Distribution of dwarfing genes (Rht-B1b and Rht-D1b) in Martonvásár wheat breeding materials

2011 ◽  
Vol 59 (3) ◽  
pp. 249-254 ◽  
Author(s):  
G. Gulyás ◽  
Z. Bognár ◽  
L. Láng ◽  
M. Rakszegi ◽  
Z. Bedő
Keyword(s):  
Triticum Aestivum ◽  
Molecular Markers ◽  
Plant Height ◽  
Wheat Breeding ◽  
Minor Role ◽  
Dwarfing Genes ◽  
Breeding Programmes ◽  
A Minor ◽  
Positive Results ◽  
Marker Information

A total of 266 Martonvásár (Mv) wheat (Triticum aestivum L.) accessions, including varieties and advanced lines, were examined using the “Perfect” molecular markers to detect the Rht-B1b (formerly Rht1) and Rht-D1b (formerly Rht2) semi-dwarfing genes. The gene Rht-B1b was detected in a total of 221 (83.5%) accessions. The Rht-D1b allele was found in fewer accessions. Overall 24 genotypes (9%) contained this allele. The analysis of the development date of the genotypes revealed that the introduction of the dwarfing genes into Martonvásár breeding programmes started in the early 1970s, and they were widely utilized from the 1980s. The Rht-B1b allele was the main source for reducing plant height, while the Rht-D1b allele played only a minor role in the Martonvásár breeding programme.Characterizing accessions using various molecular markers allows us to create a database offering relevant marker information about genotypes. Such a database could be very helpful for selection, allowing breeders to include varieties giving positive results in specific breeding programmes.

Variation in south Asian wheat germplasm for seedling drought tolerance traits

2009 ◽  
Vol 7 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Umesh R. Rosyara ◽  
Amrit A. Ghimire ◽  
Sushil Subedi ◽  
Ram C. Sharma
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Wheat Breeding ◽  
Dwarfing Genes ◽  
Seedling Vigour ◽  
Coleoptile Length ◽  
Wide Range ◽  
Dry Conditions ◽  
Breeding Programmes ◽  
Positive Correlations

Higher seedling vigour and greater coleoptile length are important for early establishment of wheat crops and subsequently higher grain yield in many dry environments. Seedling vigour includes those seed properties that determine the potential for rapid, uniform emergence and development of normal seedlings under a wide range of field conditions. Genotypes with the widely used gibberellic acid (GA)-insensitive dwarfing genes Rht-B1b and Rht-D1b have good partitioning and grain yield under optimal conditions, but may perform poorly under stressed conditions due to poor crop establishment. Breeding programmes are in search of GA-sensitive dwarfing genes that do not affect seedling vigour under dry conditions. This study evaluated 40 genotypes currently used in wheat breeding programmes of south Asia for seedling vigour-related traits in greenhouse and field experiments during 2006–2007 at IAAS, Rampur, Nepal. Wide variation in coleoptile length, seedling vigour, as well as sensitivity to GA was observed. Among the genotypes studied, there were positive correlations among coleoptile length, leaf width and plant height. Genotypes, SW89-5193, SW89-5422/NL251 and SW89-5422, were found to have longer coleoptile, higher seedling vigour and response to GA application. This shows a promise for their further applications in the breeding programmes.

The combination of dwarfing genes Rht4 and Rht8 reduced plant height, improved yield traits of rainfed bread wheat (Triticum aestivum L.)

2018 ◽  
Vol 215 ◽  
pp. 149-155 ◽  
Author(s):  
Yingying Du ◽  
Liang Chen ◽  
Yushen Wang ◽  
Zhiyuan Yang ◽  
Iqbal Saeed ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Plant Height ◽  
Bread Wheat ◽  
Triticum Aestivum L ◽  
Yield Traits ◽  
Dwarfing Genes

The allelic state at the major semi-dwarfing genes in a panel of Turkish bread wheat cultivars and landraces

2011 ◽  
Vol 9 (3) ◽  
pp. 423-429 ◽  
Author(s):  
F. E. Yediay ◽  
E. E. Andeden ◽  
F. S. Baloch ◽  
A. Börner ◽  
B. Kilian ◽  
...  
Keyword(s):  
Bread Wheat ◽  
Microsatellite Locus ◽  
Wheat Breeding ◽  
Dwarfing Genes ◽  
Wheat Cultivars ◽  
Allelic State ◽  
Production Environments ◽  
Allelic Distribution ◽  
Breeding Programmes ◽  
Polymerase Chain

Dwarfing genes play an important role in improving yield and adaptability of wheat cultivars in most production environments. Understanding the allelic distribution at dwarfing loci is very important for any wheat-breeding programmes. In this study, we reported the allelic constitution at microsatellite locus Xgwm261 and the two major height-reducing genes Rht-B1 and Rht-D1 among a set of 56 bread wheat cultivars and nine landraces, based on diagnostic polymerase chain reaction assays. With respect to Rht-B1, 37% of the accessions carried the dwarfing allele Rht-B1b, while at Rht-D1, only one accession carried the dwarfing allele Rht-D1b. The allelic state at Rht8 was assayed indirectly by genotyping for the linked microsatellite locus Xgwm261. About 26% of the accessions carried the 192 bp allele (linked with Rht8 gene in some cases), whereas 35 and 12% genotypes carried 165 and 174 bp allele at the microsatellite locus Xgwm261. Cultivars released from 1980 onwards increasingly carried either Rht-B1b or Rht8. This information should allow for a more rational use of this collection for the purpose of wheat improvement in Turkey.

scholarly journals Comparative Genetic Effect of Dwarfing Genes on Yield and Yield Contributing Traits in Bread Wheat (Triticum aestivum L.)

