scholarly journals R-Loci Arrangement Versus Downy and Powdery Mildew Resistance Level: A Vitis Hybrid Survey

2019 ◽  
Vol 20 (14) ◽  
pp. 3526 ◽  
Author(s):  
Elena Zini ◽  
Chiara Dolzani ◽  
Marco Stefanini ◽  
Verena Gratl ◽  
Paola Bettinelli ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Resistance Level ◽  
Disease Symptoms ◽  
Mildew Resistance ◽  
Resistant Varieties ◽  
Chemical Inputs ◽  
The Impact ◽  
Essential Prerequisite ◽  
R Loci

For the viticulture of the future, it will be an essential prerequisite to manage grapevine diseases with fewer chemical inputs. The development and the deployment of novel mildew resistant varieties are considered one of the most promising strategies towards a sustainable viticulture. In this regard, a collection of 102 accessions derived from crossing Vitis hybrids with V. vinifera varieties was studied. In addition to the true-to-type analysis, an exhaustive genetic characterization was carried out at the 11 reliable mildew resistance (R) loci available in the literature to date. Our findings highlight the pyramiding of R-loci against downy mildew in 15.7% and against powdery mildew in 39.2% of the total accessions. The genetic analysis was coupled with a three-year evaluation of disease symptoms in an untreated field in order to assess the impact of the R-loci arrangement on the disease resistance degree at leaf and bunch level. Overall, our results strongly suggest that R-loci pyramiding does not necessarily mean to increase the overall disease resistance, but it guarantees the presence of further barriers in case of pathogens overcoming the first. Moreover, our survey allows the discovery of new mildew resistance sources useful for novel QTL identifications towards marker-assisted breeding.

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.

scholarly journals Identification of barley accessions from the VIR collection carrying the mlo11(cnv2) powdery mildew resistance allele

2021 ◽  
Vol 4 (3) ◽  
pp. 37-44
Author(s):  
R. A. Abdullaev ◽  
N. V. Alpatieva ◽  
T. V. Lebedeva ◽  
O. N. Kovaleva ◽  
E. E. Radchenko ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Disease Symptoms ◽  
Mildew Resistance ◽  
Promoter Sequences ◽  
Allele Variant ◽  
Russian Plant ◽  
Necrotic Spots ◽  
First Time

Background. The search for barley (Hordeum vulgare L.) genotypes that carry effective genes for resistance to powdery mildew agent Blumeria graminis f. sp. hordei is a present-day issue for Russian plant breeding. The mlo11 allele that confers long-term protection of barley against the pathogen is rarely found among the varieties, approved for cultivation in the territory of Russia. There is no information on the occurrence among Russian varieties of another effective allele, mlo11 (cnv2), therefore, the search for its source is a current necessity. Materials and methods. Seven barley accessions from Ethiopia and 7 accessions from Japan have been tested for resistance to the northwestern population of the powdery mildew agent in the field and in laboratory conditions. To identify of the Mlo gene alleles, nucleotide sequences of the Stowaway-MITE (Miniature Inverted-repeat Transposable Elements) and the adjacent promoter fragments were determined. Results. Phytopathological tests in the field and greenhouse conditions, as well as molecular markers were used to study 14 barley accessions from Ethiopia and Japan. According to the preliminary tests, plants were resistant to powdery mildew. The highly effective allele of powdery mildew resistance mlo11 (cnv2) was for the first time identified in four barley accessions from Ethiopia, k-20087, k-20523, k-20524 and k-28126. Under field conditions, adult plants were resistant, and in the greenhouse they were moderately damaged by powdery mildew (1-2 points). The disease symptoms were similar to those described for the sample Eth295, a carrier of the mlo11(cnv2) allele variant: single pustules and the absence of necrotic spots on the leaves. The fragments of Stowaway-MITE and adjacent Mlo 5' promoter sequences were amplified in all 14 accessions. The amplicons were cloned and sequenced. The unique marker SNPs within the MITE and Mlo 5’ promoter sequences, i.e. the substitutions of cytosine by thymine in positions 262 and 452, were found only in k-20087, k-20523, k-20524 and k-28126. These accessions belong to different botanical varieties and differ from each other in a number of morphological features, i.e. they are not duplicates. Conclusions. The genotypes selected as a result of the study can serve as a source of the mlo11(cnv2) allele in breeding powdery mildew-resistant barley varieties.

