Dataset Information

Genetic analysis of loose smut (Ustilago tritici) resistance in Sonop spring wheat.

ABSTRACT:

Background

The genetics of resistance to loose smut of wheat (Triticum aestivum L.) caused by the fungus Ustilago tritici (Pers.) Rostr. is not well understood. This study examines loose smut resistance in Sonop (TD-14), a South African spring wheat variety. A doubled haploid (DH) population of 163 lines derived from the cross Diamont/TD-14 was studied. The parents and progenies were inoculated with U. tritici races T2, T9, and T39 individually in growth facilities at Morden and Swift Current, Canada. Loose smut incidence (LSI) and partial loose smut resistance (PLSR) were assessed.

Results

A whole genome linkage map was developed consisting of 11,519 SNP loci found on 31 linkage groups spanning 2845?cM. A new major resistance gene Ut11 was located to the distal end of chromosome arm 7BS. Ut11 conferred resistance to U. tritici race T2, but not races T9 and T39. Quantitative trait locus (QTL) mapping identified four QTL controlling LSI in the Diamont/TD-14 DH population on chromosomes 3B, 4B, 5B, and 7B (at Ut11) with TD-14 contributing the resistance alleles at three of these loci. The major QTL QUt.mrc-5B was effective against all three races and explained up to 81% of the phenotypic variation. The only QTL identified for PLSR coincided with the LSI QTL QUt.mrc-5B indicating that this locus affected both loose smut incidence and partial smutting of spikes.

Conclusions

A race-specific resistance gene Ut11 and a broadly effective resistance QTL QUt.mrc-5B were the main loci controlling loose smut resistance in the differential line TD-14 (cultivar Sonop). This study provides insight into the genetics of loose smut resistance in spring wheat Sonop and the single nucleotide polymorphism (SNP) markers linked to the resistance gene Ut11 and QTL QUt.mrc-5B will be useful for selecting loose smut resistance in breeding programs.

SUBMITTER: Thambugala D

PROVIDER: S-EPMC7333308 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

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Publications

Genetic analysis of loose smut (Ustilago tritici) resistance in Sonop spring wheat.

Thambugala Dinushika D Menzies Jim G JG Knox Ron E RE Campbell Heather L HL McCartney Curt A CA

BMC plant biology 20200703 1

<h4>Background</h4>The genetics of resistance to loose smut of wheat (Triticum aestivum L.) caused by the fungus Ustilago tritici (Pers.) Rostr. is not well understood. This study examines loose smut resistance in Sonop (TD-14), a South African spring wheat variety. A doubled haploid (DH) population of 163 lines derived from the cross Diamont/TD-14 was studied. The parents and progenies were inoculated with U. tritici races T2, T9, and T39 individually in growth facilities at Morden and Swift Cu ...[more]

PMID: 32620083

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Project description:Septoria tritici blotch (STB) of wheat, caused by the ascomycete Zymoseptoria tritici (formerly Mycosphaerella graminicola), is one of the most important foliar diseases of wheat. In Morocco, STB is a devastating disease in temperate wheat-growing regions, and the yield losses can exceed up to 50% under favorable conditions. The aims of this study were to identify sources of resistance to STB in Septoria Association Mapping Panel (SAMP), which is composed of 377 advanced breeding lines (ABLs) from spring bread wheat breeding program of ICARDA, and to identify loci associated with resistance to STB at seedling (SRT) as well as at the adult plant (APS) stages using genome-wide association mapping (GWAM). Seedling resistance was evaluated under controlled conditions with two virulent isolates of STB (SAT-2 and 71-R3) from Morocco, whereas adult plant resistance was assessed at two hot spot locations in Morocco (Sidi Allal Tazi, Marchouch) under artificial inoculation with a mixture of STB isolates. At seedling stage, 45 and 32 ABLs were found to be resistant to 71-R3 and SAT-2 isolates of STB, respectively. At adult plant stage, 50 ABLs were found to be resistant at hot spot locations in Morocco. Furthermore, 10 genotypes showed resistance in both locations during two cropping seasons. GWAM was conducted with 9,988 SNP markers using phenotypic data for seedling and the adult plant stage. MLM model was employed in TASSEL 5 (v 5.2.53) using principal component analysis and Kinship Matrix as covariates. The GWAM analysis indicated 14 quantitative trait loci (QTL) at the seedling stage (8 for isolate SAT-2 and 6 for isolate 71-R3), while 23 QTL were detected at the adult plant stage resistance (4 at MCH-17, 16 at SAT-17, and 3 at SAT-18). SRT QTL explained together 33.3% of the phenotypic variance for seedling resistance to STB isolate SAT-2 and 28.3% for 71-R3, respectively. QTL for adult plant stage resistance explained together 13.1, 68.6, and 11.9% of the phenotypic variance for MCH-17, SAT-17, and SAT-18, respectively. Identification of STB-resistant spring bread wheat germplasm in combination with QTL detected both at SRT and APS stage will serve as an important resource in STB resistance breeding efforts.

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Dataset Information

Genetic analysis of loose smut (Ustilago tritici) resistance in Sonop spring wheat.

Background

Results

Conclusions

Publications

Genetic analysis of loose smut (Ustilago tritici) resistance in Sonop spring wheat.

Similar Datasets

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