Molecular and Cytogenetic Characterization of a Powdery Mildew-Resistant Wheat-Aegilops mutica Partial Amphiploid and Addition Line

2015 ◽  
Vol 147 (2-3) ◽  
pp. 186-194 ◽  
Author(s):  
Cheng Liu ◽  
Guang-Rong Li ◽  
Wen-Ping Gong ◽  
Gen-Ying Li ◽  
Ran Han ◽  
...  

Aegilops mutica Boiss., a diploid species (2n = 2x = 14, TT), has been rarely studied before. In this research, a hexaploid wheat (cv. Chinese Spring)-Ae. mutica partial amphiploid and a wheat-Ae. mutica addition line were characterized by chromosome karyotyping, FISH using oligonucleotides Oligo-pTa535-1, Oligo-pSc119.2-1, and (GAA)8 as probes, and EST-based molecular markers. The results showed that the partial amphiploid strain consisted of 20 pairs of wheat chromosomes and 7 pairs of Ae. mutica chromosomes, with both wheat 7B chromosomes missing. EST-based molecular marker data suggested that the wheat-Ae. mutica addition line carries the 7T chromosome. Resistance tests indicated that both the partial amphiploid and the 7T addition line were highly resistant to powdery mildew, whereas the wheat control line Chinese Spring was highly susceptible, indicating the presence of a potentially new powdery mildew resistance gene on the Ae. mutica 7T chromosome. The karyotype, FISH patterns, and molecular markers can now be used to identify Ae. mutica chromatin in a wheat background, and the 7T addition could be used as a new powdery mildew resistance source for wheat breeding.

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.


Author(s):  
Žilvinas Liatukas ◽  
Vytautas Ruzgas

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.


Plant Disease ◽  
2021 ◽  
Author(s):  
Huanhuan Li ◽  
Xiubin Tian ◽  
Shaolong Pei ◽  
Wenqiang Men ◽  
Chao Ma ◽  
...  

Powdery mildew of wheat, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease of wheat. Cultivation of resistant varieties is the most cost-effective disease management strategy. Previous studies reported that chromosome 3Sl#2 present in Chinese Spring (CS)-Aegilops longissima 3Sl#2(3B) disomic substitution line TA3575 conferred resistance to powdery mildew. In this study, we further located the powdery mildew resistance gene(s) to the short arm of chromosome 3Sl#2 (3Sl#2S) by evaluating for Bgt-resistance of newly developed CS-Ae. longissima 3Sl#2 translocation lines. Meanwhile, TA7545, a previously designated CS-Ae. longissima 3Sl#3 disomic addition line, was re-identified as an isochromosome 3Sl#3S addition line and evaluated to confer resistance to powdery mildew, thus locating the resistance gene(s) to the short arm of chromosome 3Sl#3 (3Sl#3S). Based on transcriptome sequences of TA3575, ten novel chromosome 3SlS-specific markers were developed, of which, five could be used to distinguish between 3Sl#2S and 3Sl#3S derived from Ae. longissima accessions TL20 and TA1910 (TAM4), and the remaining five could identify both 3Sl#2S and 3Sl#3S. Besides, CL897, one of five markers specific to both 3Sl#2S and 3Sl#3S, could be used to detect Pm13 located at chromosome 3Sl#1S from Ae. longissima accession TL01 in diverse wheat genetic backgrounds. The powdery mildew resistance genes on chromosomes 3Sl#2S and 3Sl#3S, the CS-Ae. longissima 3Sl#2 translocation lines, and the 3SlS-specific markers developed in this study will provide new germplasm resources for powdery mildew resistance breeding and facilitate the transfer of Bgt-resistance genes into common wheat.


Sign in / Sign up

Export Citation Format

Share Document