scholarly journals Durable resistance to Puccinia triticina by accumulation of resistance genes

Genetika ◽  
2009 ◽  
Vol 41 (3) ◽  
pp. 353-378 ◽  
Author(s):  
Jelena Boskovic ◽  
Momcilo Boskovic
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Durable Resistance ◽  
Puccinia Triticina ◽  
Recurrent Parent ◽  
Considerable Influence ◽  
Wheat Leaf Rust ◽  
Resistant Genes ◽  
Wheat Leaf ◽  
Hybrid Lines

The individual use of single race-specific resistance genes with major phenotypic effects has rarely provided lasting resistance. However, breeding and combining or pyramiding of resistance genes into individual cultivars has had considerable success, particularly in situations in which the pathogen does not reproduce sexually, as in the case of wheat leaf rust pathogen. In European-Mediterranean region perfomed international investigations of wheat leaf rust proved that breeding of new lines of wheat resistant to Puccinia triticina Eriks. for differentiation of pathogen population, as well as for sources of durable resistance is necessary. Breeding of such resistant lines has proved necessary due to the unsatisfatory survey results of these regions on standard isogenic Lr lines. It has become clear that these regions needed new, more efficient differential resistance genes, as well as sources of resistance. In the beginning, after extensive screening tests of several International Rust Nurseries, 18 donors of resistance had been selected as crosses with recurrent parents' varieties Princ and Starke. These hybrid lines had been comparatively tested with twenty six Lr single gene lines using twenty especially virulent cultures of P. triticina in order to check the presence of these known Lr genes in our hybrid lines. Considerable influence of recurrent parent to the number of resistant genes in used donors was demonstrated. On the other hand, considerable influence of the pathogen culture was established to the number of resistance genes in used donors. In order to enhance resistance and pyramiding genes in these hybrids, the most interesting selected eight lines have been crossed with only effective isogenic ones, containing the strong genes Lr9, Lr19 and Lr24. On the basis of different segregation rations of all crossing combinations it was proved that no one of resistant donors contained the applied strong resistant genes. It means that our hybrid lines contained resistant genes from the donors, as well as three strong resistant genes Lr9, Lr19 and Lr24.

scholarly journals Accumulations of genes for durable resistance to wheat leaf rust pathogen

2008 ◽  
Vol 53 (3) ◽  
pp. 163-172 ◽  
Author(s):  
Jelena Boskovic ◽  
M. Boskovic ◽  
Zeljana Prijic
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Puccinia Recondita ◽  
Recurrent Parent ◽  
Considerable Influence ◽  
Wheat Leaf Rust ◽  
Resistant Genes ◽  
Rust Pathogen ◽  
Wheat Leaf ◽  
Puccinia Recondita Tritici

The individual use of single race-specific resistance genes with major phenotypic effects has rarely provided lasting resistance. However, breeding and combining or pyramiding of resistance genes into individual cultivars has had considerable success, particularly in situation where the pathogen does not reproduce sexually, as in the case of wheat leaf rust pathogen. Within international leaf rust of wheat investigations it was necessary, to create by breeding new resistant wheat lines to Puccinia recondita tritici for differentiation of pathogen population, as well as for sources of resistance in European-Mediterranean regions. In the beginning 18 donors of resistance had been selected after an extensive screening test of several International Rust Nurseries, to be crosses with recur- rent parents varieties Princ and Starke. These tests proved that in those lines were present new resistant genes. Eighth genetically different hybrids of the first back-cross had been selected and tested in the seedling stage with three international pathogen cultures (YU-13-19-1; H-13-9-1 and C2-13-Ar-3). Considerable influence of recurrent parent to the number of resistant genes in donors used was demonstrated. On the other side, it was established considerable influence of the pathogen culture to the number of resistant genes in donors used. The same crossing combinations tested with one pathogen culture results in presence of two resistance genes, but with another culture three or one resistant gene. In order to enhancement resistance and pyramiding genes in these hybrids, eight selected the most interesting lines have been crossed with only effective isogenic containing the strong genes Lr9, Lr19 and Lr24.The genetic analysis of twenty two crossing combinations have been realized by testing with three pathotypes of Puccinia recondita tritici ( Bg.s. 12/89; Is.w 8/89 and Chl.w. 14/89). On the base of different segregation ratios of all crossing combinations it was proved that no one of the resistant donors contained the strong resistant genes used. It means that our hybrid lines contained resistant genes from the donors and in addition three strong resistant genes Lr9, Lr19 and Lr24.

