The University of Jordan
Faculty of Agriculture
Dept. of Plant Protection
Prof. H. Khlaif
Email: H-khlaif@ju.edu.jo
Office: 227
Office hrs: All week days (10-11)
Seed Pathology
606931
Time: : Mon. Wed. 14:00-15:30
Course Description :
The objectives of this course is to give the students an idea about seed - borne
diseases, their causal agents, including fungi, bacteria, viruses, and nematodes, their
mode of transmission, economic importance, the effect on seed viability, seed
anatomy in relation to pathogens transmission, the effect of environmental factors on
pathogens transmission, seed healthy tests ,production of disease free seedlings, the
recent techniques for the detection of these diseases in the seeds, and control methods.
Week
1
2
3
4
5
6
Introduction:
Historical development. Development of seed health
testing,
Significance
Seed borne pathogens
Fungi, Bacteria, Mycoplasma like organisms. Fastidious
vascular bacteria, Spiroplasma, Viruses, viroids, Nematodes
Location of seedborne inoculum : I
Histopathology of some seedborne pathogens, Seed infection (embryo,
endosperm and perisperm. seed coat and pericarp. glume infection), Seed
infestation or contamination
Mechanism of seed infection ( seed infection, seed infestation or
contamination)
Factors affecting seed infection:
Host genotype, environment, crop management, type of inoculum, seed
quality, plant growth stage, mother plant infection, insect infestation and
pathogen interaction.
Longevity of seedborne pathogens:
Longevity, factors influencing longevity
7
Seed transmission and inoculation:
Seed transmission ( systemic and nonsystemic), seed inoculation
8
Factors affecting seed transimission:
Crop species. Environment, inoculum, survival of inoculum.
cultural practices. seed abnormalities, seed germination. seed ,
leachates, and presence of other microflora.
9
Epidemiology and inoculum thresholds of seedborne
pathogens: epidemiology ( classification of seedborne diseases
based on epidemiology), inoculum thresholds, development of inoculum
thresholds.
10
Nonparasitic seed disorders:
Genetic effects. mechanical injuries, environmental effects.
mineral deficiencies, and insect damage
11
Deterioration of seeds by storage fungi:
Field and storage fungi, invasion by storage fungi. losses.
conditions favoring storage fungi development, detection of damage. and
control.
12
Mycotoxins and mycotoxicoses:
* Mycotoxins, fungi known to produce mycotoxins, factors affecting
mycotoxins production, effects of mycotoxins. and detection.
13
Control of seedboine pathogens:
Introduction, selection of seed production area, crop, management, seed
treatment. certification. plant quarantine, disease resistance
Course outcomes:
At the end of this course the students will be able to :
1. Know the different diseases transmitted by seeds.
2. The role of seeds as a source of inoculum.
3. The economic importance of seedborne diseases.
4. Recent techniques of seed testing for detection of seedborne disease
5. Production of healthy seeds.
Class participation:
Students should attend class on time, participate in discussion and other activities.
Exams and Grades
Exams
Grades
Medterrn.exam
30%
Presentahon and
term papers
30%
Final Exam
40%
Day
Date
References
l -Vijendra K. Agarwal.
Sinclair, J.B 1987
Principles of Seed Pathology. vol. 1. and 2. CRC Press, Inc
Boca Raton, Florida.
2- S. B. Mathur, Johs Jrargensen, Technical Centre for Agriculture and Rural Cooperation (Ede, Netherlands), 1993, seed pathology