scholarly journals Dwarfing gene Rht18 from tetraploid wheat responds to exogenous GA3 in hexaploid wheat

2017 ◽  
Vol 45 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Z.Y. Yang ◽  
C.Y. Liu ◽  
Y.Y. Du ◽  
L. Chen ◽  
Y.F. Chen ◽  
...  
Keyword(s):  
Hexaploid Wheat ◽  
Tetraploid Wheat ◽  
Dwarfing Gene

scholarly journals Histone acetyltransferase TaHAG1 acts as a crucial regulator to strengthen salt tolerance of hexaploid wheat

2021 ◽  
Author(s):  
Mei Zheng ◽  
Jingchen Lin ◽  
Xingbei Liu ◽  
Wei Chu ◽  
Jinpeng Li ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Bread Wheat ◽  
Hexaploid Wheat ◽  
Histone Acetyltransferase ◽  
Tetraploid Wheat ◽  
Triticum Aestivum L ◽  
Ros Production ◽  
Signal Specificity ◽  
H3 Acetylation

Abstract Polyploidy occurs prevalently and plays an important role during plant speciation and evolution. This phenomenon suggests polyploidy could develop novel features that enable them to adapt wider range of environmental conditions compared with diploid progenitors. Bread wheat (Triticum aestivum L., BBAADD) is a typical allohexaploid species and generally exhibits greater salt tolerance than its tetraploid wheat progenitor (BBAA). However, little is known about the underlying molecular basis and the regulatory pathway of this trait. Here, we show that the histone acetyltransferase TaHAG1 acts as a crucial regulator to strengthen salt tolerance of hexaploid wheat. Salinity-induced TaHAG1 expression was associated with tolerance variation in polyploidy wheat. Overexpression, silencing and CRISPR-mediated knockout of TaHAG1 validated the role of TaHAG1 in salinity tolerance of wheat. TaHAG1 contributed to salt tolerance by modulating ROS production and signal specificity. Moreover, TaHAG1 directly targeted a subset of genes that are responsible for hydrogen peroxide production, and enrichment of TaHAG1 triggered increased H3 acetylation and transcriptional upregulation of these loci under salt stress. In addition, we found the salinity-induced TaHAG1-mediated ROS production pathway is involved in salt tolerance difference of wheat accessions with varying ploidy. Our findings provide insight into the molecular mechanism of how an epigenetic regulatory factor facilitates adaptability of polyploidy wheat and highlights this epigenetic modulator as a strategy for salt tolerance breeding in bread wheat.

scholarly journals Genetically Divergent Types of the Wheat Leaf Fungus Puccinia triticina in Ethiopia, a Center of Tetraploid Wheat Diversity

2016 ◽  
Vol 106 (4) ◽  
pp. 380-385 ◽  
Author(s):  
J. A. Kolmer ◽  
M. A. Acevedo
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Hexaploid Wheat ◽  
Rust Fungus ◽  
Tetraploid Wheat ◽  
Low Frequency ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Virulence Phenotype ◽  
Wheat Leaf

Collections of Puccinia triticina, the wheat leaf rust fungus, were obtained from tetraploid and hexaploid wheat in the central highlands of Ethiopia, and a smaller number from Kenya, from 2011 to 2013, in order to determine the genetic diversity of this wheat pathogen in a center of host diversity. Single-uredinial isolates were derived and tested for virulence phenotype to 20 lines of Thatcher wheat that differ for single leaf rust resistance genes and for molecular genotypes with 10 simple sequence repeat (SSR) primers. Nine virulence phenotypes were described among the 193 isolates tested for virulence. Phenotype BBBQJ, found only in Ethiopia, was predominantly collected from tetraploid wheat. Phenotype EEEEE, also found only in Ethiopia, was exclusively collected from tetraploid wheat and was avirulent to the susceptible hexaploid wheat ‘Thatcher’. Phenotypes MBDSS and MCDSS, found in both Ethiopia and Kenya, were predominantly collected from common wheat. Phenotypes CCMSS, CCPSS, and CBMSS were found in Ethiopia from common wheat at low frequency. Phenotypes TCBSS and TCBSQ were found on durum wheat and common wheat in Kenya. Four groups of distinct SSR genotypes were described among the 48 isolates genotyped. Isolates with phenotypes BBBQJ and EEEEE were in two distinct SSR groups, and isolates with phenotypes MBDSS and MCDSS were in a third group. Isolates with CCMSS, CCPSS, CBMSS, TCBSS, and TCBSQ phenotypes were in a fourth SSR genotype group. The diverse host environment of Ethiopia has selected and maintained a genetically divergent population of P. triticina.