2014 ◽  
Vol 18 (2) ◽  
pp. 49-55
Author(s):  
MA Jahan ◽  
MS Hossain ◽  
M Khalekuzzaman ◽  
MM Hassan
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Plant Height ◽  
Bread Wheat ◽  
Yield Components ◽  
Genetic Effect ◽  
Triticum Aestivum L ◽  
High Yield ◽  
Strong Positive Correlation ◽  
Dwarfing Genes

Norin 10 based dwarfing genes (Rht1 and Rht2) have been widely exploited for increasing the grain yield in bread wheat (Triticum aestivum L.) by improving partitioning of assimilates to grain. Eight semi-dwarf wheat genotypes having either Rht1 or Rht2 dwarfing genes were compared with a tall control named, Kheri (rht) having no dwarfing genes were evaluated at Rajshahi University, Bangladesh for yield and yield contributing traits. Significant differences in grain yield and yield components were observed in genotypes under study showing the effects of dwarfing genes. Genotype Seri 82 (Rht1) and Kanchan (Rht2) had medium plant height of 75.73 and 72.22 cm respectively, highest number of tillers/plant (7.33 and 7.67), highest number of spikes/plant (6.33 and 6.67) resulted the highest grain yield per plant. Because the dwarfing genes not only provide lodging tolerance but also perhaps pleiotropically affected high yield by allowing more tillers to survive. Number of tillers/plant and number of spikes/plant showed very strong positive correlation with grain yield per plant in all the genotypes. Kheri (rht) with highest plant height (95.17cm) reduced number of tillers/plant (4.00) and spikes/plant (3.67) had the lowest grain yield per plant (3.85g). Aghrani possessed significantly the highest number of grains/spike with medium grain yield/plant (5.94g). The degree of relationship varied from genotype to genotype.DOI: http://dx.doi.org/10.3329/pa.v18i2.18075 Progress. Agric. 18(2): 49 - 55, 2007

scholarly journals Allelic Variation at theRht8Locus in a 19th Century Wheat Collection

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Linnéa Asplund ◽  
Matti W. Leino ◽  
Jenny Hagenblad
Keyword(s):  
Plant Breeding ◽  
20Th Century ◽  
19Th Century ◽  
Allelic Variation ◽  
Allelic Diversity ◽  
Wheat Breeding ◽  
Minor Role ◽  
Functional Markers ◽  
Wheat Cultivars ◽  
A Minor

Wheat breeding during the 20th century has put large efforts into reducing straw length and increasing harvest index. In the 1920s an allele ofRht8with dwarfing effects, found in the Japanese cultivar “Akakomugi,” was bred into European cultivars and subsequently spread over the world.Rht8has not been cloned, but the microsatellite marker WMS261 has been shown to be closely linked to it and is commonly used for genotypingRht8. The “Akakomugi” allele is strongly associated withWMS261-192bp. Numerous screens of wheat cultivars with different geographical origin have been performed to study the spread and influence of theWMS261-192bpduring 20th century plant breeding. However, the allelic diversity of WMS261 in wheat cultivars before modern plant breeding and introduction of the Japanese dwarfing genes is largely unknown. Here, we report a study of WMS261 allelic diversity in a historical wheat collection from 1865 representing worldwide major wheats at the time. The majority carried the previously reported 164 bp or 174 bp allele, but with little geographical correlation. In a few lines, a rare 182 bp fragment was found. Although straw length was recognized as an important character already in the 19th century,Rht8probably played a minor role for height variation. The use of WMS261 and other functional markers for analyses of historical specimens and characterization of historic crop traits is discussed.

scholarly journals The effect of pinholes of different sizes on visual acuity under different refracting states and ambient lighting conditions*

2009 ◽  
Vol 68 (1) ◽  
Author(s):  
N. Abdul ◽  
N. Meyer ◽  
M. Van Bosch ◽  
A. Van Zyl ◽  
M. Viljoen ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Minor Role ◽  
Lighting Conditions ◽  
Ambient Lighting ◽  
High Illumination ◽  
Drastic Effect ◽  
Low Illumination ◽  
A Minor ◽  
Forward Process ◽  
Positive Results

