scholarly journals Genetic Protection of Soft Wheat from Diseases in the Southern Ural of Russia and Virulence Variability of Foliar Pathogens

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 703
Author(s):  
Igor Kushnirenko ◽  
Ekaterina Shreyder ◽  
Nadezhda Bondarenko ◽  
Ekaterina Shaydayuk ◽  
Nadezhda Kovalenko ◽  
...  
Keyword(s):  
Leaf Rust ◽  
High Efficiency ◽  
Genetic Material ◽  
Puccinia Triticina ◽  
Wheat Breeding ◽  
Tan Spot ◽  
Aegilops Speltoides ◽  
Wheat Cultivars ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch

The southern Ural is consistently among the 10 best regions in Russia for agricultural production, including wheat. Breeding in the Chelyabinsk Research Institute of Agriculture aims to develop wheat cultivars genetically protected from the main diseases (leaf and stem rust, septoria leaf blotch and tan spot). The genes for resistance to leaf rust, Lr1, Lr9, Lr10 and Lr26/Sr31, alone or in combination, are widespread in cultivars grown in the southern Ural. In 2012, a new wheat cultivar, Chelyaba 75, was proposed for commercial production in the southern Ural, being highly resistant to leaf rust with the highly effective genes LrSp and SrSp transferred from the cuckoo line with the genetic material Aegilops speltoides. Isolates virulent to cv. Chelyaba 75 were not found in Russian populations of Puccinia triticina. Additionally, for a long period, genes Lr29, Lr 41, Lr42, Lr45, Lr47, Lr50, Lr51, Lr53 and Lr57 were characterized by high efficiency. Virulence frequencies to other Lr genes vary annually, but no races with new virulence have been identified. The resistance of lines with the Sr31 and Sr24 genes indicates that the Puccinia graminis population does not contain genotypes with the potentially damaging race Ug99. Mixed septoria and tan spot infections occurred in the southern Ural, with the latter dominating. Races producing the exotoxin ToxA are widely distributed in Pyrenophora tritici-repentis populations. Two causal agents of septoria leaf blotch (Parastagonospora nodorum and P. avenae f. sp. tritici) occur in the region, with the first dominating. Aggressiveness of P. nodorum isolates to wheat cultivars was higher than that of P. avenae f. sp. tritici. All Parastagonospora isolates showed the presence of the SnTox3 marker. SnToxA and SnTox1 markers were found in P. nodorum isolates, usually separately, but in one isolate, these genes were found together. The analysis of the genetic diversity of wheat cultivars grown in the southern Ural, and the pathogenic complex present, indicate that pathogens continuously evolve under the influence of the host plant.

scholarly journals Leaf Rust on Aegilops speltoides Caused by a New Forma Specialis of Puccinia triticina

2004 ◽  
Vol 94 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Pnina Ben Yehuda ◽  
Tamar Eilam ◽  
Jacob Manisterski ◽  
Ayelet Shimoni ◽  
Yehoshua Anikster
Keyword(s):  
Leaf Rust ◽  
Host Preference ◽  
Natural Habitat ◽  
Puccinia Triticina ◽  
Aegilops Speltoides ◽  
Wheat Cultivars ◽  
Wheat Leaf Rust ◽  
Forma Specialis ◽  
Wheat Leaf ◽  
First Time

A leaf rust attacking Aegilops speltoides in its natural habitat is reported for the first time. It was found in two locations in northern and central Israel. The two collections from A. speltoides resemble wheat leaf rust, Puccinia triticina, in most spore dimensions, in the morphology of the substomatal vesicle of the urediniospore, and in DNA content in pycniospore nuclei. Similarly to P. triticina isolates from wheat, isolates taken from A. speltoides are compatible with Thalictrum speciosissimum as an aecial host and they are crossed easily with wheat leaf rust isolates. However, isolates from A. speltoides differ from wheat leaf rust in their telial host range. They are avirulent to cultivated wheat cultivars, but attack hundreds of A. speltoides accessions that were immune to wheat leaf rust. This distinct host preference justifies delineation of the newly found leaf rust as a forma specialis (f. sp. speltoides) within P. triticina.

scholarly journals Cytogenetic analysis and mapping of leaf rust resistance in Aegilops speltoides Tausch derived bread wheat line Selection2427 carrying putative gametocidal gene(s)

Genome ◽  
2017 ◽  
Vol 60 (12) ◽  
pp. 1076-1085 ◽  
Author(s):  
M. Niranjana ◽  
Vinod ◽  
J.B. Sharma ◽  
Niharika Mallick ◽  
S.M.S. Tomar ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Bread Wheat ◽  
Rust Resistance ◽  
Dominant Gene ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Aegilops Speltoides ◽  
Lr Genes ◽  
Gametocidal Gene ◽  
Chromosome 3B

