Molecular Cytogenetic Analysis of the Introgression between Agropyroncristatum P Genome and Wheat Genome

Agropyroncristatum (2n = 4x = 28, PPPP) is an important wild relative of common wheat (Triticum aestivum L., 2n = 6x = 42). A previous report showed that the wheat-A. cristatum 6P translocation line WAT655 carrying A. cristatum 6PS (0.81–1.00) exhibited high resistance to prevalent physiological races of stripe rust (CYR32 and CYR33). In this study, three disease resistance-related transcripts, which were mapped to A. cristatum 6PS (0.81–1.00) through the analysis of specific molecular markers, were acquired from among A. cristatum full-length transcripts. The BC5F2 and BC5F2:3 genetic populations of the translocation line WAT655 were analyzed by using three disease resistance-related gene markers, A. cristatum P genome-specific markers, and fluorescence in situ hybridization (FISH). The results revealed that the introgression between A. cristatum P genome and wheat genome was observed in progenies of the genetic populations of the translocation line WAT655 and the physical positions of the three genes were considerably adjacent on A. cristatum 6PS (0.81–1.00) according to the FISH results. Additionally, kompetitive allele-specific PCR (KASP) markers of the three genes were developed to detect and acquire 24 breeding lines selected from the progenies of the distant hybridization of wheat and A. cristatum, which showed resistance to physiological races of stripe rust (CYR32 and CYR33) and other desirable agronomic traits according to the field investigation. In conclusion, this study not only provides new insights into the introgression between A. cristatum P genome and wheat genome but also provides the desirable germplasms for breeding practice.

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New Insights Into the Introgression Between Agropyron Cristatum P Genome and Wheat Genome

10.21203/rs.3.rs-534937/v1 ◽

2021 ◽

Author(s):

Zhi Zhang ◽

Shenghui Zhou ◽

Weihua Liu ◽

Liqiang Song ◽

Jinpeng Zhang ◽

...

Keyword(s):

Disease Resistance ◽

In Situ Hybridization ◽

Common Wheat ◽

Agronomic Traits ◽

Wheat Genome ◽

Agropyron Cristatum ◽

Translocation Line ◽

Gene Markers ◽

Physiological Races

Abstract Agropyron cristatum (2n = 4x = 28, PPPP) is an important wild relative of common wheat and confers desirable agronomic traits to common wheat. A previous report showed that the wheat-A. cristatum 6P translocation line WAT655 carrying A. cristatum 6PS (0.81–1.00) exhibited high resistance to prevalent physiological races (CYR32 and CYR33). In this study, three disease resistance-related transcriptomes, which were mapped to A. cristatum 6PS (0.81–1.00) through the analysis of specific molecular markers, were searched from among A. cristatum full-length transcriptomes. Then, three disease resistance-related gene markers, A. cristatum P genome-specific markers, and fluorescence in situ hybridization (FISH)/genomic in situ hybridization (GISH) probes made from the DNA of three bacterial artificial chromosome (BAC) clones, three genes, and A. cristatum “Z559” were used to analyze the BC5F2 and BC5F2:3 genetic populations of the translocation line WAT655. The results revealed the introgression can spontaneously occur between A. cristatum P genome and wheat genome, and indicated the three genes could constitute a gene cluster according to the positions of their FISH signals. Additionally, kompetitive allele-specific PCR (KASP) markers of the three genes were developed to detect and acquire 24 wheat-A. cristatum breeding materials, which showed resistance to physiological races (CYR32 and CYR33) and other desirable agronomic traits according to the field investigation. In conclusion, our study not only provides new insights into the introgression between A. cristatum P genome and wheat genome, but also provides the desirable breeding materials for breeding practice.

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Breeding With Major and Minor Genes: Genomic Selection for Quantitative Disease Resistance

Frontiers in Plant Science ◽

10.3389/fpls.2021.713667 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lance F. Merrick ◽

Adrienne B. Burke ◽

Xianming Chen ◽

Arron H. Carter

Keyword(s):