Purpose: The purpose of this pilot study was to investigate the effect of different size pinholes on visual acuity (VA) at near (0.4 m) while various factors were altered. The alterations made involved accommodation and illumination.Method: Four subjects were selected and their ages ranged from 7 to 14 years. Subjective refractions were performed and then near visual acuities were measured at 0.4 m under two different lighting conditions (460 lux and 1 lux) by adding stigmatic (or spherical) lenses of positive and negative powers in front of pinholes of diameters 1.5 mm and 2 mm.Results: The results showed that there was an improvement in VA in most, however, the size of the pinhole played a minor role. Low illumination did have a drastic effect on our results not only by decreasing the amount of lenses used for near that gave more positive results, but also when the pinhole was placed in front of the subjects. According to Borish, the pinhole does improve VA by a straight forward process of elimination produced by spherical aberrations of the eye. However, this did not seem to be the case in this study under conditions of low illumination.Conclusion: The pinhole effect offers improvement in VA at near by reducing the amount of blupresented to the retina. This study showed that alsubjects had an improvement in VA of at least twolines in high illumination. Pinhole size did not alte the results sufficiently thus suggesting that a pinhole, no matter the size, should increase the VA. However this was not the case when illumination was decreased.

scholarly journals Effects of Rht17 in combination with Vrn-B1 and Ppd-D1 alleles on agronomic traits in wheat in black earth and non-black earth regions

2020 ◽  
Vol 20 (S1) ◽  
Author(s):  
Pavel Yu. Kroupin ◽  
Gennady I. Karlov ◽  
Ludmila A. Bespalova ◽  
Elena A. Salina ◽  
Anastasiya G. Chernook ◽  
...  
Keyword(s):  
Plant Height ◽  
Genetic Background ◽  
Harvest Index ◽  
Agronomic Traits ◽  
Wheat Breeding ◽  
Pleiotropic Effects ◽  
Grain Weight ◽  
Dwarfing Genes ◽  
Spring Bread Wheat ◽  
Krasnodar Krai

Abstract Background Plant height is an important wheat trait that is regulated by multiple genes, among which Rht is of the utmost value. In wheat, Rht-B1p (=Rht17) is a mutant allele of the Rht gene that encodes for a DELLA-protein and results in the development of gibberellin-insensitive plants with a dwarfing phenotype. The pleiotropic effects of dwarfing genes on yield are highly dependent on both the genetic background and the environmental conditions. In Russia, the Central Non-Black Earth Region and Krasnodar Krai are two economically important regions that require differing management for sustainable wheat production for food, feed and industry. The purpose of our study was to compare the pleiotropic effects of Rht-B1p on the main valuable agronomic traits in the F3:4 families of the spring bread wheat Chris Mutant/Novosibirskaya 67 in the genetic background of Vrn-B1a/vrn-B1 (spring/winter phenotype) and Ppd-D1a/Ppd-D1b (insensitivity/sensitivity to photoperiod) alleles in a field experiment in Moscow and Krasnodar Krai. Results Plant height was reduced on average by 21 cm (28%) and 25 cm (30%), respectively; Ppd-D1a slightly strengthened the dwarfing effect in Moscow and mitigated it in Krasnodar Krai. Grain weight of the main spike was reduced by Rht-B1p in Moscow and to lesser extent in Krasnodar; Ppd-D1a and Vrn-B1a tended to partially compensate for this loss in Krasnodar Krai. Thousand grain weight was reduced on average by 5.3 g (16%) and 2.9 g (10%) in Moscow and Krasnodar Krai, respectively, but was partially compensated for by Ppd-D1a in Krasnodar Krai. Harvest index was increased due to Rht-B1p by 6 and 10% in Moscow and Krasnodar Krai, respectively. Rht-B1p resulted in a delay of heading by 1–2 days in Moscow. Ppd-D1a accelerated heading by 1 day and 6 days in Moscow and in Krasnodar Krai, respectively. Conclusions Rht-B1p could be introduced into wheat breeding along with dwarfing genes such as Rht-B1b and Rht-D1b. Special attention should be paid to its combination with Ppd-D1a and Vrn-B1a as regulators of developmental rates, compensators of adverse effects of Rht-B1p on productivity and enhancers of positive effect of Rht-B1p on harvest index.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Produktivkraft als Versprechen

2016 ◽  
Vol 46 (185) ◽  
pp. 621-638 ◽  
Author(s):  
Christian Siefkes
Keyword(s):  
Private Consumption ◽  
Minor Role ◽  
Progressive Reduction ◽  
Internal Forces ◽  
A Minor

The ‘Fragment on Machines’ from Marx’s Grundrisse is often cited as an argument that the internal forces of capitalism will lead to its doom. But the argument that the progressive reduction of labor must doom capitalism lacks a proper foundation, as a comparison with the ‘Schemes of Reproduction’ given in Capital II shows. The latter, however, aren’t fully convincing either. In reality, more depends on the private consumption of capitalists than either model recognizes. Ultimately, most can be made of the ‘Fragment on Machines’ by reading it not as an exposure of capitalism’s internal contractions, but as a discussion of a possible communist future where labor (or work) will play but a minor role.

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