A quantitative approach detects three QTLs involved in powdery mildew resistance at the seedling stage in the winter wheat line RE714

2008 ◽  
Vol 59 (8) ◽  
pp. 714 ◽  
Author(s):  
H. Muranty ◽  
M.-T. Pavoine ◽  
B. Jaudeau ◽  
W. Radek ◽  
G. Doussinault ◽  
...  

Powdery mildew (Blumeria graminis f. sp. tritici) is one of the major diseases of wheat (Triticum aestivum). The objective of the present study was to describe the quantitative resistance to powdery mildew of the winter wheat line RE714 at the seedling stage and to identify microsatellite markers tightly linked to the RE714 resistance QTL, which could be used in marker-assisted selection. A population of 160 recombinant inbred lines obtained from the cross between RE714 (resistant) and Hardi (susceptible) was genotyped with microsatellite and AFLP markers. Fifteen powdery mildew isolates were used to test the resistance of these lines at the seedling stage. QTL analysis enabled us to identify three major QTLs controlling powdery mildew resistance in RE714: a QTL located on chromosome 2A, corresponding to the Pm4b gene, explaining 76–93% of the phenotypic variance for resistance to six isolates; two QTLs located on chromosomes 5D and 6A, each explaining 20–67% of the phenotypic variance for resistance to five isolates. A minor QTL for resistance to four of the six isolates revealing Pm4b was detected in the same region as the 5D QTL. Other minor QTLs were detected on chromosomes 2A and 6B, explaining, respectively, 10.9 and 11.5% of the phenotypic variance for resistance to isolate 96-27. The maps around the three major QTLs were enriched with microsatellite markers that could be used in marker-assisted selection of these QTLs.

Plant Disease ◽  
2021 ◽  
Author(s):  
Wenrui Wang ◽  
Huagang He ◽  
Huiming Gao ◽  
Hongxing Xu ◽  
Wenyue Song ◽  
...  

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease seriously threatening yield and quality of common wheat (Triticum aestivum L., 2n=6x=42, AABBDD). Characterization of resistance genes against powdery mildew is useful in parental selection and for developing disease resistant cultivars. Chinese wheat breeding line KN0816 has superior agronomic performance and resistance to powdery mildew at all growth stages. Genetic analysis using populations of KN0816 crossed with different susceptible parents indicated that a single dominant gene, tentatively designated PmKN0816, conferred seedling resistance to different Bgt isolates. Using a bulked segregant analysis (BSA), PmKN0816 was mapped to the Pm6 interval on chromosome arm 2BL using polymorphic markers linked to the catalogued genes Pm6, Pm52, and Pm64, and flanked by markers CISSR02g-6 and CIT02g-2 both with genetic distances of 0.7 cM. Analysis of closely linked molecular markers indicated that the marker alleles of PmKN0816 differed from those of other powdery mildew resistance genes on 2BL, including Pm6, Pm33, Pm51, Pm64, and PmQ. Based on the genetic and physical locations and response pattern to different Bgt isolates, PmKN0816 is most likely a new powdery mildew resistance gene and confers effective resistance to all the 14 tested Bgt isolates. In view of the elite agronomic performance of KN0816 combined with the resistance, PmKN0816 is expected to become a valuable resistance gene in wheat breeding. To transfer PmKN0816 to different genetic backgrounds using marker-assisted selection (MAS), closely linked markers of PmKN0816 were evaluated and four of them (CIT02g-2, CISSR02g-6, CIT02g-10, and CIT02g-17) were confirmed to be applicable for MAS in different genetic backgrounds.


2006 ◽  
Vol 96 (7) ◽  
pp. 784-789 ◽  
Author(s):  
S. S. Liang ◽  
K. Suenaga ◽  
Z. H. He ◽  
Z. L. Wang ◽  
H. Y. Liu ◽  
...  

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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