The application of tissue culture for large-scale plant production meant for commercial purposes is well demonstrated in the case of several crops and horticulture species. Many varieties have grown remarkably well in vitro, allowing various kinds of experimental manipulations. In many instances, the objectives of the investigations have been more than fulfilled and many solutions have been found to problems of plant growth, differentiation, morphogenesis and in the application of different growth substances.

Much valuable information has been added recently to our knowledge of the nutrition of cells, tissues and organs grown in vitro. In the last 30 years several improvements have been made in the composition of the media to suit both general and specific needs, resulting in a two or three fold increase in the number of media commonly used. Similarly more sophisticated experimental innovations like shakers, laminar flow clean air work stations culture jars, incubation chambers, and many more were introduced which improved the techniques and the convenience considerably.

The optimum physical conditions for good tissue growth of various species have been determined. These include light, temperature and humidity. Miniphytotrons have been developed in the form of growth chambers. By using them, various types of tissues and organs can be cultured, resulting in organised or disorganised growth.

By including induction for further differentiation, a large number of propagules of a growth given or chosen explant can be obtained. In certain cases, plants have been freed from specific pathogens.

The most outstanding premiums offered by aseptic propagation technology, over the conventional methods are; o In a relatively short time and space large number of plants can be produced, starting from single explant.o Unlike the conventional methods of plant propagation, micropropagation of even temperature species may be carried out throughout the year.

o Tissue cultured plants are generally free from fungal and bacterial diseases. Virus eradication and maintenance of plants in a virus-free- state are also readily achieved in tissue culture.

Pharmaceuticals from Natural Plants Progress in the field of pharmaceuticals has been spectacular. Most of the herbal medicinal plants can be cultivated at various parts of the country. Extracts obtained from the plants like Catharanthus roseus, Taxus baccata, Solanum khasium, Artemisia annua, Digitalis lanata, Commifora mukal, Cassia angustifolia etc have found a tremendous export potential.

The demand for vinblastine [$75/gm] and vincristine [135 $/gm] isolated from Periwinkle or Catharanthus roseus is around 20-25kg/year. These figures represent the local as well as export market demands.

Companies like Cipla and Tamilnadu Dada and Tamilnadu Herbals Ltd produce currently about 15-18 kg of vinblastine. In addition compounds like vindolin can be isolated but the exact market potential of vindolin is still untapped.Vinblastine and vincristine can be sold to the local manufacturer who prepare or market formulations based on them.

The second plant product which has very good market potential is podophyllotoxin which is used in the manufacture of `etoposside.' Podophyllum hexandrum is cultivated in Kashmir and can be cultivated in the hilly regions of Maharashtra and Gujarat through tissue culture techniques. Podophyllum resin, which is isolated from the rhizome and which constitutes about 9% of the plant can be sold at the rate of $2.50 per gram, and when pure podophyllotoxin is isolated from the rhizome, it commands the price of $17.00 per gram. The current demand for podophyllum resin is around 62 to 80 kg per year.

Currently, podophyllum resin is supplied by Amsar Products and Cipla. Pure podophyllotoxin is isolated and marketed by Cipla {about 30 kg per year,} and 50% of which is used for captive consumption.

The third product, which has a good export potential, is Camptothecin, which is isolated from Nothapodytes foetida. Camptothecin is present to the tune of 0.1% in leaves and the bark of the plant. This plant can be cultivated throughout the Western Ghats and hilly tracks of Gujarat. The demand for Campthothecin is around 15 kgs per annum. Currently, there is no local competition to CIPLA, who is actively engaged in producing Camptothecin.The fourth product is Taxol, which is isolated from Taxus baccata {Indian Yew.} The compound is present in the bark and the spines. Although a native of North Eastern India, the plant, through the technique of tissue culture can be cultivated in many parts of Maharashtra and Gujarat. Taxol currently fetches a rate of $200.00 a kilogram. All these four products mentioned earlier possess antineoplastic {anti cancer} activity.

In addition, the following plant products also have good marketing potential. Artemisin, isolated from Artimisia annua or Quinghas, which possesses a dual activity {anti malarial and curing brain fever} can be sold to the extent of about 35 to 40kgs per year. Currently there is no local competition whatsoever.

The second product is Solanidine, which is isolated from Solanum khasium or Solanum virum. This product enhances womb fertility and can be exported to the Middle Eastern Countries, European countries, and to America. The product fetches a rate of about $8,000 per kg, and the estimated demand is around 70 kg per year. From the same plant, one can isolate solasidine which provides a starting point for the synthesis of corticosteroids like Dexamethasone, Betamethasone, Prednisolone, Prednisone, etc. The annual production of corticsteroids is around 12 tonnes per annum and this figure indicates that the deficit of 6 to 7 tonnes per annum. Currently, Jain Industries Jalgaon and Cipla are actively engaged in production of solasidine, but the production is quite low. The price for 16-DPA is around Rs 6,000 per kg for the local market. The major beneficiaries are John Wyth and Glaxo India. The export price is around $100 per kg. The third product, which has great market potential, is sennosides. Sennosides usually,are of A and B type and they are isolated from Cassia angustifolia and possess catharitic activity.

Sennosides have good export potential in the Middle Eastern and European market. The local competitors actively engage in the production of sennosides are none other than Cipla. The current demand for sennosides is around 200 kg per annum. The selling price for sennosides is around $1000 per kg.

The most important mandate for cultivators of medicinal plants is use of chemical fertilizers and chemical pesticides is complete taboo. If chemical fertilizers and pesticides are used then quality as well as quantity of active ingredients is adversely affected. Nevertheless, cultivators can freely use soild and liquid biofertilizers like Growmore and Shootup, Growzyme manufactured by Suvash Biogenics Pvt which are found to be totally safe and without any side effects whatsoever to increase he yield of active ingredients.