Chromosome engineering in triticale

1984 ◽  
Vol 26 (2) ◽  
pp. 105-110 ◽  
Author(s):  
P. J. Kaltsikes ◽  
J. P. Gustafson ◽  
A. J. Lukaszewski
Keyword(s):  
Chromosome Pairing ◽  
Cereal Crop ◽  
Chromosome Engineering ◽  
The Past ◽  
Chromosome Manipulation

Triticale has been treated as a botanical oddity until the past few years when it has become accepted as a commercial cereal crop. This paper assesses the improvements that have been made to triticale through chromosome manipulation and modification. In addition, insights into further chromosome manipulations are discussed.Key words: heterochromatin, triticale, chromosome pairing, endosperm.

Chromosome aberrations induced by zebularine in triticale

Genome ◽  
2016 ◽  
Vol 59 (7) ◽  
pp. 485-492 ◽  
Author(s):  
Xuhui Ma ◽  
Qing Wang ◽  
Yanzhi Wang ◽  
Jieyun Ma ◽  
Nan Wu ◽  
...  
Keyword(s):  
Chromosome Aberrations ◽  
Additional Treatment ◽  
Chromosome Engineering ◽  
Chromosome Translocations ◽  
Ring Chromosomes ◽  
Chromosome Manipulation ◽  
Important Approach ◽  
Rye Translocations ◽  
Alien Genes ◽  
Octoploid Triticale

Chromosome engineering is an important approach for generating wheat germplasm. Efficient development of chromosome aberrations will facilitate the introgression and application of alien genes in wheat. In this study, zebularine, a DNA methylation transferase inhibitor, was successfully used to induce chromosome aberrations in the octoploid triticale cultivar Jinghui#1. Dry seeds were soaked in zebularine solutions (250, 500, and 750 μmol/L) for 24 h, and the 500 μmol/L treatment was tested in three additional treatment times, i.e., 12, 36, and 48 h. All treatments induced aberrations involving wheat and rye chromosomes. Of the 920 cells observed in 67 M1 plants, 340 (37.0%) carried 817 aberrations with an average of 0.89 aberrations per cell (range: 0–12). The aberrations included probable deletions, telosomes and acentric fragments (49.0%), large segmental translocations (28.9%), small segmental translocations (17.1%), intercalary translocations (2.6%), long chromosomes that could carry more than one centromere (2.0%), and ring chromosomes (0.5%). Of 510 M2 plants analyzed, 110 (21.6%) were found to carry stable aberrations. Such aberrations included 79 with varied rye chromosome numbers, 7 with wheat and rye chromosome translocations, 15 with possible rye telosomes/deletions, and 9 with complex aberrations involving variation in rye chromosome number and wheat–rye translocations. These indicated that aberrations induced by zebularine can be steadily transmitted, suggesting that zebularine is a new efficient agent for chromosome manipulation.

scholarly journals Improvement in Salinity Tolerance in Rice Using Biotechnology

2021 ◽  
Vol 9 (11) ◽  
pp. 551-560
Author(s):  
Ankita Roy
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Rice Crop ◽  
Cereal Crop ◽  
Rice Varieties ◽  
The Past ◽  
The Future ◽  
Staple Diet ◽  
Held Back

Abstract: Rice has been amongst the most important cereal crop on earth, or more correctly the second most staple diet of people after wheat. The statement is self-explanatory to the demand of rice worldwide and the supply. But with increasing population, the demand of rice is also undoubtedly increasing. The increase in supply is though held back by many factors that adversely affect the growth of a healthy rice crop. One of these factors is salinity. Rice being a glycophyte has very low tolerance to salt, and salt stress results in a damaged yield. However, rice has its own mechanisms for salt tolerance to a certain level, the knowledge of which scientists have put in use to develop the few improvements in rice varieties providing them with better tolerance. Though these improvements have faced many challenges themselves, science still strives to make further achievements. This study aims to highlight the mechanisms rice use to tolerate salt up to a certain level and how they are affected by salinity at levels above that. It also aims to enumerate the methods biotechnology has developed in the past years to improve the varieties, the advantages they have had, the increase in yield they have shown and the challenges they have had to face. Also, it includes if there are any further developments undergoing and the future scope of salinity tolerance increase in rice, with the help of biotechnology.

