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1.
Front Plant Sci ; 13: 837410, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35498638

RESUMO

Even frequently used in wheat breeding, we still have an insufficient understanding of the biology of the products via distant hybridization. In this study, a transcriptomic analysis was performed for six Triticum aestivum-Thinopyrum elongatum substitution lines in comparison with the host plants. All the six disomic substitution lines showed much stronger "transcriptomic-shock" occurred on alien genomes with 57.43-69.22% genes changed expression level but less on the recipient genome (2.19-8.97%). Genome-wide suppression of alien genes along chromosomes was observed with a high proportion of downregulated genes (39.69-48.21%). Oppositely, the wheat recipient showed genome-wide compensation with more upregulated genes, occurring on all chromosomes but not limited to the homeologous groups. Moreover, strong co-upregulation of the orthologs between wheat and Thinopyrum sub-genomes was enriched in photosynthesis with predicted chloroplastic localization, which indicates that the compensation happened not only on wheat host genomes but also on alien genomes.

2.
Plant Dis ; 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35196099

RESUMO

Thinopyrum intermedium (JJJsJsStSt, 2n = 6x = 42), a wild relative of common wheat, possesses many desirable agronomic genes for wheat improvement. The production of wheat-Th. intermedium introgression lines is a key step for transferring these beneficial genes into wheat. In this study, we characterized three wheat-Th. intermedium introgression lines TA3681, TA5566, and TA5567 using non-denaturing fluorescence in situ hybridization (ND-FISH), genomic in situ hybridization (GISH), polymerase chain reaction (PCR)-based landmark unique gene (PLUG) and intron targeting (IT) markers. Our results showed that TA3681 is a wheat-Th. intermedium 1St disomic addition line, TA5566 is a wheat-Th. intermedium non-Robertsonian translocation line carrying two pairs of 3A-7Js translocation chromosomes, and TA5567 is a wheat-Th. intermedium non-Robertsonian translocation line carrying a pair of 3A-7Js translocation chromosomes. We developed 13, 36, and 15 Th. intermedium chromosome-specific markers for detecting the introgressed Thinopyrum chromosomes in TA3681, TA5566, and TA5567, respectively. Stem rust assessment revealed that TA3681 exhibited high level of seedling resistance to Chinese prevalent Puccinia graminis f. sp. tritici (Pgt) pathotypes, and both TA5566 and TA5567 were highly resistant to Australian Pgt pathotypes, indicating that Th. intermedium chromosomes 1St and 7Js might carry new stem rust resistance genes. Therefore, the new identified introgression lines may be useful for improving wheat stem rust resistance.

3.
Curr Protoc ; 2(2): e364, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35157369

RESUMO

We developed seven oligonucleotide (oligo) pools based on single-copy sequences, targeting chromosomes 1 to 7 of barley (Hordeum vulgare L.) and wheat (Triticum aestivum) for chromosomal Oligo-FISH painting methods. The probes were applied to high-throughput karyotyping for the Triticeae tribe of over 350 species including 30 genera such as Triticum, Hordeum, Secale, Aegilops, Thinopyrum, and Dasypyrum, as well as several wheat alien-derived lines. In combination with other nondenaturing FISH (ND-FISH) procedures using tandem-repeat oligos, the newly developed Oligo-FISH painting technique provides an efficient tool for the identification of individual chromosomes with homologous linkage groups to establish standard karyotypes, particularly with any wild Triticeae species having nonsequenced genomes for chromosome evolutionary analysis. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Oligo-pool probe development Basic Protocol 2: Nondenaturing FISH Basic Protocol 3: Oligo-FISH painting.


