Stem and leaf rust resistance in wild relatives of wheat with D genome (Aegilops spp.)

Abstract Triticum monococcum L. and T. boeoticum L., diploid wild relatives of bread wheat (T. aestivum L.), possess resistance to leaf rust (also known as brown rust) caused by Puccinia triticina Eriks. Haustorium formation-based resistance mechanisms (i.e. pre-haustorial and post-haustorial resistance) to leaf rust have been studied and reported in various T. monococcum accessions. In the present study, the mechanism of leaf rust resistance in T. monococcum and T. boeoticum accessions was studied using confocal laser scanning microscopy. Components of resistance studied at a histological level against leaf rust pathotypes, a Mexican pathotype (TCB/TD) and a Swiss pathotype (97512-19), indicated different types of resistance mechanism operative in the two accessions. The resistance in T. monococcum ranged from pre-haustorial resistance against 97512-19 to post-haustorial resistance against TCB/TD. The response in T. boeoticum was post-haustorial with necrosis against the two pathotypes. Pre-haustorial resistance observed in T. monococcum could serve as a potential source of durable rust resistance in wheat breeding.

Download Full-text

Identification of New Leaf Rust Resistance Loci in Wheat and Wild Relatives by Array-Based SNP Genotyping and Association Genetics

Frontiers in Plant Science ◽

10.3389/fpls.2020.583738 ◽

2020 ◽

Vol 11 ◽

Author(s):

Fizza Fatima ◽

Brent D. McCallum ◽

Curtis J. Pozniak ◽

Colin W. Hiebert ◽

Curt A. McCartney ◽

...

Keyword(s):

Leaf Rust ◽

Rust Resistance ◽

Leaf Rust Resistance ◽

Wild Relatives ◽

Snp Genotyping ◽

Association Genetics

Download Full-text

Phenotypic and genetic diversity of leaf rust resistance in wheat wild relatives

Journal of Phytopathology ◽

10.1111/jph.12907 ◽

2020 ◽

Vol 168 (7-8) ◽

pp. 428-438

Author(s):

Ali Aliakbari Sadeghabad ◽

Ali Dadkhodaie ◽

Bahram Heidari

Keyword(s):

Genetic Diversity ◽

Leaf Rust ◽

Rust Resistance ◽

Leaf Rust Resistance ◽

Wild Relatives ◽

Wheat Wild Relatives ◽

Phenotypic And Genetic Diversity

Download Full-text

Alien genetic resources for wheat leaf rust resistance, cytogenetic transfer, and molecular analysis

Australian Journal of Agricultural Research ◽

10.1071/ar07315 ◽

2008 ◽

Vol 59 (3) ◽

pp. 197 ◽

Cited By ~ 24

Author(s):

B. S. Gill ◽

L. Huang ◽

V. Kuraparthy ◽

W. J. Raupp ◽

D. L. Wilson ◽

...

Keyword(s):

Leaf Rust ◽

Common Wheat ◽

Resistance Genes ◽

Rust Resistance ◽

Leaf Rust Resistance ◽

Wheat Leaf Rust ◽

D Genome ◽

Wheat Leaf ◽

Rust Resistance Genes ◽

Leaf Rust Resistance Genes

Wild relatives of wheat are useful sources of alien resistance genes for wheat breeding. The objective of this review is to document research on the evaluation, transfer, and molecular analysis of alien resistance to wheat leaf rust especially in Aegilops tauschii, the diploid D-genome donor of common wheat. Nine named resistance genes (Lr1, Lr2, Lr15, Lr21, Lr22, Lr32, Lr34, Lr39, and Lr42) occur in the D genome. Twelve new leaf rust resistance genes have been documented in Ae. tauschii. The south-west Caspian Sea region is the centre of genetic diversity for seedling resistance. Adult-plant resistance is widespread in all geographic regions and should be exploited more in the future. Lr1 and Lr21 have been cloned and are typical NBS-LRR genes. The recent documentation of cryptic introgressions of Lr57/Yr40 from Ae. geniculata and Lr58 from Ae. triuncialis offers exciting possibilities for transferring alien genes without linkage drag. Both Lr21 and Lr34 presumably arose during or following the origin of common wheat ~8000 years ago. Leaf rust resistance genes often are located towards the physical ends of wheat chromosomes. These regions are known to be high in recombination, and this may explain their rapid rate of evolution.

