Quantitative detection of Exserohilum turcicum in northern leaf blight diseased sorghum and maize leaves

Approximately 200 sweet corn inbred lines were screened for two years for resistance to northern leaf blight, caused by Exserohilum turcicum, and Stewart's wilt, caused by Erwinia stewartii. Inbreds with the best levels of partial resistance to races 1 and 2 of E. turcicum included IL11d, IL676a, IL677a, IL685d, IL766a, IL767a and IL797a. Inbreds with the best partial resistance to E. stewartii included IL126b, IL676a, IL767a, IL772a, IL774g, IL797a, IL798a and M6011. Several of these resistant and moderately resistant inbreds had common ancestors; however, inspection of pedigrees suggested that resistance was derived from Puerto Rican, Bolivian, and other tropical sources and/or dent corn. Thus, many of the sweet corn inbreds may carry different genes for resistance and can be used for the development of populations with improved resistance.

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Interaction of Ht and Partial Resistance to Exserohilum turcicum in Maize

Plant Disease ◽

10.1094/pdis.1997.81.3.277 ◽

1997 ◽

Vol 81 (3) ◽

pp. 277-282 ◽

Cited By ~ 19

Author(s):

P. E. Lipps ◽

R. C. Pratt ◽

J. J. Hakiza

Keyword(s):

Partial Resistance ◽

Specific Resistance ◽

Field Studies ◽

Leaf Blight ◽

Disease Development ◽

Exserohilum Turcicum ◽

Northern Leaf Blight ◽

Progress Curve ◽

Lesion Number ◽

Lower Severity

Components of northern leaf blight resistance in maize due to race-specific resistance controlled by the Ht gene, partial resistance derived from inbred H99, and a combination of the two kinds of resistance, were studied subsequent to inoculation with Exserohilum turcicum race O. Lesion types, number of lesions (lesion number), percent leaf area affected (severity), and area under the disease progress curve (AUDPC) based on lesion number and severity were assessed in field studies conducted at two locations in Uganda and one location in Ohio in 1993. Lesion types observed were consistent for genotypes across locations. In general, significant differences among genotypes for data based on lesion number and severity were consistent for AUDPC based on lesion number and severity, respectively, at all locations. In Ohio, both Ht and partial resistance were effective in limiting disease development. In Uganda, susceptible inbreds (A619, A635, and B73) generally had higher severity than genotypes with partial resistance (H99, Mo17, and Babungo 3). However, there was a difference in response among genotypes depending on disease intensity at each location. Ht resistance and moderate partial resistance did not greatly affect lesion number at the higher disease intensity location, compared with the susceptible inbreds, but at the lower disease intensity location genotypes with partial resistance had fewer lesions than susceptible inbreds or the Ht conversions of the susceptible inbreds. At both plot locations, genotypes with partial resistance had lower severity than the susceptible inbreds or Ht conversions of the susceptible inbreds. Hybrids derived from crossing H99 with genotypes with moderate levels of partial resistance (Mo17 and Babungo 3) did not have significantly lower lesion numbers than hybrids of susceptible inbreds crossed with H99, but severity was significantly lower on these hybrids at the high disease intensity location. Results indicate that the level of partial resistance in H99 would be as effective in controlling northern leaf blight as using Ht resistance, or a combination of Ht resistance and moderate levels of partial resistance as found in Mo17.

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Efficacy of epiphytic bacteria to prevent northern leaf blight caused by Exserohilum turcicum in maize

Revista Argentina de Microbiología ◽

10.1016/j.ram.2016.09.008 ◽

2017 ◽

Vol 49 (1) ◽

pp. 75-82 ◽

Cited By ~ 4

Author(s):

Melina Sartori ◽

Andrea Nesci ◽

Julián García ◽

María A. Passone ◽

Analía Montemarani ◽

...

Keyword(s):

Leaf Blight ◽

Epiphytic Bacteria ◽

Exserohilum Turcicum ◽

Northern Leaf Blight

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Association mapping and genetic control for northern leaf blight (Exserohilum turcicum) resistance in maize lines

Australian Journal of Crop Science ◽

10.21475/ajcs.17.11.10.pne678 ◽

2017 ◽

Vol 11 (10) ◽

pp. 1346-1353 ◽

Cited By ~ 2

Author(s):

Kaian Albino Corazza Kaefer ◽

◽

Adilson Ricken Schuelter ◽

Ivan Schuster ◽

Jonatas Marcolin ◽

...

