Phenotypic identification of near isogenic maize teosinte lines ( Zea spp.) involved for resistance to gray leaf spot

2021 ◽  
Author(s):  
Abraham Guerrero‐Corona ◽  
Fernando Santacruz Ruvalcaba ◽  
José Alberto Sánchez Nuño ◽  
Gustavo Moya Raygoza ◽  
José Ariel Ruiz Corral ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Gray Leaf Spot ◽  
Phenotypic Identification

High-density mapping for gray leaf spot resistance using two related tropical maize recombinant inbred line populations

2021 ◽  
Author(s):  
Long Chen ◽  
Li Liu ◽  
Ziwei Li ◽  
Yudong Zhang ◽  
Manjit S. Kang ◽  
...  
Keyword(s):  
Inbred Line ◽  
Recombinant Inbred Line ◽  
Recombinant Inbred ◽  
Leaf Spot ◽  
Gray Leaf Spot ◽  
High Density ◽  
Tropical Maize ◽  
Density Mapping

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 Epidemiology and predictive management of gray leaf spot of maize

2003 ◽  
Author(s):  
Pierce Anderson Paul
Keyword(s):  
Leaf Spot ◽  
Gray Leaf Spot

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.

scholarly journals Sibling Species of Cercospora Associated with Gray Leaf Spot of Maize

1998 ◽  
Vol 88 (12) ◽  
pp. 1269-1275 ◽  
Author(s):  
Juan Wang ◽  
Morris Levy ◽  
Larry D. Dunkle
Keyword(s):  
United States ◽  
Genetic Distance ◽  
Sibling Species ◽  
Fragment Length ◽  
Leaf Spot ◽  
The United States ◽  
Nucleotide Sequences ◽  
Gray Leaf Spot ◽  
5.8S Rdna ◽  
Its Regions

Monoconidial isolates of the fungus causing gray leaf spot of maize were obtained from diseased leaves collected throughout the United States and analyzed for genetic variability at 111 amplified fragment length polymorphism (AFLP) loci. Cluster analysis revealed two very distinct groups of Cercospora zeae-maydis isolates. Both groups were found to be relatively uniform internally with an average genetic similarity among isolates of approximately 93 and 94%, respectively. The groups were separated from each other by a genetic distance of approximately 80%, a distance greater than that separating each group from the sorghum pathogen, C. sorghi (67 to 70%). Characteristics and dimensions of conidia and conid-iophores produced on infected plants or nutrient media were unreliable criteria for taxonomic differentiation of isolates composing the two groups of C. zeae-maydis. Nucleotide sequences of 5.8S ribosomal DNA (rDNA) and the internal transcribed spacer (ITS) regions were identical within each group but different between the two groups and different from C. sorghi. Restriction fragment length polymorphisms generated by digestion of the 5.8S rDNA and ITS regions with TaqI readily distinguished each group and C. sorghi. Isolates in one group were generally distributed throughout maize-producing regions of the United States; isolates in the other group were localized in the eastern third of the country. Both types were present in the same fields at some locations. The genetic distance based on AFLP profiles and different ITS nucleotide sequences between the two morphologically indistinguishable groups indicate that they are sibling species. Although it is unlikely that breeding for resistance to gray leaf spot will be confounded by local or regional variation in the pathogen, a vigilant approach is warranted, because two pathogenic species exist with unknown abilities to evolve new pathotypes.

Diallel Analysis of Maize Inbreds for Resistance to Gray Leaf Spot

Crop Science ◽  
1990 ◽  
Vol 30 (6) ◽  
pp. 1198-1200 ◽  
Author(s):  
J. F. Ulrich ◽  
J. A. Hawk ◽  
R. B. Carroll
Keyword(s):  
Leaf Spot ◽  
Diallel Analysis ◽  
Gray Leaf Spot ◽  
Maize Inbreds

scholarly journals Field Characterization of Partial Resistance to Gray Leaf Spot in Elite Maize Germplasm

2020 ◽  
Vol 110 (10) ◽  
pp. 1668-1679
Author(s):  
James O. Nyanapah ◽  
Patrick O. Ayiecho ◽  
Julius O. Nyabundi ◽  
Washington Otieno ◽  
Peter S. Ojiambo
Keyword(s):  
Disease Resistance ◽  
Leaf Area ◽  
Plant Development ◽  
Leaf Spot ◽  
Partial Resistance ◽  
Inflection Point ◽  
Inbred Lines ◽  
Gray Leaf Spot ◽  
Diseased Leaf ◽  
Diseased Leaf Area

Forty-eight inbred lines of maize with varying levels of resistance to gray leaf spot (GLS) were artificially inoculated with Cercospora zeina and evaluated to characterize partial disease resistance in maize under field conditions from 2012 to 2014 across 12 environments in western Kenya. Eight measures of disease epidemic—that is, final percent diseased leaf area (FPDLA), standardized area under the disease progress curve (SAUDPC), weighted mean absolute rate of disease increase (ρ), disease severity scale (CDSG), percent diseased leaf area at the inflection point (PDLAIP), SAUDPC at the inflection point (SAUDPCIP), time from inoculation to transition of disease progress from the increasing to the decreasing phase of epidemic increase (TIP), and latent period (LP)—were examined. Inbred lines significantly (P < 0.05) affected all measures of disease epidemic except ρ. However, the proportion of the variation attributed to the analysis of variance model was most strongly associated with SAUDPC (R2 = 89.4%). Inbred lines were also most consistently ranked for disease resistance based on SAUDPC. Although SAUDPC was deemed the most useful variable for quantifying partial resistance in the test genotypes, the proportion of the variation in SAUDPC in each plot was most strongly (R2 = 93.9%) explained by disease ratings taken between the VT and R4 stages of plant development. Individual disease ratings at the R4 stage of plant development were nearly as effective as SAUDPC in discerning the differential reaction of test genotypes. Thus, GLS rankings of inbred lines based on disease ratings at these plant developmental stages should be useful in prebreeding nurseries and preliminary evaluation trials involving large germplasm populations.

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