Wheat leaf rust (Puccinia triticina Eriks.) virulence frequency and detection of resistance genes in wheat cultivars registered in the Czech Republic in 2016-2018

Abstract

In 2016–2018 virulence of the Czech wheat leaf rust population was studied on Thatcher near-isogenic lines, carrying different Lr genes, and 130 leaf rust isolates. Virulence to Lr9 was found only sporadically. Virulence frequency to Lr2a, Lr2b, Lr2c and Lr28 was lower than in previous years. All tested isolates were avirulent to Lr19. Lr24 conditioned resistance to majority of isolates. Nineteen recently registered Czech cultivars were tested with six isolates of the pathogen and Lr genes were postulated. Presence of genes Lr1, Lr10, Lr19, Lr24, Lr26, Lr28, Lr34 and Lr37 was tested by molecular markers. Lr37 prevailed, followed by Lr genes 10, 24, 28, 1 and 26; genes Lr19 and Lr34 were not determined.

Mining of Leaf Rust Resistance Genes Content in Egyptian Bread Wheat Collection

“…Regarding Lr34 , as expected, we identified this gene in almost all test Egyptian varieties, which is in good accordance with previous reports of Singh and Rajaram (1992) [ 66 ], Imbaby et al, (2014) [ 67 ] and Fahmi et al (2015) [ 59 ]. For Lr37 , which has been reported to mainly confer the adult plant’s resistance rather than in seedlings, it was found to be represented in about 60% of the tested Egyptian wheat genotypes.…”

“…With the guidance of molecular marker techniques, the pyramiding breeding of Lr genes (even those functional at the seedling and/or adult plant stages) is expected to facilitate the designing of efficient breeding programs for durable resistance against this pandemic wheat disease. Undoubtedly, the resistance mechanisms against leaf rust are still poorly understood, but the information gained from resistance genes that are found in many varieties can help breeders to develop resistant varieties [67]. This could be the most ecological and economical solution to manage wheat rust disease [8]; additionally, the resistance durability seems to be dramatically improved when Lr resistance genes are combined [68], whereby when more LR genes are accumulated in a variety, the combined effects of these genes give this variety a large base to resistance to disease [8].…”

Analyzing wheat cultivars grown in Czech Republic for eight stem rust resistance genes

“…It was postulated in 8 German cultivars including 'Elixer' and 'Gordian' which are also registered in Czech Republic and present in our study (Flath et al, 2018). In our previous study focused on leaf rust resistance, we detected Sr24/Lr24 in 3 Czech cultivars out of 19 tested (Hanzalová et al, 2020). Although Sr6 was reported in cultivar 'Košútka'registered in Czechoslovakia in 1981(McVey, 1992 and Sr36 was present in a 1985 Czechoslovakian cultivar 'Agra'(https:// old.…”

Challenges and prospects for developing genetic resistance in common wheat against stem rust in Western Siberia

“…Комплекс генов Lr24/Sr24 обеспечивает эффективную защиту от основных ржавчинных заболеваний пшеницы по всему миру за исключением Южной Африки (Roux, 1985;Pretorius et al, 2010), Индии (Bhardwaj et al, 2010;Manjunatha et al, 2015) и Кении (Jin et al, 2008), где выявлены новые вирулентные расы стеблевой ржавчины. Вирулентные к гену Lr24 клоны возбудителя бурой ржавчины зарегистрированы в Австралии, Чехии, Иране и США (Park et al, 2002;Kolmer, 2019;Hanzalova et al, 2020;Nemati et al, 2020). В России, в Омской области, недавно выявлены расы P. graminis, вирулентные к гену Sr24 (Shamanin et al, 2020;Skolotneva et al, 2020).…”