DNA TECHNOLOGIES IN MODERN CROP IMPROVEMENT

Abstract

DNA is a hereditary molecule present in the nucleus of a cell. The small steps of humankind to know the basics & importance of this molecule in the early 19th century have now much advanced in knowledge. It is a double helical structure made of a phosphodiester backbone with nitrogenous bases inside the backbone attached by hydrogen bonds, held in a staircase manner. DNA is called the hereditary molecule as it is the first important component of the central dogma of a cell, where it stores hereditary information of an organism. This stored information is transcribed to mRNA in the cell's nucleus, translating into different kinds of proteins performing important functions for an organism. Its hereditary property comes from the fact that it can generate its identical copy through replication. Processes like mitosis and meiosis maintain their number and quantity in an organism generation after generation. The knowledge about the molecule of DNA is exponentially increasing after humankind was able to sequence it in the early 1980s. Now, DNA based advanced technologies are available and are widely used, especially in the area of crop improvement. DNA markers are one of the important technologies impacting modern crop improvement through indirect selection. An ideal DNA-based marker must be reproducible, distributed throughout the genome, preferably codominant, and must have the ability to distinguish between individuals with maximization or polymorphic in nature. Apart from DNA markers, DNA is being used in many technologies that have become an essential part of modern crop improvement programmes (Agarwal et al., 2008).