Plant Pathology is an applied subject to study the pathogen, occurrence, development and control of plant diseases. It takes plant diseases as the research object, discusses the causes of the disease, or in the anatomy, physiology or biochemistry, to explore the process of infection and symptoms. In order to establish the method of disease prevention and treatment, plant pathology also studies the formation of pathogenic environment, pathogen transmission and disease diagnosis. In addition, the paper also researches preventive agents of plant pathogens or pharmacological effects, and includes all plant diseases related to the broad area.
Plant pathology is the derivative of botany, plant physiology and microbiology mutual penetration and development, and crop science, protozoology, soil science, meteorology, genetics, biochemistry disciplines are closely linked. Plant bacterial diseases, chemical control of plant viruses, chemical control of plant diseases, plant disease resistance breeding and immunology, and ecological plant pathology are the main branches of the plant diseases.
2. Research Content
Plant disease: when a strain of robust plant is disturbed, resulting in organs and tissues of the physiological mechanism of local or systemic abnormal plants showed symptoms, and from the diseased parts of the extracted substance with corresponding pathogen symptom, is the occurrence of plant diseases. According to the nature of the induced disease factors, plant diseases can be divided into two categories: non infectious diseases and infectious diseases.
1) Non infection diseases: if plant environment in some physical factors such as light, moisture, temperature and chemical factors such as imbalance of nutrient elements and the living environment of the goods deteriorated continuously affect plant, its strength and more than of plant tolerance limit, will on plant growth and development of adverse effects, disrupt the normal physiological and metabolic activities, even on the plant caused serious damage, plants in physiology and appearance of abnormal, produce lesions.
2) Infection diseases
Infectious diseases are caused by the interaction of plant pathogens under the influence of external conditions, which causes the disease of plant diseases. Common plant pathogens are fungi, bacteria, viruses, higher plants, and the. The physiological, ecological, biological and life history of various pathogens and the ways and means of infecting the host are different.
3. Pathological Analysis
Pathogen induces host to catch disease, first of all to have the opportunity to contact with the host, and invade the host. With pathogen wind, water, soil and seeds and animal and carry propagation, arrived to send the surface of the body, by sending natural hole of the body (such as stomata, lenticels, nectary) or wound (such as mechanical trauma, insects and human caused wounds) invade the host internal.
The occurrence of disease is the result of the interaction between pathogen and host.
Plants have natural immunity to pathogens, but also the performance of the immune.
The relationship between pathogen and host is affected by the influence of environmental conditions, plant disease occurrence and development must be adapted to the environmental conditions, temperature, humidity, illumination, the pH value of the soil, water and nutrient supply are in different degree affecting the disease occurrence and its severe degree.
The parasitic nature of different pathogens: obligate parasite, facultative parasites and other facultative saprophytism.
4. Prevention and Control Measures
1) Eliminate pathogens
2) Remove pathogens
3) Protection hosts
4) Utilization of host resistance