scholarly journals Discovery of powdery mildew resistance gene candidates from Aegilops biuncialis chromosome 2Mb based on transcriptome sequencing

2019 ◽  
Author(s):  
Huanhuan Li ◽  
Zhenjie Dong ◽  
Chao Ma ◽  
Xiubin Tian ◽  
Zhiguo Xiang ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Disease Resistance ◽  
Powdery Mildew ◽  
Resistance Gene ◽  
Powdery Mildew Resistance ◽  
Disease Resistance Gene ◽  
R Genes ◽  
Powdery Mildew Resistance Gene ◽  
Mildew Resistance ◽  
Resistance Gene Candidates

AbstractPowdery mildew is one of the most widespread diseases of wheat. Breeding resistant varieties by utilization of resistance genes is considered as the most economic and effective method of controlling this disease. Previous study showed that the gene(s) at 2Mb in Chinese Spring (CS)-Aegilops biuncialis 2Mb disomic addition line TA7733 conferred high resistance to powdery mildew. In this study, 15 Bgt isolates prevalent in different regions of China were used to further test the resistance spectrum of TA7733. As a result, TA7733 was high resistance to all tested isolates, indicating that the gene(s) on chromosome 2Mb was broad-spectrum powdery mildew resistance. In order to mine resistance gene candidates and develop 2Mb-specific molecular markers to assist the transfer resistance gene(s) at chromosome 2Mb, RNA-seq of TA7733 and CS was conducted before and after Bgt-infection, generating a total of 158,953 unigenes. Of which, 7,278 unigenes were TA7733-specific which were not expressed in CS, and 295 out of these 7,278 unigenes were annotated as R genes. Based on Blastn against with CS Ref Seq v1.0, 61 R genes were further mapped to homoeologous group 2. Analysis of R gene-specific molecular markers designed from R gene sequences verified 40 out of 61 R genes to be 2Mb specific. Annotation of these 40 R genes showed most genes encoded nucleotide binding leucine rich repeat (NLR) protein, being most likely resistance gene candidates. The broad-spectrum powdery mildew resistance gene(s), disease resistance gene candidates, and functional molecular markers of 2Mb-specific in present study will not only lay foundations for transferring disease resistance gene(s) from 2Mb to common wheat by inducing CS-Ae. biuncialis homoeologous recombination, but also provide useful candidates for isolating and cloning resistance gene(s) and dissecting molecular and genetic mechanisms of disease resistance from 2Mb.

scholarly journals High resolution mapping of a Hordeum bulbosum-derived powdery mildew resistance locus in barley using distinct homologous introgression lines

2019 ◽  
Author(s):  
Parastoo Hoseinzadeh ◽  
Brigitte Ruge-Wehling ◽  
Patrick Schweizer ◽  
Nils Stein ◽  
Hélène Pidon
Keyword(s):  
Powdery Mildew ◽  
Resistance Gene ◽  
Gene Pool ◽  
Powdery Mildew Resistance ◽  
Introgression Lines ◽  
Large Set ◽  
Hordeum Bulbosum ◽  
Mildew Resistance ◽  
The Impact ◽  
Mapping Populations

