Partial resistance to wheat leaf rust in 18 spring wheat cultivars

Euphytica ◽  
1989 ◽  
Vol 44 (3) ◽  
pp. 247-258 ◽  
Author(s):  
L. H. M. Broers
Keyword(s):  
Leaf Rust ◽  
Spring Wheat ◽  
Partial Resistance ◽  
Wheat Cultivars ◽  
Wheat Leaf Rust ◽  
Wheat Leaf

scholarly journals First Detection in North America of Virulence in Wheat Leaf Rust (Puccinia triticina) to Seedling Plants of Wheat with Lr21

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 1032-1032 ◽  
Author(s):  
J. A. Kolmer ◽  
J. A. Anderson
Keyword(s):  
North Dakota ◽  
Leaf Rust ◽  
Spring Wheat ◽  
Puccinia Triticina ◽  
The United States ◽  
Wheat Cultivars ◽  
Wheat Leaf Rust ◽  
Hard Red Spring Wheat ◽  
Wheat Leaf ◽  
Red Winter Wheat

Leaf rust resistance gene Lr21 is present in hard red spring wheat (Triticum aestivum) cultivars grown in Minnesota, North Dakota, South Dakota, Manitoba, and Saskatchewan. Isolates of Puccinia triticina, the causal organism of wheat leaf rust, with virulence to this gene have not been previously detected in annual virulence surveys in the United States. (2). In 2010, hard red spring wheat cvs. Faller, RB07 (1), and Glenn, all with Lr21, had 0 to 5% levels of leaf rust severity, which was higher than in previous years in research plots in North Dakota and Minnesota. Leaf rust collections from wheat cultivars and germplasm lines with Lr21 at three locations in Minnesota and North Dakota were increased on plants of the leaf rust susceptible wheat Thatcher and the Thatcher line with Lr21. Single uredinia from the collections were isolated and increased on seedlings of Thatcher. The single uredinial isolates were inoculated to 7- to 8-day-old seedling plants of the set of 19 differential lines that are currently used in the leaf rust virulence surveys (2). Thatcher lines with Lr3bg, Lr14b, Lr20, and Lr23 were also tested. The isolates were also inoculated to seedling plants of hard red spring wheat cultivars with Lr21: Glenn, Steele-ND, Faller, RB07, Amidon, AC Cora, and McKenzie (3). Previous standardized methods for growing seedling plants, increase of rust isolates, inoculation, incubation, and evaluation of infection types (IT) were used (2). All tests with the Thatcher differential lines and the cultivars with Lr21 were repeated at least twice. Virulence phenotypes were described based on virulence to the 19 differentials in the P. triticina virulence nomenclature system used in the United States. (2). Two virulence phenotypes, TFBJQ and TFBGQ, with virulence to Lr21 were found at the three locations. TFBJQ is virulent (IT 3 to 4) to genes Lr1, 2a, 2c, 3, 10, 14a, 14b, 20, 21, 24, 26, 28, and avirulent (IT 0 to 2+) to genes Lr3ka, Lr3bg, Lr9, Lr11, Lr17, Lr18, Lr30, LrB, and Lr39/41. TFBGQ was avirulent to Lr14a and Lr20, but identical to TFBJQ for virulence and avirulence to the other resistance genes. Isolates of both phenotypes were virulent on seedlings of Faller, Glenn, RB07 (1), Steele-ND, AC Cora, and Amidon. McKenzie had IT of 2+ due to the additional presence of Lr16 (3). Both TFBJQ and TFBGQ have intermediate IT of 2+ to Lr16; IT 2+3 to Lr23, and are completely virulent to Lr1, Lr2a, and Lr10 that are present in hard red spring wheat cultivars. Both phenotypes have high IT to Lr24 and Lr26 that are present in soft red winter wheat and hard red winter wheat cultivars. The Lr21 virulent phenotypes likely arose by mutation from the group of P. triticina genotypes in the simple sequence repeat group NA-5 (4) that have intermediate IT of ;2- to ;2+ to the Thatcher line with Lr21. P. triticina isolates with virulence to Lr21 are a new threat to wheat production since in 2010 more than 50% of the hard red spring wheat acreage in Minnesota and North Dakota relied on Lr21 for effective resistance to leaf rust. References: (1) J. A. Anderson et al. J. Plant Regist. 3:175, 2009. (2) J. A. Kolmer et al. Plant Dis. 94:775, 2010. (3) B. McCallum and P. Seto-Goh. Can. J. Plant Pathol. 32:387, 2010. (4) M. E. Ordoñez and J. A. Kolmer. Phytopathology 99:750, 2009.

scholarly journals Dissecting the first phased dikaryotic genomes of the wheat rust pathogen Puccinia triticina reveals the mechanisms of somatic exchange in nature

2019 ◽  
Author(s):  
Jing Qin Wu ◽  
Chongmei Dong ◽  
Long Song ◽  
Christina A. Cuomo ◽  
Robert F. Park
Keyword(s):  
Leaf Rust ◽  
Somatic Hybridization ◽  
Puccinia Triticina ◽  
Genomic Variation ◽  
Hybrid Wheat ◽  
Wheat Cultivars ◽  
Wheat Leaf Rust ◽  
Virulence Evolution ◽  
Rust Pathogen ◽  
Wheat Leaf

