Mycosphaerella graminicola
| Mycosphaerella graminicola | ||||||||||||
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Septoria tritici |
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| Scientific name | ||||||||||||
| Mycosphaerella graminicola | ||||||||||||
| ( Fuckel ) J. Schröt. |
Mycosphaerella graminicola ( anamorphic : Septoria tritici ) is a fungus that causes leaf drought, a disease of wheat and other grasses such as barley . The pathogen occurs in all wheat-growing areas of the world and is the most economically important wheat disease in the United Kingdom.
morphology
Asexual form ( Septoria tritici ): The asexual spores (pycnidiospores) are hyaline and have a size of about 1.7-3.4 × 39-86 μm, with 3 to 7 septa and are formed in pycnidia . The formation of germ tubes can take place in a lateral or terminal position. Spore tendrils (cirrhi), which emerge from the pycnidia in damp weather, have a milky to white color. If the fungus is cultivated on nutrient media, hyaline unseptated microspores are sometimes formed (size approx. 1–1.3 × 5–9 μm), which, like yeasts , can multiply by division.
Sexual form: The sexually formed ascospores are formed in fruiting bodies called pseudothecia. These fruit bodies are dark brown and have a diameter of 68 to 114 μm. The tubes, in each of which 8 ascospores are formed, are called asci and have a size of 11 to 14 × 30–40 μm. Ascospores are hyaline, elliptical, and 2.5–4 × 9–16 μm in size, with two cells of unequal length.
Epidemiology
The period between infection and formation of spores is called the latency period and is 20.35 ± 4.15 days in wheat. The length of the latency period decreases with increasing temperature.
Fungicide resistance
European isolates of Zymoseptoria tritici are largely resistant to fungicides containing strobilurins as active ingredients . The resistance is due to a mutation in the gene that codes for the protein , which in turn is the binding site for the fungicide.
Symptom pictures
Plant Disease Diagnostic Center: Septoria tritici
Web links
Individual evidence
- ^ European handbook of Plant Diseases . Blackwell Scientific Publications, 1988.
- ↑ ADAS: UK pest disease and weed incidence reports 1998-2009. Retrieved January 13, 2011 .
- ↑ PESTICIDES FORUM MEETING DATE June 17, 2003 (PDF) ADAS, accessed January 25, 2015 .
- ^ A b M. V. Wiese: Compendium of wheat diseases . American Phytopathological Society, 1987, pp. 124 .
- ↑ M. Henze, M. Beyer, H. Klink, JA. Verreet: Characterizing meteorological scenarios favorable for Septoria tritici infections in wheat and estimation of latent periods. In: Plant Disease. 91, 2007, pp. 1445-1449. apsjournals.apsnet.org
- ↑ BA Fraaije, HJ Cools, J. Fountaine, DJ Lovell, J. Motteram, JS West, JA Lucas: Role of ascospores in further spread of QoI-resistant cytochrome b alleles (G143A) in field populations of Mycosphaerella graminicola . In: Phytopathology. 95, 2005, pp. 933-941 apsjournals.apsnet.org
- ↑ bayercropscience.de