Medicinal plants have played an essential role in the development of human culture, for example religions and different ceremonies. Medicinal plants are resources of new drugs. It is estimated there are more than 250, 000 flower plant species. Plants are directly used as medicines by a majority of cultures around the world, for example Chinese medicine and Indian medicine. Medicinal herb can be a real herbal plant, a shrub, other woody plant, or a fungus. The used part may be the seeds, berries, leaves, barks, roots, fruits, or other parts of a plants, or mushroom, which may be considered "herbs" in medicinal or spiritual use. Many of the modern medicines are produced indirectly from medicinal plants, for example aspirin. The botanical survey of India has prepared a provisional list of threatened plants which includes large number wild (or) wild relatives of food, horticultural, Medicinal and aromatic plants. In India, Ayurveda (developed in North India), Siddha (developed in Tamil Nadu) and Nagarjuna (developed in Andhra Pradesh) systems of medicine were developed. Ayurveda is practiced in SriLanka, Pakistan and Bangladesh also.

In plant biotechnology, the in-vitro studies are performed by culturing the plant cell, tissue and organ on an artificially prepared nutrient medium static or liquid under aseptic conditions. The effect of some plant growth regulators were studied on seedling growth and stomatal characters of Brassica campestris L. V.mungo (L.) Hepper, V.radiate (L.) Wilczek.) through in-vitro studies. Black gram (Vigna mungo), is an important short duration pulse crop grown in many parts of India, cultivating both in Kharif and Rabi season. The optimum temperature for better growth of these crops ranges between 25 to 350C, but it can tolerate up to 420C which permit to cultivate during summer and winter season. Mungbean crop (Vigna radiata (L) Wilczek) is considered as one of the new crop in Egypt, it is important legume crop characterized by a relative high content of protein. The application of novel tissue culture and genetic engineering technology could offer efficient and stable plant regeneration. Brassica are still considered as an important source of green vegetable in the developing countries and the potential for market diversification of some new crop types.