AbstractPowdery mildew caused by Blumeria graminis f.sp. hordei (Bgh) is one of the main foliar diseases in barley (Hordeum vulgare L.; Hv). Naturally occurring resistance genes used in barley breeding are a cost effective and environmentally sustainable strategy to minimize the impact of pathogens, however, the primary gene pool of H. vulgare contains limited diversity owing to recent domestication bottlenecks. To ensure durable resistance against this pathogen, more genes are required that could be unraveled by investigation of secondary barley gene-pool. A large set of Hordeum bulbosum (Hb) introgression lines (ILs) harboring a diverse set of desirable resistance traits have been developed and are being routinely used as source of novel diversity in gene mapping studies. Nevertheless, this strategy is often compromised by a lack of recombination between the introgressed fragment and the orthologous chromosome of the barley genome. In this study, we fine-mapped a Hb gene conferring resistance to barley powdery mildew. The initial genotyping of two Hb ILs mapping populations with differently sized 2HS introgressions revealed severely reduced interspecific recombination in the region of the introgressed segment, preventing precise localization of the gene. To overcome this difficulty, we developed an alternative strategy, exploiting intraspecific recombination by crossing two Hv/Hb ILs with collinear Hb introgressions, one of which carries a powdery mildew resistance gene, while the other doesn’t. The intraspecific recombination rate in the Hb-introgressed fragment of 2HS was approximately 20 times higher than it was in the initial simple ILs mapping populations. Using high-throughput genotyping-by-sequencing (GBS), we allocated the resistance gene to a 1.4 Mb interval, based on an estimate using the Hv genome as reference, in populations of only 103 and 146 individuals respectively, similar to what is expected at this locus in barley. The most likely candidate resistance gene within this interval encodes a legume-type lectin-receptor-like protein (LecRLP). Like other LecRLPs that have been implicated in resistance, this gene could be a good candidate for Hb resistance. The reported strategy can be applied as a general strategic approach for identifying genes underlying traits of interest in crop wild relatives.

scholarly journals Fine Mapping a Broad-Spectrum Powdery Mildew Resistance Gene in Chinese Landrace Datoumai, PmDTM, and Its Relationship with Pm24

Plant Disease ◽  
2020 ◽  
Vol 104 (6) ◽  
pp. 1709-1714
Author(s):  
Nan Lu ◽  
Mingxue Lu ◽  
Pan Liu ◽  
Hongxing Xu ◽  
Xiaolong Qiu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Powdery Mildew Resistance ◽  
Bulked Segregant Analysis ◽  
Dominant Gene ◽  
Powdery Mildew Resistance Gene ◽  
Mildew Resistance ◽  
Resistant Varieties ◽  
Chinese Landrace ◽  
Chinese Wheat ◽  
Simple Sequence

Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici (Bgt), is a globally important wheat disease causing severe yield losses, and deployment of resistant varieties is the preferred choice for managing this disease. Chinese wheat landrace Datoumai was resistant to 22 of 23 Bgt isolates at the seedling stage. Genetic analysis based on the inoculation of Bgt isolate E09 on the F1, F2, and F2:3 populations derived from the cross Datoumai × Huixianhong revealed that the powdery mildew resistance of Datoumai is controlled by a single dominant gene, temporarily designated as PmDTM. Bulked segregant analysis and simple sequence repeat mapping with 200 F2 plants showed that PmDTM was located in the same genetic region as Pm24 on chromosome 1DS. To fine map PmDTM, 12 critical recombinants were identified from 1,192 F2 plants and delimited PmDTM to a 0.5-cM Xhnu58800 to Xhnu59000 interval covering 180.5 Kb (38,728,125 to 38,908,656 bp) on chromosome 1DS, and only one highly confident gene, TraesCS1D02G058900, was annotated within this region. TraesCS1D02G058900 encodes a receptor-like serine/threonine-protein kinase (STK), and a 6-bp deletion in exon 5 may confer the resistance to powdery mildew. Allele frequency analysis indicated that the STK allele with 6-bp deletion was only present in three landraces (Datoumai, Chiyacao [Pm24], and Hulutou) and was absent in all of the 353 Chinese modern cultivars and 147 foreign cultivars. These results demonstrate that PmDTM is mapped to the same locus as Pm24 and can be widely used to enhance powdery mildew resistance in wheat growing regions worldwide.

Characterization of PmHHXM, a New Broad-spectrum Powdery Mildew Resistance Gene in Chinese Wheat Landrace Honghuaxiaomai

Plant Disease ◽  
2021 ◽  
Author(s):  
Shulin Xue ◽  
Mingxue Lu ◽  
Shanshan Hu ◽  
Hongxing Xu ◽  
Yuyu Ma ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Resistance Gene ◽  
Broad Spectrum ◽  
Powdery Mildew Resistance ◽  
Dominant Gene ◽  
Powdery Mildew Resistance Gene ◽  
Mildew Resistance ◽  
Wheat Landrace ◽  
Chinese Wheat