scholarly journals Virulence and Molecular Polymorphism in International Collections of the Wheat Leaf Rust Fungus Puccinia triticina

2000 ◽  
Vol 90 (4) ◽  
pp. 427-436 ◽  
Author(s):  
J. A. Kolmer ◽  
J. Q. Liu
Keyword(s):  
New Zealand ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Fungus ◽  
Puccinia Triticina ◽  
Western Canada ◽  
Wheat Leaf Rust ◽  
Wheat Leaf ◽  
Rapd Variation ◽  
Wheat Lines

Collections of Puccinia triticina, the wheat leaf rust fungus, were obtained from Great Britain, Slovakia, Israel, Germany, Australia, Italy, Spain, Hungary, South Africa, Uruguay, New Zealand, Brazil, Pakistan, Nepal, and eastern and western Canada. All single-uredinial isolates derived from the collections were tested for virulence polymorphism on 22 Thatcher wheat lines that are near-isogenic for leaf rust resistance genes. Based on virulence phenotype, selected isolates were also tested for randomly amplified polymorphic DNA (RAPD) using 11 primers. The national collections were placed into 11 groups based on previously established epidemiological zones. Among the 131 single-uredinial isolates, 105 virulence phenotypes and 82 RAPD phenotypes were described. In a modified analysis of variance, 26% of the virulence variation was due to differences in isolates between groups, with the remainder attributable to differences within groups. Of the RAPD variation, 36% was due to differences in isolates between groups. Clustering based on the average virulence distance (simple distance coefficient) within and between groups resulted in eight groups that differed significantly. Collections from Australia-New Zealand, Spain, Italy, and Britain did not differ significantly for virulence. Clustering of RAPD marker differences (1 - Dice coefficient) distinguished nine groups that differed significantly. Collections from Spain and Italy did not differ significantly for RAPD variation, neither did collections from western Canada and South America. Groups of isolates distinguished by avirulent/virulent infection types to wheat lines with resistance genes Lr1, Lr2a, Lr2c, and Lr3 also differed significantly for RAPD distance, showing a general relationship between virulence and RAPD phenotype. The results indicated that on a worldwide level collections of P. triticina differ for virulence and molecular backgrounds.

scholarly journals Virulence in Puccinia triticina for Durum Wheat Cultivar Creso and Other Durum Wheat Cultivars Carrying Resistance Gene Lr14a in France

Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1068-1068 ◽  
Author(s):  
H. Goyeau ◽  
K. Ammar ◽  
J. Berder
Keyword(s):  
Durum Wheat ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Genetic Basis ◽  
Durable Resistance ◽  
Puccinia Triticina ◽  
Field Trials ◽  
Minor Effect ◽  
Wheat Leaf Rust ◽  
Wheat Leaf

Durum wheat cv. Creso has been mentioned as having durable resistance to leaf rust (2–4). However, an average final disease level of 70S on the modified Cobb scale was scored on Creso across three locations in inoculated field trials in France during 2009. A mixture of two durum wheat leaf rust isolates commonly found in France was used for the inoculation, one was virulent on Lr23 and the other was avirulent on this gene, their identical avirulence/virulence formula for other genes was Lr1, 2a, 2b, 3, 3bg, 3ka, 9, 11, 13, 15, 16, 17, 19, 24, 25, 26, 27+31/Lr2c, 10, 14a, 14b, 20, 21, 33, and 44. On cv. Llareta Inia and breeding line Somateria, both of which carry the resistance gene Lr14a, the average final disease level was, respectively, 95S and 80S. Creso, Llareta Inia, and Somateria displayed average final disease levels of, respectively, 0, 10S, and 1 in field trials inoculated with race CBG/BP in 2009 at two locations in Mexico (Ciudad Obregon and El Batan). Race CBG/BP, virulent on Lr3, 10, 11, 14b, 20, 23, 27 + 31, and 33, is the most widely virulent race identified so far in Mexico where Lr14a remains effective for durum wheat. Virulence for Lr14a in durum wheat leaf rust populations was already mentioned to be present in France since 2000 (1). It has been suggested that the resistance of Creso, which has remained durable in Italy since 1975 (4), could be due to a gene close to but different from Lr14a. Alternatively, the fact that Creso's reaction was significantly lower than those of Llareta Inia or Somateria could indicate the presence of another gene, of minor effect, in addition to Lr14a. Whatever the genetic basis of the Creso resistance may be, it has been overcome by common French pathotypes and its usefulness in breeding, at a regional if not global level, has become questionable. References: (1) H. Goyeau et al. Phytopathology 96:264, 2006. (2) S. A. Herrera-Foessel et al. Plant Dis. 92:469, 2008. (3) M. Maccaferri et al. Theor. Appl. Genet. 117:1225, 2008. (4) D. Marone et al. Mol. Breed. 24:25, 2009.