Assuntos
Aegilops , Cromossomos de Plantas , Cromossomos de Plantas/genética , Pintura , Secale/genética , Triticum/genética
4.
Funct Integr Genomics ; 22(2): 141-152, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34981261

RESUMO

Semi-dwarf and dwarf genes were widely used in wheat breeding for improving lodging resistant and increasing yield. Rht14 dwarf gene was identified and deployed in durum wheat, where it showed advantage on important agronomic potential. The reciprocal F2 populations derived of Castelporziano (CP) and Langdon (L) were used for mapping of Rht14, which was located in intervals 4.8 cM and 10.38 cM by KASP (Kompetitive Allele Specific PCR) markers, respectively, where corresponding to 312-454 Mbp on chromosome 6A, and finally, it was mapped to the genomic region of 402 ~ 408 Mbp in Durum Wheat Svevo RefSeq Rel. 1.0 (i.e., 405 ~ 411 Mbp in Chinese Spring RefSeq v.1.0) using recombinants by indel markers. The expression of TdGA2oxA9 was higher in dwarf line than tall lines and the bioactive GA1 was lower. No sequence difference was observed in the promoter and coding region of GA2oxA9 between the dwarf and tall parent, while obvious DNA methylation difference was found in its promoter. Two methylation-related genes with high confidence located in the candidate region and expressed differently between the tall and dwarf ones. This study proposed that Rht14 might regulate the expression of GA2oxA9 by DNA methylation in its promoter, which provided a way to clone Rht14 and to further investigate the mechanism behind.


Assuntos
Melhoramento Vegetal , Triticum , Genes de Plantas , Estudos de Associação Genética , Triticum/genética , Triticum/metabolismo
5.
Hortic Res ; 8(1): 205, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34480029

RESUMO

Zanthoxylum bungeanum is an important spice and medicinal plant that is unique for its accumulation of abundant secondary metabolites, which create a characteristic aroma and tingling sensation in the mouth. Owing to the high proportion of repetitive sequences, high heterozygosity, and increased chromosome number of Z. bungeanum, the assembly of its chromosomal pseudomolecules is extremely challenging. Here, we present a genome sequence for Z. bungeanum, with a dramatically expanded size of 4.23 Gb, assembled into 68 chromosomes. This genome is approximately tenfold larger than that of its close relative Citrus sinensis. After the divergence of Zanthoxylum and Citrus, the lineage-specific whole-genome duplication event η-WGD approximately 26.8 million years ago (MYA) and the recent transposable element (TE) burst ~6.41 MYA account for the substantial genome expansion in Z. bungeanum. The independent Zanthoxylum-specific WGD event was followed by numerous fusion/fission events that shaped the genomic architecture. Integrative genomic and transcriptomic analyses suggested that prominent species-specific gene family expansions and changes in gene expression have shaped the biosynthesis of sanshools, terpenoids, and anthocyanins, which contribute to the special flavor and appearance of Z. bungeanum. In summary, the reference genome provides a valuable model for studying the impact of WGDs with recent TE activity on gene gain and loss and genome reconstruction and provides resources to accelerate Zanthoxylum improvement.

6.
Front Plant Sci ; 12: 708551, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34381484

RESUMO

Aegilops sharonensis, a wild relative of wheat, harbors diverse disease and insect resistance genes, making it a potentially excellent gene source for wheat improvement. In this study, we characterized and evaluated six wheat-A. sharonensis derivatives, which included three disomic additions, one disomic substitution + monotelosomic addition and two disomic substitution + disomic additions. A total of 51 PLUG markers were developed and used to allocate the A. sharonensis chromosomes in each of the six derivatives to Triticeae homoeologous groups. A set of cytogenetic markers specific for A. sharonensis chromosomes was established based on FISH using oligonucleotides as probes. Molecular cytogenetic marker analysis confirmed that these lines were a CS-A. sharonensis 2Ssh disomic addition, a 4Ssh disomic addition, a 4Ssh (4D) substitution + 5SshL monotelosomic addition, a 6Ssh disomic addition, a 4Ssh (4D) substitution + 6Ssh disomic addition and a 4Ssh (4D) substitution + 7Ssh disomic addition line, respectively. Disease resistance investigations showed that chromosome 7Ssh of A. sharonensis might harbor a new powdery mildew resistance gene, and therefore it has potential for use as resistance source for wheat breeding.

