STUDIES ON THE HYPOANEUPLOIDS OF COMMON WHEAT. III. PRODUCTION OF SEXTUPLE MONOSOMICS

1976 ◽  
Vol 18 (2) ◽  
pp. 255-261
Author(s):  
Shoji Shigenaga
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
The Other ◽  
Chromosome Behavior ◽  
A Genome

Two kinds of sextuple monosomics for A-genome chromosomes, namely, one plant simultaneously deficient for chromosomes 1A, 2A, 4A, 5A, 6A and 7A and the other deficient for 1A, 2A, 3A, 4A, 5A and 6A, were produced in a systematic way in the variety Chinese Spring. Sextuple monosomics (15″ + 6′) were selected in the progenies of crosses between quintuple monosomics (16″ + 5′) and nullisomics (20″) which lacked the sixth pair of chromosomes. The sextuple monosomics were smaller, with reduced vigor and later maturity, compared with normal plants. They showed stable chromosome behavior in meiosis and retained fertility in both sexes. Female gametes with n = 16, 17, 18, 19, 20 or 21 produced from the quintuple monosomics functioned well in fertilization.

Spindle sensitivity to isopropyl-N-phenyl-carbamate and griseofulvin of common wheat plants carrying different doses of the Ph1 gene

1984 ◽  
Vol 26 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Giampiero Gualandi ◽  
Carla Ceoloni ◽  
Moshe Feldman ◽  
Lydia Avivi
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
The Other ◽  
Microtubule Organization ◽  
Chromosome 5B ◽  
Ph1 Gene ◽  
Complete Disruption ◽  
Spindle Microtubules ◽  
Different Doses ◽  
Microtubule Structure

Lines of common wheat cv. 'Chinese Spring' carrying different doses of the Ph1 gene, located on the long arm of chromosome 5B were treated with the antimitotic agents griseofulvin and isopropyl-N-phenyl-carbamate (IPC). Treatments with low griseofulvin concentrations and IPC resulted mainly in the production of a high percentage of cells exhibiting spindle disorganization at metaphase and multipolar cells at anaphase–telophase. These treatments did not differentially affect the tested genotypes. On the other hand, higher griseofulvin concentrations induced the appearance of frequent C-metaphases and C-anaphases because of complete disruption of the spindle microtubules; in such cases, more pronounced sensitivity was observed in a line lacking the Ph1 gene than in lines disomic and tetrasomic for chromosome 5B. From this evidence it can be concluded that subcellular structures regulating microtubule organization and orientation, which are apparently the target of IPC and low griseofulvin concentrations, are not related to the action of the Ph1 gene. Rather, tubulin–microtubules equilibrium, which is affected by colchicine and high griseofulvin concentrations, is influenced by the action of this gene. Thus, the Ph1 gene product may correspond to a tubulin or a microtubule-associated protein which in turn stabilizes microtubule structure. In either case, the equilibrium tubulin–microtubules would be shifted towards microtubules in plants containing two doses of Ph1 and even more in plants containing an extra dose of this gene.Key words: spindle, Triticum, microtubules, antitubulins, griseofulvin.

scholarly journals Stripe rust resistance gene Yr34 (synonym Yr48) is located within a distal translocation of Triticum monococcum chromosome 5AmL into common wheat

2021 ◽  
Author(s):  
Shisheng Chen ◽  
Joshua Hegarty ◽  
Tao Shen ◽  
Lei Hua ◽  
Hongna Li ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Common Wheat ◽  
Stripe Rust ◽  
Rust Resistance ◽  
Triticum Monococcum ◽  
Rust Resistance Gene ◽  
Stripe Rust Resistance ◽  
Polyploid Wheat ◽  
Stripe Rust Resistance Gene ◽  
A Genome

AbstractKey messageThe stripe rust resistance geneYr34 was transferred to polyploid wheat chromosome 5AL from T. monococcumand has been used for over two centuries.Wheat stripe (or yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is currently among the most damaging fungal diseases of wheat worldwide. In this study, we report that the stripe rust resistance gene Yr34 (synonym Yr48) is located within a distal segment of the cultivated Triticum monococcum subsp. monococcum chromosome 5AmL translocated to chromosome 5AL in polyploid wheat. The diploid wheat species Triticum monococcum (genome AmAm) is closely related to T. urartu (donor of the A genome to polyploid wheat) and has good levels of resistance against the stripe rust pathogen. When present in hexaploid wheat, the T. monococcum Yr34 resistance gene confers a moderate level of resistance against virulent Pst races present in California and the virulent Chinese race CYR34. In a survey of 1,442 common wheat genotypes, we identified 5AmL translocations of fourteen different lengths in 17.5% of the accessions, with higher frequencies in Europe than in other continents. The old European wheat variety “Mediterranean” was identified as a putative source of this translocation, suggesting that Yr34 has been used for over 200 years. Finally, we designed diagnostic CAPS and sequenced-based markers that will be useful to accelerate the deployment of Yr34 in wheat breeding programs to improve resistance to this devastating pathogen.

