽  
Fungal Spore ◽  
Gray Leaf Spot ◽  
Blast Disease ◽  
Leaf Spot Disease ◽  
High Humidity ◽  
Conidial Suspension ◽  
First Report ◽  
Pathogenicity Tests

St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze) is used for lawns in southern Italy because it is much more resistant to biotic and abiotic adversities than other turfgrass species. Because few seeds are viable, this species is established by vegetative propagation. A new disease was noticed during the spring of 2002 and 2003 on cuttings of St. Augustinegrass growing in three greenhouses in eastern Sicily. The disease affected leaves and culms and caused a progressive drying of the plants. The infection was first seen on leaves as gray, necrotic spots that enlarged in high-humidity conditions to form oval, and later, spindle-shaped lesions. In association with the lesions, it was possible to observe fungal spore development and sunken areas with blue-gray centers and slightly irregular, brown margins with yellow halos. Spots were concentrated without specific arrangement along longitudinal veins and the midrib and at the base, tip, and margins of the leaf blade. Symptoms on the culms consisted of brown-to-black blotches that sometimes extended throughout the internodes. From these infected tissues, 20 explants taken from leaves and culms were cut, washed with sterile water, and placed on 1.5% water agar (WA). Later, conidia and conidiophores were obtained from colonies with a sterile glass needle and placed on 4% WA. From these plates, two monoconidial isolates were obtained and transferred to rice meal medium (1). The colonies were identified as Pyricularia grisea Cooke (Sacc.), anamorphic state of Magnaporthe grisea (Hebert) Yeagashi & Udagawa, the cause of rice blast disease and gray leaf spot disease of turfgrasses. The conidia were pyriform to obclavate, narrowed toward the tip, rounded at the base, 2-septate, 21 to 31 μm × 6 to 10 μm (average 25.7 ×8.2 μm). Pathogenicity tests were performed by inoculating leaves and culms of six St. Augustinegrass plants with a conidial suspension of the fungus (1.5 ×105 conidia per ml). The same number of noninoculated plants was used as controls. All plants were incubated in a moist chamber with high humidity at 25°C. After 6 days, all inoculated plants showed typical symptoms of the disease. Koch's postulates were fulfilled by isolating P. grisea from inoculated plants. Gray leaf spot caused by P. grisea has been a chronic problem on St. Augustinegrass since it was first reported in 1957 (2). To our knowledge, this is the first report of P. grisea on St. Augustinegrass in Italy. While it does not appear to be an important disease in the field at this time in Sicily, it could cause losses in greenhouses where vegetative material is propagated for field planting. A preliminary molecular analysis has shown a clear distinction between the tested strain and other strains isolated from rice seeds and plants in northern Italy. References: (1) E. Roumen et al. Eur. J. Plant Pathol. 103:363, 1997. (2) L. P. Tredway et al. Plant Dis. 87:435, 2003.

scholarly journals Differentiation of apomictic and sexual genotypes of Brachiaria spp., using molecular markers

2018 ◽  
Vol 5 (13) ◽  
pp. 71
Author(s):  
Jaime Pblete-Vargas ◽  
Ernestina Valadez-Moctezuma ◽  
Gabino García-de los Santos ◽  
Carlos Martínez-Flores ◽  
Armando Peralta-Martínez
Keyword(s):  
Molecular Markers ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Genetic Relatedness ◽  
Fragment Length Polymorphism ◽  
Hybrid Vigor ◽  
Parental Line ◽  
High Productivity ◽  
Caps Markers ◽  
The Tropics

Some species of Brachiaria are cultivated in the tropics because of their high productivity and drought resistance; their apomictic hybrids are of interest because of the almost null segregation and xation of the hybrid vigor in seeds. In this research, Amplied Fragment Length Polymorphism (AFLP) and Cleaved Amplied Polymorphic Sequence (CAPS) markers were used to dierentiate apomictic tetraploid and sexual diploid Brachiaria parents and their progeny. Polymorphism detected with AFLP was 91.3% and with CAPS 79.7%. Phenograms dierentiated each genotype and the clustering of parents and their progeny was by their degree of genetic relatedness. AFLP did not separate the apomictic genotypes from the sexual ones, but CAPS markers did so through the C15-8 marker. Some apomictic genotypes of the progeny inherited it from their B. ruziziensis sexual mother, which may be related to some segregating character of the parental line.

scholarly journals RAR1, ROR1, and the Actin Cytoskeleton Contribute to Basal Resistance to Magnaporthe grisea in Barley

2005 ◽  
Vol 18 (5) ◽  
pp. 397-404 ◽  
Author(s):  
Birgit Jarosch ◽  
Nicholas C. Collins ◽  
Nina Zellerhoff ◽  
Ulrich Schaffrath
Keyword(s):  
Cell Wall ◽  
Actin Cytoskeleton ◽  
Magnaporthe Grisea ◽  
Penetration Resistance ◽  
Blast Disease ◽  
Dependent Manner ◽  
Basal Resistance ◽  
Major Resistance Gene ◽  
Cytochalasin E ◽  
Dose Dependent

The fungus Magnaporthe grisea, the causal agent of rice blast disease, is a major pathogen of rice and is capable of producing epidemics on other cultivated cereals, including barley (Hordeum vulgare). We explored the requirements for basal resistance of barley against a compatible M. grisea isolate using both genetic and chemical approaches. Mutants of the RAR1 gene required for the function of major resistance gene-mediated resistance and mutants of the ROR1 and ROR2 genes required for full expression of cell-wall-penetration resistance against powdery mildew pathogens were examined for macroscopic and microscopic alterations in M. grisea growth and symptoms. RAR1 contributed to resistance in epidermis and mesophyll at different stages of fungal infection dependent on the MLO/mlo-5 status. Whereas no ROR2 effect was detected, ROR1 was found to contribute to cell-wall-penetration resistance, at least in the epidermis. Application of the actin agonist cytochalasin E promoted cell wall penetration by M. grisea in a dose-dependent manner, demonstrating an involvement of the actin cytoskeleton in penetration resistance.

