Physiological races and virulence dynamics of Setosphaeria turcica in Northeast China

Plant Disease ◽  
2021 ◽  
Author(s):  
Zhoujie Ma ◽  
Shidao He ◽  
Bo Liu ◽  
Suna Wang ◽  
Yufei Huang ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Northeast China ◽  
Leaf Blight ◽  
Corn Production ◽  
Foliar Disease ◽  
Setosphaeria Turcica ◽  
Northern Corn Leaf Blight ◽  
Physiological Races ◽  
Corn Leaf Blight

Northern corn leaf blight (NCLB), caused by Setosphaeria turcica, is an important foliar disease in corn. Since 2005, the damage from NCLB has increased in Northeast China, probably due to the emergence of new physiological races. In this study, 883 single conidial isolates of S. turcica were obtained from 12 sites across three provinces of Northeast China between 2007 and 2017. The virulence of the isolates was evaluated in five corn lines (B37, B37Ht1, B37Ht2, B37Ht3, B37HtN). Sixteen physiological races (0, 1, 2, 3, N, 12, 13, 1N, 23, 2N, 3N, 123, 12N, 13N, 23N, and 123N) were obtained, depending on their resistance or susceptibility. Three races (0, 1, and 2) were most prevalent, with frequencies of 40.5%, 19.6%, and 11.3% in all isolates, respectively. Races varied across provinces and years. Virulence to more than one Ht resistance genes occurred in 21.5% of isolates, with 8.5% virulent to three or more genes. Overall, 41% of isolates were avirulent to all Ht genes, 36% were virulent to Ht1, 28% to Ht2, 11% to Ht3, and 16% to HtN. Isolates from Heilongjiang had a greater frequency of virulence to Ht2 and Ht3, whereas isolates from Jilin and Liaoning were more frequently virulent to Ht1 and HtN, respectively. The frequency of isolate virulence to Ht2 ranged from 8% in 2009 to a maximum of 29% in 2015, and in 2015, isolates were more virulent to Ht2 than Ht1. This study will help growers to purposefully select commercial hybrids with multiple effective Ht resistance genes, and reduce the utilization of Ht1 and Ht2 genes in the process of corn production to strengthen NCLB control.

Evaluation of Maize Hybrids for Identifying Resistance to Northern Corn Leaf Blight in Northeast China

Plant Disease ◽  
2021 ◽  
Author(s):  
Zhoujie Ma ◽  
Hongyan Hui ◽  
Yufei Huang ◽  
Yuan Yao ◽  
Yanqiu Sun ◽  
...  
Keyword(s):  
Northeast China ◽  
Leaf Blight ◽  
Economic Losses ◽  
Maize Hybrids ◽  
Northern Corn Leaf Blight ◽  
Progress Curve ◽  
Severity Scores ◽  
Disease Parameter ◽  
Average Size ◽  
Corn Leaf Blight

Northern corn leaf blight (NCLB) caused by Setosphaeria turcica is one of the most devastating foliar diseases in maize (Zea mays), resulting in great economic losses worldwide. The mutation of the pathogen exacerbates the occurrence and harmfulness of NCLB in China. Therefore, there is an urgent need for evaluating and cultivating resistant hybrids. Here, the response of 239 maize hybrids approved in Northeast China to NCLB was evaluated during 2019 and 2020. The results showed that 92 (38.49%) and 75 (31.38%) hybrids were rated as moderately resistant and resistant, respectively, which together constituted the predominant resistant categories. We observed that maize hybrids from different certified sources had different levels of resistance to NCLB, whose disease parameter values varied significantly (P <0.05) among 52 main cultivated hybrids. In 2019 and 2020, the average size of the lesions increased from 21.02 to 21.06 cm2, the average lesion density decreased from 1.36 to 1.33 lesions/100 cm2, and more than 30% of the hybrids registered final disease severity scores between 10% and 30%. The area under the disease progress curve of the main cultivated hybrids ranged from 57.96 to 986.86 cm2 in 2019 and from 50.75 to 1028.65 cm2 in 2020. Correlation analysis revealed a significant relationship (P <0.0001) among four disease parameters. Current research has shown that many maize hybrids in Northeast China are resistant to NCLB. This study should assist growers in purposefully selecting resistant commercial hybrids to contribute to the management of NCLB.

