The terminology of plant pathology is the specific word for a particular sentence. Those are generally used to describe a sentence in a single term. In pathology or plant pathology those given general words are used to describe the present situation of plant and caused.
Disease or Disorder: They two terms carry the same meaning when the term disease includes all types of harmful physiological changes in the plant, often the non-infectious plant diseases due to abiotic causes such as adverse soil condition are termed disorders. Components of a disease are the pathogen and the host interacting in a given set of environments.
Pathogen: In a literal sense a pathogen is any agent that causes pathos or(damage). It should, therefore, include all living organisms associated with the disease, viruses as well as the abiotic agents such as adverse atmospheric or soil conditions. However, the term generally used to denote specific living organism (bacteria, fungi, nematodes) and viruses but not such agents as nutritional deficiencies.
Parasites: Organism which derives the material they need for growth from living plants (the host or the suspect) are called parasite. Most, but not all pathogens are parasites, similarly most, but not all, parasites are pathogens.
Biotrophs: Organism which regardless of the ease with which they can be cultivated on artificial media, always obtain they food in nature from living tissues on which they complete their lifecycle are called biotrophs or obligate parasites.
Fungi causing rust, smut and powdery mildew are typical example.
Saprophytic: Organism they derive their food from dead organic matter. Parasite and saprophytes may have the faculty to change their mode of nutrition. A parasite may be hemibiotroph, i.e. it will attack in living tissue in the same way as a biotroph but will continue to grow and reproduce after the tissue is dead such parasites is called facultative saprophytic. A parasite is necrotrophy whet kill host tissue in advance for penetration and then living saprophytically.
Pathogenicity: Is the ability of pathogen to cause disease while pathogenesis. is the chai of events that lead to the development of disease in the host. Virulence is the measurement of pathogenicity of an isolate and race of the pathogen.
Systemic infection: The pathogen grow from the point of entry to varying tissues extents without showing adverse effect on tissues through which is passes.
Invasion and colonization: After infection the pathogen grows thorough the tissues of the host to varying extent drawing nutrition during its growth.
Systemic infection: the pathogen grows from the point of entry to varying extents without showing adverse effect on tissue through which it passes.
Invasion and colonization: After infection the pathogen grows through the tissue of the host to varying extent drawing nutrition during its growth.
Hypersensitivity: Is a extreme degree of susceptibility in which the host cell react violently to the invading pathogen and as a result there is rapid death of cell in a vicinity of the invading pathogen (site of infection) . This may be halt the process of the pathogen although it may or it may be not die immediately. Thus, hypersensitivity is a sign of incompatibility or very high resistance approaching immunity.
Tolerance: Is a type of defence that minimizes crop loss without restricting disease development. Disease escape: Is the ability of an otherwise susceptible plant to avoid damaging disease stress because of the way it grows. This is considered a useful system of protection in a natural ecosystem.
Recognition system: Cell recognition is defined as the even of cell-cell communication which elicits a defined biochemical, Physiological or morphological response. The term is used to explain the earliest events in the host parasite interaction or pathogenesis when molecules of the host cell surface recognize like molecules in pathogen surface and accept it for establishment of parasitic relationship. If the pathogen molecule are unlike, they are rejected an no relationship is stablished. Similarly at molecule or genetic matching leads to Compatibility between host and parasite and dissimilarity leads to incompatibility. At the molecular or genetic level the interactions are highly specific giving specificity to the host or the pathogen in the recognition system.
Incubation period: The time lapsing between inoculation and appearance of symptoms ( sign of establishment of parasitic relationship) is known as incubation period. It varies with pathogen, host and environment conditions.
Symbiosis: living together of two unlike organisms is known as symbiosis, the two organisms being called symbionts.