Green Revolution with its emphasis on increased productivity saw the selection of a few high yielding varieties based on their favourable response to high fertiliser doses – considerably narrowed down the rich genetic base of cultivated crops that existed in India till then. Traditional seeds (also called heirloom seeds) are open-pollinating varieties. These seeds produce plants which in turn reproduce to provide seeds which are true to their parents. The seeds can be ‘saved’ for another crop, and by sensible plant selection, a farmer can keep improving his stock every passing season. Traditionally, farmers also had a system of barter or exchange where seed stock was shared. With the introduction of high yielding variety (HYV) seeds, these practices have seen a gradual die-out. In the present context scientists and environmentalists espouse that local level seed banks need to be revived to ensure conservation of the many seed varieties/landraces indigenous to India which otherwise may be lost forever. According to Dr R H Richharia, a renowned rice scientist, 4,00,000 varieties of rice existed in India alone during the Vedic period – and claimed that 2,00,000 varieties of rice exist even today – a truly phenomenal number.
The genetic erosion now underway is palpable and conservation has become a major concern as seeds have to be stored and rotated under strict norms to be able to maintain its uniqueness. Large scale introductions of HVY seeds is gradually eliminating older varieties and depleting the germplasm pool. India, however is yet to take proactive steps to revive the shrinking genetic bank stock. Much of the internationally standardised HYV seed may in the long term be unsuitable for small farmers who can do better with traditional disease resistant varieties, or specially developed versions of them, which can be grown without an expensive package of chemical inputs. There is an urgent need to increase the genetic diversity of crops with an increased threat of climate change in the modern era, and government legislation to protect the rights of plant breeders must take care not to have the opposite effect.
Conservation of wild or cultivated species can be undertaken in situ – in natural habitats or bioreserves, where the evolutionary progression continues; or ex situ – in banks specially designed for the preservation of seeds or germplasm, where although there is cessation of the evolutionary progression, the desired genes are preserved. With appropriate preservation techniques genetic engineering could help recovery of desired traits from such banks. However the costs in terms of professionals and infrastructure in ex-situ conservation are indeed high and may be ill afforded by developing nations such as ours.
The International Treaty on Plant Genetic Resources for Food and Agriculture of the United Nations (the International Seed Treaty, IST), in force since June 2004, is a comprehensive international agreement in harmony with Convention on Biological Diversity. IST aims at guaranteeing food security through the conservation, exchange and sustainable use of the world’s plant genetic resources for food and agriculture. (www.fao.org/Legal/TREATIES)
With the advent of the HYV seed revolution, the modern day seedbanks are NGO or government driven projects. Many plants developed over centuries, now no longer used for commercial agricultural production, making them increasingly rare, are stored in these seed banks. However, seeds have to be recycled regularly as different seeds survive for different periods of time, some for even less than a week. Also seeds need to be protected from pests while in storage, but the risk from seed borne pests and pathogens persists. There are several seedbanks operative world over, however the one that deserves a special mention is The Svalbard Global Seed Vault that was established in Norway in 2008 – 600 miles from the North Pole. SGSV is designed to hold 4.5 billion batches of seeds of the world’s main crops. The facility is a cave-like structure, drilled 500 ft below permafrost – to store frozen samples from every seed collection in the world. The SGSV is an insurance against natural disasters and human errors such as nuclear disasters or failure of refrigeration.
India has 18 functional seedbanks operating through State Seeds Corporations, State Departments of Agriculture and through the two national public sector undertakings – State Farms Corporation of India (SFCI) and National Seeds Corporation (NSC). The banks are located in Andhra Pradesh, Assam, Bihar, Gujarat, Haryana, Karnataka, Maharashtra, Madhya Pradesh, Odisha, Punjab, Rajasthan, Tamil Nadu, Uttarakhand, Uttar Pradesh, West Bengal and Kerala (Parliament Question 946, 20. 3. 2012). The Indian government has also taken various initiatives under the National Seeds Policy, 2002 which mandates the need to popularise seed conservation of traditional varieties. It identifies policy thrust areas as – variety development; plant variety protection; seed production; quality assurance; seed distribution and marketing; infrastructure facilities; transgenic plant varieties; import of seeds and planting material; seed exports; promotion of domestic and private sector seed industry; and, strengthening of monitoring system. Also, local level movements have encouraged the maintenance of traditional seeds. The Beej Bachao Andolan (Save the seeds Movement), begun in 1980s, led by farmer and social activist Vijay Jardhari, which brought fame to the village of Jardhargaon, Tehri, Uttarakhand. A project run by Centre for Indian Knowledge System in Tamil Nadu – an independent trust, also attempts to conserve through seedbanks. Few rare varieties of paddy being saved under this project are Velchi, Norungan, Mattaikar, etc. Other methods of conservation include seed festivals and fairs where farmer to farmer seed exchange acts as a social and cultural instrument of conservation.
Plant genetic resources are of immense value to research in agriculture and forestry. Germplasm is an all inclusive term that constitutes cells, tissues, organs, whole single or few celled organisms and seeds or other propagules that serve as means of regenerating the whole organism, whether plant or animal. In the agricultural context the genetic material that is maintained in genebanks are – currently cultivated varieties (cultivars); once favoured but now discontinued old cultivars; locally developed and preferred varieties called landraces; and wild relatives of crop species. As stated by Dr R K Tyagi, Head, Division of Germplasm and Conservation, National Bureau of Plant Genetic Resources (NBPGR), the Institute and its 10 regional stations across the country in different agro-ecological zones, presently has over 3.90 lakh samples of 1,584 species, which include about 390,544 accessions of wild relatives of various crops.
As pointed out by D Bramwell in his paper ‘How many plant species are there? Plant Talk’, 2002, around year 2050, current rate of extinction will result in the loss of 60,000-100,000 plant species globally. Moreover during the past 50 years many high yielding and/or otherwise better varieties particularly those with higher pest and disease tolerance, have continuously replaced the once favoured cultivars and landraces. These dropped varieties may contain genes affording advantages to future agriculture. Also, wild relatives of crop species may contain genes useful in crop improvement. In fact, the genes for resistance against infamous red rot of sugarcane were introduced from its wild relative – Saccharum spontaneum.
Economics encourage farmers to change cropping patterns and many now grow just one or two crops at high levels of efficiency. But, these crops, may in the long run become vulnerable to the changes in the habitat, and pests and diseases – due to genetic uniformity – especially in a climate change scenario. Conservation of wild and erstwhile crop genetic resources is an insurance against such risks to food security.