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Examples of FISH identification. FISH karyotypes of At, G, D genomes in T. kiharae and its parents (a); a cell of T. timopheevii PI119442 (b), Ae. tauschii AS2388 (c), and T. kiharae Syn-AtGD-3 (d)
Source publication
Six new amphiploids, Triticum kiharae Dorof. et Migusch. (2n = 6x = 42, AtAtGGDD), are described in this study. They were developed by the chromosome doubling of F1 hybrid crosses between Triticum timopheevii Zhuk. (AtAtGG) with high resistance to stripe rust and Aegilops tauschii Cosson (DD) by colchicine treatment. These amphiploids showed a high...
Citations
... Currently, this species is held within seed banks and special collections ex situ, and is no longer cultivated as an agricultural crop (Dorofeev et al. 1979;Badaeva et al. 1994a;Czajkowska et al. 2020). T. timopheevii is resistant to fungal diseases such as leaf rust, powdery mildew, smut and stem rust, and therefore can be used for wheat breeding improvement by directly crossing it with common wheat or using synthetic amphiploids as a bridge (McIntosh and Gysuch 1971;Badaeva et al. 1991;Brown-Guedira et al. 1996, 2003Peusha et al. 1996;Jӓrve et al. 2002;Mikó et al. 2015;Liu et al. 2018;King et al. 2022). ...
... The karyotype of T. araraticum and T. timopheevii has been comprehensively characterized using chromosome banding (C-banding) (Badaeva et al. 1994b). In recent years, fluorescence in situ hybridization (FISH) has been found as an effective tool for precisely identifying the chromosomes of the A t and G genomes of T. timopheevii using different probes (Mikó et al. 2015;Badaeva et al. 2016Badaeva et al. , 2022Liu et al. 2018). Oligo-pTa535-1 preferentially targets tandem repeats on A t -genome chromosomes of T. timopheevii (Badaeva et al. 2016(Badaeva et al. , 2022Liu et al. 2018). ...
... In recent years, fluorescence in situ hybridization (FISH) has been found as an effective tool for precisely identifying the chromosomes of the A t and G genomes of T. timopheevii using different probes (Mikó et al. 2015;Badaeva et al. 2016Badaeva et al. , 2022Liu et al. 2018). Oligo-pTa535-1 preferentially targets tandem repeats on A t -genome chromosomes of T. timopheevii (Badaeva et al. 2016(Badaeva et al. , 2022Liu et al. 2018). Oligo-pSc119.2-1 ...
Genetic diversity is an important resource to improve new wheat cultivars in the breeding program. In this study, fluorescence in situ hybridization (FISH) and genotyping by sequencing (GBS) were used to evaluate the genetic diversity and population structure of the Timopheevii group (AtAtGG, 2n = 4x = 28) including 15 Triticum timopheevii Zhuk. accessions and 35 Triticum araraticum Jakubz. accessions. FISH analysis showed that there were 14 and 19 FISH signal variations in the At and G genome of T. araraticum, respectively. But there were only two signal variations in the G genome of T. timopheevii. In this study, 190,402 SNP markers were obtained from GBS, in which the lowest and highest frequencies of SNPs were found in the G and At genomes, respectively. Genetic diversity analysis of the 50 accessions indicated that the mean GD and PIC were 0.30 and 0.26, with the ranges of 0.1–0.5 and 0.1–0.4, respectively. The lowest and highest numbers of SNPs identified on the chromosomes 4G and 2At were 7748 and 17,527, respectively. Structure and cluster analyses divided 50 accessions into two subpopulations (POP1 and POP2). POP1 consisted of most T. araraticum accessions, and POP2 comprised all accessions of T. timopheevii and one T. araraticum accession AS273. In addition, the genetic variance showed that genetic variation was greater within populations (97%) than between populations (3%). The present results provided important information for the improvement of cultivated durum and hexaploid wheat production in future breeding programs of China and other countries.
... Plant height, the tiller number per plant, spike length, and seed setting were observed following Ref. 43 . Data from 10 plants were used to compare trait differences with the t test. ...