Download Full-text

Molecular mapping of linked leaf rust resistance and non-glaucousness gene introgressed from Aegilops tauschii Coss. in hexaploid wheat Triticum aestivum L.

Plant Genetic Resources ◽

10.1017/s1479262116000460 ◽

2017 ◽

Vol 16 (1) ◽

pp. 82-88 ◽

Cited By ~ 2

Author(s):

Manny Saluja ◽

Satinder Kaur ◽

Urmil Bansal ◽

Subhash Chander Bhardwaj ◽

Parveen Chhuneja

Keyword(s):

Leaf Rust ◽

Ssr Markers ◽

Rust Resistance ◽

Molecular Mapping ◽

Aegilops Tauschii ◽

Wheat Variety ◽

Leaf Rust Resistance ◽

Leaf Rust Resistance Gene ◽

Morphological Marker ◽

D Genome

AbstractAegilops tauschii, the D genome donor of wheat, is an invaluable source of genetic variability, which can be utilized for broadening the wheat gene pool. Linked leaf rust resistance and non-glaucousness genes transferred from Ae. tauschii to cultivated wheat variety WH542 were mapped in the present study. Genetic analysis in an F2 population from a BC3 plant derived from the cross Triticum durum cv. PBW114/Ae. tauschii acc. pau14195//4*T. aestivum cv. WH542 revealed monogenic dominant inheritance for both the traits. The leaf rust resistance and the non-glaucousness gene were tentatively named LrT and IwT, respectively. Leaf rust resistance gene exhibited all stage resistance. SSR markers Xbarc124, Xgdm5, Xgdm35, Xcfd51 and EST-derived markers Xcau96 and Xte6 on chromosome 2DS were linked with both genes. Chromosomal assignments of the genes were confirmed by testing linked SSR markers on Chinese Spring nulli-tetrasomics lines. SSR markers Xcau96 (1.6 cM) and Xbarc124 (0.6 cM) flanked LrT and Xgdm35 (4.1 cM) and Xte6 (2.5 cM) flanked non-glaucousness gene. LrT and IwT showed a recombination distance of 3.4 cM. Hence, IwT can be used as an easy to score morphological marker of LrT during its transfer to other glaucous backgrounds.

Download Full-text

Using the synthetic form RS5 to obtain new introgressive lines of common wheat

Vavilov Journal of Genetics and Breeding ◽

10.18699/vj21.088 ◽

2021 ◽

Vol 25 (7) ◽

pp. 770-777

Author(s):

R. O. Davoyan ◽

I. V. Bebyakina ◽

E. R. Davoyan ◽

Y. S. Zubanova ◽

D. M. Boldakov ◽

...

Keyword(s):

