Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
TISSUE CULTURE MEDIA Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. Plant tissue culture is widely used to produce clones of a plant in a method known as micropropagation. Culture media are largely responsible for the in vitro growth and morphogenesis of plant tissues. The success of the plant tissue culture depends on the choice of the nutrient medium. In fact, the cells of most plant cells can be grown in culture media. Basically, the plant tissue culture media should contain the same nutrients as required by the whole plant. It may be noted that plants in nature can synthesize their own food material. However, plants growing in vitro are mainly heterotrophic i.e. they cannot synthesize their own food. Composition of Media: The composition of the culture media is primarily dependent on two parameters: 1. The particular species of the plant. 2. The type of material used for culture i.e. cells, tissues, organs, protoplasts. Major Types of Media: The composition of the most commonly used tissue culture media is given below. White’s medium: This is one of the earliest plant tissue culture media developed for root culture. MS medium: Murashige and Skoog (MS) originally formulated a medium to induce organogenesis, and regeneration of plants in cultured tissues. B5 medium: Developed by Gamborg, B5 medium was originally designed for cell suspension and callus cultures. At present with certain modifications, this medium is used for protoplast culture. N6 medium: Chu formulated this medium and it is used for cereal anther culture, besides other tissue cultures. Nitsch’s medium: This medium was developed by Nitsch and Nitsch and frequently used for anther cultures. Synthetic and natural media: Synthetic media have almost replaced the natural media for tissue culture. The culture media usually contain the following constituents: 1. Inorganic nutrients 2. Carbon and energy sources 3. Organic supplements 4. Growth regulators 5. Solidifying agents 6. pH of medium Preparation of Media: The general methodology for a medium preparation involves preparation of stock using high purity chemicals and demineralized water. The stock solutions can be stored frozen and used as and when required. Most of the growth regulators are not soluble in water. They have to be dissolved in NaOH or alcohol. Selection of a Suitable Medium: In order to select a suitable medium for a particular plant culture system, it is customary to start with a known medium (e.g. MS medium, B5 medium) and then develop a new medium with the desired characteristics. Among the constituents of a medium, growth regulators are highly variable depending on the culture system. In practice, 3-5 different concentrations of growth regulators in different combinations are used and the best among them are selected. For the selection of appropriate concentrations of minerals and organic constituents in the medium, similar approach referred above, can be employed.