Plant Tissue Culture

2. Types of Tissue Culture

According to George et al. (2008) plant tissue culture are classified into two; namely: cultures of unorganized tissues and cultures of organized tissues. Examples of unorganized tissue culture are callus cultures (any plant tissue or organ), cell-suspension cultures (friable callus), protoplast culture (protoplast) and microspore culture (anthers).

2.1. Culture of unorganized tissue

Callus culture: Callus culture may be defined as production and maintenance of an unorganized mass of proliferative cell from isolated plant cell, tissue or organ by growing them on artificial nutrient medium in glass vials under controlled aseptic conditions.

Suspension culture: Suspension culture is a type of culture in which single

This method can, be used for clonal propagation. This group also has called termed culture of determinate organ or has a defined size and shape.

3. Media used in plant tissue culture

One of the most important factors governing the growth and morphogenesis of plant tissues on in vitro culture is the composition of the culture medium besides physical environment. Plant tissue culture provides major (macro), minor (micro), carbon source (sucrose) and trace amounts of organic additives vitamins, agar, and plant growth regulators (George et al., 2008).

But , better understanding of the nutritional requirements of cultured cells and tissues can help to choose the most appropriate culture medium for the explants used because each variety, even explants at different parts requires different types of nutrition (Loyola-vargas, 2012). Among the media formulations, MS mediums are commonly used for most plant species and have high macronutrients. 3.1. Plant growth

Gelling agents

Media for plant tissue culture can be used in either solid or liquid forms, depending on the type of culture being grown. For any plant cells or tissues culture to be grown on the surface of the medium, it has to be gelled with agar. An agar gel level is controlled by the concentration and pH of the medium. The agar concentration commonly used in plant cell culture media range between 0.5 and 0.8 % (w/v). Another gelling agent used for commercial as well as research purposes is gelrite and it is also used at 1.25-2.5 g/liter, resulting in a clear gel that aids in detecting contamination (Manchanda and Gosal, 2012).

Currently there is also another highly effective alternative gelling agent and have a higher proportion of media cost comes from agar besides sucrose.( Puchooa et al. ,1999) reported there were no significant differences between the gelling agents in terms of fresh weight, dry weight and the number of shoots produced after 32days in culture. (Gggrawal et al., 2010) reported that the total cost of medium used for in vitro conservation was decreased by 59% by using is abgol as an alternative gelling agent to agar and phytagel.enset flour „bulla‟ at 80g/l as alternative gelling agent, and there is no significant difference among the shoots number, root number, and shoot height, of the plantlets besides the good gelling ability (Ayenew et al.,