Late blight of potato: From the great Irish potato famine to the genomic era – An overview

Late blight of potato and tomato, one of the most widely reported diseases of plants, is a significant curb in global agriculture which poses severe problems in terms of yield and economic losses, and environmental pollution due to pesticides use. The disease is caused by Phytophthora infestans -an oomycete - which first drew the considerable attention of plant pathologists during the mid-1840s when the pathogen incited historic starvation in Ireland – the great Irish potato famine - as a consequence of substantial potato losses due to late blight disease. Since that period, late blight has triggered several epidemics of potato and tomato of profound intensity in different regions. Over the course, synthetic fungicides have been proved effective management practice for late blight control; nonetheless, the evolution of new genotypes with increased virulence to hosts and resistance to fungicides has been greatly regarded as an agricultural problem. Breakthroughs in genome sequencing of P. infestans and identification of resistance genes in some plants have opened ways for the development of resistant genotypes. However, there still exist numerous challenges to deal with this noxious pathogen. This review aims to highlight the historical significance of late blight disease, its chemical control strategies and associated challenges, and resistance breeding programs by employing genetic approaches.