Characterization of wheat – Secale africanum introgression lines reveals evolutionary aspects of chromosome 1R in rye

Genome ◽  
2012 ◽  
Vol 55 (11) ◽  
pp. 765-774 ◽  
Author(s):  
Meng-Ping Lei ◽  
Guang-Rong Li ◽  
Cheng Liu ◽  
Zu-Jun Yang
Keyword(s):  
Sequence Divergence ◽  
Introgression Lines ◽  
Secale Africanum ◽  
Secale Cereale L ◽  
Disease Resistance Screening ◽  
High Conservation ◽  
Chromosome 1R ◽  
Evolutionary Aspects

Wild Secale species, Secale africanum Stapf., serve as a valuable source for increasing the diversity of cultivated rye (Secale cereale L.) and provide novel genes for wheat improvement. New wheat – S. africanum chromosome 1Rafr addition, 1Rafr(1D) substitution, 1BL.1RafrS and 1DS.1RafrL translocation, and 1RafrL monotelocentric addition lines were identified by chromosome banding and in situ hybridization. Disease resistance screening revealed that chromosome 1RafrS carries resistance gene(s) to new stripe rust races. Twenty-nine molecular markers were localized on S. africanum chromosome 1Rafr by the wheat – S. africanum introgression lines. Twenty markers can also identically amplify other reported wheat – S. cereale chromosome 1R derivative lines, indicating that there is high conservation between the wild and cultivated Secale chromosome 1R. Nine markers displayed polymorphic amplification between S. africanum and S. cereale chromosome 1Rafr derivatives. The comparison of the nucleotide sequences of these polymorphic markers suggested that gene duplication and sequence divergence may have occurred among Secale species during its evolution and domestication.

Refined physical mapping of the Sec-1 locus on the satellite of chromosome 1R of rye (Secale cereale)

Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 889-893 ◽  
Author(s):  
W. Busch ◽  
R. G. Herrmann ◽  
R. Martin
Keyword(s):  
In Situ Hybridization ◽  
Genetic Mapping ◽  
Fluorescence In Situ Hybridization ◽  
Physical Mapping ◽  
Secale Cereale ◽  
Secondary Constriction ◽  
Heterologous Hybridization ◽  
Secale Cereale L ◽  
Chromosome 1R

The Sec-1 locus (ω-secalin) of rye (Secale cereale L.) was mapped in the satellite of the short arm of chromosome 1R using fluorescence in situ hybridization and a genomic probe called pSec2B. Sec-1 is located in the middle of the satellite at the junction of the proximal euchromatic and the distal heterochromatic regions. Double hybridization experiments using rDNA and pSec2B showed that the NOR spans over the secondary constriction of the short arm of chromosome 1R and that there is a clearly visible gap between the NOR and Sec-1. Heterologous hybridization of pSec2B to barley visualized the B-hordein locus on chromosome 1H.Key words: fluorescence in situ hybridization, physical mapping, genetic mapping, secalin, rye, B-hordein, rDNA.

Molecular cytogenetic and agronomic characterization of advanced generations of wheat × triticale hybrids resistant to Diuraphis noxia (Mordvilko): application of GISH and microsatellite markers

Genome ◽  
2009 ◽  
Vol 52 (4) ◽  
pp. 353-360 ◽  
Author(s):  
K. K. Nkongolo ◽  
S. D. Haley ◽  
N. S. Kim ◽  
P. Michael ◽  
G. Fedak ◽  
...  
Keyword(s):  
Triticum Aestivum L ◽  
Diuraphis Noxia ◽  
Wheat Varieties ◽  
Molecular Cytogenetic ◽  
Triticale Line ◽  
Chromosome 1R ◽  
Disomic Addition Lines ◽  
Donor Species

The PI 386148 triticale from Russia is among the highest resistant line to the Russian wheat aphid (RWA) ( Diuraphis noxia (Mordvilko)). This triticale line was used as the male parent in crosses with Lamar wheat ( Triticum aestivum L.). The F1 plants were backcrossed to Lamar wheat. The progenies were tested for RWA biotype 1 reaction for at least eight backcross and selfing generations. Five lines from these selections were identified for their resistance to the RWA and their seeds were increased for agronomic and other characterizations. Molecular and cytological analyses of these lines were performed using genomic in situ hybridization and rye chromosome-specific microsatellites markers. Three lines were cytologically stable and carried a pair of rye ( Secale strictum (C. Presl) C. Presl) chromosomes as disomic addition lines of 1R. One line was unstable and showed a moderate level of mixoploidy with monosomic additions of 1R. Duplication of rye chromosome 1R was also identified. No wheat–rye chromosome interchange was detected, suggesting little homology between S. strictum and T. aestivum chromosomes. Specific microsatellite primers were used to identify the rye chromosomes present in each line. One rye chromosome, 1R, from the donor species contains genes for RWA resistance. Grain yield and test weight of three of the lines were similar to some adapted released wheat varieties under stress conditions.

