Selasa, 14 Juni 2011


How To Find The presence of plant pathogens

The presence of pathogens into something that is very important as evidence. The presence of pathogens can be known directly and indirectly. Pathogens that macroscopic size in surface tissues such as the fungal fruiting bodies are large. In some cases a small magnifying glass is required to view the presence of pathogenic structures. In many cases of microscopic pathogens, so to see the presence microscope like most fungi and bacteria. Fungi and bacteria before seen under the microscope often have to be isolated first. Virus and viroid, his presence be seen under the electron microscope. In the development of detection of pathogens utilize the findings in various fields of basic science as an example is the serological and DNA testing

1. Jump on Plant Surfaces
Some pathogens that macroscopic structure can be seen directly on the plant surface. Golongn weeds such as rope daughter that infects many crops such as tea-tehan fence; weed demons that infect corn plants, and parasites that infect many trees is a clear contah. Some fungi also reveal macroscopic structure on the surface of the base of the tree being attacked like a white root fungus and mildew on the rubber base of the stem lingsi on palm oil and various types of trees

2. Using Loops / Glass Authorities
Some disease-causing pathogens such as rust on the leaves with a direct way will only be visible as small bumps on the leaf surface. On observation by using the loop, then the structure will appear more clearly. By using the loop structure of the pathogen can be enlarged 10X. This is quite helpful in viewing the structure of small-sized fruit.

3. Using a light microscope
Most pathogens are so small that need the help of a microscope for observation. Pathogens can be lngsung taken from the surface of the host and then viewed under a microscope. On the surface of symptomatic plant plastered with colored transparent tape and then viewed under a microscope. In many ways often used liquid so that objects appear more clearly. In the glass preparations were given a drop of water. By using a tapered needle scraping symptomatic part-match, the result korekan placed on droplets of water and covered with glass preparations, and then observed under a microscope. Often to find the pathogen, plant tissues need to be treated specially so that pathogens can be present. Most classes of pathogenic fungi require high humidity, for it is necessary humidified tissue first, then captured the structure of the pathogen to be observed. Frequently encountered structure misellium only, it is necessary to use certain vitamins or minerals that the fungus can form the desired structure in the diagnosis. Misellium fungus Phytophthora will be able to form a sporangium liset when placed in the soil.

In many cases, in which symptomatic jringan difficult to find, both mycelium and other structures. If this happens, it would require the isolation step. Isolation needs to be understood is a step to get the structure of the pathogen in pure. Thus, when the colony was obtained only in the form misellium course, it would require special treatment steps so that the desired structure can emerge.

4. Using Electron Microscope
The body sub-mkroskopis such as viruses and viroid presence can be identified by using electron microscopy. Electron microscope can enlarge objects up to hundreds of Ribi times. Parts of the fungus and bakteripun would seem very clearly by using electron microscopy.

5. Reaction Using Serology
Serological reaction is a reaction between antigen and antibody. Antigen is any substance (to be part pathogens) that can induce antibody formation in the mammalian body. Antibody can only react with antigens that can occur coagulation, or precipitation. Currently there are two types of antibodies are known, namely polyclonal and monoclonal antibodies. Monoclonal antibodies can sensitively detect the presence of certain pathogenic strains. By having diimbas antibodies by antigens derived from a particular pathogen, the presence of pathogens in a material can be detected quickly and accurately. Currently Eliza technique widely used in serological reactions.

Basic diagnose a plant disease must be understood
• The cause of disease / pathogen that can cause symptoms differently on the same host.
• Signs of disease may increase the certainty of a diagnosis, but also consider the possibility of a secondary pathogen or saprophyte that attack parts of infected plants. So that diagnosis errors can be minimized.

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