scholarly journals EARLY GENERATION TESTING AS A MEANS OF PREDICTING THE VALUE OF SPECIFIC CHROMOSOME SUBSTITUTIONS INTO COMMON WHEAT

1970 ◽  
Vol 12 (4) ◽  
pp. 711-723 ◽  
Author(s):  
J. M. McEwan ◽  
P. J. Kaltsikes
Keyword(s):  
Chromosome Pair ◽  
Experimental Methods ◽  
Specific Chromosome ◽  
Univalent Chromosome ◽  
Early Generation ◽  
Homologous Chromosomes ◽  
Relative Contribution ◽  
Chromosome Substitutions ◽  
Early Generation Testing ◽  
Different Sources

Two experimental methods were used in an attempt to establish tests by which the value of whole chromosomes for substitution could be determined. The first of these, the F1 method, depended on the comparison of the performance of reciprocal F1 monosomic × disomic hybrid combinations, in which the univalent chromosome from the two different sources was tested against the uniform genetic background provided by the F1 hybrid. The second method, the F3 bulk method, involved the establishment of the chromosome pair under test in a pure state in a F3 hybrid bulk by the use of the appropriate monosomic line. This material was tested against the F3 hybrid bulk of the parental varieties in which all the chromosomes were freely segregating, and also against existing substitution lines.The F1 method demonstrated marked differences between homologous chromosomes of different varieties when they were tested in the univalent condition for the characters investigated. From these differences the homologous chromosomes of the varieties could, in some cases, be arranged in a linear order of performance, an order which may indicate their relative contribution if they were used in the production of substitution lines.The F3 bulk method did not reveal appreciable differences between the chromosome lines studied and therefore could not be used as a predictive method.

Comparison of Three Procedures for Early Generation Testing of Soybean

Crop Science ◽  
2002 ◽  
Vol 42 (3) ◽  
pp. 705 ◽  
Author(s):  
Steven K. St. Martin ◽  
Isaias O. Geraldi
Keyword(s):  
Early Generation ◽  
Early Generation Testing

Bulk, Pedigree, and Early Generation Testing Breeding Methods Compared in Soybeans 1

Crop Science ◽  
1973 ◽  
Vol 13 (3) ◽  
pp. 363-364 ◽  
Author(s):  
V. D. Luedders ◽  
L. A. Duclos ◽  
A. L. Matson
Keyword(s):  
Breeding Methods ◽  
Early Generation ◽  
Early Generation Testing

Interpretation of Transverse Profiles to Determine the Source of Rutting within an Asphalt Pavement System

2005 ◽  
Vol 1905 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Claude Villiers ◽  
Reynaldo Roque ◽  
Bruce Dietrich
Keyword(s):  
Surface Layer ◽  
Literature Review ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Falling Weight Deflectometer ◽  
Relative Contribution ◽  
Transverse Profile ◽  
Falling Weight ◽  
Different Sources

The transverse profilograph has been recognized as one of the most accurate devices for the measurement of rut depth. However, interpretation of surface transverse profile measurements poses a major challenge in determining the contributions of the different layers to rutting. A literature review has shown that the actual rutting mechanism can be estimated from a surface transverse profile for determination of the relative contribution of the layers to rutting. Unfortunately, much of the research yielded no verification or data. In addition, some techniques presented cannot be used if the rut depth is not well pronounced. Other techniques may be costly and time-consuming. The present research developed an approach that integrates ( a) falling weight deflectometer and core data along with 3.6-m transverse profile measurements to assess the contributions of different pavement layers to rutting and ( b) identifies the presence (or absence) of instability within the asphalt surface layer. This approach can be used regardless of the magnitude of the rut depth. On the basis of the analysis conducted, absolute rut depth should not be used to interpret the performance of the asphalt mixture. In addition, continued instability may not result in an increase in rut depth because the rutted basin broadens as traffic wander compacts or moves the dilated portion of the mixture. The approach developed appears to provide a reasonable way to distinguish between different sources of rutting. The conclusions drawn from analysis of the approach agreed well with observations from the trench cuts taken from four sections.

