scholarly journals The effect of flowering stage in wheat on the infection efficiency of Ustilago tritici

2005 ◽  
Vol 80 (1) ◽  
pp. 13-19 ◽  
Author(s):  
J.G. Menzies ◽  
P.L. Thomas ◽  
S. Woods
Keyword(s):  
Lower Percentage ◽  
Viable Seed ◽  
Infection Efficiency ◽  
Head Development ◽  
Ustilago Tritici ◽  
Spike Development ◽  
Negative Effect ◽  
Vacuum Method ◽  
Wheat Lines ◽  
Partial Vacuum

In general, in western Canada, the inoculation of wheat (Triticum aestivum) lines to determine the level of resistance to Ustiiago tritici occurs when the plants are at the mid-anthesis stage of spike development. However, it is not always possible to inoculate at this stage so occasionally inoculations are done a few days before or after mid-anthesis. The objective of this study was to determine if inoculation of wheat spikes with U. tritici at different stages of spike development using the partial-vacuum method affected the number of viable seed per spike and subsequent percentage of smutted plants grown from inoculated seed. Four lines of wheat were inoculated at three different stages of spike development in the field each year for 5 years. The stages of spike development studied were preanthesis, mid-anthesis (anthers at either end of the spike were dehisced while those in the middle of the spike were yellow), and post-anthesis (all anthers dehisced). There were significant differences among the four wheat lines and the 5 years of the study for the number of viable seed per spike and the percent of smutted plants. Inoculation at post-anthesis resulted in a significantly greater number of viable seed per spike and lower percentage of smutted plants. We conclude that the partial-vacuum method of inoculation with Ustiiago tritici should be done at the pre- or midanthesis stage of wheat head development to minimize the negative effect of maturity on infection efficiency.

scholarly journals Development of common wheat lines with the 1BL/1RS translocation linked with the allele Glu-B1al

2017 ◽  
pp. 77-85
Author(s):  
N. Kozub ◽  
I. Sozinov ◽  
G. Bidnyk ◽  
N. Demianova ◽  
O. Sozinova ◽  
...  
Keyword(s):  
Common Wheat ◽  
Resistance Genes ◽  
Bread Making ◽  
High Quality ◽  
Marker Selection ◽  
Negative Effect ◽  
The Cross ◽  
Wheat Lines ◽  
Sedimentation Value

A number of F6 winter common wheat lines that carry the wheat-rye 1BL/1RS translocation of the Kavkaz type with respective resistance genes linked with high bread-making quality allele Glu-B1al have been developed via marker selection among F2 plants from the cross B16 × Odesskaya krasnokolosya. The SDS-sedimentation value in these lines proved to be in most cases similar to that of the cultivar Bezostaya 1. The lines may be used as a source of the 1BL/1RS translocation linked with the high-quality allele Glu-B1al, which compensates for the negative effect of this translocation on bread-making quality.

scholarly journals Does urbanization have positive or negative effects on Crab spider (Araneae: Thomisidae) diversity?

2017 ◽  
Vol 34 ◽  
pp. 1-8 ◽  
Author(s):  
Carina Argañaraz ◽  
Raquel M. Gleiser
Keyword(s):  
Green Spaces ◽  
Negative Effects ◽  
Community Patterns ◽  
Negative Effect ◽  
Vacuum Method ◽  
Abundant Genus ◽  
Living Organisms ◽  
Crab Spider ◽  
First Time ◽  
Crab Spiders

Urbanization has a great impact on the diversity of living organisms. Spiders, for example, have been shown to respond negatively (some orb weaving species) and positively (ground dwelling species) to urbanization. The effects of urbanization on crab spiders (Thomisidae) (sit-and-wait predators that generally ambush their prey on flowers and leaves) are not sufficiently known. This paper describes the Thomisidae community that inhabits green patches in a temperate Neotropical city, Cordoba, Argentina, and its surroundings, and ascertains whether there are differences in species richness, abundance and composition between urban and exurban sites. Samples were collected from 30 sites during the summer and spring of 2013 and 2014, using the garden-vacuum method. We compared the abundance, richness and composition of Thomisidae among three habitat categories (urban, suburban and external). Seven species in three genera, Misumenops, Wechselia and Tmarus, were detected. Misumenops was the most abundant genus in Córdoba, and Tmarus elongates Mello-Leitão, 1929 was collected in Argentina for the first time. The abundance, richness and composition of thomisid spiders did not differ between habitat categories, indicating that urbanization does not have a negative effect on the communities of these spiders in open green spaces. Site variability, on the other hand, does, suggesting that local factors may be more relevant than broad-scale factors to explain community patterns in this family.

