751-4504-00L  Plant Pathology I

Courses

Catalogue data

Abstract	Plant Pathology I will focus on pathogen-plant interactions, epidemiology, disease assessment, and disease development in agroecosystems. Themes will include: 1) how pathogens attack plants and; 2) how plants defend themselves against pathogens; 3) factors driving the development of epidemics in agroecosystems.
Learning objective	Students will understand: 1) how pathogens attack plants and; 2) how plants defend themselves against pathogens; 3) factors driving the development of epidemics in agroecosystems as a basis for implementing disease management strategies in agroecosystems.
Content	Course description: Plant Pathology I will focus on pathogen-plant interactions, epidemiology, disease assessment, and disease development in agroecosystems. Themes will include: 1) how pathogens attack plants and; 2) how plants defend themselves against pathogens; 3) factors driving the development of epidemics in agroecosystems. Topics under the first theme will include pathogen life cycles, disease cycles, and an overview of plant pathogenic nematodes, viruses, bacteria, and fungi. Topics under the second theme will include plant defense strategies, host range, passive and active defenses, and chemical and structural defenses. Topics under the third theme will include the disease triangle and cultural control strategies. Lecture Topics and Tentative Schedule Week 1 The nature of plant diseases, symbiosis, parasites, mutualism, biotrophs and necrotrophs, disease cycles and pathogen life cycles. Week 2 Nematode attack strategies and types of damage. Viral pathogens, classification, reproduction and transmission, attack strategies and types of damage. Examples TMV, BYDV. Bacterial pathogens and phytoplasmas, classification, reproduction and transmission. Week 3 Bacterial attack strategies and symptoms. Example bacterial diseases: fire blight, Agrobacterium crown gall, soft rots. Fungal and oomycete pathogens, classification, growth and reproduction, sexual and asexual spores, transmission. Week 4 Fungal and oomycete life cycles, disease cycles, infection processes, colonization, phytotoxins and mycotoxins. Attack strategies of fungal necrotrophs and biotrophs. Symptoms and signs of fungal infection. Example fungal diseases: potato late blight. Week 5 Example fungal diseases: wheat stem rust, grape powdery mildew, wheat septoria tritici blotch. Plant defense mechanisms, host range and non-host resistance. Passive structural and chemical defenses, preformed chemical defenses. Active structural defense, histological and cellular (papillae). Week 6 Active chemical defense, hypersensitive response, pathogenesis-related (PR) proteins, phytoalexins and disease resistance. Pisatin and pisatin demethylase. Local and systemic acquired resistance (LAR, SAR), induced systemic resistance (ISR), signal molecules, defense activators (Bion). Pathogen effects on food quality. Positive and negative transformations. Week 7 Negative pathogen impacts on crop yield and quality. Pathogen effects on food safety. Mycotoxins in the food chain. Aflatoxin, patulin safety assessment and action thresholds. Epidemiology: historical epidemics. Week 8 Epidemiology: Disease pyramid, environmental effects on epidemic development, plant effects on development of epidemics, including resistance, physiology, density, uniformity. Week 9 Disease assessment: incidence and severity measures, keys, diagrams, scales, measurement errors. Correlations between incidence and severity. Molecular detection and diagnosis of pathogens. Host indexing, serology, monoclonal and polyclonal antibodies, ELISA. Week 10 Molecular detection and diagnosis of pathogens: PCR, rDNA and loop-mediated isothermal amplification. Strategies for minimizing disease risks: calculating disease thresholds, disease forecasting systems. Week 11 Strategies for minimizing disease risks: lowering epidemic risk, ecological risk assessment, natural and synthetic pesticides. Disease control strategies: economic thresholds, overview of control strategies. Week 12 Physical control methods. Cultural control methods: avoidance, tillage practices, crop sanitation. Week 13 Cultural control methods: fertilizers, crop rotations. Week 14 Open lecture.
Lecture notes	Detailed lecture notes (~160 pages) will be available for purchase at the cost of reproduction at the start of the semester.
Competencies	Subject-specific Competencies Concepts and Theories assessed Techniques and Technologies assessed

Performance assessment

Performance assessment information (valid until the course unit is held again)
Performance assessment as a semester course
ECTS credits	2 credits
Examiners	B. McDonald
Type	graded semester performance
Language of examination	English
Repetition	Repetition only possible after re-enrolling for the course unit.
Additional information on mode of examination	A suitable date for the written exam will be agreed upon with the students, repetition is possible in the second week of the following semester.

Learning materials

Groups

Restrictions

Offered in

Programme	Section	Type
Agricultural Sciences Bachelor	Plant Sciences	W+
Agricultural Sciences Bachelor	Electives	W
Biology Master	Elective Compulsory Master Courses	W
Biology Master	Elective Compulsory Master Courses	W
Biology Master	Elective Compulsory Master Courses	W
Environmental Sciences Master	Electives	W