7.
Front Plant Sci ; 12: 685216, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249056

RESUMO

Thinopyrum intermedium (2n = 6x = 42, JJJSJSStSt) is one of the important resources for the wheat improvement. So far, a few Th. intermedium (Thi)-specific molecular markers have been reported, but the number is far from enough to meet the need of identifying alien fragments in wheat-Th. intermedium hybrids. In this study, 5,877,409 contigs were assembled using the Th. intermedium genotyping-by-sequencing (GBS) data. We obtained 5,452 non-redundant contigs containing mapped Thi-GBS markers with less than 20% similarity to the wheat genome and developed 2,019 sequence-tagged site (STS) molecular markers. Among the markers designed, 745 Thi-specific markers with amplification products in Th. intermedium but not in eight wheat landraces were further selected. The distribution of these markers in different homologous groups of Th. intermedium varied from 47 (7/12/28 on 6J/6St/6JS) to 183 (54/62/67 on 7J/7St/7JS). Furthermore, the effectiveness of these Thi-specific markers was verified using wheat-Th. intermedium partial amphidiploids, addition lines, substitution lines, and translocation lines. Markers developed in this study provide a convenient, rapid, reliable, and economical method for identifying Th. intermedium chromosomes in wheat. In addition, this set of Thi-specific markers can also be used to estimate genetic and physical locations of Th. intermedium chromatin in the introgression lines, thus providing valuable information for follow-up studies such as alien gene mining.

8.
BMC Plant Biol ; 21(1): 213, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980176

RESUMO

BACKGROUND: The identification of chromosomes among Avena species have been studied by C-banding and in situ hybridization. However, the complicated results from several cytogenetic nomenclatures for identifying oat chromosomes are often contradictory. A universal karyotyping nomenclature system for precise chromosome identification and comparative evolutionary studies would be essential for genus Avena based on the recently released genome sequences of hexaploid and diploid Avena species. RESULTS: Tandem repetitive sequences were predicted and physically located on chromosomal regions of the released Avena sativa OT3098 genome assembly v1. Eight new oligonucleotide (oligo) probes for sequential fluorescence in situ hybridization (FISH) were designed and then applied for chromosome karyotyping on mitotic metaphase spreads of A. brevis, A. nuda, A. wiestii, A. ventricosa, A. fatua, and A. sativa species. We established a high-resolution standard karyotype of A. sativa based on the distinct FISH signals of multiple oligo probes. FISH painting with bulked oligos, based on wheat-barley collinear regions, was used to validate the linkage group assignment for individual A. sativa chromosomes. We integrated our new Oligo-FISH based karyotype system with earlier karyotype nomenclatures through sequential C-banding and FISH methods, then subsequently determined the precise breakage points of some chromosome translocations in A. sativa. CONCLUSIONS: This new universal chromosome identification system will be a powerful tool for describing the genetic diversity, chromosomal rearrangements and evolutionary relationships among Avena species by comparative cytogenetic and genomic approaches.


Assuntos
Avena/classificação , Avena/genética , DNA de Plantas , Diploide , Genoma de Planta , Cariotipagem/classificação , Terminologia como Assunto , Produtos Agrícolas/classificação , Produtos Agrícolas/genética , Análise Citogenética
9.
Front Plant Sci ; 12: 644896, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33897735

