Evolution and adaptation of phytopathogens in perspective of intensified agroecosystem

Abstract

In recent times, increasing problem of evolution and adaptation of plant pathogens in an intensified agroecosystem have become evident from growing incidence of plant disease epidemics with associated yield loss occurring either in large scale or in small pockets of various parts of the world. The dynamics of evolution of phytopathogens is very complex and is influenced by various deriving forces like genetic homogeneity, change in agroecological factors which exert directional selection pressure in the favor of evolution, and emergence of new virulent races/ pathotypes. These new pathogenic variants are highly competent on invading new ecological niches, due to their tremendous genomic plasticity and higher adaptability to changing environmental conditions. Individual groups of pathogens take different paths to evolve and they also adopt different mechanisms in different time and space. In this content, we try to present the various evolutionary mechanisms adopted by different groups of plant pathogens in different agroecosystems and we also try to point out possible driving factors promoting the evolution and adaptation of plant pathogens in an intensified agroecosystem. Remodulation of existing agroecosystem by creating genetic heterogeneity and agroecological diversity would be the suitable approach to slow down the process of evolution. Introduction of improved monitoring system with advanced diagnostic facilities for the detection and spread of new variants and strengthening plant quarantine activity will also be helpful to prevent the entry and establishment of new pathogens or pathogenic variants in an uninvaded area. Therefore, appropriate integration of all these multidisciplinary approaches in groups are emphasized and justified to combat this situation. © 2017 by Apple Academic Press, Inc.