Sources of spring common wheat resistance to powdery mildew

Abstract

Effective breeding work to create disease-resistant wheat varieties provides for regional, retrospective studies to determine effective sources of resistance. One of the most harmful and globally significant wheat diseases is powdery mildew. In the conditions of Tatarstan, located in the Volga economic region of Russia, the mass development of powdery mildew on spring common wheat is noted annually, regardless of the prevailing weather conditions. The prevailing high natural infectious background allows us to objectively differentiate spring wheat samples by disease resistance. The purpose of our research was to search for sources of resistance to powdery mildew among the samples of spring common wheat of the VIR collection, which retain stability for a long time. The studies were conducted in the period from 2011 to 2021. In total, during the entire period, the resistance to powdery mildew of 702 samples was studied in the conditions of the Pre-Kama zone of the Republic of Tatarstan. The reaction of the samples was evaluated to a natural population of the fungus Blumeria graminis f. sp. tritici, caused by powdery mildew of wheat. The screening of spring common wheat samples for the period from 2011 to 2020 allowed us to identify sources of field resistance to powdery mildew that retain their effectiveness for a long time: Tybalt (k-64897, Netherlands), Zebra (k-64707, Sweden), CH Rubli (k-65003, Germany), Visa (k-64390, Belarus). During this period, there was a decrease in the resistance of spring common wheat samples to powdery mildew from 3.5 points in 2011-2015 to 4.6 points in 2016-2020 (on a 9-point scale). At varietals: Toma (k-66193), Sudarynya (k-6647), Laska (k-66421) from Belarus; KWS Torridon (k-66273, UK); Tybalt (k-64897, Netherlands); Griwa (k-66701), Zura (k-66702) from Poland; Florens (k-66391, France); Odeta (66394, Czech Republic); Lavett (k-66095), Boett (k-66353) from Sweden no symptoms of powdery mildew were recorded in 2019-2021. The collection of Russian varieties and varieties from the countries of the former USSR (except Belarus) is poor in resistant varieties, only two varieties of Barakat and Sitara from Tatarstan turned out to be highly resistant. Resistant to B. graminis samples mainly originate from the European part of the world (band: Great Britain ?Belarus), approximately in geographical coordinates - 50...55? north latitude.