Alternate host: A second host species required by some rusts and other organisms to complete their life cycle.
Chlorosis: Yellowing or whitening of normally green plant tissue.
Coalesce: To combine, to fuse or come together.
Conidiophore :A threadlike stalk upon which conidia (spores) are produced.
Conidium (pl. conidia) : Any asexual spore formed on a conidiophore.
Diapause :A period of dormancy
Exudate: Gel-like accumulation of spores orbacterial ooze.
Foot rot : Disease symptoms, such as discoloration, necrosis and decay, affecting the roots and basal portions of the plant or culm.
Gall :A localized proliferation of plant or parasite tissue that produces an abnormal growth or swelling, usually caused by pathogenic organisms, nematodes, or insects.
Honeydew : A sticky exudate (containing conidial) produced during one stage of the life cycle of Claviceps purpurea.
Hypha (pl. hyphae) : A tubular, threadlike filament of fungal mycelium.
Immune: Not affected by pathogens.
Inoculum :Spores or other diseased material that may cause infection.
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 (pl. 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.
Primary: Spores or fragments of a mycelium
inoculum :capable of initiating a disease.
Pustule :A spore mass developing below the epidermis, usually breaking through at maturity.
Resistance : Inherent capacity of a host plant to prevent or retard the development of an infectious disease.
Sclerotium : A dense, compact mycelial mass capable(pl. sclerotia) of remaining dormant for extended periods.
Senescence :The phase of plant growth that extends from full maturity to death.
Spore : A minute reproductive unit in fungi and lower plant forms.
Sporulation: The period of active spore production.
Striate : Displaying narrow parallel streaks or bands
Susceptible: Being subject to infection or injury by a pathogen; non-immune.
Symptom: A visible response of a host plant to a pathogenic organism.
Telium (pl. telia) :Postule containing teliospores.
Teliospore: A thick-walled resting spore produced by rust and smut fungi.
Tolerant : The ability of a host plant to develop and reproduce fairly efficiently while sustaining disease.
Transmission : The spread of a disease agent among individual hosts.
Urediospore :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.
Courtesy USDA
