CRP001 (TERMINOLOGIES) Flashcards
an injurious process caused by the continued irritation of a primary causal agent causing abnormal physiological and cellular activity expressed in abnormal morphological characteristics called symptoms
Plant Disease
any agent that cause disease which is generally referring to a living organism
Pathogen
is an organism which depends wholly or partly on another living organism for its food
Parasite
subsist on living organisms and attacks only living tissues (ex. Virus, rust fungi, downy mildew fungi, etc.)
Obligate Parasite
An organism, which has the ability to become a parasite but is ordinarily a saprophyte.
Facultative Parasite
an organism that lives on dead organic or inorganic matter
Saprophyte
Has the ability to become a saprophyte but is ordinarily a parasite
Facultative Saprophyte
refers to the plant that is being attacked by a parasite
Host
a plant that is susceptible to a disease whether or not the pathogen is parasitic
Suscept
is the capacity of a pathogen to cause disease
Pathogenicity
series of events that lead to disease development in the plant
Pathogenesis
refers to the quantitative amount of disease that a given pathogen can cause in a group of plants
Virulence
measures the rate at which virulence is expressed by a given pathogenic isolate.
Aggressiveness
The ability of an organism to overcome in any degree the effects of a pathogen
Disease Resistance
is the opposite of resistance
Susceptibility
is exhibited by a plant which is severely affected by a pathogen without experiencing a severe reduction in yield
Tolerance
are the manifestation or expressions by the suscept/host of a pathologic condition
Symptoms
are those that are the immediate and direct results of the causal
agent’s activities on the invaded tissues
Primary symptoms
the effects on the distant and uninvaded plant parts
Secondary symptoms
are characterized by distinct and very limited structural changes
Localized symptoms
more generalized pathological conditions
Systemic symptoms
is essentially internal, and seen only upon the dissection of the
diseased plant portion and examination under the microscope
Histological symptoms
are those malformations and other changes that are visible to the naked eye
Morphological symptoms
The various symptoms were categorized by Kenaga (1974) into: (7)
▪ Abnormal coloration
▪ Wilting
▪ Death of host tissue
▪ Defoliation and fruit drop
▪ Abnormal growth increase of host
▪ Stunting
▪ Replacement of host tissue