scholarly journals Mechanical properties of concrete for radioactive waste repositories

2019 ◽  
Vol 282 ◽  
pp. 02104
Author(s):  
Dana Koňáková ◽  
Eva Vejmelková ◽  
Vojtěch Pommer ◽  
Lenka Scheinherrová ◽  
Petr Konvalinka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Radioactive Waste ◽  
Lower Percentage ◽  
Mechanical Parameters ◽  
Suitable Material ◽  
Concrete Mixtures ◽  
The Matrix ◽  
Negative Effect ◽  
Radioactive Waste Repositories ◽  
Waste Repositories

Concrete casing for radioactive repositories have to meet many strict requirements. One of the most important is a radiation protection and a radionuclide inhabitation. Bentonite, with a great sorption capacity, seems to be a suitable material for this purpose. Therefore, the main aim of this study was to assess an impact of the bentonite utilization as a component in concrete mixtures. For this reason, basic physical properties and mechanical parameters of concretes containing different amount of bentonite were determined. Bentonite applications led to the open porosity growth, while the matrix densities were not influenced. Regarding the mechanical parameters, the compressive strengths as well as the flexural strengths were significantly deteriorated by the bentonite application. Despite the presented negative effect, the obtained results seems to prove a possible applicability of a lower percentage of bentonite in concrete structures not as a cement replacement, but just as a component.

Tapping to Ragtime: Cues to Pulse Finding

2001 ◽  
Vol 18 (4) ◽  
pp. 455-489 ◽  
Author(s):  
Joel Snyder ◽  
Carol L. Krumhansl
Keyword(s):  
Lower Percentage ◽  
Musical Experience ◽  
Left Hand ◽  
Right Hand ◽  
Temporal Cues ◽  
Hand Part ◽  
Pitch Information ◽  
Negative Effect ◽  
The Right ◽  
Stimulus Materials

Two experiments investigated cues to pulse finding using a relatively unconstrained, naturalistic paradigm. Participants tapped what they felt was a comfortable pulse on a keyboard playing a percussive sound. The stimulus materials were based on ragtime excerpts, played metronomically (i.e., without expressive timing or tempo variation). The first experiment, with 8 musically experienced and 8 musically inexperienced subjects, played each excerpt in two versions: a pitch-varied version (the original excerpt) and a monotonic version (with all tones changed to middle C) that was designed to remove all melodic and harmonic cues to pulse. Neither the absence of pitch information nor musical experience significantly affected performance. The second experiment tested 12 musically experienced subjects on shorter excerpts from the same ragtime pieces. Full (right-hand and left-hand parts together) and right-hand-only versions of the excerpts were each played in pitch-varied and monotonic versions. Removing the left-hand part significantly affected tapping performance on a number of measures, causing a lower percentage of tapping on the downbeat, more off-beat taps, more aperiodic taps, more switches between tapping modes, a higher variability of the intertap interval, and larger deviations from the beat. As a whole, these indicate a negative effect of removing the left-hand part. Again, differences between pitch-varied and monotonic versions were generally small. Analysis of the music revealed the following cues to pulse finding: a predictable alternating bass pattern in the left-hand part and a majority of notes on metrically strong positions in both the right-hand and left-hand parts. These results suggest that, for piano ragtime music, temporal cues are prominently available for finding and following the pulse and that pulse finding is largely independent of pitch information. Implications of the experimental measures and music-analytic techniques for models of pulse perception are considered.

