Chromosome instability in wheat plants regenerated from suspension culture

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 627-629 ◽  
Author(s):  
George Fedak ◽  
K. C. Armstrong ◽  
R. J. Handyside
Keyword(s):  
Triticum Aestivum ◽  
Suspension Culture ◽  
Key Words ◽  
Chinese Spring ◽  
Meiotic Chromosome ◽  
Chromosome Instability ◽  
Wheat Chromosome ◽  
Chromosome Behaviour ◽  
Meiotic Configuration ◽  
Culture Suspension

Plants of Triticum aestivum cv. Chinese Spring were regenerated from 30 calli obtained from suspension cultures. All four plants showed abnormal meiotic chromosome behaviour relative to the control. The average meiotic configuration over all plants was 1.55 I + 18.16 II + 0.30 III + 0.82 IV. In addition, an isochromosome was frequently observed in cells of all plants, which was indicative of centromeric breaks. Key words: culture (suspension), wheat, chromosome instability.

scholarly journals Dmc1 is a candidate for temperature tolerance during wheat meiosis

2019 ◽  
Author(s):  
Tracie Draeger ◽  
Azahara Martin ◽  
Abdul Kader Alabdullah ◽  
Ali Pendle ◽  
María-Dolores Rey ◽  
...  
Keyword(s):  
High Temperatures ◽  
Chromosome Pairing ◽  
Meiotic Recombination ◽  
Low Temperatures ◽  
Chinese Spring ◽  
Deletion Mutant ◽  
Meiotic Chromosome ◽  
Wheat Chromosome ◽  
Chromosome Synapsis ◽  
Recombination Gene

AbstractWe have assessed the effects of high and low temperatures on meiotic chromosome synapsis and crossover formation in the hexaploid wheat (Triticum aestivum L.) variety ‘Chinese Spring’. At low temperatures, asynapsis and chromosome univalence have been observed before in Chinese Spring lines lacking the long arm of chromosome 5D (5DL), which led to the proposal that 5DL carries a gene (Ltp1) that stabilises wheat chromosome pairing at low temperatures. In the current study, Chinese Spring wild type and 5DL interstitial deletion mutant plants were exposed to low (13°C) or high (30°C) temperatures in controlled environment rooms during a period from premeiotic interphase to early meiosis I. A 5DL deletion mutant was identified whose meiotic chromosomes exhibit extremely high levels of asynapsis and chromosome univalence at metaphase I after seven days at 13°C. This suggests that the mutant, which we name ttmei1 (temperature tolerance in meiosis 1) has a deletion of a gene that, like Ltp1, normally stabilises chromosome pairing at low temperatures. Immunolocalisation of the meiotic proteins ASY1 and ZYP1 on ttmei1 mutants showed that low temperature results in a failure to complete synapsis at pachytene. After 24 hours at 30°C, ttmei1 mutants exhibited a reduced number of crossovers and increased univalence, but to a lesser extent than at 13°C. KASP genotyping revealed that ttmei1 has a 4 Mb deletion in 5DL. Of 41 genes within this deletion region, the strongest candidate for the stabilisation of chromosome pairing at low (and possibly high) temperatures is the meiotic recombination gene Dmc1.Key messageThe meiotic recombination gene Dmc1 on wheat chromosome 5D has been identified as a candidate for the maintenance of normal chromosome synapsis and crossover at low and possibly high temperatures.

THE CYTOGENETIC STRUCTURE OF A 56-CHROMOSOME DERIVATIVE FROM A CROSS BETWEEN TRITICUM AESTIVUM AND AGROPYRON ELONGATUM (2n = 70)

1976 ◽  
Vol 18 (2) ◽  
pp. 271-279 ◽  
Author(s):  
Jan Dvořák
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Wheat Chromosome ◽  
Agropyron Elongatum ◽  
Synthetic Genome ◽  
Chromosome Associations ◽  
Chromosome Segments ◽  
The Relationship ◽  
Chromosome 3B

