Improvement of Wheat Genetic Resistance to Powdery Mildew Retrospects and Prospects

Abstract

Powdery mildew is one of the most noticeable and harmful wheat diseases in countries with temperate climates and sufficient rainfall. The most efficient, economical, and environmentally friendly means to control powdery mildew is the growing of genetically resistant wheat cultivars. The genetic resistance of wheat is quickly overcome due to the evolution of the avirulence genes of the pathogen. The problem of enriching the genetic pool of wheat with new effective resistance genes is relevant. The objective of the work is to show that the basis of the organization of the genetic protection of wheat from powdery mildew cannot be related to the simple expansion of the wheat genetic pool due to new resistance genes. The gene transfer should be preceded by the study of the molecular nature of the resistance gene products. The work presented information about resistance types in wheat against powdery mildew and the molecular nature of Pm genes’ products. They are NLR-immune receptors, tandem kinase proteins, receptor-like kinases, transporters, plant-specific proteins, and mitogen activated kinases. NLR, in interaction with the pathogen effectors, confers highly specific resistance; all the rest provide resistance of a wide spectrum. Characteristics of pathogen gene products are provided, and a model of interaction between Pm and AvrPm gene products is described. A certain number of Pm genes are present in the current genetic pool of common wheat. The effectiveness of some of the most common genes has already been overcome by the pathogen. This necessitates the renewal of resistance genes in wheat. Prospects for the improvement of wheat genetic resistance to powdery mildew are provided. The prospective direction of research for providing effective long-term wheat genetic resistance to the biotrophic pathogen Blumeria is molecular genetic studies of wheat plants and pathogen races. A clear understanding of the molecular nature of the plant protein conferring resistance and its role in the development of the molecular pattern of plant protection against the pathogen is necessary to assess the prospects of any resistance gene for transfer to the genetic pool of wheat in relation to its ability to confer effective and long-lasting powdery mildew resistance.