Stem solidness is an important agronomic trait for increasing the ability of wheat to resist lodging. In this study, four new synthetic hexaploid wheat with solid stems were developed from natural chromosome doubling of F1 hybrids between a solid-stemmed durum wheat (Triticum turgidum ssp. durum, 2n = 4x = 28, AABB) and four Aegilops tauschii (2n = 2x = 14, DD) accessions. The solid expression of the second internode at the base of the stem was stable for two synthetic hexalpoid wheat Syn-SAU-117 and Syn-SAU-119 grown in both the greenhouse and field. The lodging resistance of four synthetic solid-stem wheats is stronger than that of CS, and Syn-SAU-116 has the strongest lodging resistance, followed by Syn-SAU-119. The paraffin sections of the second internode showed that four synthetic wheat lines had large outer diameters, well-developed mechanical tissues, large number of vascular bundles, and similar anatomical characteristics with solid-stemmed durum wheat. The chromosomal composition of four synthetic hexaploid wheat was identified by FISH (fluorescence in situ hybridization) using Oligo-pSc119.2-1 and Oligo-pTa535-1. At adult stage, all four synthetic hexaploid wheat showed high resistance to mixed physiological races of stripe rust pathogen (CYR31, CYR32, CYR33, CYR34). These synthetic hexaploid wheat lines provide new materials for the improvement of common wheat.
... Even though some chromosomes have similar C-banding pattern distributions, it cannot be guaranteed that they have the same origin. In recent years, uorescence in situ hybridization (FISH) has been found as an effective tool for precisely identifying the chromosomes of the A t and G genomes of T. timopheevii (Mikó et al. 2015;Badaeva et al. 2016;Liu et al. 2018). Oligo-pTa535-1 preferentially targets tandem repeats on A t -genome chromosomes of T. timopheevii (Mikó et al. 2015;Badaeva et al. 2016;Liu et al. 2018). ...
... In recent years, uorescence in situ hybridization (FISH) has been found as an effective tool for precisely identifying the chromosomes of the A t and G genomes of T. timopheevii (Mikó et al. 2015;Badaeva et al. 2016;Liu et al. 2018). Oligo-pTa535-1 preferentially targets tandem repeats on A t -genome chromosomes of T. timopheevii (Mikó et al. 2015;Badaeva et al. 2016;Liu et al. 2018). Oligo-pSc119.2-1 ...
... Oligo-pSc119.2-1 mainly hybridizes to the Ggenome chromosomes of T. timopheevii, and Oligo-pTa71-2 mainly hybridizes to the subterminal regions of the short arms of 6A t and 6G (Mikó et al. 2015;Liu et al. 2018). The combination of oligonucleotide probes OligopSc119.2-1, ...
Genetic diversity is an important resource to improve new wheat cultivars in the breeding program. In this study, fluorescence in situ hybridization (FISH) and genotyping by sequencing (GBS) were used to evaluate the genetic diversity and population structure of the timopheevii group (A t A t GG, 2n = 4x = 28) including 15 Triticum timopheevii Zhuk. accessions and 35 Triticum araraticum Jakubz. accessions. FISH analysis showed that there were 14 and 19 FISH signal variations in the A t and G genome of T. araraticum , respectively. But there were only two signal variations in the G genome of T. timopheevii . In this study, 190,402 SNP markers were obtained from GBS, in which the lowest and highest frequencies of SNPs were found in the G and A t genomes, respectively. Genetic diversity analysis of the 50 accessions indicated that the mean GD and PIC were 0.30 and 0.26, with the ranges of 0.1–0.5 and 0.1–0.4, respectively. The highest and lowest numbers of SNPs identified on the chromosomes 4G and 2A t were 7,748 and 17,527, respectively. Structure and cluster analyses divided 50 accessions into two subpopulations (POP1 and POP2). POP1 mainly consisted of most Triticum araraticum accessions, and POP2 comprised all accessions of Triticum timopheevii and one Triticum araraticum accession AS273. In addition, the genetic variance showed that genetic variation was greater within populations (97%) than between populations (3%). POP1 and POP2 had high levels of genetic diversity and POP1 showed higher genetic diversity. The POP1 ( I = 0.53, He = 0.35, uh = 0.35) showed higher genetic diversity than POP2. The present results provided important information for the improvement of cultivated durum and hexaploid wheat production in future breeding programs of China and other countries.
