PLANT DISEASE DIAGNOSIS
Academic Year 2025/2026 - Teacher: VITTORIA CATARAExpected Learning Outcomes
The course aims to provide students with an in-depth understanding of the diagnostic process in plant pathology, starting from field observation through to the detection, identification, and characterization of plant pathogens, including viruses, viroids, bacteria, fungi, and oomycetes. Through an integrated study of both traditional and innovative methods, students will be guided in exploring techniques such as isolation, biological assays, serological and molecular diagnostics, with particular attention to official protocols and phytosanitary regulations (knowledge and understanding).
Laboratory experience, practical exercises, and case study analysis will enable students not only to interpret diagnostic data correctly but also to make informed decisions in selecting the most appropriate methods based on context and management objectives (ability to apply knowledge and understanding, independent judgment).
The course also fosters the development of communication skills and the ability to independently stay updated on technical and regulatory innovations in the field (communication skills, learning ability).
Course Structure
The course is structured into lectures (3 ECTS, equivalent to 21 hours) aimed at providing students with fundamental concepts in plant disease diagnostics, with a focus on understanding processes, techniques, and key sources of scientific and regulatory updates. Lectures will be enriched with discussions and interactive sessions designed to encourage critical thinking and the connection between theory and practice.
Supplementary activities (3 ECTS, equivalent to 42 hours) may include laboratory exercises, thematic seminars, meetings with industry experts, and case study analyses approached from multidisciplinary perspectives. Where possible, group work will be organized to simulate real diagnostic scenarios. Educational visits to laboratories and companies in the agri-food sector are also planned, with the goal of strengthening practical skills and fostering engagement with professional environments.
Required Prerequisites
Attendance of Lessons
Detailed Course Content
The course provides both theoretical and practical training in the field of plant disease diagnostics, guiding students through the diagnostic process—from symptom observation to the identification of plant pathogens, including viruses, viroids, bacteria, fungi, and oomycetes. Key techniques such as sampling, isolation, biological assays, serological and molecular diagnostics will be explored, with reference to validated protocols and scientific sources. Particular attention will be given to the distinction between symptom-based and instrumental diagnosis, and to the selection of appropriate methods based on the phytopathological context.
The course also introduces emerging technologies such as next-generation sequencing (NGS), genomics, and metagenomics, offering an updated perspective on diagnostic potential. Practical exercises, simulations, and case study analysis will allow students to apply their knowledge directly, with opportunities for discussion and visits to laboratories and professional settings. Emphasis will be placed on the role of early diagnosis in innovative approaches to sustainable plant disease management, aligned with the Sustainable Development Goals of the 2030 Agenda.
Textbook Information
The instructor’s lectures are made available on Studium and must be supplemented with foundational topics that can be extracted from the textbooks used in Plant Pathology courses:
- Fondamenti di patologia vegetale (Matta A., Buonaurio R., Favaron F., Scala A., Scala F. 2017)
- Patologia vegetale (Vannacci G. et al. 2021)
- Elementi di Patologia Vegetale (Belli G. 2012)
Diagnostic concepts related to different groups of pathogens and diagnostic methods are covered in section 6 (page 600-662) of the book Patologia vegetale molecolare (M. Reverberi, M. Ruocco, L. Covarelli, L. Sella 2022).
Laboratory exercise protocols and reference websites are provided during the course lectures.
Course Planning
| Subjects | Text References | |
|---|---|---|
| 1 | Definition and structure of the diagnostic process in plant pathology: diagnosis, detection, identification, and characterization of plant pathogens. Fields of application. National and international institutional references for phytosanitary regulations and official diagnostic protocols | Plant pathology textbooks; instructor’s lecture notes; recommended websites. |
| 2 | Definition of anamnesis, symptom, syndrome, and sign of disease. Study of symptoms and their distribution within the plant and in the field. Symptom-based diagnosis (in relation to the plant pathogen and its mode of action) and differential diagnosis. Koch’s postulates. Phytopathometric assessments: incidence, severity, disease scales and indices. Sampling techniques and preparation of the data recording sheet. | Plant pathology textbooks; instructor’s lecture notes; recommended websites. |
| 3 | Techniques for isolating phytopathogenic bacteria and fungi from plant material. Traditional methods of identification | Plant pathology textbooks; instructor’s lecture notes; |
| 4 | Principles and applications of serology in plant disease diagnostics. Techniques based on antigen-antibody interactions for the detection of plant pathogens: ELISA, immunofluorescence, immunoblotting, and related methods. Polyclonal and monoclonal antisera. Interpretation of results and evaluation criteria for sensitivity and specificity | Instructor's lecture notes, Text: Patologia vegetale molecolare, sezione 6 'La diagnostica fitopatologica' |
| 5 | Principles and applications of molecular techniques for the detection and identification of plant pathogens. Methods based on DNA and RNA analysis: conventional PCR, real-time PCR, RT-PCR, and related variants. Criteria for method selection, sensitivity, and specificity | Instructor's lecture notes, Text: Patologia vegetale molecolare, sezione 6 'La diagnostica fitopatologica' |
| 6 | Principles and applications of biological assays for confirming pathogenicity. Whole-plant and plant-part assays for the identification of pathogen races, pathotypes, and variants. Specific biological tests for viruses through inoculation on indicator plants. Symptom observation and interpretation of results. | Instructor's lecture notes |
| 7 | Overview of advanced diagnostic technologies for the detection and characterization of plant pathogens (biosensors, digital techniques and portable diagnostic tools, DNA barcoding, MLST, genomics). Theoretical introduction to the use of high-throughput sequencing (HTS) for the identification of emerging pathogens and the study of microbial biodiversity. | Instructor's lecture notes, Text: Patologia vegetale molecolare, sezione 6 'La diagnostica fitopatologica' |
| 8 | Analysis of the criteria for selecting the most appropriate diagnostic method based on the type of pathogen, the plant material, and the operational context. Structuring the diagnostic workflow with particular focus on the evaluation and application of official and validated protocols within the phytosanitary framework | Results and deliverables from collaborative discussions and group activities. |
| 9 | Case studies related to laboratory exercises, seminars, and supplementary activities carried out during the course. | Laboratory protocols, instructor’s lecture notes, seminar reports. |
Learning Assessment
Examples of frequently asked questions and / or exercises
- What are the main diagnostic objectives in the field of plant pathology?
- Which national and international bodies or organizations regulate phytosanitary activities and/or develop diagnostic protocols?
- How are symptoms, syndromes, and signs distinguished in plant diseases, and what role do they play in differential diagnosis?
- What are the main traditional techniques for the isolation and identification of phytopathogenic bacteria and fungi?
- What are the fundamental principles of serology applied to plant pathology, and what advantages does it offer compared to other diagnostic methods?
- What are the main molecular techniques used for the detection of plant pathogens, and what criteria guide their selection?
- What is the role of biological assays in confirming pathogenicity, and how do assays for viruses differ from those for other pathogens?
- What are the main emerging technologies for plant disease diagnosis, and what advantages do they offer over conventional methods?
- What factors influence the selection of the most appropriate diagnostic method in plant pathology, and how is an official diagnostic workflow analyzed?
- Questions related to integrative activities carried out and discussed in class (diagnostic workflows for quarantine pathogens, laboratory topics, seminars)