HYBRIDIZATION OF TRITICUM AND AGROPYRON: I. CROSSING RESULTS AND DESCRIPTION OF THE FIRST GENERATION HYBRIDS

1936 ◽  
Vol 14c (5) ◽  
pp. 190-202 ◽  
Author(s):  
J. M. Armstrong
Keyword(s):  
Hexaploid Wheat ◽  
First Generation ◽  
Tetraploid Wheat ◽  
Morphological Characters ◽  
Hybrid Vigor ◽  
The Other ◽  
Other Hand ◽  
Better Than

Two species of tetraploid (2n = 28) and three varieties of hexaploid (2n = 42) wheat were crossed with A. glaucum (2n = 42), and A. elongatum (2n = 70), with an average crossing success of 18%. The seed obtained from tetraploid wheat × A. glaucum was slightly plumper and germinated better than that obtained from tetraploid wheat × A. elongatum. On the other hand, hexaploid wheat × A. elongatum gave decidedly plumper and better germinating seed than hexaploid × A. glaucum.Grown under greenhouse conditions the F1 hybrids proved to be self-sterile and perennial in habit, with hybrid vigor strongly marked. The hybrids were, in general, intermediate in morphological characters, but with somewhat more resemblance to Agropyron than to wheat. This dominance, whole or partial, was more noticeable in the A. elongatum than in the A. glaucum crosses. Dominance phenomena are discussed in relation to current theories.

scholarly journals The homoeologous genes for the Rec8-like meiotic cohesin in wheat: structure, function, and evolutionary implication

2018 ◽  
Author(s):  
Guojia Ma ◽  
Wei Zhang ◽  
Liwang Liu ◽  
Wun S. Chao ◽  
Yong Qiang Gu ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Hexaploid Wheat ◽  
Expression Patterns ◽  
Aegilops Tauschii ◽  
Tetraploid Wheat ◽  
Nucleotide Polymorphisms ◽  
Origin And Evolution ◽  
Homoeologous Genes ◽  
The One ◽  
Functional Analyses

ABSTRACTThe Rec8-like cohesin is a cohesion protein essential for orderly chromosome segregation in meiosis. Here, we cloned two Rec8-like homoeologous genes (homoeoalleles) from tetraploid wheat (TtRec8-A1 and TtRec8-B1) and one from hexaploid wheat (TaRec8-D1), and performed expression and functional analyses of the homoeoalleles. Also, we identified other two Rec8 homoeoalleles in hexaploid wheat (TaRec8-A1 and TaRec8-B1) and the one in Aegilops tauschii (AetRec8-D1) by comparative analysis. The coding DNA sequences (CDS) of these six Rec8 homoeoalleles are all 1,827 bp in length, encoding 608 amino acids. They differed from each other primarily in introns although single nucleotide polymorphisms were detected in CDS. Substantial difference was observed between the homoeoalleles from the subgenome B (TtRec8-B1 and TaRec8-B1) and those from the subgenomes A and D (TtRec8-A1, TaRec8-A1, and TaRec8-D1). TtRec8-A1 expressed dominantly over TtRec8-B1, but comparably to TaRec8-D1. Therefore, the Rec8 homoeoalleles from the subgenomes A and D may be functionally more active than the one from the subgenome B in wheat. The structural variation and differential expression of the Rec8 homoeoalleles indicate a unique cross-genome coordination of the homoeologous genes in the polyploid, and imply the distinction of the wheat subgenome B from other subgenomes in the origin and evolution.HIGHLIGHTThis work revealed the structural and expression patterns of the Rec8-like homoeologous genes in polyploid wheat, implying a unique origin and evolutionary route of the wheat B subgenome.

scholarly journals The semi-dwarfing gene Rht-dp from dwarf polish wheat (Triticum polonicum L.) is the "Green Revolution” gene Rht-B1b

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Songyue Chai ◽  
Qin Yao ◽  
Xu Zhang ◽  
Xue Xiao ◽  
Xing Fan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Green Revolution ◽  
Tetraploid Wheat ◽  
Reactive Oxygen ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Lodging Resistance ◽  
Dwarfing Gene ◽  
Triticum Polonicum ◽  
Grain Number Per Spike