RESUMO

Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) and Leymus mollis Trin. (2n = 4x = 28, NsNsXmXm) are valuable resources for wheat breeding improvement as they share the Ns genome, which contains diverse resistance genes. To explore the behaviors and traits of Ns chromosomes from the two species in wheat background, a series of wheat-P. huashanica and wheat-L. mollis substitution lines were developed. In the present study, line DH109 (F7 progeny of wheat-P. huashanica heptaploid line H8911 × durum wheat Trs-372) and line DM131 (F8 progeny of wheat-L. mollis octoploid line M842 × durum wheat Trs-372) were selected. Cytological observation combined with genomic in situ hybridization experiments showed that DH109 and DM131 each had 20 pairs of wheat chromosomes plus a pair of alien chromosomes (Ns chromosome), and the pair of alien chromosomes showed stable inheritance. Multiple molecular markers and wheat 55K SNP array demonstrated that a pair of wheat 3D chromosome in DH109 and in DM131 was substituted by a pair of P. huashanica 3Ns chromosome and a pair of L. mollis 3Ns chromosome, respectively. Fluorescence in situ hybridization (FISH) analysis confirmed that wheat 3D chromosomes were absent from DH109 and DM131, and chromosomal FISH karyotypes of wheat 3D, P. huashanica 3Ns, and L. mollis 3Ns were different. Moreover, the two lines had many differences in agronomic traits. Comparing with their wheat parents, DH109 expressed superior resistance to powdery mildew and fusarium head blight, whereas DM131 had powdery mildew resistance, longer spike, and more tiller number. Therefore, Ns genome from P. huashanica and L. mollis might have some different effects. The two novel wheat-alien substitution lines provide new ideas and resources for disease resistance and high-yield breeding on further utilization of 3Ns chromosomes of P. huashanica or L. mollis.

10.
Planta ; 253(1): 22, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33399998

RESUMO

MAIN CONCLUSION: A physical map of Thinopyrum intermedium chromosome 7J was constructed using translocation mapping, and a new seedling purple coleoptile gene was mapped to the bin of FL 0.35-0.63 of 7JS. Thinopyrum intermedium (2n = 6x = 42, JJJsJsStSt), a wild relative of common wheat, harbors numerous beneficial genes for wheat improvement. Previous studies showed that wheat-Th. intermedium partial amphiploid TAF46 and its derived addition line L1 had a purple coleoptile, which was derived from Th. intermedium chromosome 7J. To identify and physically map the purple coleoptile gene, 12 wheat-Th. intermedium 7J translocation lines were analyzed by sequential multicolor fluorescence in situ hybridization (mc-FISH), PCR-based landmark unique gene (PLUG) and intron targeting (IT) markers. A physical map of the 7J chromosome was constructed, consisting of eight chromosomal bins with 89 markers. Seedling evaluation of the coleoptile colors of all tested materials indicated that the purple coleoptile gene was located to the bin with a fraction length (FL) of 0.35-0.63 on chromosome 7JS. Furthermore, based on the syntenic relationships between Th. intermedium and wheat chromosomes, we developed a new chromosome 7J-specific EST-PCR marker from the chromosomal region corresponding to the purple coleoptile gene through the Triticeae multi-omics database. The approach of designing chromosome-specific markers has facilitated fine mapping of the Thinopyrum-specific purple coleoptile gene, and these translocation lines will be valuable for studying the function of the purple coleoptile gene in anthocyanin biosynthesis.


Assuntos
Cromossomos de Plantas , Genes de Plantas , Poaceae , Triticum , Antocianinas/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Cotilédone/genética , Genes de Plantas/genética , Hibridização in Situ Fluorescente , Poaceae/genética , Triticum/genética
11.
Genome ; 64(8): 789-800, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33513072

RESUMO

The perennial species Dasypyrum breviaristatum (genome Vb) contains many potentially valuable genes for the improvement of common wheat. Construction of a detailed karyotype of D. breviaristatum chromosomes will be useful for the detection of Dasypyrum chromatin in wheat background. We established the standard karyotype of 1Vb-7Vb chromosomes through nondenaturing fluorescence in situ hybridization (ND-FISH) technique using 28 oligonucleotide probes from the wheat - D. breviaristatum partial amphiploid TDH-2 (AABBVbVb) and newly identified wheat - D. breviaristatum disomic translocation and addition lines D2138 (6VbS.2VbL), D2547 (4Vb), and D2532 (3VbS.6VbL) by comparative molecular marker analysis. The ND-FISH with multiple oligo probes was conducted on the durum wheat - D. villosum amphiploid TDV-1 and large karyotype differences between D. breviaristatum and D. villosum was revealed. These ND-FISH probes will be valuable for screening the wheat - Dasypyrum derivative lines for chromosome identification, and the newly developed wheat - D. breviaristatum addition lines may broaden the gene pool of wheat breeding. The differences between D. villosum and D. breviaristatum chromosomes revealed by ND-FISH will help us understand evolutionary divergence of repetitive sequences within the genus Dasypyrum.