scholarly journals Geographical Distribution of Physiologic Races of Puccinia triticina and Postulation of Resistance Genes in New Wheat Cultivars in Egypt

2012 ◽  
Vol 1 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Nour E. K. Soliman ◽  
Ashraf M. M. Abdelbacki ◽  
Mohammad A.A. Najeeb ◽  
Reda I. Omara
Keyword(s):  
Leaf Rust ◽  
Geographical Distribution ◽  
Resistance Genes ◽  
Puccinia Triticina ◽  
Wheat Cultivars ◽  
Wheat Leaf Rust ◽  
Rust Disease ◽  
Lr Genes ◽  
Wheat Leaf ◽  
Physiologic Races

Knowledge of the geographical distribution for physiologic races of Puccinia triticina and identification of leaf rust resistance genes (Lr ,s) in the recent Egyptian wheat cultivars are essential for maximizing resistance in future-bred cultivars. The  aim   of   this   study   was   to   know   the   status  of resistance in Egyptian wheat cultivars against wheat leaf rust and the most frequent race distributed. Infected samples were collected from five Governorates, i.e.,  Dakahlia,  Kafr el-Sheikh,  Beheira,  Sharqia  and  Sohag comprised the wheat growing area in Egypt. These samples were isolated, purified and identified on the differential stes. Gene postulation was done using fifteen identified races on Egyptian wheat cultivars correlated with Lr genes. Thirty three races identified during three seasons 2009/2010, 2010/2011 and 2011/2012. The most frequent race was TK (10%) followed by race BB (7.58%), PK (6.55%), TT (4.82%), PT (3.79%) and MT (3.44%). Moreover, races; BB, TT and PT were present during three seasons while these races appeared in some Governorates and disappeared in other Governorates. On the other hand, the most frequently occurring gene in ten Egyptian wheat cultivars was Lr35 (70%), followed by Lr22 (60%), Lr27 (40%), Lr34 (30%), Lr19 (30%),Lr18 (10%),Lr36 (10%) and Lr46 (10%), eight out of sixteen Lr genes were not present in the tested cultivars. It is concluded that there was a good variation in Lr genes carried by wheat cultivars commercially grown in Egypt. Therefore, strategies for deploying resistance genes to prolong effective disease resistance are suggested to control wheat leaf rust disease.

Occurrence of wheat leaf rust (Puccinia triticina) races and virulence changes in Slovakia in 1994–2004

Biologia ◽  
2008 ◽  
Vol 63 (2) ◽  
Author(s):  
Alena Hanzalová ◽  
Jozef Huszár ◽  
Pavel Bartoš ◽  
Eva Herzová
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Field Tests ◽  
Puccinia Triticina ◽  
Near Isogenic Lines ◽  
Wheat Leaf Rust ◽  
Good Resistance ◽  
Isogenic Lines ◽  
Wheat Leaf

