Biotechnology – a step towards green revolution

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LAHORE – Pakistan is the world’s sixth most populous country. The Economic Survey 2009-2010 indicates an estimated population of 169.9 million at end of June 2009, and an annual growth rate (revised) of 2.05 percent, it is expected that Pakistan will become the fourth largest nation on earth in population terms by 2050. But unfortunately, the burgeoning population is asymmetrical with the depleted land resources and in future we have to feed this massive population with these depleted resources. Therefore, the looming scenario compels us to revolutionise our agricultural system through “Biotechnology” or “Recombinant DNA Technology” as it presents the most promising, precise and advanced strategy available today for increasing the food production by reducing crop losses and increasing yields with limited land resources. Let us have a cursory out look how it will help to revolutionise agricultural output of the country.
Photosynthesis is the process by which plants make their food i.e.sugar, glucose in the presence of light. Therefore in order to improve the yield researchers have tried to enhance photosynthetic activity of green plants with out reduction in leaf area through genetic engineering. Biotechnology assists to accelerate efficiency of photosynthesis by identifying the genes which determine the efficiency of light absorption, electron transport, protein pumping and high energy phosphate bond synthesis in the chloroplasts and then reassembling them from the best resources.
Depending upon the length of the carbon skeleton of the first product of assimilation, plants are classified as type C3 (wheat, rice, cotton) or type C4 (sugarcane, maize).The potential production rate of C3 plants is around 200kg dry matter per hectare daily and of C4 plants is 200-400 kg depending on the weather. Thus to arrange for C3 plants to carry out C4 metabolism through rDNA technology would be highly useful.
Biotechnology can assist to cultivate crops under harsh growing conditions, such as drought, soil with high salt content and in temperature extremes. The situation of per capita availability of water in the country is extremely alarming and it will further accentuate the problem of agriculture productivity as the per capita water availability has dropped from 5600 cu meters to 1200 cu meters, which could slip further to the water-deficient level below 1000 cu meters per year after 2010. Moreover, the phenomena of global warming has changed the water requirements of our crops and now they have become thirstier than ever with the rise in temperature so genetically modified crops have to be evolved in order to overcome this catastrophe.
Knowledge of biotechnology has enabled scientists introduce desirable functional characteristics, such as reduced allerginicity or toxicity, delayed ripening, increased starch content or long shelf life which has resulted in decline of malnutrition problems world wide-such as deficiencies in vitamin A, iron, iodine, and zinc. Rice has been genetically modified to contain beta-carotene and more iron to help overcome deficiencies of these nutrients where rice is a staple food. Similarly, nutrient-enhanced soybeans can be bred to produce heart-healthy oils and biotech purple tomatoes can help fight cancer.
In addition, researchers have observed that the use of rDNA technology can reduce the needs for chemical pesticides and tillage, which can cause soil erosion, as well as enhance the nutritive value of crops.Insect pest menace is one of the major factors that destabilise crop productivity. Insects have been known to damage the crops in the field and during storage conditions. Crop productivity is under constant threat of pests and diseases all over the world. The introduction of Bt. varieties of cotton in our agriculture sector has halted the indiscriminate application of pesticides against boll worms of cotton. Bt.is acronym for Bacillus thuringiensis, commonly found soil bacterium that contains a crystalline protein (Cry) which breaks down to release a toxin, known as delta toxin which is detrimental to lepidopterous larvae.
Viruses cause economically important diseases in most of the major agricultural crops. Thus so far, there are no chemical viricides that do not also harm crops. Some crops are treated with insecticides to kill insects that carry viruses from plant to plant. Plant genetic engineers have suggested a new approach to controlling viruses; they are engineering plants to contain a virus gene. The plant then produces a viral protein which enables the plant to resist attack by the same virus. Unfortunately, cotton crop in the country is under severe attack of Cotton Leaf Curl Virus (CLCV), however, rDNA technology can help overcome the menace by developing genetically modified cotton crop against CLCV.