Identification and Evaluation of Wheat-Aegilops bicornis Lines with Resistance to Powdery Mildew and Stripe Rust

Plant Disease ◽  
2021 ◽  
Author(s):  
Xiaolu Wang ◽  
Ran Han ◽  
Zhiwei Chen ◽  
Jianbo Li ◽  
Tong Zhu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Stripe Rust ◽  
Powdery Mildew Resistance ◽  
Agronomic Traits ◽  
Wheat Breeding ◽  
Tiller Number ◽  
Stripe Rust Resistance ◽  
Substitution Lines ◽  
Mildew Resistance ◽  
Negative Effect

Wheat pathogens, especially those causing powdery mildew and stripe rust, seriously threaten yield worldwide. Utilizing newly identified disease resistance genes from wheat relatives is an effective strategy to minimize disease damage. In this study, chromosome-specific molecular markers for the 3Sb and 7Sb chromosomes of Aegilops bicornis were developed using PCR-based landmark unique gene (PLUG) primers for screening wheat-Ae. bicornis progenies. Fluorescence in situ hybridization (FISH) was performed to further identify wheat-Ae. bicornis progenies using oligonucleotides probes Oligo-pSc119.2-1, Oligo-pTa535-1, and Oligo-(GAA)8. After establishing Ae. bicornis 3Sb and 7Sb chromosome-specific FISH markers, Holdfast (common wheat)-Ae. bicornis 3Sb addition, 7Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, 3Sb(3D) substitution, 7Sb(7A) substitution, and 7Sb(7B) substitution lines were identified by the molecular and cytological markers. Stripe rust and powdery mildew resistance, along with agronomic traits were investigated to evaluate the breeding potential of these lines. Holdfast and Holdfast-Ae. bicornis progenies were all highly resistant to stripe rust, indicating that the stripe rust resistance might derive from Holdfast. However, Holdfast-Ae. bicornis 3Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, and 3Sb(3D) substitution lines showed high resistance to powdery mildew while Holdfast was highly susceptible, indicating that chromosome 3Sb of Ae. bicornis carries previously unknown powdery mildew resistance gene(s). Additionally, the transfer of the 3Sb chromosome from Ae. bicornis to wheat significantly increased tiller number, but chromosome 7Sb has a negative effect on agronomic traits. Therefore, wheat germplasm containing Ae. bicornis chromosome 3Sb has potential to contribute to improving powdery mildew resistance and tiller number during wheat breeding.

QTL mapping for stripe rust and powdery mildew resistance in Triticum durum–Aegilops speltoides backcross introgression lines

2020 ◽  
Vol 18 (4) ◽  
pp. 211-221
Author(s):  
Guriqbal Singh Dhillon ◽  
Satinder Kaur ◽  
Niranjan Das ◽  
Rohtas Singh ◽  
Jesse Poland ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Qtl Mapping ◽  
Stripe Rust ◽  
Triticum Durum ◽  
Powdery Mildew Resistance ◽  
Introgression Lines ◽  
Stripe Rust Resistance ◽  
Adult Plant ◽  
Aegilops Speltoides ◽  
Mildew Resistance

AbstractWheat, a major food crop, faces significant yield constraints due to losses caused by various diseases, especially rusts and powdery mildew. Since the causal organisms are always evolving, there is a never-ending hunt for new genes/quantitative trait loci (QTLs) for resistance to control the damage. For this purpose, Triticum durum–Aegilops speltoides backcross introgression lines (DS-BILs) developed in our wide hybridization programme were screened against stripe rust and powdery mildew at both seedling and adult plant stages. DS-BILs showed complete to moderate resistance at the adult plant stage while varying resistance and susceptibility at the seedling stage. A total of 1095 single-nucleotide polymorphisms (SNPs) identified on 14 chromosomes of T. durum, using genotyping by sequencing, were used for QTL mapping. Eleven unique QTLs, across six chromosomes (chr1B, chr2A, chr2B, chr3B, chr6B and chr7B) were identified for resistance, four QTLs for field mixture of stripe rust pathotypes, two QTLs for stripe rust pathotype 78S84 and five QTLs for field mixture of powdery mildew pathotypes using stepwise regression-based likelihood ratio test for additive effect of markers and single-marker analysis. Eleven DS-BILs carrying multiple QTLs were identified which will serve as a useful resource to transfer the respective resistance to susceptible cultivars to develop all stage resistant elite cultivars where QTL for stripe rust resistance QYrAs.pau-2A.1 (LOD 3.8, PVE 24.51 linked to SNP S2A_16016633) and QTL for powdery mildew resistance QPmAs.pau-6B (logarithm of the odds (LOD) 3.2, phenotypic variation explained (PVE) 17.75 linked to SNP S6B_26793381) are major targets of the transfer.

Characterization of the Powdery Mildew Resistance Gene in Wheat Breeding Line KN0816 and its Evaluation in Marker-Assisted Selection

Plant Disease ◽  
2021 ◽  
Author(s):  
Wenrui Wang ◽  
Huagang He ◽  
Huiming Gao ◽  
Hongxing Xu ◽  
Wenyue Song ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Gene ◽  
Marker Assisted Selection ◽  
Powdery Mildew Resistance ◽  
Wheat Breeding ◽  
Agronomic Performance ◽  
Breeding Line ◽  
Powdery Mildew Resistance Gene ◽  
Mildew Resistance

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.

scholarly journals Powdery Mildew Resistance of the Lithuanian Winter Wheat Breeding Material

2009 ◽  
Vol 63 (1-2) ◽  
pp. 37-44
Author(s):  
Žilvinas Liatukas ◽  
Vytautas Ruzgas
Keyword(s):  
Powdery Mildew ◽  
Winter Wheat ◽  
Powdery Mildew Resistance ◽  
Quantitative Resistance ◽  
Wheat Breeding ◽  
Resistance Level ◽  
Mildew Resistance ◽  
Breeding Material ◽  
Progress Curve ◽  
Wheat Lines

Powdery Mildew Resistance of the Lithuanian Winter Wheat Breeding Material At the Lithuanian Institute of Agriculture, during 2004-2006, resistance to powdery mildew of approximately 1,500 winter wheat lines was assessed in check and competitive trial nurseries. Our experimental evidence showed that there were no genotypes with effective resistance singlegenes among the lines tested. Effective powdery mildew resistance from start to end of vegetation season depended on the quantitative resistance level. The most resistant lines were evaluated with a score of 2 and area under the disease progress curve (AUDPC) values ranging between 1.0-5.4. The most susceptible genotypes from the collection nurseries had score 8-9 and AUDPC values ranging between 1350-2220. The correlations between maximal disease severity and AUDPC values were strong (r = 0.79-0.92). Genotypes with AUDPC values up to 10 represented 93 lines or 7% in the check trial nursery and 22 lines or 9% in the competitive trial nursery. Lines evaluated with a score 4-5 and AUDPC value 100-300 dominated in 2004. In the next year the dominant genotypes had resistance scores 3-4 and AUDPC value 50-200. The highest powdery mildew resistance (score 2 and AUDPC value 1.0) was identified for the lines Maverich/Victo, Flair/Lut.9392, Strumok/Lut.9321, Zentos/Lut.97-6, Strumok/Lut.9313, Dirigent/Cortez in 2006.

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