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Characteristics of Plant Pathogenic Bacteria –
Agrios pp. 407-415
| Morphology |
Extremely small, one-celled, prokaryotic microorganisms. Exception:
filamentous actinomycetes. |
| Reproduction |
Cell division by binary fission. Bacteria reside in spaces
between plant cells or vascular system. Plant pathogenic bacteria
do not form spores. |
| Sites of pathogen survival |
Plants, seeds, storage organs, plant debris (original host
plant), equipment and in the bodies of insect vectors. |
| Symptoms caused |
Slimy soft rots, leaf spots, leaf and stem blights, decay
of fruits, pods and tubers, stem cankers, vascular wilts and
galls. |
| Signs of disease |
Bacterial ooze from symptomatic tissue. |
Characteristics of Plant Pathogenic Mollicutes
- Agrios pp. 457-462
| Morphology |
Prokaryotic, pleiomorphic
microbes that lack a cell wall. Phytoplasma and spiroplasma
are most common plant pathogenic mollicutes. |
| Reproduction |
Cell division by binary
fission. Mollicutes reside in phloem tissue. |
| Sites of pathogen
survival Sites of pathogen survival |
Perennial plants serve
as hosts and sources of inoculum. Mollicutes are transmitted
by many species of leafhoppers. |
| Symptoms caused |
Chlorosis, stunting,
brooms, distortion of flowers, necrosis. |
| Signs of disease |
Cells of mollicutes
are observed in host tissue, but not observed outside host
tissues. |
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