AbstractAlthough somatic hybridization (SH) has been proposed as a means of accelerating rust pathogen virulence evolution in the absence of sexual recombination, previous studies are limited to the laboratory and none have revealed how this process happens. Using long-read sequencing, we generated dikaryotic phased genomes and annotations for three Australian field-collected isolates of the wheat leaf rust pathogen (Puccinia triticina; Pt), including a putative asexual hybrid (Pt64) and two putative parental isolates (Pt104 and Pt53; 132-141 Mb,155-176 contigs, N50 of 1.9-2.1 Mb). The genetic dissection based on the high-quality phased genomes including whole-genome alignments, phylogenetic and syntenic analyses along with short-read sequencing of 27 additional Pt isolates convergently demonstrated that Pt64, which rendered several commercial hybrid wheat cultivars susceptible to leaf rust, arose from SH between isolates within the Pt53 and Pt104 lineages. Parentage analysis demonstrated the role of mitotic crossover in the derivation of both nuclei of Pt64. Within HD mating type genes, the distinct specificity regions in Pt64 and the distinct phylogenetic pattern of the remaining admixed isolates suggested high genetic variation in specificity-related regions on the b locus intrinsically associated with the SH. This study not only provided a fundamental platform for investigating genomic variation underlying virulence evolution in one of the most devastating wheat pathogens, but also offered an in-depth understanding of the mechanisms of naturally occurring SH. This asexual mechanism can be broadly exploited by any dikaryotic pathogen to accelerate virulence evolution, and understanding this process is both urgent and crucial for sustainable pathogen control.ImportanceStrategies to manage plant rust pathogens are challenged by the constant emergence of new virulence. Although somatic hybridization has been proposed as a means by which rusts could overcome host resistance rapidly and cause crop loss, there is very little evidence of this process in nature and the mechanisms underlying it are not known. This study generated and analysed the first dikaryotic phased genomes of the wheat leaf rust pathogen, identifying an isolate as a hybrid and for the first time unveiling parasexuality via mitotic crossover in a rust pathogen. The erosion of the resistance of several hybrid wheat cultivars in agriculture by the hybrid rust has important implications for breeding efforts targeting durable resistance and sustained rust control.

scholarly journals Virulence surveys of wheat leaf rust in the Czech Republic and resistance genes in registered cultivars

2014 ◽  
Vol 50 (No. 3) ◽  
pp. 241-246 ◽  
Author(s):  
A. Hanzalová ◽  
P. Bartoš
Keyword(s):  
Czech Republic ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Wheat Cultivars ◽  
Wheat Leaf Rust ◽  
The Czech Republic ◽  
Technical Report ◽  
Wheat Leaf ◽  
Physiologic Races ◽  
The Given

The technical report presents a summary of results obtained in the leaf rust race surveys carried out in Czechoslovakia/Czech Republic in the years 1966–2001. The physiologic races were determined using the standard differentials Malakoff (Lr1), Carina (Lr2b), Brevit (Lr2c), Webster (Lr2a), Loros (Lr2c), Mediterranean (Lr3), Hussar (Lr11), Democrat (Lr3) and the additional differential Salzmünder Bartweizen (Lr26). Races 14, 77, 61, 53 and 2  successively dominated in the given period. They mostly appeared in two variants, avirulent and virulent to Lr26. Genes for virulence in the leaf rust races were compared with genes for resistance in the registered wheat cultivars listed in the report. Most frequent were the genes Lr3 and Lr26.

scholarly journals Physiologic specialization of wheat leaf rust (Puccinia triticina Eriks.) in the Slovak Republic in 2005, 2006 and 2008

2010 ◽  
Vol 46 (No. 3) ◽  
pp. 114-121 ◽  
Author(s):  
A. Hanzalová ◽  
J. Huszár ◽  
E. Herzová ◽  
P. Bartoš
Keyword(s):  
Leaf Rust ◽  
Slovak Republic ◽  
Puccinia Triticina ◽  
Near Isogenic Lines ◽  
Wheat Cultivars ◽  
Wheat Leaf Rust ◽  
Wheat Leaf ◽  
Winter Wheat Cultivars ◽  
Low Incidence ◽  
Different Parts

In 2005, 2006 and 2008 the virulence of wheat leaf rust population was studied on Thatcher near-isogenic lines with Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr10, Lr13, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. Samples of leaf rust (141 in total) were obtained from different parts of Slovakia. Resistance gene Lr9 was effective to all tested isolates except three isolates from 2008. No virulence was found to Lr19 and genes Lr24 and Lr28 were also highly effective. Low incidence of virulence to Lr2a was observed. Sixty-five winter wheat cultivars registered in Slovakia were tested with seven leaf rust isolates in the greenhouse. Cultivar Bona Dea was the most resistant of all.

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