Invited Review: Functional genomics in the mouse: powerful techniques for unraveling the basis of human development and disease

2003 ◽  
Vol 94 (6) ◽  
pp. 2502-2509 ◽  
Author(s):  
Clifford W. Bogue
Keyword(s):  
Human Development ◽  
Dna Sequences ◽  
Model Organism ◽  
Biological Research ◽  
Chromosome Engineering ◽  
The Past ◽  
Human Genomes ◽  
Mutant Genes ◽  
Rich History ◽  
Made In

Now that near-complete DNA sequences of both the mouse and human genomes are available, the next major challenge will be to determine how each of these genes functions, both alone and in combination with other genes in the genome. The mouse has a long and rich history in biological research, and many consider it a model organism for the study of human development and disease. Over the past few years, exciting progress has been made in developing techniques for chromosome engineering, mutagenesis, mapping and maintenance of mutations, and identification of mutant genes in the mouse. In this mini-review, many of these powerful techniques will be presented along with their application to the study of development, physiology, and disease.

Interspecific manipulation of chromosomes

1981 ◽  
Vol 292 (1062) ◽  
pp. 519-527 ◽  
Keyword(s):  
Chromosome Pairing ◽  
Genetic System ◽  
Alien Chromosome ◽  
Polyploid Species ◽  
Crop Species ◽  
Chromosome Manipulation ◽  
Alien Gene ◽  
Species Hybrids ◽  
Similar Gene ◽  
Pairing Behaviour

The success of introducing alien variation into crop species from related species depends on the cytogenetic relations between the species. If there are no restrictions on chromosome pairing and recombination in species hybrids, a backcrossing programme can be used to obtain the desired gene transfers. However, when there is a failure of adequate chromosome pairing in species hybrids, techniques of chromosome manipulation have to be used to obtain alien gene transfers. In polyploid crop species it is possible to introduce appropriate single chromosomes of the alien species into the genotype of the recipient species, but the failure of the alien chromosome to become integrated into the genotype of the recipient species often leads to meiotic instability. The introduction of segments of alien chromosomes has been successful through the use of irradiation-induced translocations. The deletions/duplications that are a consequence of such translocations do limit the usefulness of this approach. In a number of allopolyploid crop species, regular bivalent pairing behaviour has been shown to be genetically controlled. By interfering with the genetic system controlling the diploid-like pairing it is possible to induce pairing between the alien chromosomes and its corresponding chromosomes in the crop species. Gene transfers based on this method involve exchanges between chromosomes of similar gene sequences. These techniques are discussed and application of the procedures to transfer alien variation into the cultivated oat is described. A scheme is also proposed for transferring the genes controlling regular bivalent pairing from natural polyploid species into synthetic amphiploids in Lolium/Festuca .

Observations of the continuum near the galactic centre

1967 ◽  
Vol 31 ◽  
pp. 405
Author(s):  
F. J. Kerr
Keyword(s):  
Galactic Centre ◽  
The Past ◽  
Centre Region ◽  
The Continuum

A continuum survey of the galactic-centre region has been carried out at Parkes at 20 cm wavelength over the areal11= 355° to 5°,b11= -3° to +3° (Kerr and Sinclair 1966, 1967). This is a larger region than has been covered in such surveys in the past. The observations were done as declination scans.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

On The Possibility of an Autonomous History of Modern Southeast Asia

1961 ◽  
Vol 2 (2) ◽  
pp. 73-105 ◽  
Author(s):  
John R. W. Small
Keyword(s):  
Southeast Asia ◽  
Contemporary History ◽  
The Past ◽  
History Of

It is generally accepted that history is an element of culture and the historian a member of society, thus, in Croce's aphorism, that the only true history is contemporary history. It follows from this that when there occur great changes in the contemporary scene, there must also be great changes in historiography, that the vision not merely of the present but also of the past must change.

Stellar Evolution

1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Space Craft ◽  
New Techniques ◽  
Substantial Body ◽  
Individual Stars ◽  
The Past ◽  
Evolution Of Galaxies ◽  
History Of ◽  
Fast Flow

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.

Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
University Of Michigan ◽  
The Past ◽  
Spectroscopic Information ◽  
Objective Prism ◽  
The University ◽  
Small Cloud ◽  
Low Dispersion

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

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