Chromosome pairing was studied in a number of hybrids involving a 56-chromosome wheat-Agropyron derivative, PW 327. PW 327 originated from the cross, Triticum aestivum cv. Chinese Spring (Chinese Spring × A. elongatum, 2n = 70). In hybrids between PW 327 and T. aestivum a number of multivalent chromosome associations were formed at metaphase I. These multivalents result from interchanges which occurred among wheat chromosomes 1A, 1D, 2A, 2D, 4D and 6D of PW 327. One chromosome of the Agropyron chromosome set of PW 327 occasionally pairs with wheat chromosome 3B. The rest of the Agropyron chromosomes present in PW 327 do not pair with the chromosomes of T. aestivum. It is proposed that the set of Agropyron chromosomes present in PW 327 is not an intact genome of decaploid A. elongatum but rather a modified synthetic genome combining chromosomes and/or chromosome segments from different genomes of the Agropyron parent. The incorporation of duplication-deletions into synthetic genomes of natural polyploids is discussed and it is shown that the set of Agropyron chromosomes which is present in PW 327 carries at least one such duplication-deletion. Pairing between chromosomes of diploid and decaploid A. elongatum was studied in a 56-chromosome hybrid from a cross between an amphiploid, T. aestivum × A. elongatum (2n = 14), and PW 327. It appeared that at least four chromosomes of these two Agropyrons occasionally paired with each other in this hybrid in which the diploidizing system of wheat was active. The relationship between chromosomes of diploid and decaploid A. elongatum is discussed.

Control of alien gene expression for aluminum tolerance in wheat

Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 9-12 ◽  
Author(s):  
J. P. Gustafson ◽  
K. Ross
Keyword(s):  
Gene Expression ◽  
Triticum Aestivum ◽  
Chinese Spring ◽  
Aluminum Tolerance ◽  
Wheat Chromosome ◽  
Triticum Aestivum L ◽  
D Genome ◽  
Chinese Spring Wheat ◽  
Secale Cereale L ◽  
Alien Gene

The expression of aluminum tolerance from rye (Secale cereale L.) when present in a wheat (Triticum aestivum L. em. Thell.) background has been observed to be much lower than that in rye itself. By crossing each of the ditelocentric lines of 'Chinese Spring' wheat with a tolerant rye, the effects of the presence or absence of each arm of wheat on the expression of rye aluminum tolerance could be established. Of 42 wheat chromosome arms, 18 affected the expression of rye aluminum tolerance. Tolerance was increased over that observed in the euploid wheat–rye hybrid when arms 4AL, 5AL, 6AL, 7BS, 7BL, and 3DS were absent. Tolerance was reduced when arms 2AL, 5AS, 6BS, 1DS, 1DL, 2DL, 4DL, 5DS, 5DL, 6DL, 7DS, and 7DL were absent. Thus, the control of aluminum tolerance expression from rye in a wheat background was evidently under the influence of genes located on a number of wheat chromosome arms, with a few arms tending to enhance expression and many others tending to reduce it. In fact, 5AS of 'Chinese Spring' enhances expression, while 5AL suppresses it. The D genome of bread wheat appears to have the most pronounced effect on the expression of rye aluminum tolerance.Key words: rye, activator genes, suppressor genes, alien manipulation.

INDUCED PAIRING BETWEEN A WHEAT (TRITICUM AESTIVUM) AND AN AGROPYRON ELONGATUM CHROMOSOME

1981 ◽  
Vol 23 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Y. Yasumuro ◽  
R. Morris ◽  
D. C. Sharma ◽  
J. W. Schmidt
Keyword(s):  
Triticum Aestivum ◽  
Chinese Spring ◽  
Wheat Chromosome ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Puccinia Graminis ◽  
Agropyron Elongatum ◽  
Chromosome 5B ◽  
Transfer Genes ◽  
I Cells

A study was initiated to transfer genes for stem- and leaf-rust resistance from a chromosome (designated 6Ag) of Agropyron elongatum (Host) Beauv to a homoeologous chromosome (6D) of wheat (Triticum aestivum L. aestivum group) by inducing pairing between 6Ag and 6D in the absence of the Ph gene on wheat chromosome 5B. Plants monosomic for SB, 6D and 6Ag were crossed with Chinese Spring nullisomic-5B tetrasomic-5D or with Chinese Spring monosomic or trisomic for SB with an induced mutation, phlb, of the Ph locus. Tests of 282 offspring in the seedling stage for reaction to the stem rust pathogen, Puccinia graminis Pers. f. sp. tritici Eriks. &E. Henn. race 56 or 15B-2, were used to identify 70 plants with 6Ag, which was transmitted through 25% of the female gametes. Meiotic observations on 51 of these plants indicated that six were monosomic for 6D and 6Ag, but lacked an entire 5B or had 5B with the phlb mutation. The frequency of metaphase I cells with pairing between 6D and 6Ag averaged 4.94% in three plants that were nullisomic for 5B and 2.48% in two plants that had a single dose of 5B with the phlb mutation.

