Int.J.Curr.Microbiol.App.Sci (2018) 7(8): 4651-4685 4651 Review Article https://doi.org/10.20546/ijcmas.2018.708.491 Review on Molecular Epidemiology in Relation to Devastating Late Blight Pathogen, P. infestans, de Bary Pranamika Sharma*, Anil Kumar Jena, Rimi Deuri, Surya Prakash Singh and Sangeeta Sarmah Department of Agriculture & Horticulture, Arunachal University of Studies, Namsai, Arunachal Pradesh, India *Corresponding author ABSTRACT Introduction Phytophthora infestans causes late blight on a range of solanaceous plant species and can devastate potato and tomato crops in most cool-temperate environments worldwide. Crop losses and costs of late-blight control constitute a significant financial burden on the potato industry. In many potato-growing areas, frequent fungicide applications are the main method of disease control. These applications commence when a local inoculums source is identified and/or environmental conditions are suitable for disease development. The potentially serious consequences of a late-blight infection result in many growers spraying their crops as a matter of routine from the time the plants meet in the rows through until harvest. There is a clear environmental and economic need for more sustainable late-blight control, through better management of primary inoculum, improved chemicals or more efficient application schedules and the use of ‗engineered‘ or natural host resistance. Research has demonstrated that natural host Molecular epidemiology is a science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution and prevention of disease Molecular epidemiology provides the ‗tools‘ (both laboratory and analytical) that have predictive significance and that epidemiologists can use to better define the etiology of specific diseases, and work towards their control . Application of these molecular techniques has increased the understanding of the epidemiology of the most important infectious agents, Phytophthora infestans. Recent progress in P. infestans genomics is providing the raw data for such methods and new bio molecular markers are currently being developed which have tremendous potential in the study of P. infestans. Closer collaborations between specialists in the fields of plant pathology, epidemiology, population genetics / molecular ecology, P. infestans molecular biology and plant breeding are advocated to enable such progress. Molecular techniques help to stratify and to refine data by providing more sensitive and specific measurements which facilitate epidemiologic activities including disease surveillance, outbreak investigations, identifying transmission patterns and risk factors among apparently disparate cases characterizing host pathogen interactions and providing better understanding of disease pathogenesis at the molecular level.. International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 08 (2018) Journal homepage: http://www.ijcmas.com Keywords Molecular epidemiology, Etiolgy, P. infestans, Late blight, Marker Accepted: 26 July 2018 Available Online: 10 August 2018 Article Info