Keyword(s):

Association Mapping ◽

Genetic Control ◽

Leaf Blight ◽

Exserohilum Turcicum ◽

Northern Leaf Blight

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Bioefficacy of fungicides, plant extracts and essential oils against Exserohilum turcicum (Pass.) Leonard and Suggs causing Northern leaf blight of maize

Journal of Applied and Natural Science ◽

10.31018/jans.v11i2.2030 ◽

2019 ◽

Vol 11 (2) ◽

pp. 257-262

Author(s):

Bhagyashree Bhatt ◽

Pradeep Kumar

Keyword(s):

Essential Oils ◽

Plant Extracts ◽

Mycelial Growth ◽

Disease Incidence ◽

Foliar Spray ◽

Leaf Blight ◽

Exserohilum Turcicum ◽

Northern Leaf Blight ◽

Lawsonia Inermis

Eight fungicides, ten botanicals and ten essential oils were taken for their in vitro evaluation against Exserohilum turcicum (Pass.) Leonard and Suggs incited of Northern Leaf Blight of Maize. Among all the tested fungicides (Azoxystrobin 23%, Thiophenate methyl 75%, Propiconazole 25%, Tebuconazole 25.9%, Captan 50%, Zineb 75%, Cymoxanil 8%+Mancozeb 64% and Zineb 68%+Hexaconazole 4%), propiconazole 25% showed maximum inhibition of mycelial growth (92.22%) under in vitro conditions at 5ppm concentration. Among all the tested botanicals Heena (Lawsonia inermis) was found to be most effective in inhibiting mycelial growth (71.11%) at 10% concentration. Lemon tulsi oil was found best in inhibiting mycelial growth (71.30%) of Exserohilum turcicum, among all the tested essential oils at 50ppm concentration. Fungicides, plant extracts and essential oils showing good results under in vitro conditions were tested under glasshouse conditions. Foliar spray of Propiconazole 25%[email protected]% showed reduced disease incidence (23.33%) compared to control (46.33%). Application of 5% of Heena extracts reduced the disease incidence (26.67%). Plants when sprayed with Lemon tulsi oil showed reduced disease incidence (24.17%). The study reveals that not only the fungicides but also the natural plant extracts can greatly contribute to reduce the incidence of disease because of the antifungal compounds present in plants.

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Assessment of physiological races of Exserohilum turcicum isolates from maize in Argentina and Brazil

Tropical Plant Pathology ◽

10.1007/s40858-020-00417-x ◽

2021 ◽

Author(s):

Barbara Ludwig Navarro ◽

Lucia Ramos Romero ◽

María Belén Kistner ◽

Juliana Iglesias ◽

Andreas von Tiedemann

Keyword(s):

Exserohilum Turcicum ◽

Breeding Programs ◽

Physiological Races ◽

Maize Leaves ◽

Race 1 ◽

Resistance Reaction ◽

Qualitative Resistance ◽

Maize Plants ◽

Corn Leaf Blight ◽

Resistant Genotypes

AbstractNorthern corn leaf blight (NCLB) is one of the most important diseases in maize worldwide. It is caused by the fungus Exserohilum turcicum, which exhibits a high genetic variability for virulence, and hence physiological races have been reported. Disease control is based mainly on fungicide application and host resistance. Qualitative resistance has been widely used to control NCLB through the deployment of Ht genes. Known pathogen races are designated according to their virulence to the corresponding Ht gene. Knowledge about of E. turcicum race distribution in maize-producing areas is essential to develop and exploit resistant genotypes. Maize leaves showing distinct elliptical grey-green lesions were collected from maize-producing areas of Argentina and Brazil, and 184 monosporic E. turcicum isolates were obtained. A total of 66 isolates were collected from Argentina during 2015, 2018 and 2019, while 118 isolates from Brazil were collected during 2017, 2018 and 2019. All isolates were screened on maize differential lines containing Ht1, Ht2, Ht3 and Htn1 resistance genes. In greenhouse experiments, inoculated maize plants were evaluated at 14 days after inoculation. Resistance reaction was characterized by chlorosis, and susceptibility was defined by necrosis in the absence of chlorosis. The most frequent race was 0 in both Argentina (83%) and Brazil (65%). Frequencies of race 1 (6% and 24%) and race 23N (5% and 10%) were very low in Argentina and Brazil, respectively. The high frequency of race 0 isolates provides evidence that qualitative resistance based on the tested Ht genes is not being used extensively in Argentina and Brazil to control NCLB. This information may be relevant for growers and breeding programs as the incidence of NCLB is increasing in both countries.

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