Exam 1 Flashcards
Chlorosis
Yellowish coloration of plant tissue
Interveinal chlorosis
The tissue between the veins is chlorotic and the veins remain green
Vein clearing
Veins become translucent and the rest of the leaf is green
Mosaic
Leaves have green to yellow patches with sharp edges
Mottling
Leaves have green to yellow patches with mottled edges
Symptoms of Plant Disease
- Abnormal coloration of host tissues
- Wilting
- Death of tissue
- Defoliation and fruit drop
- Abnormal growth or replacement of host tissue
Plant Pathology
- causes of plant disease
- mechanisms by which these factors cause disease
- interactions between plants and the causal agents of disease
- methods to prevent or control disease
Plant Disease
A harmful alteration of the normal physiological and biochemical development of a plant caused by a pathogenic agent ore environmental factor.
Causes of Disease
- non infectious-Abiotic, environmental
2. infectious-Biotic
Plant-microbe interactions
relationship between plants and pathogen
causal agent
whatever it is that cause disease
disease etiology
interactions between plant ant the pathogen in terms of ecology, life cycle and how it spreads.
Major causes of plant disease (Causal agents)
- Fungi
- Bacteria
- Mollicutes
- Viruses
- Viroids
- Nematodes
- Parasitic higher plants
- Protazoa
- Mycoplamas
Symptoms of plant disease
- Abnormal Coloration of Host tissues
- Wilting
- Death of tissue
- Defoliation and fruit drop
- Abnormal growth or replacement of host tissue.
Chlorosis
Yellowish coloration of plant tissue
interveinal chlorosis
the tissue between the veins is chlorotic and the veins remain green
veinclearing
veins become translucent and the rest of the leave is green.
mosaic
leaves have green to yellow patches with sharp edges
mottling
leaves have green to yellow patches with diffuse edges.
lesions
localized injury to plant tissue, usually seen as leaf spots.
necrosis
death of plant tissue, usually dark brown or black in color.
rotting
decomposition of plant tissue, may be either dry or soft rot
canker
necrotic areas in twigs, branches or stems which are often sunken
mumification
dry shriveled fruit caused by fungal colonization
hyperplasia
increase in the number of plant cells
hypertrophy
increase in the size of plant cells ( these may lead to gall formation or twisting and curling of leaves and stems)
host tissue replacement
the complete or partial replacement of host tissue by the pathogen.