Abstract Background The wheat dwarfing gene increases lodging resistance, the grain number per spike and harvest index. Dwarf Polish wheat (Triticum polonicum L., 2n = 4x = 28, AABB, DPW), initially collected from Tulufan, Xinjiang, China, carries a semi-dwarfing gene Rht-dp on chromosome 4BS. However, Rht-dp and its dwarfing mechanism are unknown. Results Homologous cloning and mapping revealed that Rht-dp is the ‘Green Revolution’ gene Rht-B1b. A haplotype analysis in 59 tetraploid wheat accessions showed that Rht-B1b was only present in T. polonicum. Transcriptomic analysis of two pairs of near-isogenic lines (NILs) of DPW × Tall Polish wheat (Triticum polonicum L., 2n = 4x = 28, AABB, TPW) revealed 41 differentially expressed genes (DEGs) as potential dwarfism-related genes. Among them, 28 functionally annotated DEGs were classed into five sub-groups: hormone-related signalling transduction genes, transcription factor genes, cell wall structure-related genes, reactive oxygen-related genes, and nitrogen regulation-related genes. Conclusions These results indicated that Rht-dp is Rht-B1b, which regulates pathways related to hormones, reactive oxygen species, and nitrogen assimilation to modify the cell wall structure, and then limits cell wall loosening and inhibits cell elongation, thereby causing dwarfism in DPW.

Frequent numerical and structural chromosome changes in early generations of synthetic hexaploid wheat

Genome ◽  
2021 ◽  
Author(s):  
Siyu Zhang ◽  
Pei Du ◽  
Xueying Lu ◽  
Jiaxin Fang ◽  
Jiaqi Wang ◽  
...  
Keyword(s):  
Hexaploid Wheat ◽  
Aegilops Tauschii ◽  
Tetraploid Wheat ◽  
Snp Markers ◽  
Synthetic Hexaploid Wheat ◽  
Chromosome Variation ◽  
Metaphase Chromosomes ◽  
Wheat Evolution ◽  
Significant Difference ◽  
Synthetic Hexaploid

Modern hexaploid wheat (Triticum aestivum L.; AABBDD) evolved from a hybrid of tetraploid wheat (closely related to Triticum turgidum L. ssp. durum (Desf.) Husn., AABB) and goatgrass (Aegilops tauschii Coss., DD). Variations in chromosome structure and ploidy played important roles in wheat evolution. How these variations occurred and their role in expanding the genetic diversity in modern wheat is mostly unknown. Synthetic hexaploid wheat (SHW) can be used to investigate chromosome variation that occurs during the early generations of existence. SHW lines derived by crossing durum wheat ‘Langdon’ with twelve Ae. tauschii accessions were analyzed using oligonucelotide probe multiplex fluorescence in situ hybridization (FISH) to metaphase chromosomes and SNP markers. Cluster analysis based on SNP markers categorized them into three groups. Among 702 plants from the S8 and S9 generations, 415 (59.12%) carried chromosome variations involving all 21 chromosomes but with different frequencies for each chromosome and sub-genome. Total chromosome variation frequencies varied between lines, but there was no significant difference among the three groups. The non-random chromosome variations in SHW lines detected in this research may be an indication that similar variations occurred in the early stages of wheat polyploidization and played important roles in wheat evolution.

The frequency of fertilization in wheat × pearl millet crosses

Genome ◽  
1989 ◽  
Vol 32 (6) ◽  
pp. 1063-1067 ◽  
Author(s):  
D. A. Laurie
Keyword(s):  
Pearl Millet ◽  
Hexaploid Wheat ◽  
Chinese Spring ◽  
Tetraploid Wheat ◽  
Chromosome Complement ◽  
Chromosome Elimination ◽  
Hybrid Origin ◽  
Hordeum Bulbosum ◽  
Chromosome Counts ◽  
Wheat Genotype