AbstractIn 1995–2004 we investigated leaf rust virulence in Slovakia on Thatcher near isogenic lines (NILs) with genes Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr10, Lr11, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. According to reaction of leaf rust isolates resistance genes Lr9 and Lr19 were completely effective to all examined pathotypes in all years. The resistance genes Lr24 and Lr28 were also completely effective to all examined pathotypes till the year 2001. In the year 2001 we detected 20% and 10% virulent isolates on NILs Lr24 and Lr28, respectively. According to the reaction of investigated isolates from the territory of Slovakia on NILs, resistance genes Lr2c, Lr3a, Lr11, Lr17, Lr21, Lr23 and Lr26 were mostly ineffective.During the 1994–2004 period we detected 16 races of leaf rust (races 2, 2SaBa, 6, 6SaBa, 12, 12SaBa, 14, 14SaBa, 57, 57SaBa, 61, 61SaBa, 62SaBa, 77, 77SaBa, 77/57SaBa). The most frequently determined races were 61SaBa and 77SaBa, which occurred in all years. Among frequently determined races we can assign race 12SaBa as well.According to the field tests in 2001–2004 good resistance to leaf rust was displayed by the cvs Arida (Lr13, Lru), Eva (Lr3, Lru) and Solara (Lru).

Virulence dynamics, phenotypic diversity, and virulence complexity in two populations of Puccinia triticina in Canada from 1987 to 1997

1999 ◽  
Vol 77 (3) ◽  
pp. 333-338 ◽  
Author(s):  
J A Kolmer
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Phenotypic Diversity ◽  
Puccinia Triticina ◽  
The United States ◽  
Host Population ◽  
Population Diversity ◽  
Wheat Leaf Rust ◽  
Wheat Leaf ◽  
Selection For

Populations of Puccinia triticina (causal agent of wheat leaf rust) in Ontario, Quebec, Manitoba, and Saskatchewan were analysed for frequency of isolates with virulence to leaf rust resistance genes Lr1, Lr2a, Lr2c, Lr3, Lr9, Lr16, Lr24, Lr26, Lr3ka, Lr11, Lr17, and Lr30 for the years 1987-1997. Winter wheats in the southern plains of the United States with resistance genes Lr24, Lr26, Lr11, Lr3ka, Lr17, and Lr16 selected virulent P. triticina phenotypes in the Manitoba and Saskatchewan population. The P. triticina population in Quebec and Ontario was comparatively stable, showing no directional trends in selection of virulence phenotypes. In the Manitoba and Saskatchewan population, diversity of virulence phenotypes changed relatively little despite the selection that occurred in this population. The average number of virulences per isolate in the Manitoba and Saskatchewan population increased from 1987 to 1994 during the period of selection for virulence to Lr24, Lr26, Lr3ka, and Lr11, and declined from 1995 to 1997 when selection for virulence to Lr16 and Lr17 occurred. The most complex virulence phenotypes were not necessarily selected in the Manitoba and Saskatchewan population because of how the resistance genes were deployed in the host population and the nonrandom distribution of virulences in the P. triticina population.Key words: Puccinia recondita f.sp. tritici, specific resistance, wheat leaf rust, Triticum aestivum, specific virulence.

scholarly journals A Chromosome-Scale Assembly of the Wheat Leaf Rust Pathogen Puccinia triticina Provides Insights Into Structural Variations and Genetic Relationships With Haplotype Resolution

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Qin Wu ◽  
Long Song ◽  
Yi Ding ◽  
Chongmei Dong ◽  
Mafruha Hasan ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Molecular Mechanisms ◽  
Genetic Relationships ◽  
Durable Resistance ◽  
Puccinia Triticina ◽  
Wheat Leaf Rust ◽  
Structural Variations ◽  
Rust Disease ◽  
Rust Pathogen ◽  
Wheat Leaf

