Plant Diseases Flashcards
Give an example of a plant virus
Tobacco mosaic virus
Give some examples of symptoms of tobacco mosaic virus
Stunted growth
Yellow spotting on leaves
Malformation of leaves mosaic pattern of discolouration
Give an example of a plant disease caused by bacteria
Crown gall
Give some symptoms of crown gall bacteria
Swellings (galls)
Stunted growth
Give an example of a plant disease caused by a fungus
Rose black spot
Give some symptoms of the rose black spot fungus
Purple/black spots on leaves
Leaves fall
Leaves yellowing
Give an example of a plant disease caused by nematode worms
Root knot nematodes
Give some symptoms of the disease root knot nematodes
Stunting
Wilting
Yellowing
Give some symptoms of aphids
Twisted and curled leaves
Yellowed leaves
Stunted growth
Give two examples of plant diseases caused by mineral ion deficiency
Nitrogen deficiency
Magnesium deficiency
Give some symptoms of nitrogen deficiency
Slow growth
Yellow/pale leaves
Give a symptom of magnesium deficiency
Yellowing
Give examples of physical defences plants have against pathogens
• Waxy cuticle on leaves
• Bark on trees
• Cellulose cell walls
• Lignified cell walls
• Callus formation (like scars)
• Leaf fall e.g. in autumn
What are the three types of plant defences
Physical
Mechanical
Chemical
Give some examples of chemical defences
Antibacterial chemicals
Poisons to deter herbivores
Give some examples of mechanical defences
Thorns and hair to deter animals
Leaves which droop or curl when touched
Mimicry to trick animals
Give ways that a pathogen can enter a plant
Stem (soil)
Enzymes
Stomata
Puncturing plant tissue
Wound