Assuntos
Cariotipagem , Melhoramento Vegetal , Poaceae , Cromossomos de Plantas/genética , Genômica , Hibridização in Situ Fluorescente , Sondas de Oligonucleotídeos , Poaceae/genética , Triticum/genética
12.
Plant Dis ; 105(4): 997-1005, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33200970

RESUMO

Wheat sharp eyespot, a disease mainly caused by soilborne fungus Rhizoctonia cerealis, is a threat to world wheat production. Wheat's genetic resistance to sharp eyespot is a potential approach to reducing the application of fungicides and farming practice inputs. To identify the genetic basis of sharp eyespot resistance in Niavt14, a recombinant inbred line population comprising 215 F8 lines from Niavt14 × Xuzhou25, was developed. An earlier linkage map (148 simple sequence repeat markers) was updated with 5,792 polymorphic Affymetrix Axiom 55K single-nucleotide polymorphisms to a new map of 5,684.2 centimorgans with 1,406 nonredundant markers. The new linkage map covered all 21 chromosomes of common wheat and showed a good collinearity with the IWGSC RefSeq v1.0 genome. We conducted quantitative trait locus (QTL) mapping for sharp eyespot resistance using the adult plant response data from the field of five consecutive growing seasons and one greenhouse test. Two stable QTL on chromosomes 2B and 7D that were identified in the previous study were confirmed, and three novel, stable QTL, explaining 4.0 to 17.5% phenotypic variation, were mapped on 1D, 6D, and 7A, which were independent of QTL for phenology and plant height. The QTL on 1D, 2B, 6D, and 7A showed low frequencies in 384 landraces (0 to 10%) and 269 elite cultivars (5 to 23%) from the southern winter wheat region and the Yellow and Huai River Valley facultative wheat region in China, respectively. These identified QTL could be used in wheat breeding programs for improving sharp eyespot resistance through marker-assisted selection.


Assuntos
Resistência à Doença , Triticum , Basidiomycota , China , Resistência à Doença/genética , Dissecação , Humanos , Melhoramento Vegetal , Doenças das Plantas/genética , Estações do Ano , Triticum/genética
13.
Plant J ; 105(4): 978-993, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33210785

RESUMO

A chromosome-specific painting technique has been developed which combines the most recent approaches of the companion disciplines of molecular cytogenetics and genome research. We developed seven oligonucleotide (oligo) pools derivd from single-copy sequences on chromosomes 1 to 7 of barley (Hordeum vulgare L.) and corresponding collinear regions of wheat (Triticum aestivum L.). The seven groups of pooled oligos comprised between 10 986 and 12 496 45-bp monomers, and these then produced stable fluorescence in situ hybridization (FISH) signals on chromosomes of each linkage group of wheat and barley. The pooled oligo probes were applied to high-throughput karyotyping of the chromosomes of other Triticeae species in the genera Secale, Aegilops, Thinopyrum, and Dasypyrum, and the study also extended to some wheat-alien amphiploids and derived lines. We demonstrated that a complete set of whole-chromosome oligo painting probes facilitated the study of inter-species chromosome homologous relationships and visualized non-homologous chromosomal rearrangements in Triticeae species and some wheat-alien species derivatives. When combined with other non-denaturing FISH procedures using tandem-repeat oligos, the newly developed oligo painting techniques provide an efficient tool for the study of chromosome structure, organization, and evolution among any wild Triticeae species with non-sequenced genomes.