Despite the global economic importance of the wheat leaf rust pathogen Puccinia triticina (Pt), genomic resources for Pt are limited and chromosome-level assemblies of Pt are lacking. Here, we present a complete haplotype-resolved genome assembly at a chromosome-scale for Pt using the Australian pathotype 64-(6),(7),(10),11 (Pt64; North American race LBBQB) built upon the newly developed technologies of PacBio and Hi-C sequencing. PacBio reads with ∼200-fold coverage (29.8 Gb data) were assembled by Falcon and Falcon-unzip and subsequently scaffolded with Hi-C data using Falcon-phase and Proximo. This approach allowed us to construct 18 chromosome pseudomolecules ranging from 3.5 to 12.3 Mb in size for each haplotype of the dikaryotic genome of Pt64. Each haplotype had a total length of ∼147 Mb, scaffold N50 of ∼9.4 Mb, and was ∼93% complete for BUSCOs. Each haplotype had ∼29,800 predicted genes, of which ∼2,000 were predicted as secreted proteins (SPs). The investigation of structural variants (SVs) between haplotypes A and B revealed that 10% of the total genome was spanned by SVs, highlighting variations previously undetected by short-read based assemblies. For the first time, the mating type (MAT) genes on each haplotype of Pt64 were identified, which showed that MAT loci a and b are located on two chromosomes (chromosomes 7 and 14), representing a tetrapolar type. Furthermore, the Pt64 assembly enabled haplotype-based evolutionary analyses for 21 Australian Pt isolates, which highlighted the importance of a haplotype resolved reference when inferring genetic relationships using whole genome SNPs. This Pt64 assembly at chromosome-scale with full phase information provides an invaluable resource for genomic and evolutionary research, which will accelerate the understanding of molecular mechanisms underlying Pt-wheat interactions and facilitate the development of durable resistance to leaf rust in wheat and sustainable control of rust disease.

scholarly journals Race and Virulence Dynamics of Puccinia triticina in China During 2000–2006

Plant Disease ◽  
2012 ◽  
Vol 96 (11) ◽  
pp. 1601-1607 ◽  
Author(s):  
T. G. Liu ◽  
W. Q. Chen
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Code System ◽  
Wheat Leaf Rust ◽  
Wheat Leaf ◽  
Rust Resistance Genes ◽  
Leaf Rust Resistance Genes

Wheat leaf rust, caused by Puccinia triticina, is an important foliar disease of wheat in China. The dynamics of races and virulence in P. triticina populations in China during 2000 to 2006 were studied. Leaf rust samples were collected during surveys of wheat fields and trap nurseries in 16 provinces, and provided by coworkers throughout China. The virulence of single-pustule isolates was determined on near-isogenic Thatcher lines for leaf rust resistance genes Lr1, Lr2a, Lr2c, Lr3, Lr9, Lr16, Lr24, Lr26, Lr3ka, Lr11, Lr17, and Lr30, and races were denominated using the Prt code system. During 2000 to 2006, 79 races were identified from a total of 613 isolates. Races PHT (23.7%), THT (14.7%), PHJ (11.4%), and THJ (4.2%) were the four common races, all avirulent to Lr9 and Lr24. The frequency of isolates with virulence to Lr1, Lr2c, Lr3, Lr11, Lr16, Lr17, and Lr26 was over 80%, and these isolates were widely distributed in China, whereas the frequencies of virulence to Lr9, Lr19, Lr24, Lr25, Lr28, and Lr29 were 0.2 to 2.5%. The diversity of virulence phenotypes of Chinese P. triticina populations appeared to increase from 2000 to 2006. P. triticina races and virulences in China appear to be isolated from those in other countries.

scholarly journals Genetic Analysis of Leaf Rust Resistance in Six Durum Wheat Genotypes

2014 ◽  
Vol 104 (12) ◽  
pp. 1322-1328 ◽  
Author(s):  
Alexander Loladze ◽  
Dhouha Kthiri ◽  
Curtis Pozniak ◽  
Karim Ammar
Keyword(s):  
Durum Wheat ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Durable Resistance ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Adult Plant ◽  
Seedling Resistance ◽  
Allelism Tests

Leaf rust, caused by Puccinia triticina, is one of the main fungal diseases limiting durum wheat production. This study aimed to characterize previously undescribed genes for leaf rust resistance in durum wheat. Six different resistant durum genotypes were crossed to two susceptible International Maize and Wheat Improvement Center (CIMMYT) lines and the resulting F1, F2, and F3 progenies were evaluated for leaf rust reactions in the field and under greenhouse conditions. In addition, allelism tests were conducted. The results of the study indicated that most genotypes carried single effective dominant or recessive seedling resistance genes; the only exception to this was genotype Gaza, which carried one adult plant and one seedling resistance gene. In addition, it was concluded that the resistance genes identified in the current study were neither allelic to LrCamayo or Lr61, nor were they related to Lr3 or Lr14a, the genes that already are either ineffective or are considered to be vulnerable for breeding purposes. A complicated allelic or linkage relationship between the identified genes is discussed. The results of the study will be useful for breeding for durable resistance by creating polygenic complexes.

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