Genetic mapping of powdery mildew resistance genes in wheat landrace Guizi 1 via genotyping by sequencing

• Published in: Molecular biology reports Vol. 49; no. 6; pp. 4461 - 4468
• Main Authors: Li, Luhua, Yang, Xicui, Wang, Zhongni, Ren, Mingjian, An, Chang, Zhu, Susong, Xu, Ruhong
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-06-2022; Springer Nature B.V
• Subjects: Actin; Animal Anatomy; Animal Biochemistry; Biomedical and Life Sciences; Blumeria graminis; Chromosomes; Cultivars; Epistasis; Gene mapping; Genes; Genetic analysis; Genotyping; Histology; Life Sciences; Morphology; Original Article; Phenotypic variations; Plant breeding; Powdery mildew; Quantitative trait loci; Single-nucleotide polymorphism; Triticum aestivum; Quantitative trait loci; Resistance; Wheat powdery mildew; Single-nucleotide polymorphisms; Genotyping by sequencing
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-022-07287-3

Background
Wheat (
Triticum aestivum
L.) powdery mildew (
Pm
), which caused by
Blumeria graminis
f. sp.
tritici
(
Bgt
), is a destructive disease worldwide that causes severe yield losses in wheat. Resistant wheat cultivars easily lose their ability to effectively resist newly emerged
Bgt
strains; therefore, identifying new resistance genes is necessary for breeding resistant cultivars.
Methods and Results
Guizi 1 (GZ1) is a Chinese wheat cultivar with moderate and stable resistance to
Pm
. Genetic analysis indicated that the
Pm
resistance of GZ1 was controlled by a single dominant gene, designated
PmGZ1
. In total, 110
F
2
individual plants and their 2 parents were subjected to genotyping by sequencing (GBS), which yielded 23,134 high-quality single-nucleotide polymorphisms (SNPs). The SNP distributions across the 21 chromosomes ranged from 134 on chromosome 6D to 6288 on chromosome 3B. Chromosome 6A has 1866 SNPs, among which 16 are physically located between positions 307,802,221 and 309,885,836 in an approximate 2.3-cM region; this region also had the greatest SNP density. The average map distance between SNP markers was 0.1 cM. A quantitative trait locus (QTL) with a significant epistatic effect on
Pm
resistance was mapped to chromosome 6A. The logarithm of odds (LOD) value of
PmGZ1
was 34.8, and
PmGZ1
was located within the confidence interval marked by chr6a-307802221 and chr6a-309885836. Moreover, 74.7% of the phenotypic variance was explained by
PmGZ1
. Four candidate genes (which encoded two TaAP2-A and two actin proteins) were annotated maybe as resistance genes.
Conclusions
The present results provide valuable information for wheat genetic improvement, QTL fine mapping, and candidate gene validation.