Wheat × pearl millet crosses were studied to determine whether fertilization occurred and whether any resulting hybrids were karyotypically stable. Crosses between the hexaploid wheat genotype 'Chinese Spring' (kr1, kr2) and the pearl millet genotype 'Tift 23BE' gave fertilization in 28.6% of the 220 florets pollinated. Chromosome counts from zygotes at metaphase confirmed the hybrid origin of the embryos. Three had the expected F1 combination of 21 wheat and 7 pearl millet chromosomes and a fourth had 21 wheat and 14 pearl millet chromosomes. The expected F1 chromosome complement was also found in a primary endosperm mitosis. The hybrid embryos were karyotypically unstable and probably lost all the pearl millet chromosomes in the first four cell division cycles. Similar results were obtained using two other wheat genotypes. Crosses between the hexaploid wheat genotype 'Highbury', which differs from 'Chinese Spring' in having alleles for reduced crossability with rye and Hordeum bulbosum at the Kr1 and Kr2 loci, and 'Tift 23BE' gave fertilization in 32% of analyzed florets. This was not significantly different from the frequency found in 'Chinese Spring', indicating that 'Tift 23BE' was insensitive to the action of the Kr genes. Crosses between the tetraploid wheat genotype 'Kubanka' and 'Tift 23BE' gave fertilization in 48% of florets. The potential of pearl millet for wheat haploid production is discussed.Key words: wheat, pearl millet, wide hybridization, chromosome elimination.

Hybrid necrosis as a problem in handling hexaploid × tetraploid wheat crosses

1980 ◽  
Vol 94 (2) ◽  
pp. 377-382 ◽  
Author(s):  
R. S. Gregory
Keyword(s):  
Hexaploid Wheat ◽  
Tetraploid Wheat ◽  
Wheat Breeding ◽  
Small Scale ◽  
Hybrid Necrosis ◽  
Agronomic Characters ◽  
Wheat Varieties ◽  
Hybrid Plants ◽  
Plant Breeding Institute ◽  
Selection For

SummaryA tetraploid wheat breeding programme was initiated at the Plant Breeding Institute in 1970. Hexaploid × tetraploid wheat crosses were expected to contribute to the improvement of the tetraploid wheats but severe hybrid necrosis caused the death of the pentaploid Fxhybrid plants in most crosses. The genotypes of tetraploid wheat selections derived from crosses involving Rampton Rivet, a non-carrier of Neu were determined by test crossing to hexaploid wheat varieties which were known to carry the Neim allele. Similarly, hexaploid wheat selections which did not carry Ne2 were identified from crosses involving Maris Ranger by test crossing to durum selections which carried the Nef allele. By the careful choice of one parent, hexaploid x tetraploid wheat crosses were then made which avoided the hybrid necrosis problem. Segregation of the Ne% gene was as expected but selection for agronomic characters appeared to favour the retention of the dominant allele of the Ne1gene. Nevertheless, test crossing on a relatively small scale still identified many non-carriers.

Molecular genetic maps of the group 6 chromosomes of hexaploid wheat (Triticum aestivum L. em. Thell.)

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 359-366 ◽  
Author(s):  
Celso L. Marino ◽  
Neal A. Tuleen ◽  
Gary E. Hart ◽  
James C. Nelson ◽  
Mark E. Sorrells ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Hexaploid Wheat ◽  
Tetraploid Wheat ◽  
Triticum Aestivum L ◽  
Genetic Maps ◽  
Wheat Bread ◽  
Linkage Maps ◽  
Homoeologous Group ◽  
Group 6 ◽  
Orthologous Loci

Restriction fragment length polymorphism (RFLP) maps of chromosomes 6A, 6B, and 6D of hexaploid wheat (Triticum aestivum L. em. Thell.) have been produced. They were constructed using a population of F7–8 recombinant inbred lines derived from a synthetic wheat × bread wheat cross. The maps consist of 74 markers assigned to map positions at a LOD ≥ 3 (29 markers assigned to 6A, 24 to 6B, and 21 to 6D) and 2 markers assigned to 6D ordered at a LOD of 2.7. Another 78 markers were assigned to intervals on the maps. The maps of 6A, 6B, and 6D span 178, 132, and 206 cM, respectively. Twenty-one clones detected orthologous loci in two homoeologues and 3 detected an orthologous locus in each chromosome. Orthologous loci are located at intervals of from 1.5 to 26 cM throughout 70% of the length of the linkage maps. Within this portion of the maps, colinearity (homosequentiality) among the three homoeologues is strongly indicated. The remainder of the linkage maps consists of three segments ranging in length from 47 to 60 cM. Colinearity among these chromosomes and other Triticeae homoeologous group 6 chromosomes is indicated and a consensus RFLP map derived from maps of the homoeologous group 6 chromosomes of hexaploid wheat, tetraploid wheat, Triticum tauschii, and barley is presented. Key words : RFLP, wheat, linkage maps, molecular markers.

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