A COLLECTION OF CULTIVARS OF OATS IMMUNE OR HIGHLY RESISTANT TO SMUT

1977 ◽  
Vol 57 (1) ◽  
pp. 199-212 ◽  
Author(s):  
J. NIELSEN
Keyword(s):  
Loose Smut ◽  
Department Of Agriculture ◽  
Large Numbers ◽  
Diverse Origin ◽  
Vacuum Method ◽  
Oat Cultivars ◽  
Partial Vacuum ◽  
The U.S

A partial-vacuum method was developed for inoculating large numbers of oat cultivars with smut. It was used over a period of 5 yr to test 5,485 entries, of diverse origin in the U.S. Department of Agriculture World Oat Collection for their reaction to races of loose smut that, in combination, carried all known genes for virulence. There were 305 immune, and 142 highly resistant entries, some of which may contain genes for resistance that can be employed once the presently used genes are no longer effective.

scholarly journals Development of common wheat lines with the 1BL/1RS translocation linked with the allele Glu-B1al

2017 ◽  
pp. 248-256
Author(s):  
N.A. Kozub ◽  
I.A. Sozinov ◽  
G.Ya. Bidnyk ◽  
N.A. Demianova ◽  
O.I. Sozinova ◽  
...  
Keyword(s):  
Common Wheat ◽  
Resistance Genes ◽  
Bread Making ◽  
High Quality ◽  
Marker Selection ◽  
Negative Effect ◽  
The Cross ◽  
Wheat Lines ◽  
Sedimentation Value

A number of F6 winter common wheat lines that carry the wheat-rye 1BL/1RS translocation of the Kavkaz type with respective resistance genes linked with high bread-making quality allele Glu-B1al have been developed via marker selection among F2 plants from the cross B16 × Odesskaya krasnokolosya. The SDS-sedimentation value in these lines proved to be in most cases similar to that of the cultivar Bezostaya 1. The lines may be used as a source of the 1BL/1RS translocation linked with the high-quality allele Glu-B1al, which compensates for the negative effect of this translocation on bread-making quality.

scholarly journals The study of the effects of reducing the negative influence of 1BL-1RS translocation on the bread making quality in spring bread wheat lines

2021 ◽  
pp. 27-33
Author(s):  
Sergey Nikolaevich Sibikeev ◽  
Alexander Yevgenyevich Druzhin ◽  
Lyubov Vladimirovna Andreeva
Keyword(s):  
Bread Wheat ◽  
Great Influence ◽  
Negative Influence ◽  
Bread Making ◽  
Spring Bread Wheat ◽  
Negative Effect ◽  
Synthetic Hexaploid ◽  
Wheat Lines

The effects of the combinations 7DS-7DL-7Ae#1L (Lr19 gene) and 1BL-1RS (Lr26 gene) translocations, substitution of 6D(6Agi) (Lr6Agi gene) and 1BL-1RS translocation, as well as translocations of 7DS-7DL-7Ae#1L, 1BL-1RS and Lr39 gene on the bread making quality were evaluated in spring bread wheat introgressive lines. It was found that the genotype of recipient, the 1BL-1RS translocation donor, and the vegetation conditions have a great influence on the parameters quality of flour and bread. The role of selection within a single crosses combination for production of lines with good quality indicators is revealed. The high compensatory ability of the cultivar L505 and the synthetic hexaploid line with the pedigree Croc/Ae.squarosa(205)//Weaver (1BL-1RS translocation + Lr39 gene) for reducing the negative effect of the 1BL-1RS translocation on bread making quality was noted.

Modification of the Electron Microscope for Investigation of Fully Hydrated Biological Specimens

1969 ◽  
Vol 27 ◽  
pp. 418-419 ◽  
Author(s):  
R. C. Moretz ◽  
D. F. Parsons
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Structural Damage ◽  
Lower Percentage ◽  
Vacuum Drying ◽  
Total Removal ◽  
Total Absence ◽  
Biological Studies ◽  
Electron Microscopes ◽  
Beam Damage

Short lifetime or total absence of electron diffraction of ordered biological specimens is an indication that the specimen undergoes extensive molecular structural damage in the electron microscope. The specimen damage is due to the interaction of the electron beam (40-100 kV) with the specimen and the total removal of water from the structure by vacuum drying. The lower percentage of inelastic scattering at 1 MeV makes it possible to minimize the beam damage to the specimen. The elimination of vacuum drying by modification of the electron microscope is expected to allow more meaningful investigations of biological specimens at 100 kV until 1 MeV electron microscopes become more readily available. One modification, two-film microchambers, has been explored for both biological and non-biological studies.

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