Locating the Agropyron segment in wheat–Agropyron transfer no. 12

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 365-366 ◽  
Author(s):  
G. C. Eizenga
Keyword(s):  
Triticum Aestivum ◽  
Key Words ◽  
Leaf Rust ◽  
Chromosome Pairing ◽  
Wheat Chromosome ◽  
Triticum Aestivum L ◽  
Puccinia Recondita ◽  
Agropyron Elongatum ◽  
Transfer Lines ◽  
Puccinia Recondita Tritici

Twelve lines of wheat (Triticum aestivum L.) were originally identified as having a segment of Agropyron elongatum chromatin carrying a gene for resistance to leaf rust (Puccinia recondita tritici) transferred to wheat chromosome 7D. By studying the chromosome pairing of one of these lines, transfer no. 12, with telosomes 7AL, 7AS, 7BL, 7BS, 7DL, 7DS, and 7AgS, it was determined that the Agropyron chromatin was carried on the long arm of wheat chromosome 7A rather than 7D. This determination was confirmed by acetocarmine–N-banding. Key words: Triticum aestivum, Agropyron elongatum, transfer lines, Puccinia recondita tritici, telosomic analysis.

A chromosome of Hordeum chilense homoeologous to group 7 of wheat

1985 ◽  
Vol 27 (1) ◽  
pp. 101-104 ◽  
Author(s):  
T. E. Miller ◽  
S. M. Reader ◽  
C. C. Ainsworth
Keyword(s):  
Triticum Aestivum ◽  
Key Words ◽  
Isoelectric Focusing ◽  
Wheat Chromosome ◽  
Hordeum Chilense ◽  
Chromosome Substitution ◽  
Substitution Lines ◽  
Telocentric Chromosome ◽  
Chromosome Markers ◽  
Gel Isoelectric Focusing

Individual substitution lines have been produced with Hordeum chilense chromosome A substituted in turn for chromosome 7A, 7B, or 7D of Triticum aestivum. Telocentric substitutions with the α arm, substituted for chromosome 7A or 7D, or the β arm substituted for chromosome 7B have also been produced. The substitutions have been confirmed by the presence of a purple straw marker, by gel isoelectric focusing of α-amylase isozymes, and cytologically using telocentric chromosome markers. Chromosome A has consequently been designated 7Hch.Key words: Hordeum chilense, wheat, chromosome substitution, homoeology, α-amylase.

Gametocidal genes in wheat and its relatives. I. Genetic analyses in common wheat of a gametocidal gene derived from Aegilops speltoides

1984 ◽  
Vol 26 (1) ◽  
pp. 78-84 ◽  
Author(s):  
H. Tsujimoto ◽  
K. Tsunewaki
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
Meiotic Chromosome ◽  
Wheat Chromosome ◽  
Female Fertility ◽  
Aegilops Speltoides ◽  
Alloplasmic Lines ◽  
Male Gametes ◽  
First Case ◽  
Gametocidal Gene

Alloplasmic lines of 12 common wheats carrying G-type cytoplasm derived from an aucheri-type strain of Aegilops speltoides show about 50% reduction of female fertility compared with the alloplasmic lines of the same common wheats carrying G-type cytoplasms from other sources. This reduction of female fertility is caused by a gametocidal gene derived from Ae. speltoides. This gene has been preferentially transmitted through 16 successive backcrosses in which common wheat was the recurrent pollen parent, and has been present in the heterozygous state in every backcross generation. The karyotype and meiotic chromosome pairing of hybrid from reciprocal crosses between (Ae. speltoides) – cv. Chinese Spring and (Triticum aestivum) – cv. Chinese Spring are normal, indicating that the gametocidal gene derived from an Ae. speltoides chromosome subsequently was translocated to a wheat chromosome. This is the first case reported of the integration of a gametocidal gene into a wheat genome; the symbol given to it is Gcl. The F1 female and male gametes not carrying this gene abort and, consequently, all F2 progeny are homozygous for the gene and fully fertile. The origin and distribution of the Gcl gene and its potential use for hybrid wheat production have been discussed.

