by Athula Perera
One important goal of the World Biodiversity Convention is the protection and use of biological resources in ways that do not diminish the worlds variety of genes and species or destroy important habitats and ecosystems, the three basic elements being saving, studying and sustainable and equitable use of biodiversity.
The world has 5-7 million different species of plants, animals and microorganisms, many of which are used in agriculture. Sri Lanka, which has high endemic species of flowering plants (23%) and mammals (16%) is considered one of 25 biodiversity hot spots of the world !
Advances in agriculture will in time decrease the farming population and enable more people to be employed in industry, medicine, science, arts etc. The success in agriculture is partly due to -the use of biological diversity by selecting and breeding new varieties of crops and new breeds of animals. Today, 80 crops provide 90% of the worlds food from plants and 50 animal species give food and fibre. Thousands of other species are actively farmed. Hundreds of animal species are harvested for food and domesticated. Thousands of insect species are involved in pollination and provide plants with protection from pests. Thousands of microbial species in soil and plants are responsible for nutrient cycling and decomposition. Humans must use this diversity to their advantage by developing new crops, new varieties, new farm animals, new medicines etc. to avoid devastation by drought, insect outbreaks, famine etc.
Diversity, created by millions of genes, is found in the multitude of ancestral and domesticated forms, in close relatives of cultivated crops, in different cultivated varieties of each crop and in Landraces which are local varieties developed by farmers for their own use. Breeds of different animals (4,500 - 5,000 mammalian and avian breeds) consist of an array of different genetic types. All of these harbour genetic diversity. Moreover, different varieties of crops can be developed for different regions having different soil types, climates, cultivation methods, pests and diseases. In Turkey, wheat - Landraces gave the highest yields on non-irrigated hillside fields and in Mexico, a maize Landrace is used in infertile soils. In Sri Lanka, traditional rice varieties were grown for specific purposes (medicinal value, superior grain quality etc.), and in different regions (saline soils, drought conditions etc.). Where there are heterogeneous habitats, greater diversity is needed.
Plant breeders have to search for genes that provide for increasing yield, resistance to pests & diseases, tolerance to drought, salinity etc. Such genes have been found and used in other parts of the world. A wild species of tomato has provided a gene for enhanced soluble solids and sugar content, and high yielding genes were identified and transferred from wild rice Oryza rufipogon to a commercial rice cultivar resulting in higher yield of the improved commercial variety. A wild species of potato has provided a gene for producing specialized leaf hairs for better insect resistance. Our own traditional rice varieties are known to carry many such useful genes - Kalu heenati for developing strength and anti- venom properties, Sudu heenati for seed quality, oiliness of cooked rice and flavour, Kuru wee for small grains, Nyan wee for drought resistance, El wee, Hetada wee for developing brain cells, Rath el as treatment for diabetes etc. Sri Lanka possesses more than 2,500 traditional varieties and wild rices harboring some wonderful genes. What about the numerous varieties of medicinal plants that we have? Add to these, forest trees, tea, rubber, coconut, spice crops and the thousands of ornamental flowering plants with a myriad of colours and shapes. They harbor millions of wonderful genes, waiting to be used - a gift of nature to this beautiful little country!
Natural material in the worlds biodiversity has also been used to produce pesticides and herbicides, known as biopesticides and bioherbicides. In 1998, there were 175 registered natural active ingredients and 700 natural products used as biopesticides and bioherbicides. Microbial pesticides use bacteria, fungi, viruses and even protozoans. Neem is a very well known plant-based pesticide. Biochemical pesticides contain naturally occurring substances such as sex pheromones and scented plant extracts. These natural products are less harmful, affect only the target organisms, are required in small quantities and decompose quickly.
Natural ingredients obtained from the biodiversity are also used to produce biofertilizer containing beneficial microbes, seaweed extracts, plant hormones, humic acid, volcanic rock powder etc. A green manure has been produced for use in saline soils that contains salt tolerant microalgae and dormant plant cells. A biofertilizer containing cyanobacterial cells that fix nitrogen, deposit organic matter to soil and provide oxygen to roots is available for use in rice fields. Bacterial and enzyme mixtures are available to digest unwanted solids in manure as a biotreatment of organic waste.
There is more emphasis now to introduce genes to forest trees to improve their timber properties and pulp quality.
Natural ecosystems provide us with services in terms of plant and animal species, pollinators and other insects and microbes in addition to aesthetic beauty and intellectual stimulation. They provide us with goods, in terms of sea food, wild game, forage, timber, biomass fuels, natural fibre, pharmaceuticals, industrial products and their precursors.
They provide us with life support functions in terms of purifying the air and water, mitigating drought and floods, generating soil & renewing fertility, detoxifying and decomposing waste, providing pollinators, cycling nutrients, controlling pests, protecting us from harmful u-v rays, moderating extreme weather and maintaining biodiversity.
It is therefore of prime importance not only to conserve our biodiversity but also to study the diversity in terms of identifying important genes in them by morphological and molecular characterization. This necessitates the creation of local databases which should also include the documentation of traditional knowledge. This should include the documentation of farmers perception of biodiversity, folk knowledge, indigenous recipes of cooking, making pickles, medicines etc., womens knowledge systems showing how they ensure food security, collect, use and sell uncultivated wild food, cooking methods etc. This will provide opportunities for local scientists/institutes to patent genes and their uses (thus preventing gene piracy), sharing the benefits of patents with relevant people and communities. It will require the establishment and development of national research centers. The Agricultural Biotechnology Centre of the University of Peradeniya can be developed into a national center where the databases can be established and where centralized research such as the production of transgenic plants can be initiated, developed and monitored. It can also be used as a service center for the production of DNA sequences, probes, primers etc. and also for sequencing genes and other DNA fragments. This center can also establish linkages between scientists and institutes within Sri Lanka and also with regional and international agencies. It can plan and implement programmes to take new technology to the villages in the form of, for example, establishing resources for micropropagation of plants such as bananas, potatoes, ornamentals, forest trees and medicinal plants; establishment of resources for production of biofertilizer, biogas, biopesticides, vermiculture, mushroom culture and aquaculture which could involve marine, freshwater, brackish water and ornamental fish as well as production of prawns, sea weeds, pearl oysters and the introduction of integrated farming such as fish/pig/duck farming, rice-fish farming etc.
It is time for us to plan and implement national programmes to conserve, study and especially use our biodiversity for the benefit of our own people. It is a gift of nature to our people. It is more valuable than gold or gems. Our people have suffered enough. They deserve more.
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