Map-Based Cloning and its Application in Cloning Plant Disease Resistance Genes

Map-based cloning is an unique approach that identifies the underlying genetic cause of a variation. This approach has the ability to tap into a nearly unlimited resource of natural and induced genetic variation without prior information of specific genes. Scientist are therefore trying to utilize this technique in cloning disease resistance gene in plants. Diseases caused by different microorganisms are a potential threat to the cultivation of crop plants as plant diseases can cause yield reductions of up to 40% or more. Although timely application of chemicals against such pathogens can provide adequate control, but it increases the production costs and is not safe for the environment. Breeding for resistance is considered as the most effective and efficient strategy for controlling the pathogens, as it does not add up input costs and environmentally safe. Molecular approaches have been found to be most reliable while looking for disease resistance genes. Therefore, more focus is given to molecular mapping and tagging of disease resistance genes and to make such information available to scientific community across the world. This article reviews the principles, requirements of mapbased cloning and its application in plants.