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Virus Symptoms
- Chlorosis
- Stunting and malformation
- Yield reduciton
- Usually not death of plant
- Rugosity- ruffled
- Color breaking (tulips)
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Life cycle of Virus
- 1. entry: wounds needed
- 2. Release nucleic acid
- 3. Protein Synthesis: use host machinery
- 4. Nucleic acid replicaiton
- 5. Virus assembly: encapsulate D/RNA
- 6. Cell to cell movement through plasmodesmata (not disease if in only one cell)
- 7. Systemic movement through phloem: need capsid coat protein, passive movement
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Spread of viruses
- mechanical
- vegetative propagation
- infected seeds and pollen
- nematodes
- fungus vector
- insects (non-persistent, quick to pick up, transmit, and lose)
- aphids (persistent, long time to get pick up and transmit)
- white flies
- thrips (tomato)
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Vector
- Organism
- Transmits virus from diseased plant to healthy plant
- has a specific association with the virus it transmits
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