Fluorescent in situ hybridization and characterization of the SalI family of satellite repeats in the Haliotis L. species (abalone) of the Northeast Pacific

Genome ◽  
2008 ◽  
Vol 51 (8) ◽  
pp. 570-579 ◽  
Author(s):  
Norma Karina Hernández-Ibarra ◽  
Andrew R. Leitch ◽  
Pedro Cruz ◽  
Ana M. Ibarra
Keyword(s):  
Tandem Repeats ◽  
Sequence Divergence ◽  
Satellite Repeat ◽  
Northeast Pacific ◽  
Satellite Repeats ◽  
In The Wild ◽  
High Sequence Conservation ◽  
Heterochromatin Silencing

The SalI satellite repeat previously identified in Haliotis L. (abalone) was thought to be present in H. rufescens and absent in H. fulgens . However, we show here that SalI is also found in H. fulgens and is not useful for screening hybrid individuals bred in aquaculture or occurring naturally in the wild. SalI is a family of predominantly subtelomeric tandemly repeated sequences, and sequenced clones revealed clustering to species and little intraspecific variation. Analysis of SalI sequence divergence between Haliotis species of the Northeast Pacific revealed that evolutionary distances correlate well with bathymetric and latitudinal species distributions. Analysis of the structure of the tandem repeats revealed two regions of high sequence conservation that may contain conserved transcription factor binding sites, a surprise for an apparently “non-coding” tandem repeat. We speculate that these regions might be involved in heterochromatin silencing, perhaps mediated via transcriptional activity and RNA interference. The repeats show substantial differences in their chromosomal distributions, even between individuals of the same species, indicating a dynamic organization of repeats, perhaps mediated via sequence homogenization.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

Coherent electron nanodiffraction from clean silver nano particles in a UHV STEM

1993 ◽  
Vol 51 ◽  
pp. 1058-1059
Author(s):  
J. Liu ◽  
M. Pan ◽  
G. E. Spinnler
Keyword(s):  
Supported Catalysts ◽  
Imaging Techniques ◽  
Nano Particles ◽  
Metal Particles ◽  
Shape Structure ◽  
Dynamical Simulations ◽  
Small Metal Particles ◽  
Extract Information

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.

Characterization of the glycoconjugates of boar testis and epididymis

Reproduction ◽  
2000 ◽  
pp. 325-335 ◽  
Author(s):  
A Calvo ◽  
LM Pastor ◽  
S Bonet ◽  
E Pinart ◽  
M Ventura
Keyword(s):  
Ricinus Communis ◽  
Lectin Histochemistry ◽  
Apical Part ◽  
Seminiferous Tubules ◽  
In Situ Characterization ◽  
Intense Staining ◽  
Terminal Galactose ◽  
Boar Spermatozoa

Lectin histochemistry was used to perform in situ characterization of the glycoconjugates present in boar testis and epididymis. Thirteen horseradish peroxidase- or digoxigenin-labelled lectins were used in samples obtained from healthy fertile boars. The acrosomes of the spermatids were stained intensely by lectins with affinity for galactose and N-acetyl-galactosamine residues, these being soybean, peanut and Ricinus communis agglutinins. Sertoli cells were stained selectively by Maackia ammurensis agglutinin. The lamina propria of seminiferous tubules showed the most intense staining with fucose-binding lectins. The Golgi area and the apical part of the principal cells of the epididymis were stained intensely with many lectins and their distribution was similar in the three zones of the epididymis. On the basis of lectin affinity, both testis and epididymis appear to have N- and O-linked glycoconjugates. Spermatozoa from different epididymal regions showed different expression of terminal galactose and N-acetyl-galactosamine. Sialic acid (specifically alpha2,3 neuraminic-5 acid) was probably incorporated into spermatozoa along the extratesticular ducts. These findings indicate that the development and maturation of boar spermatozoa are accompanied by changes in glycoconjugates. As some lectins stain cellular or extracellular compartments specifically, these lectins could be useful markers in histopathological evaluation of diseases of boar testis and epididymis.

Spectro-mechanical Characterization of Aromaticity and Maturity of Kerogens in Oil Shale at 6 nm Spatial Resolution

2018 ◽  
Author(s):  
Devon Jakob ◽  
Le Wang ◽  
Haomin Wang ◽  
Xiaoji Xu
Keyword(s):  
Spatial Resolution ◽  
Oil Shale ◽  
Infrared Imaging ◽  
Mechanical Characterization ◽  
Optical Diffraction ◽  
Chemical Compositions ◽  
Valuable Insight ◽  
Eagle Ford Shale

<p>In situ measurements of the chemical compositions and mechanical properties of kerogen help understand the formation, transformation, and utilization of organic matter in the oil shale at the nanoscale. However, the optical diffraction limit prevents attainment of nanoscale resolution using conventional spectroscopy and microscopy. Here, we utilize peak force infrared (PFIR) microscopy for multimodal characterization of kerogen in oil shale. The PFIR provides correlative infrared imaging, mechanical mapping, and broadband infrared spectroscopy capability with 6 nm spatial resolution. We observed nanoscale heterogeneity in the chemical composition, aromaticity, and maturity of the kerogens from oil shales from Eagle Ford shale play in Texas. The kerogen aromaticity positively correlates with the local mechanical moduli of the surrounding inorganic matrix, manifesting the Le Chatelier’s principle. In situ spectro-mechanical characterization of oil shale will yield valuable insight for geochemical and geomechanical modeling on the origin and transformation of kerogen in the oil shale.</p>

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