scholarly journals Aneuhaploids in bread wheat

1976 ◽  
Vol 28 (1) ◽  
pp. 37-45 ◽  
Author(s):  
T. E. Miller ◽  
Victor Chapman
Keyword(s):  
Triticum Aestivum ◽  
Genetic Control ◽  
Bread Wheat ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Meiotic Chromosome ◽  
Hordeum Bulbosum ◽  
Meiotic Abnormalities ◽  
Meiotic Chromosome Pairing

SUMMARYEuploid and aneuploid plants of Triticum aestivum, variety Chinese Spring were pollinated with, pollen of Hordeum bulbosum. Euhaploids and aneuhaploids of Chinese Spring were obtained from the crosses. Meiotic chromosome pairing was analysed in 25 different aneuhaploids and the results were compared with those obtained from euhaploids. The evidence provided by the meiotic studies was used to identify chromosomes whose activities affected the genetic control of chromosome pairing.Meiosis was abnormal in a 23-chromosome aneuhaploid and in the 22-chromosome sectors of a chimaeral plant. Both plants were thought to have resulted from the incomplete elimination of the genome of H. bulbosum from hybrid embryos. It is suggested that the meiotic abnormalities in the two aneuhaploids were caused by the residual barley chromosomes.

Persisting demibivalents: a unique meiotic behaviour in Cuscuta babylonica Choisy

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Batia Pazy ◽  
Uzi Plitmann
Keyword(s):  
Key Words ◽  
Chromosome Segregation ◽  
Meiotic Behaviour ◽  
Chromosome Behaviour ◽  
Chromosome Movement ◽  
Pollen Mother Cells ◽  
Key Words Meiosis ◽  
Mother Cells ◽  
Telomeric Association

Idiosyncratic chromosome behaviour during meiosis was found in pollen mother cells of Cuscuta babylonica Choisy, a thread-like holoparasitic herb. Its main features are among the following: (i) telomeric association between homologues through most stages of the process, which leads to persisting chromatid bivalents (= "demibivalents"); (ii) uncommon chromosome segregation in first and second anaphase; and (iii) prolonged intensified heterochromatinization. Although "regular" in its own way, this process leads to the formation of unviable products. Its further investigation might contribute to our understanding of the role of the spindle and chromosome movement in the ordinary process of meiosis. Key words: meiosis (abnormal), persisting demibivalents, Cuscuta babylonica.

Chilling injury and chlorotic reactions of euploids and aneuploids of the group 6 homoeologues of common wheat

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 468-473 ◽  
Author(s):  
Ernest D. P. Whelan ◽  
G. B. Schaalje
Keyword(s):  
Triticum Aestivum ◽  
Common Wheat ◽  
Chinese Spring ◽  
Prolonged Exposure ◽  
Chilling Injury ◽  
Triticum Aestivum L ◽  
Recessive Trait ◽  
Cytoplasmic Effects ◽  
Group 6 ◽  
Winter Wheat Cultivars

Aneuploid seedlings of the common wheat (Triticum aestivum L.) cv. Chinese Spring (CS) that are nullisomic or telosomic for the long arm of chromosome 6D are susceptible to chilling injury under prolonged exposure to 6 °C; normal euploids or telosomics for the short arm are not. Studies of seedling grown for various durations at 20 °C prior to growth at 6 °C showed that chilling injury was a juvenile phenomenon and that the extent of injury was inversely proportional to the duration of growth at 20 °C to a maximum of about 14 days. When reciprocal crosses were made between susceptible 6D nullisomics or long-arm ditelocentrics of CS and resistant 6D nullisomics of three spring and one winter wheat cultivars, progenies from aneuploid F1 hybrids all segregated for susceptibility as a recessive trait and at a frequency approximating a dihybrid ratio; no cytoplasmic effects were detected. Aneuploids of the group 6 homoeologues of the spring wheat cvs. Cadet and Rescue were resistant, as were group 6 whole-chromosome substitutions of eight different donor wheats in the recipient parent CS and 56 other euploids tested. Genes for resistance to chilling injury appear to involve the group 6 chromosomes and the short arm of 6D in Chinese Spring. In contrast with chilling injury, all aneuploid lines with only four doses of the "corroded" loci on group 6 chromosomes exhibited chlorotic symptoms.Key words: Triticum aestivum, chilling injury.

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