Genetic Mapping of Powdery Mildew Resistance Genes in Wheat Landrace ‘Guizi 1’ Using Genotyping-By-Sequencing

Abstract Wheat powdery mildew (Pm), caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease of wheat (Triticum aestivum L.) worldwide that causes severe yield losses. Resistant wheat cultivars easily lose effective resistance against newly emerged Bgt strains; therefore, identifying new resistance genes is necessary for breeding resistant cultivars. ‘Guizi 1’ is a Chinese wheat cultivar with effective moderate and stable resistance against powdery mildew. A genetic analysis indicated that powdery mildew resistance in ‘Guizi 1’ was controlled by a single dominant gene, designated PmGZ1. In total, 110 F2 individual plants and the 2 parents were used for genotyping-by-sequencing, which produced 23,134 high-quality single-nucleotide polymorphisms (SNPs). The SNP distributions on the 21 chromosomes ranged from 134 on chromosome 6D to 6,288 on chromosome 3B. Chromosome 6A has 1,866 SNPs, among which 16 are located in a physical region between positions 307,802,221 and 309,885,836 in an approximate 2.3-cM region, which possessed the greatest SNP density. The average map distance between SNP markers was 0.1 cM. A quantitative trait locus with a significant epistatic effect on powdery mildew resistance was mapped to Chromosome 6A. The LOD value of PmGZ1 reached 34.8, and PmGZ1 was located within the confidence interval marked by chr6a-307802221 and chr6a-309885836. The phenotypic variance explained by PmGZ1 was 74.7%. Four candidate genes (two each encoding TaAP2-A and actin proteins) were annotated as resistance genes. The present results provide valuable information for wheat genetic improvement, quantitative trait loci fine mapping, and candidate gene validation.

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Quantitative Trait Loci Mapping for Adult-Plant Resistance to Powdery Mildew in Bread Wheat

Phytopathology ◽

10.1094/phyto-96-0784 ◽

2006 ◽

Vol 96 (7) ◽

pp. 784-789 ◽

Cited By ~ 44

Author(s):

S. S. Liang ◽

K. Suenaga ◽

Z. H. He ◽

Z. L. Wang ◽

H. Y. Liu ◽

...

Keyword(s):

Quantitative Trait Loci ◽

Powdery Mildew ◽

Plant Resistance ◽

Quantitative Trait ◽

Powdery Mildew Resistance ◽

Adult Plant Resistance ◽

Adult Plant ◽

Phenotypic Variance ◽

Mildew Resistance ◽

Trait Loci

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a major disease to wheat (Triticum aestivum) worldwide. Use of adult-plant resistance (APR) is an effective method to develop wheat cultivars with durable resistance to powdery mildew. In the present study, 432 molecular markers were used to map quantitative trait loci (QTL) for APR to powdery mildew in a doubled haploid (DH) population with 107 lines derived from the cross Fukuho-komugi × Oligoculm. Field trials were conducted in Beijing and Anyang, China during 2003-2004 and 2004-2005 cropping seasons, respectively. The DH lines were planted in a randomized complete block design with three replicates. Artificial inoculation was carried out in Beijing with highly virulent isolate E20 of B. graminis f. sp. tritici and the powdery mildew severity on penultimate leaf was evaluated four times, and the maximum disease severity (MDS) on penultimate leaf was investigated in Anyang under natural inoculation in May 2004 and 2005. The heritability of resistance to powdery mildew for MDS in 2 years and two locations ranged from 0.82 to 0.93, while the heritability for area under the disease progress curve was between 0.84 and 0.91. With the method of composite interval mapping, four QTL for APR to powdery mildew were detected on chromosomes 1AS, 2BL, 4BL, and 7DS, explaining 5.7 to 26.6% of the phenotypic variance. Three QTL on chromosomes 1AS, 2BL, and 7DS were derived from the female, Fukuho-komugi, while the one on chromosome 4BL was from the male, Oligoculm. The QTL on chromosome 1AS showed high genetic effect on powdery mildew resistance, accounting for 19.5 to 26.6% of phenotypic variance across two environments. The QTL on 7DS associated with the locus Lr34/Yr18, flanked by microsatellite Xgwm295.1 and Ltn (leaf tip necrosis). These results will benefit for improving powdery mildew resistance in wheat breeding programs.