Leaf rust (Puccinia triticina) is a major biotic stress affecting wheat yields worldwide. Host-plant resistance is the best method for controlling leaf rust. Aegilops speltoides is a good source of resistance against wheat rusts. To date, five Lr genes, Lr28, Lr35, Lr36, Lr47, and Lr51, have been transferred from Ae. speltoides to bread wheat. In Selection2427, a bread wheat introgresed line with Ae. speltoides as the donor parent, a dominant gene for leaf rust resistance was mapped to the long arm of chromosome 3B (LrS2427). None of the Lr genes introgressed from Ae. speltoides have been mapped to chromosome 3B. Since none of the designated seedling leaf rust resistance genes have been located on chromosome 3B, LrS2427 seems to be a novel gene. Selection2427 showed a unique property typical of gametocidal genes, that when crossed to other bread wheat cultivars, the F1 showed partial pollen sterility and poor seed setting, whilst Selection2427 showed reasonable male and female fertility. Accidental co-transfer of gametocidal genes with LrS2427 may have occurred in Selection2427. Though LrS2427 did not show any segregation distortion and assorted independently of putative gametocidal gene(s), its utilization will be difficult due to the selfish behavior of gametocidal genes.

scholarly journals Lr19 Resistance in Wheat Becomes Susceptible to Puccinia triticina in India

Plant Disease ◽  
2005 ◽  
Vol 89 (12) ◽  
pp. 1360-1360 ◽  
Author(s):  
S. C. Bhardwaj ◽  
M. Prashar ◽  
S. Kumar ◽  
S. K. Jain ◽  
D. Datta
Keyword(s):  
Leaf Rust ◽  
Wheat Variety ◽  
Puccinia Triticina ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Adult Plant ◽  
Distribution Data ◽  
Agropyron Elongatum ◽  
Peninsular India ◽  
Slow Rusting

Lr19, a resistance gene originally transferred from Agropyron elongatum to wheat (Triticum aestivum L.), has remained effective worldwide against leaf rust (Puccinia triticina Eriks.) except in Mexico (1). This report records a new pathotype of P. triticina virulent on Lr19 from India. From 2003 to 2004, 622 wheat leaf rust samples from 14 states were subjected to pathotype analysis. Samples were established on susceptible wheat cv. Agra Local, and pathotypes were identified on three sets of differentials following binomial nomenclature (3). Virulence on Lr19 (Agatha T4 line) was observed in approximately 2% of samples. These samples were picked from Lr19 (NIL), cvs. Ajit, Lal Bahadur, Local Red, Lok1, and Nirbhay from Karnataka and Gujarat states. All Lr19 virulent isolates were identical. The reference culture is being maintained on susceptible wheat cv. Agra Local and has also been put under long-term storage in a national repository at Flowerdale. From 2004 to 2005, this pathotype was detected in 6.3% of samples from central and peninsular India. There is no wheat variety with Lr19 under cultivation in India, however, it is being used in wheat breeding programs targeted at building resistance against leaf and stem rusts. NIL's Lr19/Sr25 (LC25) and Lr19/Sr25 (82.2711) were also susceptible to this isolate, whereas Lr19/Sr25 (spring accession) was resistant. The new isolate, designated as 253R31 (77-8), appears to be close to the pathotype 109R31 (4) with additional virulence for Lr19. The avirulence/virulence formula of pathotype 253R31 is Lr9, 23, 24, 25, 26, 27+31, 28, 29, 32, 36, 39, 41, 42, 43, 45/Lr1, 2a, 2b, 2c, 3, 10, 11, 12, 13, 14a, 14b, 14ab, 15, 16, 17, 18, 20, 21, 22a, 22b, 30, 33, 34, 35, 37, 38, 40, 44, 48, and 49. To our knowledge, this is the first report of virulence on Lr19 from two states of India. On international rust differentials, it is designated as TGTTQ (2), and is different from CBJ/QQ (1), the other isolate reported virulent on Lr19 from Mexico. The Mexican isolate is avirulent on Lr1, 2a, 2b, 2c, 3ka, 16, 21, and 30 to which the Indian isolate is virulent. However, both isolates are avirulent on Lr9, 24, 26, 36, and Lr42. Among the wheat cultivars identified during the last 6 years, HD2824, HD2833, HD2864, HI1500, HS375, HUW 510, HW 2044, HW 5001, Lok 45, MACS 6145, MP4010, NW 2036, PBW 443, PBW 498, PBW 502, PBW 524, Raj 4037, UP 2565, VL 804, VL 829, and VL 832 and lines of wheat possessing Lr9, Lr23, Lr24, and Lr26 showed resistance to this pathotype. PBW 343, which occupies more than 5 million ha in India, is also resistant to this pathotype along with PBW 373. An integrated strategy using a combination of diverse resistance genes, deployment of cultivars by using pathotype distribution data, slow rusting, and adult plant resistance is in place to curtail selection of new pathotypes and prevent rust epiphytotics. References: (1) J. Huerta-Espino and R. P. Singh. Plant Dis. 78:640,1994. (2) D. V. Mc Vey et al. Plant Dis. 88:271, 2004. (3) S. Nagarajan et al. Curr. Sci. 52:413, 1983. (4) S. K. Nayar et al. Curr. Sci. 44:742, 1975.

