Plant tissue culture is the art of science to grow new plant with the help of different parts of plants. A small part of the plant can produce the whole plant. Plant are totipotency in nature which means that every parts have capacity to grow in new plant. This technique can be used for the enhancement of the different rare plants. With the help of different parts of rare plant, they can be produce in large number.
Grems free enviroment is known as the sterilized zone. The plant tissue culture is sensative type of experiment in which persence of germs may harm the experiment. So the media which is use for the plant tissue culture should be sterilized before placing the tissues. Though the plant may be grown but the resulting plant may not be healthly. It can be the dangerous for the other too. So, it ismost important to sterilized the everything that involve in the tissue culturre.
There are many sources that may contaminate the medium. Some of the sources are described below:
1.Medium- Firstly medium itself can the sourece of contamination because there may be the presence of microbs at the very beginning. Everythings that are included in the medium should be sterilized. Every vessels that are included in the medium must be sterilized in steel autoclaves or in pressure cooker at 120 degree celcius for 15-20 minutes.
2.Culture vessels and instruments- All the metal vessel and instrument which are required for the plant tissue culture must be sterilized by pleceing them in the oven at 160-180 degree celcius for 2-3 hours . Some instrument like forceps, needle, etc. are needed to be dipped in 95% ethyl alcohol and flamed before use.
3. Plants materials- Those plants whose tissue is going to be cultured must be sterilized before their tissue is taken . Generally, calcium or sodium hypochlorite solution is use for the sterilization process of the plant surface.Generally, calcium or sodium hypochlorite solution is use for the sterilization process of the plant surface.
Generally reproduction in plants take place by two means,either by vegetative means or by apomixis( seed that develop without meiosis and fertilization). Vegetative reproduction is the natural process which produce genetically identical plants. It is mostly used for the propagatino and multiplication of different important plants. This process produce genetically identical plants by asexual means which is also called clonal propagation. When clonal propagation is done in vitro, it is called micropropagation.
Micropropagation has following merits over conventional method of clonal propagation:
When clonal propagation is done in vitro, it known as micropropagation. There are three stages of micropropagation which are described below:
Shoots involve following three main approach in vitro:
Roots are absent in the culture formed by adventitious and axillary shoot. So, they most be placed to a root initiating medium which differs from shoot multiplication medium which contain growth hormone composition . Before planting in the mixing plot, the basal cut is treated with the root initiating powder which helps in the formation of root. All cytokinins inhibit rooting. Instead of using BAP in final stage of multiplication, use of kinetin improves rooting. Improvement of root can be done by lowering the concentration of macro salts to a half and the concentration of sucrose from 2 or 3% to 0.5 or 1%.
When the rooting is finished the plants are removed from the medium to the soil carefully. It is necessary to maintain humidity for 10-15 days. The plot can be covered with polythene having holes for aeration to maintaining humidity .The suitable time for transplanting is when roots begin to emerge out and the leaves are in photosynthetically self-supporting phase.
Simply, it is an art of science of culturing meristem aseptically in an artificial medium in the laboratory condition to get plants. Meristem is the apical growing part of plants which is always multiplying and diseases free. This culture is capable of producing virus free plants. Therefore, this technique has its major application in eliminating various diseases.
Application of plant tissue culture in agriculture
Some of the names of tissue culture laboratory in Nepal are as follows:
Arvind K. Keshari,Kamak K. adhikari. A Text Book of Higher Secondary Biology. Kathmandu: Vidyarthi Pustak Bhandar, 2014.
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1. Adventitious shoots develop naturally on the plant at a place other than normal axial regions which show the structure like stem and leaf.
2. This process produce genetically identical plants by asexual means which is also called clonal propagation.
3. Generally, calcium or sodium hypochlorite solution is use for the sterilization process of the plant surface.
4. Every vessels that are included in the medium must be sterilized in steel autoclaves or in pressure cooker at 120 degree celcius for 15-20 minutes..