Assuntos
Coloração Cromossômica/métodos , Cromossomos de Plantas/genética , Rearranjo Gênico/genética , Hordeum/genética , Hibridização in Situ Fluorescente/métodos , Poaceae/genética , Triticum/genética , Aegilops/genética , Biblioteca Gênica , Ligação Genética/genética , Oligonucleotídeos/genética , Secale/genética , Translocação Genética/genética
14.
Plant J ; 103(6): 2225-2235, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32578280

RESUMO

Reliable identification of individual chromosomes in eukaryotic species is the foundation for comparative chromosome synteny and evolutionary studies. Unfortunately, chromosome identification has been a major challenge for plants with small chromosomes, such as the Citrus species. We developed oligonucleotide-based chromosome painting probes for all nine chromosomes in Citrus maxima (Pummelo). We were able to identify all C. maxima chromosomes in the same metaphase cells using multiple rounds of sequential fluorescence in situ hybridization with the painting probes. We conducted comparative chromosome painting analysis in six different Citrus and related species. We found that each painting probe hybridized to only a single chromosome in all other five species, suggesting that the six species have maintained a complete chromosomal synteny after more than 9 million years of divergence. No interchromosomal rearrangement was identified in any species. These results support the hypothesis that karyotypes of woody species are more stable than herbaceous plants because woody plants need a longer period to fix chromosome structural variants in natural populations.


Assuntos
Cromossomos de Plantas/genética , Citrus/genética , Sintenia/genética , Coloração Cromossômica , Sequência Conservada/genética , Filogenia , Polimorfismo Genético/genética
15.
BMC Plant Biol ; 20(1): 134, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32234016

RESUMO

BACKGROUND: Introgression of chromatin from Secale species into common wheat has for decades been a successful strategy for controlling the wheat diseases. The wild Secale species, Secale africanum Stapf., is a valuable source for resistance to foliar disease of wheat. A wheat-S. africanum chromosome 6Rafr substitution line displayed resistance to both powdery mildew and stripe rust at the adult-plant stage. RESULTS: Wheat-S. africanum chromosome 6Rafr deletion and translocation lines were produced and identified by sequential non-denaturing fluorescence in situ hybridization (ND-FISH) using multiple Oligo-based probes. Different ND-FISH patterns were observed between S. cereale 6R and S. africanum 6Rafr. With reference to the physical map of the draft genome sequence of rye inbred line Lo7, a comprehensive PCR marker analysis indicated that insertions and deletions had occurred by random exchange between chromosomes 6R and 6Rafr. A survey of the wheat- S. africanum 6Rafr lines for disease resistance indicated that a powdery mildew resistance gene(s) was present on the long arm of 6Rafr at FL0.85-1.00, and that a stripe rust resistance gene(s) was located in the terminal region of 6RafrS at FL0.95-1.00. The wheat-S. africanum 6Rafr introgression lines also displayed superior agronomic traits, indicating that the chromosome 6Rafr may have little linkage drag in the wheat background. CONCLUSIONS: The combination of molecular and cytogenetic methods allowed to precisely identify the chromosome rearrangements in wheat- S. africanum 6Rafr substitution, deletion and translocation lines, and compare the structural difference between chromosomes 6R and 6Rafr. The wheat- S. africanum 6Rafr lines containing gene(s) for powdery mildew and stripe rust resistance could be used as novel germplasm for wheat breeding by chromosome engineering.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/microbiologia , Secale/genética , Ascomicetos , Basidiomycota , Quimera/genética , Cromatina , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Análise Citogenética , Hibridização Genética , Hibridização in Situ Fluorescente , Doenças das Plantas/genética , Secale/microbiologia , Translocação Genética , Triticum/genética , Triticum/microbiologia
16.
BMC Plant Biol ; 20(1): 163, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32293283

