Wheat yellow rust resistance improvement in wheat and maize cross progenies using double haploid method

Two sequence-tagged site (STS) markers for the wheat yellow rust resistance (R) gene Yr5 have been derived through the identification and characterization of linked amplified fragment length polymorphisms (AFLPs). The sequences of the 2 AFLP markers partially overlap with one another, but belong to discrete loci: S19M93-140 completely cosegregates with Yr5, whereas S23M41-310 maps at a distance of 0.7 cM. The DNA sequence of S23M41-310 shows significant homology with the 3′ end of nucleotide-binding site (NBS) - leucine-rich repeat (LRR) - type R-genes, in particular with orthologues of the rice bacterial blight R-gene Xa-I. The distinct genetic location of the 2 AFLP loci suggests that Yr5 falls within an R-gene cluster. Because neither sequence forms part of a detectable transcription product, we propose that the Yr5 R-gene cluster includes R-gene analogues and pseudogenes. A Yr5 flanking simple sequence repeat (SSR) marker has also been identified, which allows Yr5 to be effectively incorporated, along with other R-genes for yellow rust, into elite wheat genetic backgrounds, through marker-assisted selection.

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Genome-wide association mapping identifies Yellow Rust resistance locus in Ethiopian Durum Wheat germplasm

10.1101/2020.11.27.400895 ◽

2020 ◽

Author(s):

Sisay Kidane Alemu ◽

Ayele Badebo Huluka ◽

Kassahun Tesfaye Geletu ◽

Cristobal Uauy

Keyword(s):

Durum Wheat ◽

Rust Resistance ◽

Yellow Rust ◽

Genome Wide Association ◽

Lattice Design ◽

Genome Wide ◽

Population Structure Analysis ◽

Significant Difference ◽

Yellow Rust Resistance ◽

Improvement Programs

AbstractDurum wheat is an important cereal grown in Ethiopia, a country which is also its center for genetic diversity. Yellow (stripe) rust caused by Puccinia striiformis fsp tritici is one of the most devastating diseases threatening Ethiopian wheat production. To identify sources of genetic resistance to combat this pathogen, we conducted a genome wide association study of yellow rust resistance on 300 durum wheat accessions comprising 261 landraces and 39 cultivars. The accessions were evaluated for their field resistance in an alpha lattice design (10 × 30) in two replications at Meraro, Kulumsa and Chefe-Donsa in the 2015 and 2016 main growing seasons. Disease Scoring was carried out using a modified Cobb scale and then converted to Coefficient of Infection (CI). Analysis of the 35K Axiom Array genotyping data resulted in a total of 8,797 polymorphic SNPs of which 7,093 were used in subsequent analyses. Population structure analysis suggested two groups in which the cultivars clearly stood out separately from the landraces. We identified twelve SNPs significantly associated with yellow rust resistance across four chromosomes (1A, 1B, 2B, and 7B). Six of the SNPs (AX-95171339, AX-94436448, AX-95238778, AX-95096041, AX-94730403 & AX-94427201), were consistently identified on chromosome 1B at the three field locations and combined across the six environments. The phenotypic variation (R2) explained by all six SNPs on chromosome 1B ranged from 63.7 – 65.4%. Locus-based analysis of phenotypic values between resistant and susceptible allele resulted in a significant difference at (p < 0.001). Further investigation across the genomic interval encompassing the identified loci indicated the presence of disease resistance protein (NBS-LRR class) family and RPM1 in the vicinity of the loci. This study provides SNPs for tracking the QTL associated with yellow rust resistance in durum wheat improvement programs.

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An EST-SSR marker, bu099658, and its potential use in breeding for yellow rust resistance in wheat

Czech Journal of Genetics and Plant Breeding ◽

10.17221/109/2013-cjgpb ◽

2014 ◽

Vol 50 (No. 1) ◽

pp. 11-18 ◽

Cited By ~ 4

Author(s):

S. Hasancebi ◽

Z. Mert ◽

F. Ertugrul ◽

K. Akan ◽

Y. Aydin ◽

...

Keyword(s):

Rust Resistance ◽

Ssr Marker ◽

Yellow Rust ◽

Female Parent ◽

Adult Plant ◽

Resistant Parent ◽

Yellow Rust Resistance ◽

Plant Stage ◽

Susceptible Bulk ◽

Dna Fragment

EST-SSR markers, derived from the A and B genomes of wheat were used to identify molecular markers associated with yellow rust resistance. For this purpose, bulk segregant analysis was performed using 114 EST-SSR primer pairs. They were screened on the parent genotypes and resistant/susceptible DNA pools from the cross between Izgi2001 (resistant male parent) × ES14 (susceptible female parent) at the seedling and adult plant stage. An EST-SSR marker, bu099658, generated the 206 bp DNA fragment that was present in the resistant parent and resistant bulk, but it was not present in the susceptible parent and the susceptible bulk. To investigate its association with Yr genes, 20 individuals of NILs were also amplified with BU099658 and the 206 bp marker fragment was obtained only in Yr1/6 × Avocet S. Additionally, bu099658 was screened on 65 genotypes which possessed different Yr genes/gene combination(s) and Yr1. The results indicate a close linkage of bu099658 with the Yr1 gene.

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