Genetic Diversity of Barley Foliar Fungal Pathogens.

Powdery mildew, net blotch, scald, spot blotch, barley stripe, and leaf rust are important foliar fungal pathogens of barley. Fungal leaf pathogens negatively affect the yield and quality in barley plant. Virulence changes, which can occur in various ways, may render resistant plants to susceptible ones. Factors such as mutation, population size and random genetic drift, gene and genotype flow, reproduction and mating systems, selection imposed by major gene resistance, and quantitative resistance can affect the genetic diversity of the pathogenic fungi. The use of fungicide or disease-resistant barley genotypes is an effective method of disease control. However, the evolutionary potential of pathogens poses a risk to overcome resistance genes in the plant and to neutralize fungicide applications. Factors affecting the genetic diversity of the pathogen fungus may lead to the emergence of more virulent new pathotypes in the population. Understanding the factors affecting pathogen evolution, monitoring pathogen biology, and genetic diversity will help to develop effective control strategies. [ABSTRACT FROM AUTHOR]