RESUMO

BACKGROUND: Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) carries many outstanding agronomic traits, therefore is a valuable resource for wheat genetic improvement. Wheat-P. huashanica translocation lines are important intermediate materials for wheat breeding and studying the functions of alien chromosomes. However, powdery mildew resistance in these translocation lines has not been reported previously. RESULTS: This study developed a novel wheat-P. huashanica translocation line TR77 by selecting a F7 progeny from the cross between heptaploid hybrid H8911 (2n = 7x = 49, AABBDDNs) and durum wheat line Trs-372. Chromosome karyotype of 2n = 42 = 21II was observed in both mitotic and meiotic stages of TR77. Genomic in situ hybridization analysis identified two translocated chromosomes that paired normally at meiosis stage in TR77. Molecular marker analysis showed that part of chromosome 5D was replaced by part of alien chromosome fragment 5Ns. It meant replacement made part 5DL and part 5NsL·5NsS existed in wheat background, and then translocation happened between these chromosomes and wheat 3D chromosome. Fluorescence in situ hybridization demonstrated that TR77 carries dual translocations: T3DS-5NsL·5NsS and T5DL-3DS·3DL. Analysis using a 15 K-wheat-SNP chip confirmed that SNP genotypes on the 5D chromosome of TR77 matched well with these of P. huashanica, but poorly with common wheat line 7182. The translocation was physically located between 202.3 and 213.1 Mb in 5D. TR77 showed longer spikes, more kernels per spike, and much better powdery mildew resistance than its wheat parents: common wheat line 7182 and durum wheat line Trs-372. CONCLUSIONS: TR77 is a novel stable wheat-P. huashanica T3DS-5NsL·5NsS and T5DL-3DS·3DL dual translocation line and showed significant improved spike traits and resistance to powdery mildew compared to its parents, thus, it can be an useful germplasm for breeding disease resistance and studying the genetic mechanism of dual translocations.


Assuntos
Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Triticum/genética , Triticum/microbiologia , Cruzamento , Resistência à Doença/genética , Etiquetas de Sequências Expressas , Hibridização Genética , Hibridização in Situ Fluorescente , Cariótipo , Repetições de Microssatélites , Fenótipo , Poaceae/genética , Poaceae/microbiologia , Translocação Genética
17.
Proc Natl Acad Sci U S A ; 117(11): 5955-5963, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123089

RESUMO

In plants, the mechanism for ecological sympatric speciation (SS) is little known. Here, after ruling out the possibility of secondary contact, we show that wild emmer wheat, at the microclimatically divergent microsite of "Evolution Canyon" (EC), Mt. Carmel, Israel, underwent triple SS. Initially, it split following a bottleneck of an ancestral population, and further diversified to three isolated populations driven by disruptive ecological selection. Remarkably, two postzygotically isolated populations (SFS1 and SFS2) sympatrically branched within an area less than 30 m at the tropical hot and dry savannoid south-facing slope (SFS). A series of homozygous chromosomal rearrangements in the SFS1 population caused hybrid sterility with the SFS2 population. We demonstrate that these two populations developed divergent adaptive mechanisms against severe abiotic stresses on the tropical SFS. The SFS2 population evolved very early flowering, while the SFS1 population alternatively evolved a direct tolerance to irradiance by improved ROS scavenging activity that potentially accounts for its evolutionary fate with unstable chromosome status. Moreover, a third prezygotically isolated sympatric population adapted on the abutting temperate, humid, cool, and forested north-facing slope (NFS), separated by 250 m from the SFS wild emmer wheat populations. The NFS population evolved multiple resistant loci to fungal diseases, including powdery mildew and stripe rust. Our study illustrates how plants sympatrically adapt and speciate under disruptive ecological selection of abiotic and biotic stresses.


Assuntos
Resistência à Doença/genética , Simpatria/genética , Triticum/genética , Ascomicetos , Basidiomycota , Cromossomos de Plantas , Fluxo Gênico , Genes de Plantas/genética , Homozigoto , Israel , Cariotipagem , Doenças das Plantas/microbiologia , Estresse Fisiológico
18.
Theor Appl Genet ; 133(4): 1095-1107, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31955232