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 Practical application of integrated disease management

2002 ◽  
Vol 38 (SI 1 - 6th Conf EFPP 2002) ◽  
pp. 212-220 ◽  
Author(s):  
V. Zinkernagel ◽  
H. Hausladen ◽  
H. Habermeyer
Keyword(s):  
Decision Support ◽  
Disease Management ◽  
Powdery Mildew ◽  
Tan Spot ◽  
Integrated Disease Management ◽  
Practical Application ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Advisory Service ◽  
Glume Blotch

A decision support system for cereal diseases and late blight of potatoes has been developed at the Chair of Phytopathology,<br />Technische Universität München. The Wheat and Barley Prognosis System has been in use for many years by the<br />Bavarian official advisory service. It is based on an exact diagnosis and established biological thresholds influenced by<br />weather. Certain fungicides are recommended also covering diseases which have not reached the threshold. Diseases under<br />consideration are eye spot disease, powdery mildew, Septoria leaf blotch, Septoria leaf and glume blotch, tan spot, brown<br />and yellow rusts.The PhytophthoraModel Weihenstephan consists of two parts, weather based prognosis and monitoring in<br />the unsprayed control plots. Spraying recommendations are given based on the results of the above-mentioned parts and<br />considering cultivar behaviour and blight development in the field. The first spraying in the season as well as the timing<br />of the following ones are crucial. This model does not give any recommendations regarding which active ingredient should<br />applied. However there is a distinction made with regard to contact (protective) fungicides and systemic fungicides. The<br />PhytophthoraModel Weihenstephan has been in use for several years in Germany as well as in Austria.

Inheritance of leaf rust and stem rust resistances in wheat cultivars Agent and Agatha

1977 ◽  
Vol 28 (1) ◽  
pp. 37 ◽  
Author(s):  
RA McIntosh ◽  
PL Dyck ◽  
GJ Green
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Rust Resistance ◽  
Wheat Chromosome ◽  
Wheat Breeding ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Wheat Cultivars ◽  
Agropyron Elongatum ◽  
Adult Plants

The wheat cultivars Agent and Agatha each possess closely linked genes for resistance to Puccinia graminis tritici and P. recondita derived from Agropyron elongatum. The genes in Agent, located in chromosome 3D, were designated Sr24 and Lr24. The gene in Agatha for resistance to P. graminis tritici was designated Sr25 and is linked with Lr19 in chromosome 7D. Both Agent and Agatha possess additional genes for resistance to certain cultures of P. graminis tritici. Sr24 is considered a valuable source of resistance for wheat-breeding purposes, but Sr25 conferred an inadequate level of resistance to adult plants. A translocation from an A. elongatum chromosome to wheat chromosome 6A, present in Australian cultivars Eagle, Kite and Jabiru, carries a third gene, Sr26, for stem rust resistance.

scholarly journals Genome-Wide Expression Profiling of Genes Associated with the Lr47-Mediated Wheat Resistance to Leaf Rust (Puccinia triticina)

2019 ◽  
Vol 20 (18) ◽  
pp. 4498 ◽  
Author(s):  
Jiaojiao Wu ◽  
Jing Gao ◽  
Weishuai Bi ◽  
Jiaojie Zhao ◽  
Xiumei Yu ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Fungal Pathogens ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Puccinia Triticina ◽  
Gene Families ◽  
Aegilops Speltoides ◽  
Post Inoculation ◽  
Q Value ◽  
Pr Genes

Puccinia triticina (Pt), the causal agent of wheat leaf rust, is one of the most destructive fungal pathogens threatening global wheat cultivations. The rational utilization of leaf rust resistance (Lr) genes is still the most efficient method for the control of such diseases. The Lr47 gene introgressed from chromosome 7S of Aegilops speltoides still showed high resistance to the majority of Pt races collected in China. However, the Lr47 gene has not been cloned yet, and the regulatory network of the Lr47-mediated resistance has not been explored. In the present investigation, transcriptome analysis was applied on RNA samples from three different wheat lines (“Yecora Rojo”, “UC1037”, and “White Yecora”) carrying the Lr47 gene three days post-inoculation with the epidemic Pt race THTT. A comparison between Pt-inoculated and water-inoculated “Lr47-Yecora Rojo” lines revealed a total number of 863 upregulated (q-value < 0.05 and log2foldchange > 1) and 418 downregulated (q-value < 0.05 and log2foldchange < −1) genes. Specifically, differentially expressed genes (DEGs) located on chromosomes 7AS, 7BS, and 7DS were identified, ten of which encoded receptor-like kinases (RLKs). The expression patterns of these RLK genes were further determined by a time-scale qRT-PCR assay. Moreover, heatmaps for the expression profiles of pathogenesis-related (PR) genes and several transcription factor gene families were generated. Using a transcriptomic approach, we initially profiled the transcriptional changes associated with the Lr47-mediated resistance. The identified DEGs, particularly those genes encoding RLKs, might serve as valuable genetic resources for the improvement of wheat resistance to Pt.

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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