Green revolution and high impact agriculture have satisfied the food requirement of most of the human population as it has doubled since 1960. But increase in food productions has led to serious environmental problems, i.e., high impact agriculture is not sustainable for more than a few decades. So, more and more farmers are trying forms of agriculture that cause less environmental problems. Sustainable agriculture (or alternative agriculture of low-input agriculture) is based on beneficial biological processes and environment friendly chemicals. In sustainable agriculture, certain modern agricultural techniques are combined with traditional farming methods. Sustainable Agriculture may be simply defined as, "Agricultural methods that rely on beneficial biological processes and environment friendly chemicals rather than conventional agricultural techniques."
In other way, Sustainable Agriculture may be defined as, "The successful management of resources for agriculture to satisfy human needs while maintaining or enhancing the natural resource base and avoiding environmental degradation".
Hence we can say, Sustainable Agriculture is not a single programme but there is a series of programmes that are adapted for specific soils, climates and farming requirements. Water and energy conservation, crop rotation, breeding of disease resistant crop plants, use of biofertilizers (BGA fertilizers mycorrhizae, symbiotic and asymbiotic nitrogen fixers, organic fertilizers, green manures), biological pest control methods and bio-pesticides or Integrated Pest Management (IPM) are practiced in sustainable agriculture.
(Bio-fertilizers and biological pest control are given separately in detail in this unit.
In addition to these practices, biotechnology also plays a promising role in sustainable agriculture. Biotechnology held the potential of marrying biology and engineering and is essentially interdisciplinary area consisting of biochemistry, molecular biology, microbiology and genetics. Plant biotechnology includes two major technologies cell, tissue and organ culture and the recombinant DNA technology/genetic engineering. Cell and tissue culture has many commercial applications which include micro propagation, haploid breeding, productions of secondary metabolites and use in production of transgenic crops or genetically modified crops. Recombinant DNA technology has two major uses namely molecular marker technology and production of genetically modified transgenic crops. In general genetic engineering promises greater productivity and more nutritious foods.
The molecular markers have been utilized in characterization, maintenance and sustainable use of PGRs, (plant genetic resources). Their main uses in plant breeding include selection of desirable plants in early segregating generations at the seedling stage and selection of diverse parents for hybridization.
The most important use of plant biotechnology has been in the production of superior transgenic crops which are having not only resistance to different biotic and abiotic stresses but are also having improved nutritional quality of food.
Using traditional breeding methods, it takes 15 years or more to introduce disease resistance genes into a particular crop plant but genetic engineering or recombinant DNA technology takes a fraction of that time in achieving the same goal. Further in this desirable genes from any organisation can be used.
Genetic engineering may produce more nutritious food plants because they would contain all the essential amino acids. Recently in 2000, an international team of scientists has successfully engineered rice grains to produce beta-carotene or vitamin A (Golden rice or miracle rice).This rice has the potential to improve world health because about half of the world's population use rice as their staple food and rice is a poor source of many vitamins including vitamin A.
Using genetic engineering,crop plants resistant to insect-pests, viral diseases, drought, heat, cold, herbicides and salty or acidic soils can be developed.
In a cross of agriculture and medicine, molecular biologists are developing GM plants ( Genetically modified plants) that give edible vaccines, e.g., antidiarrhea vaccine and cholera vaccine both contain in raw potato. Similarly, extract preventing tooth decay and a vaccine against ulcers have been obtained from GM crops. Bananas (more palatable than potato) are also being genetically modified to provide edible vaccines, Edible vaccines hold important role for developing countries as they can be grown where most needed and they will not require clean needles and constant refrigeration.
Genetically modified crops transgenic crops have already transformed agriculture and they have been grown in more than 100 million acres of farmer's fields, each in year 1999 and 2000 despite of protests and debates.
Plant genomics is the latest or new field of plant biotechnology. Under this discipline, complete genome of Arabidopsis has been sequenced and of rice is being sequenced. This will lead to find the functions of all genes (reverse genetics), which will be having a great impact in field of cytogenetics, plants breeding and plant pathology. The Knowledge from genomics research will be utilized in detection, isolation and manipulation of genes in a variety of crops and thus, novel transgenic crops will be produced. As there is a great complexity of plant system, so let us see which way the wind blows.
Thus plant biotechnology has a great potential to improve agriculture
No comments:
Post a Comment