| alternate host |
a second host species required by some rusts and other organisms to complete their life cycle |
| chlorosis |
a yellowing or whitening of normally green plant tissue. |
| conidiophore |
a threadlike stalk upon which conidia are produced. |
conidium
(plural conidia) |
any asexual spore formed on a conidiophore. |
| exudate |
a gel-like accumulation of spores or bacterial ooze. |
hypha
(plural hyphae) |
a tubular, threadlike filament of fungal mycelium. |
| inoculum |
spores or other diseased material that may cause infection. |
| isolate |
an individual culture of a pathogenic species |
| lesion |
a visible area of diseased tissue on an infected plant. |
| mosaic |
a pattern of disease symptoms displaying mixed green and lighter colored patches. |
mycelium
(pural mycelia) |
a mass of hyphae that form the body of a fungus. |
| necrosis |
death of plant tissue, usually accompanied by discoloration. |
| pathogen |
a microorganism that causes disease. |
| pustule
|
a lesion caused by rust fungi; a spore mass of a rust fungus developing below the epidermis, usually breaking through at maturity. |
pycnidium
(plural pycnidia) |
a flask shaped fruiting body of certain fungi that produces asexual spores (conidia). |
| race
|
a group of pathogen isolates that are characterized by their ability to attack certain varieties of a crop but not other varieties. |
sclerotium
(plural sclerotia) |
a dense, compact mycelial mass capable of remaining dormant for extended periods. |
| senescence |
the phase of plant growth that extends from full maturity to death. |
| spore |
a minute reproductive unit of fungi and lower plant forms. |
| sporulation |
the period of active spore production. |
| symptom |
a visible response of a host plant to a pathogenic organism. |
telium
(plural telia) |
pustule containing teliospores. |
| teliospore |
a thick-walled resting spore produced by rust and smut fungi. |
| uredsiospore |
an asexual spore of the rust fungi. |
| vector |
an organism capable of transmitting inoculum. |
| virulence |
the relative ability of a microorganism to overcome the resistance of a host. |
| water soaked |
appearing wet, darkened, and partially transparent. |