Genetic analyses of electrophoretic enzyme variants, mating type, and hermaphroditism in Pyricularia oryzae Cavara

1985 ◽  
Vol 27 (6) ◽  
pp. 697-704 ◽  
Author(s):  
Hei Leung ◽  
Paul H. Williams
Keyword(s):  
Lactate Dehydrogenase ◽  
Mating Type ◽  
Rice Blast ◽  
Magnaporthe Grisea ◽  
Finger Millet ◽  
Single Gene ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Electrophoretic Variants ◽  
Variant Alleles

Pyricularia oryzae (teleomorph: Magnaporthe grisea) parasitizes a variety of gramineous hosts and causes the rice blast disease worldwide. Through matings among P. oryzae isolates from rice, finger millet, and weeping lovegrass the inheritance of electrophoretic variants of six enzymes, phosphoglucomutase (PGM), phosphoglucose isomerase (PGI), glycerate-2-dehydrogenase (G2DH), malate dehydrogenase-3 (MDH-3), lactate dehydrogenase-1 (LDH-1), and lactate dehydrogenase-3 (LDH-3) was determined. All six variants were under single gene control as determined by tetrad and random spore analysis. However, at Ldh-3 and Mdh-3, there were consistent excesses of variant alleles among ascospore segregants. Preliminary data on the genetic control of hermaphroditism suggested that maleness in two Japanese rice isolates might be due to a single gene mutation. Linkage analyses among the six electrophoretic markers, mating type, and hermaphroditism suggested loose linkage between Pgm and G2dh with a recombination frequencies of 43.0%.Key words: linkage, Magnaporthe grisea, rice blast fungus.

scholarly journals Characterization of Mexican Isolates of Colletotrichum lindemuthianum by Using Differential Cultivars and Molecular Markers

1998 ◽  
Vol 88 (4) ◽  
pp. 292-299 ◽  
Author(s):  
Mario González ◽  
Raul Rodríguez ◽  
Maria Elena Zavala ◽  
Juan L. Jacobo ◽  
Fernando Hernández ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Random Amplified Polymorphic Dna ◽  
Geographic Location ◽  
Genetic Distances ◽  
Colletotrichum Lindemuthianum ◽  
Aflp Data ◽  
Bootstrap Analysis ◽  
Differential Cultivars ◽  
Bean Anthracnose

Differential cultivars and molecular markers were used to analyze 59 isolates of the bean anthracnose pathogen, Colletotrichum lindemuthianum, from different regions of Mexico. Ten distinct races were determined, three of which had not been reported previously in Mexico. Isolates were found to infect only a narrow range of the differential cultivars used and were restricted to cultivars of Middle American origin. A comparison of random amplified polymorphic DNA and amplified fragment length polymorphism (AFLP) analyses was carried out on a subset of the fungal isolates. Determination of genetic distances based on AFLP data and production of a dendrogram demonstrated two levels of association: i) isolates classified into two major groups according to the type of cultivar or system of cultivation from which they originated, and ii) isolates could be classified into smaller subgroups generally associated with the geographic location from which they were obtained. Bootstrap analysis and determination of confidence intervals showed these geographic groupings to be extremely robust.

scholarly journals Redox-Active Pyocyanin Secreted by Pseudomonas aeruginosa 7NSK2 Triggers Systemic Resistance to Magnaporthe grisea but Enhances Rhizoctonia solani Susceptibility in Rice

2006 ◽  
Vol 19 (12) ◽  
pp. 1406-1419 ◽  
Author(s):  
David De Vleesschauwer ◽  
Pierre Cornelis ◽  
Monica Höfte
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Rhizoctonia Solani ◽  
Magnaporthe Grisea ◽  
Root Surface ◽  
Sheath Blight ◽  
Blast Disease ◽  
Systemic Resistance ◽  
Sodium Ascorbate ◽  
In Planta ◽  
Pyocyanin Production

Pseudomonas aeruginosa 7NSK2 induces resistance in dicots through a synergistic interaction of the phenazine pyocyanin and the salicylic acid-derivative pyochelin. Root inoculation of the monocot model rice with 7NSK2 partially protected leaves against blast disease (Magnaporthe grisea) but failed to consistently reduce sheath blight (Rhizoctonia solani). Only mutations interfering with pyocyanin production led to a significant decrease in induced systemic resistance (ISR) to M. grisea, and in trans complementation for pyocyanin production restored the ability to elicit ISR. Intriguingly, pyocyanin-deficient mutants, unlike the wild type, triggered ISR against R. solani. Hence, bacterial pyocyanin plays a differential role in 7NSK2-mediated ISR in rice. Application of purified pyocyanin to hydroponically grown rice seedlings increased H2O2 levels locally on the root surface as well as a biphasic H2O2 generation pattern in distal leaves. Co-application of pyocyanin and the antioxidant sodium ascorbate alleviated the opposite effects of pyocyanin on rice blast and sheath blight development, suggesting that the differential effectiveness of pyocyanin with respect to 7NSK2-triggered ISR is mediated by transiently elevated H2O2 levels in planta. The cumulative results suggest that reactive oxygen species act as a double-edged sword in the interaction of rice with the hemibiotroph M. grisea and the necrotroph R. solani.

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