Early Generation Testing in Upland Cotton

Crop Science ◽  
2006 ◽  
Vol 46 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Darren G. Jones ◽  
C. Wayne Smith
Keyword(s):  
Upland Cotton ◽  
Early Generation ◽  
Early Generation Testing

scholarly journals PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN RYE AND GRASSHOPPERS

Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 677-684
Author(s):  
J L Santos ◽  
J Orellana ◽  
R Giraldez
Keyword(s):  
Secale Cereale ◽  
Banding Pattern ◽  
Chromosome Pair ◽  
Meiotic Pairing ◽  
Homologous Pairing ◽  
Eyprepocnemis Plorans ◽  
Homologous Chromosomes ◽  
Random Pairing ◽  
Structural Differences ◽  
Telomeric Heterochromatin

ABSTRACT Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in spontaneous tetraploid/diploid chimeras of three male grasshoppers (Eyprepocnemis plorans) whose chromosome pair 11 were heterozygous for C-banding pattern and in four induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heterochromatin C-bands in chromosomes 1R and 2R. In the grasshoppers, a preference for identical over homologous pairing was observed, whereas in rye both a preference for homologous rather than identical pairing and random pairing between the four chromosomes of the set was found. From the results in rye, it can be deduced that pairing preferences do not depend exclusively on the similarities between chromosomes involved. It is suggested that genotypic or cryptic structural differences between the homologous chromosomes of each pair analyzed might be responsible for the pairing preferences found. This hypothesis can also explain the results obtained in grasshoppers, although the possibility of premeiotic association cannot be excluded in this material.

Ephemeral Growth span and Rapid Veg-repo shift is Critical for Survival against Naturally Rainfed Upland and Erratic Drought in Rice Growing Regions

2018 ◽  
Vol 7 (6) ◽  
pp. 255-261
Author(s):  
Prafull Kumar ◽  
R S Netam ◽  
A K Thakur ◽  
Poonam Kumari
Keyword(s):  
Carbon Accumulation ◽  
Yield Potential ◽  
Research Station ◽  
College Of Agriculture ◽  
Early Generation ◽  
Flowering Duration ◽  
Early Generation Testing ◽  
Rainfed Upland ◽  
Source Sink ◽  
Biochemical Development

Two experiments were undertaken simultaneously (early generation evalua-tion and advanced generation evaluation respectively) during Kharif 2013-14 at S G College of Agriculture and Research Station, Jagdalpur, IGKV, Raipur, Chhattisgarh, to indentify and analyze ephemeral genotypes for their suitability in rainfed upland and present era’s climate change-laid unpredicted water stress production agro-ecosystem. In early generation testing, mean plot flowering was recorded to be 72 Days After Sowing (DAS), plant height 83cm, panicles per square meter 212 and grain yield to be 2330kg/ha. Regional check Vandana and CRR-676-1 flowered earliest by 68 DAS followed by CRR-627-35-1-5 (69 DAS) and CRR-507-11-B-1 and CRR-605-23-1. The CRR-433-2-1-1 flowered latest by 83 DAS and as per hypothesis; yield was con-siderably reduced since plant could not develop optimum source-sink bal-ance and carbon accumulation in seeds eventually. Regarding, crop yield, five genotypes placed above the local check, namely CRR-597-5-1 (29.47%), the national check i.e. Anjali (21.05%), CRR-676-1 (15.79%), CRR-433-2-1-1 (10.53%) and the regional check i.e. Vandana (7.92%). Among advanced ma-terial, interestingly, the highest yielding genotype flowered earliest (69 DAS) that suggests the accomplishment of crop growth and physio-biochemical development while utilizing the soil and environmental reserve appropriate-ly. On overall, mean yield was 2349kg/ha, whereas genotype CRR-616-B-2-54-1 ranked 1st with 2718 kg/ha yield, 69 days of flowering duration and short bold grains. The bimodal experiment concludes that ephemeral growth span and rapid veg-repo shift is critical for survival against naturally rainfed-upland and erratic drought in rice growing regions and those genotypes which maintain the physiological buffer at the shift will be able to sustain genetic yield potential.

