scholarly journals Identification of Sources of Resistance to Gray leaf spot in Stenotaphrum germplasm

Crop Science ◽  
2020 ◽  
Author(s):  
Esdras M. Carbajal ◽  
Bangya Ma ◽  
M. Carolina Zuleta ◽  
W. Casey Reynolds ◽  
Consuelo Arellano ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Gray Leaf Spot ◽  
Sources Of Resistance

scholarly journals Identification and characterization of maize lines resistant to leaf diseases

2019 ◽  
Vol 40 (2) ◽  
pp. 517
Author(s):  
Kaian Albino Corazza Kaefer ◽  
Adilson Ricken Schuelter ◽  
Ivan Schuster ◽  
Jonatas Marcolin ◽  
Eliane Cristina Gruszka Vendruscolo
Keyword(s):  
Genetic Diversity ◽  
Leaf Spot ◽  
Block Design ◽  
Snp Markers ◽  
Gray Leaf Spot ◽  
Leaf Blight ◽  
Yield Reduction ◽  
Northern Leaf Blight ◽  
Sources Of Resistance ◽  
White Leaf

Among the maize leaf diseases, white leaf spot, northern leaf blight, gray leaf spot, and southern rust are recognized not only by the potential for grain yield reduction but also by the widespread occurrence in the producing regions of Brazil and the world. The aim of this study was to characterize common maize lines for resistance to white leaf spot, northern leaf blight, gray leaf spot, and southern rust and suggest crosses based on the genetic diversity detected in SNP markers. The experiment was conducted in a randomized block design with three replications in order to characterize 72 maize lines. Genotypic values were predicted using the REML/BLUP procedure. These 72 lines were genotyped with SNP markers using the 650K platform (Affymetrix®) for the assessment of the genetic diversity. Genetic diversity was quantified using the Tocher and UPGMA methods. The existence of genetic variability for disease resistance was detected among maize lines, which made possible to classify them into three large groups (I, II, and III). The maize lines CD 49 and CD50 showed a good performance and can be considered sources of resistance to diseases. Therefore, their use as gene donors in maize breeding programs is recommended. Considering the information of genetic distance together with high heritability for leaf diseases, backcrossing of parent genotypes with different resistance levels, such as those of the lines CD49 x CD69 and CD50 x CD16, may result in new gene combinations, as they are divergent and meet good performances.

Sources of Resistance to Gray Leaf Spot of Corn

Plant Disease ◽  
1994 ◽  
Vol 78 (12) ◽  
pp. 1153 ◽  
Author(s):  
S. T. COATES
Keyword(s):  
Leaf Spot ◽  
Gray Leaf Spot ◽  
Sources Of Resistance

scholarly journals Interactions in the Brassica napus ‐ Pyrenopeziza brassicae pathosystem and sources of resistance to P . brassicae (light leaf spot)

2021 ◽  
Author(s):  
C. S. Karandeni Dewage ◽  
A. Qi ◽  
H. U. Stotz ◽  
Y. J. Huang ◽  
B. D. L. Fitt
Keyword(s):  
Brassica Napus ◽  
Leaf Spot ◽  
Sources Of Resistance

scholarly journals The Utility of the Upcoming HyspIRI’s Simulated Spectral Settings in Detecting Maize Gray Leafy Spot in Relation to Sentinel-2 MSI, VENµS, and Landsat 8 OLI Sensors

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 846
Author(s):  
Mbulisi Sibanda ◽  
Onisimo Mutanga ◽  
Timothy Dube ◽  
John Odindi ◽  
Paramu L. Mafongoya
Keyword(s):  
Food Security ◽  
Precision Agriculture ◽  
Leaf Spot ◽  
Gray Leaf Spot ◽  
Economic Losses ◽  
Leaf Spot Disease ◽  
Landsat 8 ◽  
Landsat 8 Oli ◽  
Maize Crop ◽  
Sentinel 2