... Plant height, the tiller number per plant, spike length, and seed setting were observed following Ref. 43 . ...
Stem solidness is an important agronomic trait for increasing the ability of wheat to resist lodging. In this study, four new synthetic hexaploid wheat with solid stems were developed from natural chromosome doubling of F 1 hybrids between a solid-stemmed durum wheat ( Triticum turgidum ssp. durum , 2n = 4x = 28, AABB) and four Aegilops tauschii (2n = 2x = 14, DD) accessions. The solid expression of the second internode at the base of the stem was stable for two synthetic hexalpoid wheat Syn-SAU-117 and Syn-SAU-119 grown in both the greenhouse and field. The lodging resistance of four synthetic solid-stem wheats is stronger than that of CS, and Syn-SAU-116 has the strongest lodging resistance, followed by Syn-SAU-119. The paraffin sections of the second internode showed that four synthetic wheat lines had large outer diameters, well-developed mechanical tissues, large number of vascular bundles, and similar anatomical characteristics with solid-stemmed durum wheat. The chromosomal composition of four synthetic hexaploid wheat was identified by FISH (fluorescence in situ hybridization) using Oligo-pSc119.2-1 and Oligo-pTa535-1. At adult stage, all four synthetic hexaploid wheat showed high resistance to mixed physiological races of stripe rust pathogen (CYR31, CYR32, CYR33, CYR34). These synthetic hexaploid wheat lines provide new materials for the improvement of common wheat.
... ) [52] , , , [33,53] , , , [35][36][37] , , 54] , AABBMM AABBUU , , [55][56] (AABBDDA m A m AABBDDDD) ...
Triticeae tribe houses a number of allopolyploid species that harbor combinations of various genomes. The different genomes of an allopolyploid may have asymmetric contributions to morphological traits. For instance, the taxon traits of allopolyploids within genus Triticum is highly like those from the donor species of A-genome, termed this phenomenon as A-genome dominance. Because of genome dominance, the allopolyploids of Triticeae are grouped into different species clusters with A, D, U, or St as the pivotal (dominant) genome. Genome dominance may confer the advantages in evolution and adaptation. In breeding, it is an important factor to influence the development of novel allopolyploid crops and the design of wheat-alien chromosome translocations.
Triticum timopheevii (AtAtGG) was previously cultivated in western Georgia, and Triticum zhukovskyi (AtAtGGAmAm) is a natural allohexaploid originating from hybridization of T. timopheevii and Triticum monococcum (AmAm). In this study, two synthetic amphiploids (Triticum timococcum, AtAtGGAmAm), Syn‐AtGAm‐20 and Syn‐AtGAm‐21, were developed by chromosome doubling of F1 hybrids between T. timopheevii and T. monococcum. Chromosomes of these two amphiploids were identified by fluorescence in situ hybridization (FISH) utilizing oligonucleotide probes Oligo‐pSc119.2‐1, Oligo‐pTa535‐1, Oligo‐pTa71‐2 and Oligo‐(AAC)7. Each amphiploid had 42 chromosomes derived from its parents, but the Glu‐A1mx subunits from einkorn were both not expressed. Syn‐AtGAm‐20 had low average seed setting rates of 19.86% and 20.50% in two different years, with abnormal spikes similar to those reported before. Syn‐AtGAm‐21 had normal spikes with average seed setting rates of 65.88% and 61.56% in two different years, comparable with those of natural T. zhukovskyi. However, the relationship between Syn‐AtGAm‐21 and natural T. zhukovskyi requires further study. This research provides new materials for studying the origin of T. zhukovskyi.
Background
Triticum kiharae (A t A t GGDD, 2n = 42) is of interest for the improvement of bread wheat as a source of high grain protein and gluten content, as well as resistance to many diseases. The use of T. kiharae for the improvement of T. aestivum L. is complicated by the fact that the homology degree of their genomes is low and this leads to an unbalanced set of chromosomes in the gametes of its first generations and the elimination of some genotypes. The aim of this study was to analyze the nature of alien introgressions and their effect on the cytological stability of hybrids obtained from crossing of bread wheat varieties with T. kiharae .
