Genetic diversity of cereal crops for powdery mildew resistance

Abstract

Powdery mildew (causal agent Blumeria graminis) is a widespread and harmful fungi disease of cereal crops especially in the regions with humid climate. The pathogen is differentially interacting with plant host genotypes. Growing cereal crop varieties protected with different resistance genes is the most rational, costly and ecologically safe way of combating powdery mildew. The supply of effective genes can be increased due to studies of crop genetic resources collection, introgression of resistance from wild relatives, and also at the expense of mutant forms created with the use of traditional (induced mutagenesis) and biotechnological methods including genome editing. This causes the increasing interest to searching and identifying resistance genes, elucidation of their structural and functional organization, and analysis of molecular mechanisms of the character development. The review summarizes modern information on the identified genes of powdery mildew resistance of the main cereal crops wheat, barley and oat. The list of wheat and barley genes identified at the molecular level is presented. It includes genes encoding NLR and CNL proteins (Pm2, Pm3, TaMla2, TaMla3 genes of wheat, rye Pm8 gene, barley Mla gene), receptor-like proteins (barley Mlo gene), transport proteins and receptor-like kinases (Lr34, Lr67, Pm21 of wheat).