Considering the high maize yield loses caused by incidences of disease, as well as incomprehensive monitoring initiatives in crop farming, there is a need for spatially explicit, cost-effective, and consistent approaches for monitoring, as well as for forecasting, food-crop diseases, such as maize Gray Leaf Spot. Such approaches are valuable in reducing the associated economic losses while fostering food security. In this study, we sought to investigate the utility of the forthcoming HyspIRI sensor in detecting disease progression of Maize Gray Leaf Spot infestation in relation to the Sentinel-2 MSI and Landsat 8 OLI spectral configurations simulated using proximally sensed data. Healthy, intermediate, and severe categories of maize crop infections by the Gray Leaf Spot disease were discriminated based on partial least squares–discriminant analysis (PLS-DA) algorithm. Comparatively, the results show that the HyspIRI’s simulated spectral settings slightly performed better than those of Sentinel-2 MSI, VENµS, and Landsat 8 OLI sensor. HyspIRI exhibited an overall accuracy of 0.98 compared to 0.95, 0.93, and 0.89, which were exhibited by Sentinel-2 MSI, VENµS, and Landsat 8 OLI sensor sensors, respectively. Furthermore, the results showed that the visible section, red-edge, and NIR covered by all the four sensors were the most influential spectral regions for discriminating different Maize Gray Leaf Spot infections. These findings underscore the potential value of the upcoming hyperspectral HyspIRI sensor in precision agriculture and forecasting of crop-disease epidemics, which are necessary to ensure food security.

scholarly journals Comparative Genetic Analysis of Magnaporthe oryzae Isolates Causing Gray Leaf Spot of Perennial Ryegrass Turf in the United States and Japan

Plant Disease ◽  
2007 ◽  
Vol 91 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Tosa ◽  
W. Uddin ◽  
G. Viji ◽  
S. Kang ◽  
S. Mayama
Keyword(s):  
United States ◽  
Perennial Ryegrass ◽  
Magnaporthe Oryzae ◽  
Leaf Spot ◽  
Genetic Relationships ◽  
The United States ◽  
Gray Leaf Spot ◽  
Genetic Lineage ◽  
Type I ◽  
Type Ii

Gray leaf spot caused by Magnaporthe oryzae is a serious disease of perennial ryegrass (Lolium perenne) turf in golf course fairways in the United States and Japan. Genetic relationships among M. oryzae isolates from perennial ryegrass (prg) isolates within and between the two countries were examined using the repetitive DNA elements MGR586, Pot2, and MAGGY as DNA fingerprinting probes. In all, 82 isolates of M. oryzae, including 57 prg isolates from the United States collected from 1995 to 2001, 1 annual ryegrass (Lolium multiflorum) isolate from the United States collected in 1972, and 24 prg isolates from Japan collected from 1996 to 1999 were analyzed in this study. Hybridization with the MGR586 probe resulted in approximately 30 DNA fragments in 75 isolates (designated major MGR586 group) and less than 15 fragments in the remaining 7 isolates (designated minor MGR586 group). Both groups were represented among the 24 isolates from Japan. All isolates from the United States, with the exception of one isolate from Maryland, belonged to the major MGR586 group. Some isolates from Japan exhibited MGR586 fingerprints that were identical to several isolates collected in Pennsylvania. Similarly, fingerprinting analysis with the Pot2 probe also indicated the presence of two distinct groups: isolates in the major MGR586 group showed fingerprinting profiles comprising 20 to 25 bands, whereas the isolates in the minor MGR586 group had less than 10 fragments. When MAGGY was used as a probe, two distinct fingerprint types, one exhibiting more than 30 hybridizing bands (type I) and the other with only 2 to 4 bands (type II), were identified. Although isolates of both types were present in the major MGR586 group, only the type II isolates were identified in the minor MGR586 group. The parsimony tree obtained from combined MGR586 and Pot2 data showed that 71 of the 82 isolates belonged to a single lineage, 5 isolates formed four different lineages, and the remaining 6 (from Japan) formed a separate lineage. This study indicates that the predominant groups of M. oryzae associated with the recent outbreaks of gray leaf spot in Japan and the United States belong to the same genetic lineage.

scholarly journals The role of silicon in suppressing gray leaf spot development in St. Augustinegrass

EDIS ◽  
1969 ◽  
Vol 2003 (17) ◽  
Author(s):  
M. Brecht ◽  
Lawrence Datnoff ◽  
Russell Nagata ◽  
Thomas Kucharek
Keyword(s):  
Leaf Spot ◽  
Magnaporthe Grisea ◽  
Field Research ◽  
Cooperative Extension Service ◽  
Gray Leaf Spot ◽  
South Florida ◽  
Pyricularia Grisea ◽  
Publication Date ◽  
University Of Florida

If you maintain St. Augustinegrass (Stenotaphrum secundatum) in Florida, its possible that gray leaf spot, caused by the fungus Magnaporthe grisea (Pyricularia grisea), will be a problem in your lawn or sod field. Research has proven the effectiveness of amendments of silicon (Si) to soils that are deficient in soluble Si (<25 mg/L) for control of diseases on a number of hosts including rice and sugarcane, which are regularly fertilized with Si in south Florida. This document is PP-67, one of a series of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: July, 2003. https://edis.ifas.ufl.edu/pp114

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.

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