Results
Using C-banding, the presence of entire chromosomes of T. kiharae in the karyotypes of hybrid lines (intergenomic substitution 2G/2B), chromosome arms (centric translocation Т2A t S:2AL) and large inserts in the form of terminal translocations involving chromosomes of 1st, 3rd and 5th homoeologous groups of B- and G-genomes were found. Molecular markers revealed short introgression of T. kiharae into the genome of common wheat varieties. The highest introgression frequency was shown for 1A, 1B, 2A, 5B, and 6A chromosomes, while no foreign chromatin was detected in 4A and 4B chromosomes. A high level of cytological stability (a meiotic index of 88.18–93.0%) was noted for the majority of introgression lines. An exception was found for the lines containing the structural reorganization of chromosome 5B, affecting the main genes of chromosome synapsis in terms of their functioning.
Conclusions
During the stabilization of hybrid karyotypes, the introgression of genetic material from T. kiharae into the genome of T. aestivum occurs in the form of short fragments detectable only by molecular markers and in the form of whole chromosomes (intergenomic substitution) and their large fragments (centric and terminal translocations). The level of cytological stability achieved in F 10 by the majority of introgression lines ensures the formation of functional gametes sufficient for the successful reproduction of the obtained hybrids.
Triticum boeoticum (2n = 2x = 14, AbAb) contains beneficial traits for common wheat improvement. The discrimination of Ab-genome chromosomes from A-genome chromosomes is an important step in gene transfer from T. boeoticum to common wheat. In this study, fluorescence in situ hybridization (FISH) analysis using nine oligonucleotide probes revealed high divergence between chromosomes of the common wheat germplasm Crocus and T. boeoticum accession G52. The combination of Oligo-pTa535-HM and Oligo-pSc119.2-HM can differentiate Ab and A chromosomes within homologous groups 2, 4, 5, and 6; chromosomes 2Ab and 6Ab can be identified by using (ACT)7, (CTT)7, and (GAA)7. The probes Oligo-pTa713 and (ACT)7 can be utilized for the identification of chromosomes 1Ab and 3Ab, respectively. Probes (CAG)7 and (CAC)7 can be applied in the identification of 7Ab. Moreover, probe combinations consisting of Oligo-pTa535-HM and (AAC)7 with (ACT)7 or (CTT)7 and of Oligo-pTa535-HM and Oligo-pTa713 with (CAC)7 or (CTT)7 will help discriminate the Ab-genome chromosomes of T. boeoticum. These probes are being used as potential markers to select common wheat Crocus-T. boeoticum G52 alien chromosome lines. Moreover, FISH patterns are highly divergent between Ab- and A-genome chromosomes, indicating that obvious chromosome structural variations arose during wheat evolution.
Diploid wild einkorn wheat, Triticum boeoticum Boiss (AbAb, 2n = 2x = 14), is a wheat-related species with a blue aleurone layer. In this study, six blue-grained wheat lines were developed from F8 progeny of crosses between common wheat and T. boeoticum. The chromosome constitutions of these lines were characterized by fluorescence in situ hybridization (FISH) using the oligonucleotide probes Oligo-pTa535-1, Oligo-pSc119.2-1, Oligo-pTa71-2, and (AAC)7. Multicolor FISH using Oligo-pTa535-1, Oligo-pSc119.2-1, and Oligo-pTa71-2 identified all 42 common wheat chromosomes, while Oligo-pTa535-1 and (AAC)7 discriminated the 14 chromosomes of T. boeoticum. FISH revealed that all six blue-grained lines were wheat-T. boeoticum 4Ab (4B) disomic substitution lines. The substitution lines were validated by genotyping using the wheat 55 K single nucleotide polymorphism (SNP) array containing 53,063 markers. These 4Ab (4B) substitution lines represent novel germplasm for blue-grained wheat breeding. The FISH probes and SNP markers used here can be applied in the development of blue-grained wheat-Triticum boeoticum translocation lines.
