Investigation of Phytophthora Infestans Causing Potato Late Blight Disease

Abstract
Phytophthora infestans (Mont.) cause potato late blight disease and can infect of roots, tubers, and shoots of the plant. The majority of significant factors in determining the spread of the potato late blight is the cultivation of infected potato tubers and their presence as agricultural plant debris in the agricultural field. Mycelium, zoospores, Oospores, and sporangia, all these structures can make infection, also Oospores with their thick wall can survive for 3 to 4 years under low temperatures. P. infestans responsible to yield losses may arrive at 100% in optimum condition. There are two types of mating patterns for A1 and A2, and this depends on the spread of each type in different environments. This fungus also contains several genetic patterns that have been identified through molecular analysis. The different genotypes in this fungus led to new challenges to make an unstable guideline for the study of virulence and aggressiveness. Different strategies or methods were used to prevent or control late blight disease, included of chemicals, crop rotation, bio-agents, and resistant plants. There are many advantages or disadvantages to each strategy, but several studies mention that using resistant plants and fungicide together on conditions in suitable times and strategies led to perfect effect. This paper investigated in important factors in the spread of late blight disease, and some challenges in this fungus.