scholarly journals Identification of Gray Leaf Spot Disease Candidate Gene in Narrow-Leafed Lupin (Lupinus angustifolius L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Gaofeng Zhou ◽  
Huaan Yang ◽  
Daniel Renshaw ◽  
Meilin Zou ◽  
Geoff Thomas ◽  
...  
Keyword(s):  
Candidate Gene ◽  
Leaf Spot ◽  
Recombinant Inbred Lines ◽  
Major Gene ◽  
Segregation Ratio ◽  
Gray Leaf Spot ◽  
Wild Accession ◽  
Leaf Spot Disease ◽  
Breeding Line ◽  
Phylogenetic Tree Analysis

Selection for resistance against gray leaf spot (GLS) is a major objective in the lupin breeding programs. A segregation ratio of 1:1 (resistant:susceptible) in F8 recombinant inbred lines (RIL8) derived from a cross between a breeding line 83A:476 (resistant to GLS) and a wild accession P27255 (susceptible to GLS) indicated that GLS was controlled by a single major gene. To develop molecular markers linked to GLS, in the beginning, only 11 resistant lines and six susceptible lines from the 83A:476 and P27255 population were genotyped with MFLP markers, and three MFLP markers were identified to be co-segregated with GLS. This method was very efficient, but the markers were located outside of the gene, and could not be used in other germplasms. Then QTL analysis and fine mapping were conducted to identify the gene. Finally, the gene was narrowed down to a 241-kb region containing two disease resistance genes. To further identify the candidate gene, DNA variants between accessions Tanjil (resistant to GLS) and Unicrop (susceptible to GLS) were analyzed. The results indicated that only one SNP was detected in the 241 kb region. This SNP was located in the TMV resistance protein N-like gene region and also identified between 83A:476 and P27255. Genotyping the Tanjil/Unicrop RIL8 population showed that this SNP co-segregated with GLS resistance. The phylogenetic tree analysis of this gene among 18 lupin accessions indicates that Australian resistant breeding line/varieties were clustered into one group and carry two resistant alleles, while susceptible accessions were clustered into different groups.

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 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 A review on threat of gray leaf spot disease of maize in Asia

2015 ◽  
Vol 1 (1) ◽  
pp. 71-85 ◽  
Author(s):  
Narayan Bahadur Dhami ◽  
SK Kim ◽  
Arjun Paudel ◽  
Jiban Shrestha ◽  
Tirtha Raj Rijal
Keyword(s):  
Disease Management ◽  
Leaf Spot ◽  
Management Strategies ◽  
Premature Death ◽  
Gray Leaf Spot ◽  
Disease Spread ◽  
Limiting Factors ◽  
Leaf Spot Disease ◽  
Negative Consequences ◽  
Group I

Biotic and biotic constraints are yield limiting factors in maize producing regions. Among these gray leaf spot is a yield limiting foliar disease of maize in high land regions of Asia. This review is done from related different national and international journals, thesis, books, research papers etc. The objectives of this review are to become familiar with genetics and inheritance, epidemiology, symptoms and disease management strategies etc. High relative humidity, temperature, minimum tillage and maize monoculture are important factors responsible for disease development. The sibling species of Cercospora zeae-maydis (Tehon and Daniels, 1925) Group I and Group II and Cercospora sorghai var. maydis (Chupp, 1954) are associated with this disease. Pathogens colonize in maize debris. Conidia are the source of inoculums for disease spread. Severe blighting of leaves reduces sugars, stalk lodging and causes premature death of plants resulting in yield losses of up to 100%. Disease management through cultural practices is provisional. The use of fungicides for emergencies is effective however; their prohibitive cost and detrimental effects on the environment are negative consequences. The inheritance of tolerance is quantitative with small additive effects. The introgression of resistant genes among the crosses of resistant germplasm enhances the resistance. The crosses of resistant and susceptible germplasm possess greater stability than the crosses of susceptible and resistant germplasm. The development of gray leaf spot tolerant populations through tolerance breeding principle is an economical and sustainable approach to manage the disease.Journal of Maize Research and Development (2015) 1(1):71-85DOI: http://dx.doi.org/10.5281/zenodo.34286

scholarly journals Inheritance of Resistance to Halo Blight Flower and Stem Color and Association in Common Beans

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 621d-621
Author(s):  
H.M. Ariyarathne ◽  
D.P. Coyne
Keyword(s):  
Pseudomonas Syringae ◽  
Recombinant Inbred Lines ◽  
Major Gene ◽  
Segregation Ratio ◽  
Inbred Lines ◽  
Gene Control ◽  
Common Beans ◽  
Bacterial Diseases ◽  
Halo Blight ◽  
Ri Lines

Halo blight is one of the most important bacterial diseases of common beans (Phaseolus vulgaris L.). It is serious under moderate temperature and high humidity conditions. The disease is caused by a seed-borne bacterium, Pseudomonas syringae pv. phaseolicola (Burkh.) Dowson (Psp). The inheritance of leaf reactions to Psp, flower, and stem color was studied using greenhouse-grown 109 F9 recombinant inbred lines (RI) from the P. vulgaris cross BelNeb 1 [resistant (R)] (USDA/NE) × A 55 [susceptible (S)] (CIAT). Two Psp strains, HB16 (NE) and 83-Sc2A (NE), were inoculated using the water-soaking method. A segregation ratio of 1 R:1 S RI lines were observed for disease reactions in leaves for both strains indicating major gene control. The presence of recombinants for SR, RS to the strains indicated that different genes were involved. Stem (SC) and flower (FC) color traits were each determined by two major genes. Linkages were found for reactions to the two Psp strains and also between FC and SC. No linkages were observed from FC and also SC with reactions to Psp strains.

Prediction model for gray leaf spot disease of fodder Sorghum

2020 ◽  
Author(s):  
Nitish Rattan Bhardwaj ◽  
Ashlesha Atri ◽  
Upasana Rani ◽  
Ajoy Kumar Roy
Keyword(s):  
Prediction Model ◽  
Leaf Spot ◽  
Gray Leaf Spot ◽  
Leaf Spot Disease ◽  
Spot Disease
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