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.

THE INHERITANCE OF LEAF RUST RESISTANCE IN SEVEN VARIETIES OF COMMON WHEAT

1961 ◽  
Vol 41 (2) ◽  
pp. 342-359 ◽  
Author(s):  
R. G. Anderson
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Susceptible Variety ◽  
The Other ◽  
Seedling Resistance ◽  
Genetic Studies ◽  
Type Reaction ◽  
Biological Studies

The inheritance of seedling resistance to races 1a, 5a, 11, 15a and 126a of leaf rust was studied in the varieties Exchange and Selkirk and to races 1a and 15a in the varieties Lee, Gabo, Timstein, Mayo 52 and Mayo 54. Thatcher was used as the susceptible variety. Rust tests were carried out on F1 and F2 populations of diallel crosses among these varieties and on F2 families from the backcrosses to Thatcher. Two genes were found. One gene LrE conditions a (2) type reaction to all five races in Exchange and Selkirk. The other gene LrL conditions a (; 1 =) type reaction to races 1a and 15a in all seven varieties. Isogenic lines possessing these genes are being developed in the varieties Prelude and Thatcher. The importance of such lines in future genetic studies and their application in other biological studies are discussed.The increase in amount of leaf rust found on Lee and Selkirk in Canada during the period 1951–1958 is accounted for by the increase of races which render the gene LrL ineffective in these two varieties.

scholarly journals A fast and robust iterative genome-editing method based on a Rock-Paper-Scissors strategy

2020 ◽  
Author(s):  
Jichao Wang ◽  
Xinyue Sui ◽  
Yamei Ding ◽  
Yingxin Fu ◽  
Xinjun Feng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Genome Editing ◽  
The Other ◽  
Plasmid Curing ◽  
Gene Deletions ◽  
A Genome ◽  
Single Clone ◽  
Previous Round ◽  
Genome Modifications

Abstract The production of optimized strains of a specific phenotype requires the construction and testing of a large number of genome modifications and combinations thereof. Most bacterial iterative genome-editing methods include essential steps to eliminate selection markers, or to cure plasmids. Additionally, the presence of escapers leads to time-consuming separate single clone picking and subsequent cultivation steps. Herein, we report a genome-editing method based on a Rock-Paper-Scissors (RPS) strategy. Each of three constructed sgRNA plasmids can cure, or be cured by, the other two plasmids in the system; plasmids from a previous round of editing can be cured while the current round of editing takes place. Due to the enhanced curing efficiency and embedded double check mechanism, separate steps for plasmid curing or confirmation are not necessary, and only two times of cultivation are needed per genome-editing round. This method was successfully demonstrated in Escherichia coli and Klebsiella pneumoniae with both gene deletions and replacements. To the best of our knowledge, this is the fastest and most robust iterative genome-editing method, with the least times of cultivation decreasing the possibilities of spontaneous genome mutations.

Construction of chromosomal recombination maps of three genomes of lilies (Lilium) based on GISH analysis

Genome ◽  
2009 ◽  
Vol 52 (3) ◽  
pp. 238-251 ◽  
Author(s):  
Nadeem Khan ◽  
Rodrigo Barba-Gonzalez ◽  
M. S. Ramanna ◽  
Richard G.F. Visser ◽  
Jaap M. Van Tuyl
Keyword(s):  
Molecular Markers ◽  
Interspecific Hybrids ◽  
The Other ◽  
A Genome ◽  
Chromosomal Recombination ◽  
Gish Analysis ◽  
The Way

Chromosomal recombination maps were constructed for three genomes of lily ( Lilium ) using GISH analyses. For this purpose, the backcross (BC) progenies of two diploid (2n = 2x = 24) interspecific hybrids of lily, viz. Longiflorum × Asiatic (LA) and Oriental × Asiatic (OA), were used. Mostly the BC progenies of LA hybrids consisted of both triploid (2n = 3x = 36) and diploid (2n = 2x = 24) with some aneuploid genotypes and those of OA hybrids consisted of triploid (2n = 3x = 36) and some aneuploid genotypes. In all cases, it was possible to identify the homoeologous recombinant chromosomes as well as accurately count the number of crossover points, which are called “recombination sites”. Recombination sites were estimated in the BC progeny of 71 LA and 41 OA genotypes. In the case of BC progenies of LA hybrids, 248 recombination sites were cytologically localized on 12 different chromosomes of each genome (i.e., L and A). Similarly, 116 recombinant sites were localized on the 12 chromosomes each from the BC progenies of OA hybrids (O and A genomes). Cytological maps were constructed on the basis of the percentages of distances (micrometres) of the recombination sites from the centromeres. Since an Asiatic parent was involved in both hybrids, viz. LA and OA, two maps were constructed for the A genome that were indicated as Asiatic (L) and Asiatic (O). The other two maps were Longiflorum (A) and Oriental (A). Remarkably, the recombination sites were highly unevenly distributed among the different chromosomes of all four maps. Because the recombination sites can be unequivocally identified through GISH, they serve as reliable landmarks and pave the way for assigning molecular markers or desirable genes to chromosomes of Lilium and also monitor introgression of alien segments.

