Role of biotechnology in vegetable improvement
Author: Mahesh Kumar Samota
Biotechnology is a rapidly developing area of contemporary science. Biotechnology can bring new ideas, improved tools and novel approaches to the solution of some persistent, seemingly intractable problems in food crop production. It is comprised of a continuum of technologies, ranging from traditional biotechnology such as plant tissue culture to modern biotechnology such as genetic engineering of plants and animals and represents the latest front in the ongoing scientific progress of this century. However, its increasing importance, at least in plant improvement, should not obscure the fact that traditional plant breeding, based on hybridization followed by selection and evaluation of a large population in the field, accounts for over 50% of the global increase in agricultural productivity. Not only have particularly important new genotypes been bred in Asia through the so-called Green Revolution but also, worldwide, new varieties have been bred in response to the changing needs of agriculture.
Current Role of Biotechnology in Crop Improvement
The fact that a whole plant can be regenerated from a single cell, explant, or organ makes tissue culture a valuable technique to proliferate genetically identical material and select interesting variants for commercial purposes. Totipotency, which states that cells are autonomic and, in principle, capable of regenerating to give a complete new plant, also allows a genetic change, made at the cellular level, to become an established traits of a whole plant. In vitro culture of zygotic embryos (embryo rescue) has enabled us to overcome barriers to a number of interspecific crosses from zygotic failure. Several interspecific hybrids have been obtained in this way-for example, between Lycopersicunm species and So a species, among cucurbits, and among legumes. Plants regenerated in vitro can show some modifications (somaclonal variation) as a result of the mutagenic effect of the culture or the chimeric nature of the cultured tissue. Useful traits have been obtained in variants derived from tissue or anther cultures by adding metabolites and other substances to the media. New plants can be obtained through somatic embryogenesis from pedicels, stems, leaves, roots, and other explants. This technique makes possible the production of "artificial seeds", provided that improved synchronization of the somatic embryo development, good propagate vigor, appropriate embryo desiccation, and encapsulation are achieved.The main problem with the technique is not somatic embryogenesis, now possible in several vegetable species. Several crops, for which transformation and regeneration systems are available, can be genetically engineered at present . All the transgenic plants that have been released following genetic engineering were obtained using Agrobacterium tumefaciens as the vector.Transformed plants of tobacco, potato, tomato, soybean, and other species are now in field trials to evaluate product quality and to test their tolerance to viruses, insects, and herbicides. The concept of DNA-based markers has revolutionized our ability to follow chromosome segments, including minute regions, and has led to new opportunities such as map based cloning and directed plant breeding. Species with little genetic information available in the past now have hundreds of genetic markers. In some cases, the map from one species can be transferred almost directly to another species, such as from tomato to potato. Genetic engineering, in which specific genes are inserted into selected, improved vegetable lines' chromosomes to create a new vegetable with desirable qualities.
Future Role of Biotechnology
In the near future, efforts should be devoted to obtaining transformed plants from apparently recalcitrant species. There is a need to increase the number of isolated genes, particularly those conferring resistance to pests, diseases, and abiotic stresses, and for quality improvement. Mapping the genomes of the most important crops should be one of the priorities of current and future genetic research. This will result in the production of new crop plants with desirable traits and in a better understanding of plant physiological processes. The greatest concerns about biotechnology is patent legislation relating to genes and their use in plant breeding. There is a risk that while new biotechnology will certainly improve knowledge of crop genetics, patents could severely limit its application in crop improvement. This problem should not be under-estimated; a solution must be found that takes account of both private interests and agricultural progress.
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About Author / Additional Info:
I am currently pursuing Ph.D. in biochemostry from IARI new delhi.