scholarly journals Managing Foliar Diseases of Processing Sweet Corn in New York with Strobilurin Fungicides

Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 213-220 ◽  
Author(s):  
D. A. Shah ◽  
H. R. Dillard
Keyword(s):  
New York ◽  
Disease Severity ◽  
Sweet Corn ◽  
Cost Effective ◽  
Field Trials ◽  
Leaf Blight ◽  
Foliar Disease ◽  
Northern Corn Leaf Blight ◽  
Strobilurin Fungicides ◽  
Corn Leaf Blight

Processing sweet corn (Zea mays) growers in New York are more concerned about the cost effectiveness of fungicide use against foliar fungal diseases (common rust and Northern corn leaf blight) and less about whether such sprays will reduce disease intensity. To address this concern, field trials were done in 2006 and 2007 with three processing sweet corn hybrids (Jubilee, Bold, and GH 9597) that differed in susceptibility to common rust and Northern corn leaf blight, and two strobilurin fungicides (azoxystrobin and pyraclostrobin). Single strobilurin applications were applied in response to foliar disease severity thresholds of 1, 10, and 20%. Single fungicide applications did reduce foliar disease severities. Applications were most cost effective when made in response to the 1 and 10% foliar severity thresholds, and generally only in the susceptible hybrid Bold. Spraying at the 20% severity threshold did reduce final foliar disease severity but was not cost effective. Azoxystrobin and pyraclostrobin were equally effective in disease management. The results suggest that a single application of a strobilurin fungicide against common rust and Northern corn leaf blight can be cost effective for New York processing sweet corn growers when such an application is made before foliar disease severity exceeds 20%.

scholarly journals First Report of Northern Corn Leaf Blight Caused by Setosphaeria turcica on Corn (Zea mays) in Fujian Province, China

Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 831
Author(s):  
N. N. Shi ◽  
Y. X. Du ◽  
H. C. Ruan ◽  
X. J. Yang ◽  
Y. L. Dai ◽  
...  
Keyword(s):  
Zea Mays ◽  
Leaf Blight ◽  
Fujian Province ◽  
Setosphaeria Turcica ◽  
First Report ◽  
Northern Corn Leaf Blight ◽  
Corn Leaf Blight

Morphological and molecular markers based screening of maize hybrids against northern corn leaf blight

2020 ◽  
Vol 53 (1) ◽  
Author(s):  
Sadaf Naeem ◽  
Muhammad Tahir ◽  
Kiramat Khan ◽  
Amjad Hasan ◽  
Rafiq Ahmad
Keyword(s):  
Molecular Markers ◽  
Leaf Blight ◽  
Maize Hybrids ◽  
Northern Corn Leaf Blight ◽  
Corn Leaf Blight

Klebsiella jilinsis 2N3 promotes maize growth and induces resistance to northern corn leaf blight

2021 ◽  
Vol 156 ◽  
pp. 104554
Author(s):  
Meng Zhang ◽  
Cheng Zhang ◽  
Sisheng Zhang ◽  
Huilin Yu ◽  
Hongyu Pan ◽  
...  
Keyword(s):  
Leaf Blight ◽  
Northern Corn Leaf Blight ◽  
Maize Growth ◽  
Corn Leaf Blight

scholarly journals A Quantitative Disease Severity Rating Scale for Northern Corn Leaf Blight

2016 ◽  
Vol 17 (1) ◽  
pp. 49-50 ◽  
Author(s):  
Trey Price ◽  
Myra Purvis ◽  
Hunter Pruitt
Keyword(s):  
United States ◽  
Disease Severity ◽  
Rating Scale ◽  
The United States ◽  
Leaf Blight ◽  
Analysis Software ◽  
Northern Corn Leaf Blight ◽  
Severity Rating ◽  
Corn Leaf Blight

Northern corn leaf blight (NCLB) is an annual issue for corn producers throughout the United States. Consequently, researchers are constantly evaluating hybrids for resistance and fungicides for efficacy. In most cases, NCLB severity is evaluated by visually estimating the percentage of affected foliage. Perceptions of disease severity are variable among stakeholders; therefore, a rating scale was created using photo analysis software that may be used to increase accuracy of disease severity estimations. Accepted for publication 15 March 2016. Published 28 March 2016.

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