|
Characteristics of Plant Pathogenic Viruses - Agrios pp. 479-490
| Morphology |
Submicroscopic molecules,
consists of nucleic acid (RNA or DNA) surrounded by a protein
coat. |
| Reproduction |
Viruses are obligate
parasites that take control of host cells to replicate new
virus particles (virions). |
| Sites of pathogen
survival |
Viruses survive in
living plants, especially perennials, vectors (organisms that
transmit viruses) and seed. |
| Symptoms caused |
Yellows, mosaics,
stripes, anthocyanescence and stunting. |
| Signs of disease |
Virus virions are
observed via electron miscroscopy. |
Characteristics of Plant Pathogenic Viroids - Agrios pp. 556-560
| Morphology |
Submicroscopic molecules,
consists of nucleic acid RNA only; a protein coat is absent. |
| Reproduction |
Viroids are low molecular
weight RNAs that take control of host cells to replicate new
RNA. |
| Sites of pathogen
survival |
Viroids survive in
living plants, especially perennials, outside of hosts for
varying lengths of time. Most hosts are perennial or vegetatively
propagated annuals. |
| Symptoms caused |
Yellows, mosaics,
stripes, anthocyanescence, necrosis, plant decline, distorted
flower and fruit, and stunting. |
| Signs of disease |
Virus virions are
observed via electron miscroscopy. |
|
|