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Genotyping by Sequencing-Based Discovery of SNP Markers and Construction of Linkage Map from F5 Population of Pepper with Contrasting Powdery Mildew Resistance Trait

BioMed Research International ◽

10.1155/2021/6673010 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Abinaya Manivannan ◽

Sena Choi ◽

Tae-Hwan Jun ◽

Eun-Young Yang ◽

Jin-Hee Kim ◽

...

Keyword(s):

Powdery Mildew ◽

Linkage Map ◽

Powdery Mildew Resistance ◽

Genotyping By Sequencing ◽

Snp Markers ◽

Read Mapping ◽

Single Nucleotide ◽

Mildew Resistance ◽

Polymorphic Snps ◽

Resistance Trait

Powdery mildew (PM) is a common fungal disease infecting pepper plants worldwide. Molecular breeding of pepper cultivars with powdery mildew resistance is desirable for the economic improvement of pepper cultivation. In the present study, 188 F5 population derived from AR1 (PM resistant) and TF68 (PM sensitive) parents were subjected to high-throughput genotyping by sequencing (GBS) for the identification of single nucleotide polymorphism (SNP) markers. Further, the identified SNP markers were utilized for the construction of genetic linkage map and QTL analysis. Overall read mapping percentage of 87.29% was achieved in this study with the total length of mapped region ranging from 2,956,730 to 25,537,525 bp. A total of 41,111 polymorphic SNPs were identified, and a final of 1,841 SNPs were filtered for the construction of a linkage map. A total of 12 linkage groups were constructed corresponding to each chromosome with 1,308 SNP markers with the map length of 2506.8 cM. Further, two QTLs such as Pm-2.1 and Pm-5.1 were identified in chromosomes 2 and 5, respectively, for the PM resistance. Overall, the outcomes of the present endeavor can be utilized for the marker-assisted selection of pepper with powdery mildew-resistant trait.

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Molecular Characterization of a Powdery Mildew Resistance Gene in Wheat Cultivar Suwon 92

Phytopathology ◽

10.1094/phyto-96-0496 ◽

2006 ◽

Vol 96 (5) ◽

pp. 496-500 ◽

Cited By ~ 10

Author(s):

X.-Y. Xu ◽

G.-H. Bai ◽

B. F. Carver ◽

G. E. Shaner ◽

R. M. Hunger

Keyword(s):

Powdery Mildew ◽

Resistance Gene ◽

Resistance Genes ◽

Powdery Mildew Resistance ◽

Durable Resistance ◽

Phenotypic Variance ◽

Powdery Mildew Resistance Gene ◽

Gene Markers ◽

Mildew Resistance ◽

Ril Population

Powdery mildew, caused by Blumeria graminis f. sp tritici, is an important foliar disease of wheat worldwide. Pyramiding race-specific genes into a single cultivar and combining race-specific resistance genes with durable resistance genes are the preferred strategies to improve the durability of powdery mildew resistance. The objectives of this study were to characterize a powdery mildew resistance gene in Suwon 92 and identify gene-specific or tightly linked molecular markers for marker-assisted selection (MAS). A population of recombinant inbred lines (RILs) was derived by single seed descent from a cross between Suwon 92 and a susceptible cultivar, CI 13227. The RILs were screened for adult-plant infection type of powdery mildew and characterized with amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. The linked markers explained 41.3 to 69.2% of the phenotypic variances measured in 2 years. A morphological marker, hairy glume, was also associated with powdery mildew resistance in Suwon 92, and explained 43 to 51% of the phenotypic variance. The powdery mildew resistance gene in Suwon 92 was located on the short arm of chromosome 1A where Pm3 was located. Two gene-specific markers were developed based on the sequence of the cloned Pm3b gene. These two markers, which were mapped at the same locus in the peak region of the LOD score for the RIL population, explained most of the phenotypic variance for powdery mildew resistance in the RIL population. The powdery mildew resistance in Suwon 92 is most likely conditioned by the Pm3 locus. The gene markers developed herein can be directly used for MAS of some of the Pm3 alleles in breeding programs.

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