Disease Resistance ◽

Genomic Selection ◽

Stripe Rust ◽

Fixed Effects ◽

Prediction Accuracy ◽

Major Gene ◽

Gene Markers ◽

Quantitative Disease Resistance ◽

Minor Genes ◽

Population Type

Disease resistance in plants is mostly quantitative, with both major and minor genes controlling resistance. This research aimed to optimize genomic selection (GS) models for use in breeding programs that are needed to select both major and minor genes for resistance. In this study, stripe rust (Puccinia striiformis Westend. f. sp. tritici Erikss.) of wheat (Triticum aestivum L.) was used as a model for quantitative disease resistance. The quantitative nature of stripe rust is usually phenotyped with two disease traits, infection type (IT) and disease severity (SEV). We compared two types of training populations composed of 2,630 breeding lines (BLs) phenotyped in single-plot trials from 4 years (2016–2020) and 475 diversity panel (DP) lines from 4 years (2013–2016), both across two locations. We also compared the accuracy of models using four different major gene markers and genome-wide association study (GWAS) markers as fixed effects. The prediction models used 31,975 markers that are replicated 50 times using a 5-fold cross-validation. We then compared GS models using a marker-assisted selection (MAS) to compare the prediction accuracy of the markers alone and in combination. GS models had higher accuracies than MAS and reached an accuracy of 0.72 for disease SEV. The major gene and GWAS markers had only a small to nil increase in the prediction accuracy more than the base GS model, with the highest accuracy increase of 0.03 for the major markers and 0.06 for the GWAS markers. There was a statistical increase in the accuracy using the disease SEV trait, BLs, population type, and combining years. There was also a statistical increase in the accuracy using the major markers in the validation sets as the mean accuracy decreased. The inclusion of fixed effects in low prediction scenarios increased the accuracy up to 0.06 for GS models using significant GWAS markers. Our results indicate that GS can accurately predict quantitative disease resistance in the presence of major and minor genes.

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Development and Molecular Cytogenetic Identification of a New Wheat–Psathyrostachys huashanica Keng Translocation Line Resistant to Powdery Mildew

Frontiers in Plant Science ◽

10.3389/fpls.2021.689502 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yuxiu Liu ◽

Shuhua Huang ◽

Jing Han ◽

Chenchen Hou ◽

Dasheng Zheng ◽

...

Keyword(s):

Powdery Mildew ◽

Agronomic Traits ◽

Genetic Material ◽

Translocation Line ◽

Specific Marker ◽

Fish Analysis ◽

Addition Line ◽

Psathyrostachys Huashanica ◽

Distant Hybridization

Psathyrostachys huashanica Keng, a wild relative of common wheat with many desirable traits, is an invaluable source of genetic material for wheat improvement. Few wheat–P. huashanica translocation lines resistant to powdery mildew have been reported. In this study, a wheat–P. huashanica line, E24-3-1-6-2-1, was generated via distant hybridization, ethyl methanesulfonate (EMS) mutagenesis, and backcross breeding. A chromosome karyotype of 2n = 44 was observed at the mitotic stage in E24-3-1-6-2-1. Genomic in situ hybridization (GISH) analysis revealed four translocated chromosomes in E24-3-1-6-2-1, and P. huashanica chromosome-specific marker analysis showed that the alien chromosome fragment was from the P. huashanica 4Ns chromosome. Moreover, fluorescence in situ hybridization (FISH) analysis demonstrated that reciprocal translocation had occurred between the P. huashanica 4Ns chromosome and the wheat 3D chromosome; thus, E24-3-1-6-2-1 carried two translocations: T3DS·3DL-4NsL and T3DL-4NsS. Translocation also occurred between wheat chromosomes 2A and 4A. At the adult stage, E24-3-1-6-2-1 was highly resistant to powdery mildew, caused by prevalent pathotypes in China. Further, the spike length, numbers of fertile spikelets, kernels per spike, thousand-kernel weight, and grain yield of E24-3-1-6-2-1 were significantly higher than those of its wheat parent 7182 and addition line 24-6-3-1. Thus, this translocation line that is highly resistant to powdery mildew and has excellent agronomic traits can be used as a novel promising germplasm for breeding resistant and high-yielding cultivars.

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Cytogenetic identification and molecular marker development for the novel stripe rust-resistant wheat–Thinopyrum intermedium translocation line WTT11

aBIOTECH ◽

10.1007/s42994-021-00060-3 ◽

2021 ◽

Author(s):

Guotang Yang ◽

Qi Zheng ◽

Pan Hu ◽

Hongwei Li ◽

Qiaoling Luo ◽

...