FREQUENCY OF MICRONUCLEI IN POLLEN QUARTETS OF COMMON WHEAT MONOSOMICS

1952 ◽  
Vol 30 (4) ◽  
pp. 371-378 ◽  
Author(s):  
J. W. Morrison ◽  
John Unrau
Keyword(s):  
Cell Wall ◽  
Common Wheat ◽  
Chinese Spring ◽  
Wheat Variety ◽  
Early Developmental Stage ◽  
D Genome ◽  
Distinct Cell ◽  
The Common ◽  
Early Developmental ◽  
Common Wheat Variety

The frequency with which 20 different monosomes of the common wheat variety, Chinese Spring, formed micronuclei in pollen quartets was determined. It was found that unless the study was made at an early developmental stage characterized by a distinct cell wall surrounding the quartets, the counts were unreliable, because some micronuclei were lost. The frequency of micronucleus formation was similar for anthers of a floret, florets of a spike, and plants of a monosome. Among the monosomes studied, there were three groups of three and four of two in which the total frequency of quartets with micronuclei, and the distribution of numbers of micronuclei per quartet, were strikingly similar. In the case of the groups of three, two monosomes were from the A and B genomes while one was from the D genome. This is interpreted as evidence of homoeology of chromosomes of a group and also that such chromosomes have undergone less change than those that do not form such series.

scholarly journals Genome-Wide Association Mapping of Adult-Plant Resistance to Stripe Rust in Common Wheat (Triticum aestivum)

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2174-2180 ◽  
Author(s):  
Fangping Yang ◽  
Jindong Liu ◽  
Ying Guo ◽  
Zhonghu He ◽  
Awais Rasheed ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Common Wheat ◽  
Stripe Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Genome Wide Association ◽  
Stripe Rust Resistance ◽  
Economic Losses ◽  
Genome Wide ◽  
A Genome

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a globally devastating disease of common wheat (Triticum aestivum L.), resulting in substantial economic losses. To identify effective resistance genes, a genome-wide association study was conducted on 120 common wheat lines from different wheat-growing regions of China using the wheat 90K iSelect SNP array. Seventeen loci were identified, explaining 9.5 to 21.8% of the phenotypic variation. Most of these genes were detected in the A (seven) and B (seven) genomes, with only three in the D genome. Among them, 11 loci were colocated with known resistance genes or quantitative trait loci reported previously, whereas the other six are likely new resistance loci. Annotation of flanking sequences of significantly associated SNPs indicated the presence of three important candidate genes, including E3 ubiquitin-protein ligase, F-box repeat protein, and disease resistance RPP13-like protein. This study increased our knowledge in understanding the genetic architecture for stripe rust resistance and identified wheat varieties with multiple resistance alleles, which are useful for improvement of stripe rust resistance in breeding.

The origin of wheat chromosomes 4A and 4B and their genome reallocation

1983 ◽  
Vol 25 (3) ◽  
pp. 210-214 ◽  
Author(s):  
J. Dvořák
Keyword(s):  
Triticum Aestivum ◽  
Banding Pattern ◽  
The Other ◽  
Evolutionary Lineage ◽  
C Banding ◽  
B Genome ◽  
A Genome

Triticum aestivum chromosome "4A" is, like the B genome chromosomes, extensively heterochromatic while the remaining six A genome chromosomes are not. In the presence of the Ph gene it does not pair with any chromosome of einkorn wheats, T. monococcum and T. urartu, the source of the A genome. It is shown here that the same chromosome is also present in T. timopheevii which represents the other evolutionary lineage of wheats. The "4A" chromosomes of T. timopheevii and T. aestivum pair poorly with each other, like the B genome chromosomes of the two lineages, while the remaining A genome chromosomes, except for one arm, pair relatively well. Hence, in both lineages chromosome "4A" has the attributes of the B genome chromosomes, not of the A genome chromosomes. The C-banding pattern of chromosome "4A" of T. aestivum and T. timopheevii closely resembles the C-banding pattern of a chromosome of T. speltoides and less closely chromosome 4B1 of T. sharonense. On the basis of this and other evidence it is concluded that this chromosome was contributed by a species of the section Sitopsis and, consequently, belongs to the B genome. Additionally, there is evidence that the chromosome that was originally designated "4B" belongs to the A genome.

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