Farmers over the ages have always been associated with biotechnology, albeit inadvertently. Sowing seeds of plants that grew quickly, producing bigger and better fruits, cross-breeding of plant crops to raise yields are some of the things that farmers have always been doing as a way of life in the farm. It is only now modern biotechnology through genetic engineering has facilitated the crossing of natural selection barriers for producing better and profitable crop variety like crops that can withstand frost and insect attacks.
This article focuses on transgenic farm crops, how biotechnology helps combat frosts and insects and also details some of the advantages and concerns that biotechnology raises in the farm scenario.
Transgenic farm crops
At the outset what is meant by transgenics? It simply means transferring a gene from one organism to another, and specifically in relation to crops it means transferring a foreign gene from one plant to another.
Why do we need transgenics? That is because conventional breeding has certain deficiencies. For example if cross breeding is done with certain wild varieties some undesirable characteristics could get transferred. Other common reasons for the failure of conventional breeding are seed abnormality, failure of pollen germination or hybrid sterility.
An important point is, what are the steps involved in making transgenic plants? Although it is beyond the scope of this article to discuss in detail the steps involved in making transgenic plants, this is a three step process namely making the recombinant DNA, transformation of particular gene into plant and regeneration of transgenic plant cells.
Transgenic farm crops allow farmers to grow more food crops in less acreage, with reduced inputs of water, fuel, pesticide and with less of soil tillage. That means transgenic plants are more productive. Starting from the first transgenic tobacco plant, as of today there are more than fifty plant species that have accepted foreign genes. For example today one could find wheat varieties with CP4-EPSPS (5-enolpyruvyl shikimate-3-phosphate synthase) and gox genes which have modified starch content and are herbicide resistant; disease resistant potatoes that have the bacteriophage T-4 lysozyme; herbicide resistant tomato with aro A gene; insect resistant Bt sugarcane; nutritionally enhanced varieties of cassava; delayed ripening tomato called Flavr Savr; and many more farm crops.
Biotechnology can also help to change the profile of the farm produce. For example, using genetically engineered plant breeding programmes the composition of rape oil can be changed to have lesser amounts of erucic acids ( this has goitrogenic properties). Similarly the animal feed component can be made to have less of thioglucosides.
Combating frost and insects
Some farmers especially in North America and Canada have always had to contend with frost and insects.
The bacteria pseudomonas syringae is an ice-nucleating bacterium. It can be found on the leaf surfaces of plants. When temperature becomes sub zero these bacteria cause ice crystals to form on the leaves. This type of frost causes the death of plant cells and consequently substantial crop loss. Researchers have now isolated the gene in pseudomonas syringae to make another variant bacterium which does not have the ice-nucleating protein. It's called ice-minus pseudomonas syringae which when sprayed on plant leaves will over grow the ice-plus protein and that takes care of any frost damage from occurring.
In transgenic crops, the soil bacterium Bacillus thuringiensis (Bt) is the source for making toxins that can counter insecticides. Different Bt strains have specific genes that encode for specific insecticidal proteins each with different kinds of insecticidal activity. Examples of biotech engineered plants that are resistant to insects are cotton plants that are resistant to caterpillars and maize plant that is resistant to rootworms.
However, Bt strains is not the universal solution for eliminating the scourge of insect attacks. For example, elimination of sap-sucking pests continues to remain a problem. Another unrelated problem is that, even after the crop is harvested the Bt toxins could remain active in the soil.
But as of today, more than 500 varieties of pests have been found to be resistant to conventional insecticides, so Bt toxins in transgenic crops is a major boon to farmers.
If farming activity has to be environment friendly, it naturally entails using available resources optimally without causing harm to the environment. Biotech crops do not need intensive tilling which means there is considerable savings in fuel consumption perhaps running into millions of gallons. For example soil is parted only at the hole in which seeds are expected to be planted. This means that seed bed remains covered with detritus from previous crops, which in turn enhances the carbon retention in the soil by several times as compared to conventional farming methods.
Biofuels from farm crops
In maize cultivation, the leaves and stalks of maize similar to straw are left over after harvest. This is called corn stover, and constitutes almost half the crop yield. Corn stover can be converted to biofuels and this result in net reduction of greenhouse gas emissions.
Although biotechnology allows us to combine the genes of totally unrelated species of plants this very fact often raises the specter of fear in people using GM foods. After all can we forget the instance of a fish gene that was transferred to a tomato which neither made the tomato swim nor provide the tomato with any other beneficial attributes?
In short, sustainability is the key to farming and biotechnology has helped advance its cause by developing advanced cultivation techniques. Moreover biotechnology will change the way our farms are run because as farm productivity rises, the farm model may change intrinsically in favor of large farms with integrated product processing facilities, whether it is for wheat, soybean, rice or cotton.
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