Keyword(s):

Common Wheat ◽

Stripe Rust ◽

Agronomic Traits ◽

Puccinia Striiformis ◽

Snp Array ◽

Stripe Rust Resistance ◽

Translocation Line ◽

Resistance Locus ◽

Thinopyrum Intermedium ◽

Wheat Group

AbstractStripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive diseases of wheat (Triticum aestivum L.) worldwide. Xiaoyan 78829, a partial amphidiploid developed by crossing common wheat with Thinopyrum intermedium, is immune to wheat stripe rust. To transfer the resistance gene of this excellent germplasm resource to wheat, the translocation line WTT11 was produced by pollen irradiation and assessed for immunity to stripe rust races CYR32, CYR33 and CYR34. A novel stripe rust-resistance locus derived from Th. intermedium was confirmed by linkage and diagnostic marker analyses. Molecular cytogenetic analyses revealed that WTT11 carries a TTh·2DL translocation. The breakpoint of 1B was located at 95.5 MB, and the alien segments were found to be homoeologous to wheat-group chromosomes 6 and 7 according to a wheat660K single-nucleotide polymorphism (SNP) array analysis. Ten previously developed PCR-based markers were confirmed to rapidly trace the alien segments of WTT11, and 20 kompetitive allele-specific PCR (KASP) markers were developed to enable genotyping of Th. intermedium and common wheat. Evaluation of agronomic traits in two consecutive crop seasons uncovered some favorable agronomic traits in WTT11, such as lower plant height and longer main panicles, that may be applicable to wheat improvement. As a novel genetic resource, the new resistance locus may be useful for wheat disease-resistance breeding.

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Inheritance of Some Morphological Characteristics of Parental Lines in Mustard-Rape Hybrid

Scientific and Technical Bulletin of the Institute of Oilseed Crops NAAS ◽

10.36710/ioc-2020-29-03 ◽

2020 ◽

pp. 23-30

Keyword(s):

First Generation ◽

Agronomic Traits ◽

Morphological Characteristics ◽

Morphological Characters ◽

Hybrid Plant ◽

Distant Hybridization ◽

Degree Of Dominance ◽

Whole Plant ◽

Row Width ◽

The Difference

Distant hybridization is known to play an important role in expanding the gene pool of any crop. It is believed that the combination of different genomes in one nucleus, as a rule, is accompanied by the phenomenon of “genomic shock”, resulting in a variety of genetic and epigenetic changes. This provides a wealth of material for the selection of genotypes adapted to different environmental conditions. Interspecific hybrids in different combinations were obtained in the genus Brassica, however, until now, interest in distant hybridization in this genus has not died out, since such important crops as rapeseed and mustard demand an improvement of many important agronomic traits. The aim of this work was to study the degree of manifestation of morphological characters of a leaf, flower, and plant as a whole in the hybrid obtained by crossing of brown mustard of the variety Slavyanka and a collection specimen of spring rape. Seeds were sown in the spring of 2019 in a field with 30 cm row width. During the flowering period a number of morphological characters of a flower, leaf, and the whole plant were analyzed. Each parameter was evaluated with 10 plants. The degree of dominance in first-generation hybrid was calculated by the formula of Beil, Atkins (1965). The dominance coefficients were not determined in the case when the difference between the parental samples was insignificant. Differences between parental samples were determined by Student t-test. The level of heterosis was calculated according to the formula of Rasul et al (2002). In a mustard-rapeseed hybrid, the size of the leaves of the lower row was inherited by the type of rapeseed, which had larger leaves than mustard. The height of the hybrid plant was inherited by the type of mustard (hp = 1.32, Ht = 4.89%), and intermediate inheritance was observed for the length of the internodes (hp = -0.48). The size of the flower petals and sepals was inherited by the type of rapeseed, and significant heterosis was observed for the length of the pistil (Ht = 33.57%). The data obtained are of interest for understanding the interaction of genes of different genomes in the genus Brassica.

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A Microsatellite Map of Wheat

Genetics ◽

10.1093/genetics/149.4.2007 ◽

1998 ◽

Vol 149 (4) ◽

pp. 2007-2023 ◽

Cited By ~ 8

Author(s):

Marion S Röder ◽

Victor Korzun ◽

Katja Wendehake ◽

Jens Plaschke ◽

Marie-Hélène Tixier ◽

...

