Genetic Analysis and Mapping of Avirulence Genes in Magnaporthe grisea

Abstract

Key concepts regarding the genetic analysis and mapping of avirulence genes. However, information gained from genetic analysis and mapping of avirulence genes provides a strong theoretical foundation which supports a systematic approach for cloning these genes by map-based strategies. In this chapter, the authors describe the genetic analysis and mapping of an avirulence gene to rice cultivar CO39 to illustrate the pn iples and practices involved in such studies. Segregation of avirulence/virulence toward these isolines coincided exactly with that on CO39; therefore, we concluded that 2539 possess additional avirulence genes corresponding to the resistance genes introgressed into these rice lines. Restriction fragment length polymorphism mapping of avirulence genes is useful for establishing a positon in the genetic map. A practical limitation to genetic and molecular studies of trasts associated with phytopathogenicity is that mutant production and subsequent complementation by transformation may require screening transformed strains on many thousands of plants.