Virulence Phenotypes of Siberian Wheat Stem Rust Population in 2017–2018

Ekaterina S Skolotneva,Alex I Morgounov,Vasiliy N Kelbin,Evsey Kosman,Mehran Patpour,Vladimir P Shamanin,Elena A Salina

doi:10.3389/fagro.2020.00006

Abstract

Management of wheat stem rust in Western Siberia has gained importance since the first outbreaks in 2007-2010 and 2016. The race composition and virulence patterns were investigated for the enlarged Puccinia graminis f. sp. tritici (Pgt) samples collected in three neighboring regions Omsk, Novosibirsk, and Altai during 2017-2018. Most of Pgt isolates were identified as virulent to wheat lines with genes Sr5, Sr9a, Sr10, Sr38, SrMcN and avirulent to Sr24, Sr31. Differentiation ability of genes Sr6, Sr7b, Sr8a, Sr9b, Sr9d, Sr9g, Sr9e, Sr11, Sr17, Sr21 Sr30, Sr36, and SrTmp to distinguish between the regional populations was established. A total of 33 virulence phenotypes or races were detected among 115 Pgt isolates tested. Based on virulence phenotypes, two different Pgt subpopulations were identified in the Altai and Omsk regions likely originating from asexual and sexual cycles, respectively. The Novosibirsk pathogen population seems to be a mixture of isolates originated from both neighboring regions with virulence phenotypes that developed in the west, Omsk (TKRPF, QHHSF, and MLLTF) and in the south, Altai (NFMSF, LKCSF, LKMSF, and PKCSF) of Western Siberia.

Highlights

Western Siberia is an extremely important wheat production area in Russia with ∼7 million ha of spring wheat, along with increasing areas of winter wheat and some durum wheat
The Novosibirsk region is the central part of Western Siberia, bordered by the Omsk region in the west and the Altai region in the south
To ascertain whether inoculum of Puccinia graminis f. sp. tritici (Pgt) in a specific region is endemic or wind disseminated from neighboring areas, monitoring of the pathogen in Western Siberia was performed in 2017–2018

Summary

Introduction

Western Siberia is an extremely important wheat production area in Russia with ∼7 million ha of spring wheat, along with increasing areas of winter wheat and some durum wheat. Tritici (Pgt) was not considered economically important in Western Siberia until the first reports of stem rust outbreak in 2007–2010 (Shamanin et al, 2015; Sochalova and Lihenko, 2015). In the Omsk region, southwest of Western Siberia, wheat production was affected by heavy epidemic in 2015; yield loss was estimated at more than 2 million tons. Understanding population structure, virulence diversity, and distribution of Pgt in the Omsk and neighboring regions has been essential for effective disease management based on resistance genes. Significant race diversity coupled with high virulence of local pathogen was revealed in the samples from Omsk and Altai (Shamanin et al, 2020).

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