Importance of Medicinal and Aromatic Plant Genetic Resources Wild and semi-wild medicinal and aromatic plant species have been used over the millennia for human welfare in the promotion of health and as drugs and fragrance materials. According to the World Health Organization (WHO), medicinal plants form the basis of traditional and indigenous health care needs used by the majority of the world’s population. This trend of using medicinal plants does not occur only in developing countries but also present in developed countries as well. In recent years, there has been a growth of interest in traditional medicine due to increase in interests in complementary medicine in industrial countries as well as the interests of the international pharmaceutical industries. Modern pharmacopeia still contains at least 25 % drugs derived from plants and many others, which are synthetic analogues built on prototype compounds isolated from plants (Silva, 1997).
Two of the largest users of medicinal plants are China and India. Traditional Chinese Medicine (TCM) uses over 5,000 plant species; India uses some 7,000 species. In China, sales of traditional medicines have more than doubled in the last five years. Use of Traditional Chinese Medicine- Ayurveda, Unani and Sidda has also been growing at a rapid rate in Western countries. In Britain the use of TCM has increased tremendously, especially for the treatment of eczemaan estimated 1.0 million TCM prescriptions were written in 1995 and the number of TCM doctors has doubled in the past five years. China has about 2,50,000 traditional medical doctors, and in 1990, TCM doctors used some 7,00,000 tones of plant materials. India has about 4,60,000 traditional medicine doctors, and export trade in medicinal plants in it has risen almost three times during the last decade, and it is booming. Latin Amer-ica, home of a third of the world’s plants, has also a long-standing tradition of use of plants as medicine, especially among the indigenous peoples. Nearly 2,000 species used in the Colombian Amazon for medicinal purposes. The use of herbal remedies is also booming in developed countries. In Germany, over 80% of all physicians regularly use herbal products. Indeed, most of Europe (except Britain and Ireland) has never lost its herbal tradition. In USA, herbal remedies are worth $1.6 billion, and it is rising. The situation is similar in Japan (Suk, 1998).
In Bangladesh, medicinal and aromatic plants have been used in Ayurvedic and folk medicine since ancient times. Even today, use of medicinal plants in primary health care systems is very important, especially in remote rural communities and poorly accessible areas. In many parts of the country, particularly in adjoining forest area, wild collections of herbs mainly by the poor are a livelihood activity and often a major source of cash income for these groups. Wild medicinal plants, therefore, play an invaluable role in the health services and the very livelihood of majority of the rural population. Given the importance of herbal medicines, the Government of Bangladesh has brought the system of Unani and Ayurvedic Medicine under the National Drug Policy in 1982 to ensure availability, commercial manufacturing and marketing of quality Unani and Ayurvedic Medicine and Drugs (Ahsan et al., 1997).
Depletion of medicinal plant species The bulk of the medicinal and aromatic plants are still wild-harvested and only a very small number of species is cultivated. The over-exploitation and destructive harvesting of medicinal plants in the wild by the escalating human populations have lead many plant species to become rare and some are on the point of extinction due to degradation and loss of habitats. Bangladesh statistics show a total forest area of 1,559 sq km or about 12.8 percent of the total land area (BBS, 1994). However, estimates of other sources reveal that the forest area of Bangladesh shrank from 16.5 % in 1971 to 6.0 % in 1982. A recent study however shows that the forest area does not exceed 5 -6 % of the total land area. An estimated 73,000 hectares of Bangladesh forest have been lost through encroachment for agriculture and aquaculture during the last two decades. It is also estimated that a loss of about 8,000 hectares of forests occurs annually due to industrialization and urbanization. A number of papers reported that herbalists now having to walk increasingly greater for herbs that once grew almost outside the door. Data on threatened species are scarce but a large number of medicinal plants are reported to be disappearing rapidly in Bangladesh due to destruction of natural habitats (FAO, 1984). It has been reported that 24 vascular plant species have been threatened in Bangladesh of which 1 species is extinct/endangered, 21 species vulnerable, 1 rare and 1 indeterminate (Walter and Gillett, 1998). Some 45 forestry species are currently threatened with extinction (Khan, 1991; Haq and Banik, 1992). Some medicinal plants have also been reported as endangered by Dr. N. Ahmed (Pers. comm.). The species are Sagittaria platyphylla (Kawatukri), Zingiber spectabile (Bonada), Vitex trifolia (Sagar nishinda), Melastoma melabathricum (Bon tejpata), Leea alata (Bon chalida). The Bangladesh National Herbarium has very recently listed 106 plant species as endangered (Khan, 1991), of them, some 35 plant species have been mentioned for medicinal purposes. It has also been known from personal communications that some other important wild medicinal plant species are now at risk of being lost in all or part of their distribution ranges because of reduction in their population numbers due to habitat destruction and over collecting. The species are: Aglaia roxburghiana (Pironga), Arbus precatorius (Rati), Bixa orellana (Doigota), Caesalpinia bonduc (Nata), Ipomoea digita (Bhuikumra), Mollotus philipinensis (Sinduri), Piper chaba (Choi), Vetiveria zizanioides (Ghandhabena), Terminalia belerica (Bohera), Terminalia. chebula (Haritaki), Terminalia arjuna (Arjune), Holarrhena antidysentrica (Kurchi), Rauvolfia sarpentina (Sarpagandha), Litsea monopetala (Kharajora) etc.