Plant tissue culture

WHAT IS
Plant tissue culture is the technique of growing plant cells, tissues and organs in an artificial prepared nutrient medium static or liquid, under aseptic conditions.

The usual explants are buds, root tips, nodal segments, or germinating seeds, and these are placed in suitable nutrient media where they are grown into an undifferentiated mass known as callus. The callus after disinfection can be propagated indefinitely by subdivision. It has advanced the knowledge of fundamental botany, especially in the field of agriculture, horticulture, plant breeding, forestry, somatic cell hybridization, phytopathology, and industrial production of plant metabolites. 


IMPORTANCE
Tissue Culture can ensure virus and disease free planting material of uniform yield potential. It enables development of newer and improved breeds in terms of productivity and pest resistance by enabling insertion of specific genetic characteristics at the cell level. Other spin offs from tissue culture include propagation of rare or difficult to naturally grow species such as orchids. Although they are more expensive than naturally propagated seedlings, the advantages tissue cultured plants offer to the floriculturist or horticulturist is that they yield flowers or fruits of uniform characteristics and this uniformity is important in international market.

INDIA - DESTINATION FOR TISSUE CULTURE
Demand for tissue cultured plantlets is growing rapidly. Global production is rising rapidly. India being a new entrant to the scene contributed only 1 % of the worldwide production. However India, with its cheap skilled labour and abundant supply of scientific manpower (both of which are essential for tissue culture) has a natural advantage over the west in this aspect. Additional favourable factors are the wide range of plant biodiversity in the country and favourable tropical climate (which enables greenhouses with low energy consumption). Hence the scope for export of tissue cultured plant is immense.

In addition, a special thrust is given to horticulture and floriculture for export and forestry on wastelands. This will lead to large domestic demand. According to Dr. MM Attawar of Indo American Hybrid Seeds Ltd., Bangalore, the global market for tissue culture is $ 15 billion per year. 

The industry is projected to grow at a fast pace till it reaches the saturation point of 15 billion plants. The Indian tissue culture industry has the potential to grab a sizeable chunk of the growing international market and even valuable foreign exchange. 

Major importing countries are Germany, UK, USA, Netherland, France, Switzerland and Canada. 

TISSUE CULTURE IN INDIA
Among the tissue culture techniques, plant - micro - propagation is the only area of biotechnology that is commercially exploited in India and this technology is most disseminated. In micro- propagation, a gram of vegetative tissue can give 1000 plants.

These techniques have been known in India since 1930s and significant development took place with establishment of two tissue culture pilot plants at National Chemical Laboratory (NCL), Pune and Tata Energy Research Institute (TERI), New Delhi. At this technology parks, nearly 4.0 million plant-lets of eucalyptus, popular teak, bamboos and anogysia (desert teak ) have been field demonstrated in 3500 Ha. covering 17 states. These parks serve as platform for technology, training and demonstration of technology for mass multiplication of horticulture and forestry species. 

Micro propagation has been carried out in several crops at ICAR which include potato, sweet potato, yarns, garlic, lemon, banana, pineapple, ginger, small cardamom, turmeric, black pepper and several medicinal, aromatic plants. Coffee, tea, pepper, cocoa, mango and citrus varieties with disease free planting material has also been produced. Banana, papaya, coconut, small cardamom, oil palm, ornamental plants have been multiplied on a commercial scale by private seed companies. 

Plant Tissue Culture is an essential component of Plant Biotechnology. Plant Cell and tissue culture has already contributed significantly to crop improvement and has great potential for the future. Commercial application of plant tissue culture started in USA with micropropagation of orchids in 1970s. It has seen tremendous expansion globally in the number of production units as well as the number of plants produced. With an estimated global market of $15 billion per annum for tissue cultured products, even with exponential expansion in the industry, the demand far exceeds production, leaving enough scope for expansion. This industry appears to be undergoing a pause in growth presently in developed countries as it is finding difficult to remain cost–effective. In US, only half the production capacity is being utilized currently due to high labour costs. 

The potential for the domestic market is enormous and by conservative estimates it is expected to be Rs. 300 cores with the annual growth rate of 15%. Currently, the focus of the companies is mainly in the floriculture sector however, micro propagation in banana arid sugarcane is also gaining popularity. Tissue Culture units in India have capacity ranges between 1 million to 5 million and above plants per annum with an aggregate production capacity of 180 million plantlets per year. Most of these tissue culture units are located in Maharashtra, Andhra Pradesh, Karnataka and Kerala. 

The growth in demand for tissue culture banana is expected to increase at a high rate of 25 to 30%. The demand for sugarcane is anticipated to grow at a higher average rate of 20% due to introduction of ethanol blended petrol. The demand for tissue culture plants for tuber crops e.g., potatoes, turmeric and ginger is increasing due to increased awareness. The demand for tissue culture ornamentals and medicinal plants is expected to increase significantly. The overall market for Tissue Culture Plants is expected to grow by at least 20 to 25% for the next few years.