Conservation protection and sustainable use of medicinal plants

The last decade has witnessed skyrocketing interest in herbal medicines. At present, 95% collection of medical plants is from the wild using unsustainable practices of collection/harvesting. Indiscriminate exploitation of natural resources to fulfil escalating consumer demands besides other anthropogenic activities have led to the decline of natural and wild populations. Current rate of species extinction coupled with inter alia ravages of diseases/insect pests has made conservation of medicinal plants, an urgent activity. There is a global recognition of safe conservation of bioresources of medicinal plants. These resources can be conserved employing holistic approach of amalgamating both in situ and ex situ methods using new emerging technologies to ensure sustainable use. In situ conservation approach allows for continued and dynamic adaptation of plants to environment. Contrastingly, ex-situ conservation requires maintenance of germplasm outside their original habitat. Plant diversity is being conserved in field gene bank, seed gene bank, in vitro gene bank and cryobank. Among the ex situ methods, rare and curious plants can be conserved as living collection in field genebanks, arboreta, botanical/herbal gardens etc. Conventional conservation of seeds in seed genebanks is the most popular strategy. However, it sometimes poses problems in case of threatened species, as the seeds may be inadequate and/or recalcitrant. In vitro genebanks are increasingly being used as an alternative to conserve such species. Cryopreservation offers the possibility of conserving germplasm under suspended growth for indefinite period in a limited space with minimum inputs. DNA storage also needs to be integrated in conservation programme in a planned manner. The comprehensive and safe conservation of available diversity including medicinal plants is the major aim of conservation efforts at National Bureau of Plant Genetic Resources (NBPGR). The collection, conservation, documentation and scientific management of the precious biowealth has thus emerged as a priority area. In this endeavour, considering the need to survey enormous genetic resources and their distribution, priorities have been worked out, keeping in view the relative degree of threat. Attention is given to adopt different conservation methodologies available in a complementary way to conserve the collected germplasm. The precious germplasm has been collected at NBPGR through explorations from different phytogeographical zones of India. The germplasm is collected from forests, villages and herbal gardens in the form of live plants, seeds, fruits and other plant propagules. Of these, over 100 species are maintained in pots and under field genebanks at its regional stations. Seed samples of 579 and 220 accessions are conserved in seed genebank and cryobanks, respectively. In vitro techniques have been used as an aid to clonal propagation and conservation especially for threatened species. The application of tissue culture techniques for multiplication and conservation of these plants appears a promising option. Employing these strategies, cultures of a few medicinal plants such as Kaempferia galanga, Rauvolfia serpentina, Tylophora indica, Picrorhiza kurrooa, Rheum spp and Gentiana kurroo have been conserved for varying periods. In vitro repository maintains 60 collections comprising 20 threatened/important species as shoot cultures. Many important forest medicinal plants like Sandalwood (Santalum indicum and Santalum album), Eucalyptus suffer from infection with Phytoplasma (earlier designated as Mycoplasma like organisms, MLOs). Raychhaudhuri and his group worked on `Spike disease`, which has devastated the chief sandal growing areas of South India. Temporary remission of the disease symptoms by tetracycline treatment and electron microscopy confirmed Phytoplasma to be the causative agent. The present paper will elaborate on the above activities.