External or internal physical characteristics of disease expressed by the host plant.
A plant with several tissue sectors or layers differing in genetic or chromosomal constitution from the original plant.
The underdevelopment of cells, tissues, or organs.
Symptom of a disease characterized by yellowish or dead (necrotic) rings with green tissue inside them, as in certain virus diseases.
Lapin cherry leaf with ringspots and line patterns due to the Prune Dwarf Virus.
Jay W. Pscheidt, 2016.
Lack of freshness and turgor and drooping of leaves from lack of water; a vascular disease that interrupts the plant's normal uptake and distribution of water.
The plant on the left is wilting due to Verticillium wilt, while plant on right has leaf spot and stem rot.
Photo by Jay W. Pscheidt, 1992.
The spread of infectious material (inoculum) from a diseased to a healthy plant by wind, water, humans, insects, animal, machinery, or other means.
Nematodes that feed from outside roots, moving from cell to cell and piercing them to feed without entering root tissue. (Examples: dagger nematodes, Xiphinema spp.)
A compact aggregation of spores and/or sporophores growing out to the surface of the host.
The need of only one host for completing the life cycle of a rust.
Western Gall Rust does not need an alternate host.