Powdery mildew, caused by fungal pathogen Blumeria graminis f. sp. tritici (Bgt), is one of agronomically important and widespread wheat diseases causing severe yield losses. Deployment of broad‐spectrum disease-resistance genes is the preferred strategy to prevent this pathogen. Chinese wheat landrace Honghuaxiaomai (HHXM) was resistant to all 23 tested Bgt isolates at the seedling stage. The F1, F2, and F2:3 progenies derived from the cross HHXM × Yangmai 158 were used in this study, and genetic analysis revealed that a single dominant gene, designated as PmHHXM, conferred resistance to Bgt isolate E09. Bulked segregant analysis and molecular mapping initially located PmHHXM to the distal region of chromosome 4AL. To fine map PmHHXM, two critical recombinants were identified from 592 F2 plants and delimited PmHHXM to a 0.18-cM Xkasp475200–Xhnu552 interval covering 1.77-Mb, in which a number of disease resistance-related gene clusters were annotated. Comparative mapping of this interval revealed a perturbed synteny among Triticeae species. This study reports the new powdery mildew resistance gene PmHHXM that seems different from three known QTL/genes identified on chromosome 4AL and has significant values for further genetic improvement. Analysis of the polymorphisms of 13 co-segregating markers between HHXM and 170 modern wheat cultivars indicates that Xhnu227 and Xsts478700 developed here are ideal for marker-assisted introgression of this resistance gene in wheat breeding.

scholarly journals Development of Novel Wheat-Rye Chromosome 4R Translocations and Assignment of Their Powdery Mildew Resistance

Plant Disease ◽  
2020 ◽  
Vol 104 (1) ◽  
pp. 260-268 ◽  
Author(s):  
Pengtao Ma ◽  
Guohao Han ◽  
Qi Zheng ◽  
Shiyu Liu ◽  
Fangpu Han ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Common Wheat ◽  
Powdery Mildew Resistance ◽  
Translocation Line ◽  
Growth Stages ◽  
Alien Chromosome ◽  
Mildew Resistance ◽  
Wheat Improvement ◽  
Chromosome Arm

Rye (Secale cereale L.) is an important gene donor for wheat improvement because of its many valuable traits, especially disease resistance. Development of novel wheat-rye translocations with disease resistance can contribute to transferring resistance into common wheat. In a previous study, a wheat-rye T4BL·4RL and T7AS·4RS translocation line (WR41-1) was developed by distant hybridization, and it was speculated that its resistance to powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), was derived from rye based on pedigree analysis. To make accurate use of chromosome 4R in wheat improvement, a set of new 4R translocations involving different arm translocations (e.g., 4RS monosomic, 4RL monosomic, 4RL disomic, 4RS monosomic plus 4RL monosomic, 4RS monosomic plus 4RL disomic, and 4RS disomic plus 4RL disomic translocations) was developed from crosses with common wheat. Those translocations were characterized by genomic in situ hybridization and expressed sequence tag simple sequence repeat marker analysis. To confirm the source of powdery mildew resistance, the translocation plants were tested against Bgt isolate E09. The results indicated that all translocations with 4RL were resistant at all tested growth stages, whereas those with only 4RS translocation or no alien translocation were susceptible. This further indicated that the powdery mildew resistance of WR41-1 was derived from the alien chromosome arm 4RL. To effectively use 4RL resistance in wheat improvement, two competitive allele-specific PCR markers specific for chromosome arm 4RL were developed to detect the alien chromosome in the wheat genome. These new translocation lines with diagnostic markers can efficiently serve as important bridges for wheat improvement.

Identification and SSR Mapping of Two Powdery Mildew Resistance Genes in Wild Emmer (Triticum dicoccoides) Accessions IW3 and IW10

2009 ◽  
Vol 35 (5) ◽  
pp. 761-767 ◽  
Author(s):  
Gen-Qiao LI ◽  
Ti-Lin FANG ◽  
Hong-Tao ZHANG ◽  
Chao-Jie XIE ◽  
Zuo-Min YANG ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Powdery Mildew Resistance ◽  
Triticum Dicoccoides ◽  
Wild Emmer ◽  
Mildew Resistance
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