Wheat diseases common in ukraine: harmfulness, genetic control and effectiveness of breeding for resistance

Abstract

The review of literature on the most harmful diseases of wheat in Ukraine (snow mold, septoria spot, tan spot, powdery mildew, brown rust, wheat streak mosaic virus, barley yellow dwarf virus) is presented. Symptoms of these diseases, their harmfulness, genetic bases of resistance and the main results of breeding are in the focus of attention.

Discussion. The research of scientists of Ukraine, neighboring countries and non-CIS countries gave the following results.

There is no clear genetic control of resistance to snow mold; resistance genes have not been identified. The main method of breeding is the selection on severe natural infectious background. Search for donors of resistance among wild relatives is promising.

18 Stb genes of resistance to septoria spot have been identified. No immune varieties have been found, but a clear differentiation in disease resistance is observed. A number of lines with resistance genes from wild relatives were created.

Pm1- Pm53 genes of resistance to powdery mildew are known. Wheat has both specific and non-specific resistance. Local varieties and forms of bread wheat are valuable sources of resistance. A number of lines with known resistance genes were produced by hybridization.

Genes of resistance to tan spot were investigated. They are categorized into genes of  insensitivity to pathogen toxins (tsn) and tan spot resistance genes themselves. There are sources of high resistance to tan spot among modern wheat varieties and lines and related species.

Classical gene-gene interaction was established for the majority of cases of wheat inheritance of resistance to brown rust. Over 90 Lr resistance genes, resistance suppressor genes as well as quantitative trait loci QTL have been identified. The efficiency of distant hybridization in breeding for resistance to brown rust of wheat is high, in particular, a number of winter wheat varieties carry rye-wheat translocation 1AL / 1RS, which contains a set of resistance genes.

Frequent viral diseases of wheat are looked into: wheat streak mosaic virus (WSMV) and barley yellow dwarf virus (BYDV). No genes of resistance to these diseases have been identified in wheat, but we know that wheat grass have them. Transgenic plants is the most effective way to fight viral diseases.

Conclusions. Basing on the literature review results, we concluded that studies aimed at the creation of disease-resistant varieties, search for new sources of resistance, expansion of the genetic diversity of existing wheat varieties, exploration of pathogen population composition and identification of new resistance genes are expedient and relevant.