Pathology L1 Flashcards
Phytopathology
Study of plant disease caused by biotic and abiotic factors
Disease
Any problem of plant cells and tissues that result from a pathogenic or environmental factor that leads to symptoms
Symptom
Reaction of plant to disease
Sign
Physical evidence of a pathogen
Examples of a sign
Fungal pathogen - mycelium, fruiting bodies
Bacterial pathogen - exudates
Pathogen
Disease causing organism that negatively affects the host
Host
Living organism that is attacked by the parasite or pathogen
What does disease do?
Interrupts function and damages cells and tissues
Results of disease on roots/crown
Gall and root rot result in wilting in later stages
Results of disease on stems
Results in lodging of plants
Results of disease on leaves
Reduces photosynthetic area of the plant
Results of disease on flower/fruit
Reduces yield, quality of fruit/grain
Chlorosis
Yellowing of leaves due to reduced chlorophyll
Necrosis
Death of tissue
Symptoms of disease
Chlorosis, necrosis, galls/tumors, wilts, scabs, cankers/lesions/pustules
Healthy plant
Carries out physiological functions and grows to bet of its genetic potential
Diseased plant
Malfunctioning of host cells and tissues duets pathogenic agent or environmental factor
Abnormal changes in form or integrity of plant
May cause partial impairment or death of host
Examples of abiotic stresses
Cold, heat, flooding, drought, salinity, heavy metal
Water stress
To much (waterlogged) or too little (drought)
Temperature stress
Freezing
too hot causing desication, wilting, abortion, etc