Leaf Rust ◽

Common Wheat ◽

Yellow Rust ◽

Aegilops Tauschii ◽

Genetic Material ◽

Leaf Rust Resistance ◽

Wild Relatives ◽

Aegilops Speltoides ◽

D Genome ◽

Synthetic Form

The use of the gene pool of wild relatives, which have a significant reserve of genetic diversity, is of immediate interest for breeding common wheat. The creation and use of synthetic forms as “bridges” is an effective method of transferring valuable genetic material from wild relatives to cultivated wheat. For this purpose, genome addition, genome substitution and recombinant “secondary” synthetic forms have been created in the P.P. Lukyanenko National Center of Grain. The synthetic recombination form RS5 (BBAASDt ), in which the third genome consists of chromosomes of Aegilops speltoides (S) and Aegilops tauschii (Dt ), was obtained from crossing the synthetic forms Avrodes (BBAASS) and M.it./Ae. tauschii (BBAADt Dt ), in which the D genome from Ae. tauschii was added to the BBAA genomes of the durum wheat cultivar Mutico italicum. Introgression lines resistant to leaf rust, yellow rust and powdery mildew have been obtained from backcrosses with the susceptible common wheat cultivars Krasnodarskaya 99, Rostislav and Zhirovka. Twelve resistant lines that additionally have high technological characteristics of grain and flour have been selected. The cytological study (С-banding) has revealed chromosomal modifications in 6 of 8 lines under study. The rearrangements mainly affected the chromosomes of the D genome, 1D, 3D, 4D, 6D and 7D. It was found that in most cases the genetic material from the synthetic form RS5 in the studied lines was represented by substituted chromosomes from Ae. tauschii. In line 5791p17, the substitution of chromosomes 6D from Ae. tauschii and 7D from Ae. speltoides was revealed. Substitutions 4D(4Dt ), 6D(6Dt ) from Ae. tauschii and 7D(7S) from Ae. speltoides were obtained for the first time. Molecular analysis of 12 lines did not reveal effective leaf rust resistance genes, presumably present in synthetic forms of M.it./Ae. tauschii and Avrodes. It is assumed that the lines may carry previously unidentified genes for fungal disease resistance, in particular for resistance to leaf rust, from Ae. tauschii and Ae. speltoides.

Download Full-text

Suppression of rust resistance in bread wheat (Triticum aestivum L.) by D-genome chromosomes

Genome ◽

10.1139/g92-043 ◽

1992 ◽

Vol 35 (2) ◽

pp. 276-282 ◽

Cited By ~ 54

Author(s):

D. Bai ◽

D. R. Knott

Keyword(s):

Triticum Aestivum ◽

Leaf Rust ◽

Bread Wheat ◽

Stem Rust ◽

Chinese Spring ◽

Rust Resistance ◽

Leaf Rust Resistance ◽

Triticum Aestivum L ◽

D Genome ◽

Or Genes

Several tests were done in bread wheat (Triticum aestivum L.) to demonstrate the occurrence of genes on D-genome chromosomes that suppress resistance to leaf rust (Puccinia recondita f. sp. tritici Rob. ex Desm.) and stem rust (Puccinia graminis f. sp. tritici Eriks. &Henn.). Ten rust-resistant wild tetraploid wheats (T. turgidum var. dicoccoides) were crossed with both durum (T. turgidum var. durum) and bread wheats. In all cases, resistance to leaf rust and stem rust was expressed in the hybrids with durum wheats but suppressed in the hybrids with bread wheats. Crosses were made between five diverse durum wheats and four diverse bread wheats. The pentaploid hybrid seedlings of 12 crosses were tested with leaf rust race 15 and in all cases the resistance of the durum parents was suppressed. Fourteen D-genome disomic chromosome substitution lines in the durum wheat 'Langdon' were tested with stem rust race 15B-1 and leaf rust race 15. Chromosomes 1B, 2B, and 7B were found to carry genes for resistance to stem rust but no suppressors were detected. Chromosomes 2B and 4B carried genes for resistance to leaf rust, and 1D and 3D carried suppressors. Crosses between seven D-genome monosomies of 'Chinese Spring' and three dicoccoides accessions showed that 'Chinese Spring' possesses genes on 1D, 2D, and 4D, which suppress the stem rust resistance of all three dicoccoides accessions. All three chromosomes must be present to suppress resistance, indicating that some form of complementary gene interaction is involved. In addition, 'Chinese Spring' carries a gene or genes on 3D that suppresses the leaf rust resistance of all three dicoccoides accessions, plus a gene or genes on 1D that suppresses the leaf rust resistance of only one of them. The data raise some interesting questions about the specificity of the suppressors. The high frequency of occurrence of suppressors in the bread wheat population suggests that they must have a selective advantage.Key words: Triticum aestivum, stem rust, leaf rust, rust resistance, suppressor.

Download Full-text