Keyword(s):

Bread Wheat ◽

Reference Population ◽

Triticum Aestivum L ◽

Wheat Genome ◽

D Genome ◽

B Genome ◽

Microsatellite Map ◽

A Genome ◽

Polymorphic Microsatellite ◽

Primer Sets

Abstract Hexaploid bread wheat (Triticum aestivum L. em. Thell) is one of the world's most important crop plants and displays a very low level of intraspecific polymorphism. We report the development of highly polymorphic microsatellite markers using procedures optimized for the large wheat genome. The isolation of microsatellite-containing clones from hypomethylated regions of the wheat genome increased the proportion of useful markers almost twofold. The majority (80%) of primer sets developed are genome-specific and detect only a single locus in one of the three genomes of bread wheat (A, B, or D). Only 20% of the markers detect more than one locus. A total of 279 loci amplified by 230 primer sets were placed onto a genetic framework map composed of RFLPs previously mapped in the reference population of the International Triticeae Mapping Initiative (ITMI) Opata 85 × W7984. Sixty-five microsatellites were mapped at a LOD >2.5, and 214 microsatellites were assigned to the most likely intervals. Ninety-three loci were mapped to the A genome, 115 to the B genome, and 71 to the D genome. The markers are randomly distributed along the linkage map, with clustering in several centromeric regions.

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Map-Based Cloning of Leaf Rust Resistance Gene Lr21 From the Large and Polyploid Genome of Bread Wheat

Genetics ◽

10.1093/genetics/164.2.655 ◽

2003 ◽

Vol 164 (2) ◽

pp. 655-664 ◽

Cited By ~ 3

Author(s):

Li Huang ◽

Steven A Brooks ◽

Wanlong Li ◽

John P Fellers ◽

Harold N Trick ◽

...

Keyword(s):

Amino Acid ◽

Leaf Rust ◽

Resistance Gene ◽

Bread Wheat ◽

Rust Resistance ◽

Agronomic Traits ◽

Leaf Rust Resistance ◽

Triticum Aestivum L ◽

Rust Resistance Gene ◽

Leaf Rust Resistance Gene

Abstract We report the map-based cloning of the leaf rust resistance gene Lr21, previously mapped to a generich region at the distal end of chromosome arm 1DS of bread wheat (Triticum aestivum L.). Molecular cloning of Lr21 was facilitated by diploid/polyploid shuttle mapping strategy. Cloning of Lr21 was confirmed by genetic transformation and by a stably inherited resistance phenotype in transgenic plants. Lr21 spans 4318 bp and encodes a 1080-amino-acid protein containing a conserved nucleotide-binding site (NBS) domain, 13 imperfect leucine-rich repeats (LRRs), and a unique 151-amino-acid sequence missing from known NBS-LRR proteins at the N terminus. Fine-structure genetic analysis at the Lr21 locus detected a noncrossover (recombination without exchange of flanking markers) within a 1415-bp region resulting from either a gene conversion tract of at least 191 bp or a double crossover. The successful map-based cloning approach as demonstrated here now opens the door for cloning of many crop-specific agronomic traits located in the gene-rich regions of bread wheat.

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F-Box Genes in the Wheat Genome and Expression Profiling in Wheat at Different Developmental Stages

Genes ◽

10.3390/genes11101154 ◽

2020 ◽

Vol 11 (10) ◽

pp. 1154

Author(s):

Min Jeong Hong ◽

Jin-Baek Kim ◽

Yong Weon Seo ◽

Dae Yeon Kim

Keyword(s):

Developmental Stages ◽

Brachypodium Distachyon ◽

Triticum Aestivum L ◽

Wheat Genome ◽

Post Translational Modification ◽

Genome Wide ◽

A Genome ◽

High Sequence Homology ◽

Wide Scale

Genes of the F-box family play specific roles in protein degradation by post-translational modification in several biological processes, including flowering, the regulation of circadian rhythms, photomorphogenesis, seed development, leaf senescence, and hormone signaling. F-box genes have not been previously investigated on a genome-wide scale; however, the establishment of the wheat (Triticum aestivum L.) reference genome sequence enabled a genome-based examination of the F-box genes to be conducted in the present study. In total, 1796 F-box genes were detected in the wheat genome and classified into various subgroups based on their functional C-terminal domain. The F-box genes were distributed among 21 chromosomes and most showed high sequence homology with F-box genes located on the homoeologous chromosomes because of allohexaploidy in the wheat genome. Additionally, a synteny analysis of wheat F-box genes was conducted in rice and Brachypodium distachyon. Transcriptome analysis during various wheat developmental stages and expression analysis by quantitative real-time PCR revealed that some F-box genes were specifically expressed in the vegetative and/or seed developmental stages. A genome-based examination and classification of F-box genes provide an opportunity to elucidate the biological functions of F-box genes in wheat.

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