Plant Disease and Defence Flashcards
List the types of defenses
Mechanical
Chemical
Physical
Examples of MECHANICAL defenses
THORNS and HAIRS - stop animas touching and eating them
LEAVES DROOP or CURL- prevent being eaten by knocking insects off or moving away from danger
MIMICRY - can prevent laying of eggs on leaves (passion flower) or prevent being eaten
Examples of CHEMICAL defenses
ANTIBACTERIAL CHEMICALS - kil bacteria - (mint plant, witch hazel)
POISONS - deter herbivores - (tobacco plants, foxgloves, deadly nightshade)
Examples of PHYSICAL defenses
WAXY CUTICLE - provides barrier to stop pathogens entering
CELL WALLS - physical barrier against pathogens that have passed the waxy cuticle
LAYERS OF DEAD CELLS AROUND THE STEM - acts as a barrier to prevent pathogens from entering (outer part of bark on trees)
Ways to diagnose plant diseases
Consulting gardening manual or website
Take a plant to a lab and identify pathogen
Use test kits containing monoclonal antibodies
Symptoms of plant diseases
Stunted growth Spots on leaves Discolouration Areas of decay Malformations of stems or leaves Growths Presence of pests
NITRATE ions needed for…
production and synthesis of proteins
Effects of NITRATE deficiency…
stunted growth (proteins are required for growth)
MAGNESIUM ions needed for…
production of chlorophyll
Effects of MAGNESIUM deficiency…
leaves turn yellow
chlorosis
(cannot absorb sunlight for photosynthesis so glucose is not made so growth is also stunted)
Plant virus…
Tobacco mosaic virus
Plant fungi…
Rose black spot
Plant pests…
Aphids (insects) - greenflies and black flies