RESUMO

KEY MESSAGE: A physical map of Secale cereale chromosome 6R was constructed using deletion mapping, and a new stripe rust resistance gene Yr83 was mapped to the deletion bin of FL 0.73-1.00 of 6RL. Rye (Secale cereale L., RR) possesses valuable genes for wheat improvement. In the current study, we report a resistance gene conferring stripe rust resistance effective from seedling to adult plant stages located on chromosome 6R. This chromosome was derived from triticale line T-701 and also carries highly effective resistance to the cereal cyst nematode species Heterodera avenae Woll. A wheat-rye 6R(6D) disomic substitution line exhibited high levels of seedling resistance to Australian pathotypes of the stripe rust (Puccinia striiformis f. sp. tritici; Pst) pathogen and showed an even greater resistance to the Chinese Pst pathotypes in the field. Ten chromosome 6R deletion lines and five wheat-rye 6R translocation lines were developed earlier in the attempt to transfer the nematode resistance gene to wheat and used herein to map the stripe rust resistance gene. These lines were subsequently characterized by sequential multicolor fluorescence in situ hybridization (mc-FISH), genomic in situ hybridization (GISH), mc-GISH, PCR-based landmark unique gene (PLUG), and chromosome 6R-specific length amplified fragment sequencing (SLAF-Seq) marker analyses to physically map the stripe rust resistance gene. The new stripe rust resistance locus was located in a chromosomal bin with fraction length (FL) 0.73-1.00 on 6RL and was named Yr83. A wheat-rye translocation line T6RL (#5) carrying the stripe rust resistance gene will be useful as a new germplasm in breeding for resistance.


Assuntos
Basidiomycota/fisiologia , Cromossomos de Plantas/genética , Resistência à Doença/genética , Genes de Plantas , Doenças das Plantas/microbiologia , Secale/genética , Secale/microbiologia , Triticum/genética , Metáfase/genética , Mapeamento Físico do Cromossomo , Doenças das Plantas/genética , Plantas Geneticamente Modificadas , Plântula/microbiologia , Translocação Genética
19.
Int J Mol Sci ; 20(14)2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31336736

RESUMO

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating fungal diseases of wheat worldwide. It is essential to discover more sources of stripe rust resistance genes for wheat breeding programs. Specific locus amplified fragment sequencing (SLAF-seq) is a powerful tool for the construction of high-density genetic maps. In this study, a set of 200 recombinant inbred lines (RILs) derived from a cross between wheat cultivars Chuanmai 42 (CH42) and Chuanmai 55 (CH55) was used to construct a high-density genetic map and to identify quantitative trait loci (QTLs) for stripe rust resistance using SLAF-seq technology. A genetic map of 2828.51 cM, including 21 linkage groups, contained 6732 single nucleotide polymorphism markers (SNP). Resistance QTLs were identified on chromosomes 1B, 2A, and 7B; Qyr.saas-7B was derived from CH42, whereas Qyr.saas-1B and Qyr.saas-2A were from CH55. The physical location of Qyr.saas-1B, which explained 6.24-34.22% of the phenotypic variation, overlapped with the resistance gene Yr29. Qyr.saas-7B accounted for up to 20.64% of the phenotypic variation. Qyr.saas-2A, a minor QTL, was found to be a likely new stripe rust resistance locus. A significant additive effect was observed when all three QTLs were combined. The combined resistance genes could be of value in breeding wheat for stripe rust resistance.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Locos de Características Quantitativas , Triticum/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Ligação Genética , Hibridização in Situ Fluorescente , Endogamia , Fenótipo , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Translocação Genética , Triticum/microbiologia
20.
Plants (Basel) ; 8(6)2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31207944

RESUMO

To determine the composition of chromosome aberrations in a wheat‒Dasypyrum breviaristatum substitution line with seeds treated by a dose of gamma-rays (200 Gy), sequential non-denaturing fluorescence in situ hybridization (ND-FISH) with multiple oligonucleotide probes was used to screen individual plants of the mutagenized progenies. We identified 122 types of chromosome rearrangements, including centromeric, telomeric, and intercalary chromosome translocations from a total of 772 M1 and 872 M2 plants. The frequency of reciprocal translocations between B- and D-chromosomes was higher than that between A- and D-chromosomes. Eight translocations between D. breviaristatum and wheat chromosomes were also detected. The 13 stable plants with multiple chromosome translocations displayed novel agronomic traits. The newly developed materials will enhance wheat breeding programs through wheat‒Dasypyrum introgression and also facilitate future studies on the genetic and epigenetic effects of translocations in wheat genomics.

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