Effectiveness of early-generation testing applied to upland rice breeding

Euphytica ◽  
2018 ◽  
Vol 214 (4) ◽  
Author(s):  
Matheus S. Barros ◽  
Odilon P. Morais Júnior ◽  
Patrícia G. S. Melo ◽  
Orlando P. Morais ◽  
Adriano P. Castro ◽  
...  
Keyword(s):  
Upland Rice ◽  
Rice Breeding ◽  
Early Generation ◽  
Early Generation Testing

Use of RFLPs to determine the chromosome composition of tetraploid triticale (A/B)(A/B)RR

Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 250-254 ◽  
Author(s):  
T. Lelley ◽  
E. Kazman ◽  
K. M. Devos ◽  
M. D. Gale
Keyword(s):  
Chromosome Pair ◽  
Fragment Length Polymorphism ◽  
Tetraploid Wheat ◽  
Selective Advantage ◽  
B Chromosome ◽  
Wheat Genome ◽  
Rflp Markers ◽  
Specific Chromosome ◽  
Genome Chromosome ◽  
B Genome

Tetraploid triticale, (A/B)(A/B)RR (2n = 28), is a botanical novelty, an amphiploid composed of a diploid rye and a 14 chromosome wheat genome made up of chromosomes of the A and B genomes of tetraploid wheat. Restriction fragment length polymorphism (RFLP) markers were used to elucidate the chromosome composition of the mixed wheat genome of 35 different tetraploid triticale lines. Of 128 possible A/B chromosome pair combinations, only 6 were found among these lines, with a prevalence of the 1A, 2A, 3B, 4B, 5B, 6B, and 7B karyotype. In most triticale lines stable wheat genomes made up of only homologous A or B genome chromosome pairs were identified, however, in some lines homoeologous chromosome pairs were found. In this paper we demonstrate that RFLPs can be used successfully as an alternative to C-banding for the identification of the chromosome composition of tetraploid triticale and discuss the possible selective advantage of specific chromosome composition.Key words: tetraploid triticale, mixed wheat genome, RFLR

scholarly journals Chromosomes are predominantly located randomly with respect to each other in interphase human cells

2002 ◽  
Vol 159 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Michael N. Cornforth ◽  
Karin M. Greulich-Bode ◽  
Bradford D. Loucas ◽  
Javier Arsuaga ◽  
Mariel Vázquez ◽  
...  
Keyword(s):  
Experimental Design ◽  
Chromosome Pair ◽  
Spatial Proximity ◽  
Whole Genome ◽  
Specific Chromosome ◽  
Interphase Nuclei ◽  
Small Deviations ◽  
Chromosome Associations ◽  
Whole Chromosome Painting

To test quantitatively whether there are systematic chromosome–chromosome associations within human interphase nuclei, interchanges between all possible heterologous pairs of chromosomes were measured with 24-color whole-chromosome painting (multiplex FISH), after damage to interphase lymphocytes by sparsely ionizing radiation in vitro. An excess of interchanges for a specific chromosome pair would indicate spatial proximity between the chromosomes comprising that pair. The experimental design was such that quite small deviations from randomness (extra pairwise interchanges within a group of chromosomes) would be detectable. The only statistically significant chromosome cluster was a group of five chromosomes previously observed to be preferentially located near the center of the nucleus. However, quantitatively, the overall deviation from randomness within the whole genome was small. Thus, whereas some chromosome–chromosome associations are clearly present, at the whole-chromosomal level, the predominant overall pattern appears to be spatially random.

scholarly journals Combined selection in early generation testing of self-pollinated plants

1997 ◽  
Vol 20 (4) ◽  
pp. 673-681 ◽  
Author(s):  
José Marcelo Soriano Viana ◽  
Cosme Damião Cruz
Keyword(s):  
Early Generation ◽  
Early Generation Testing ◽  
The Mean ◽  
Selection Indexes ◽  
Combined Selection ◽  
The Individual ◽  
Selection Of

Seven selection indexes based on the phenotypic value of the individual and the mean performance of its family were assessed for their application in breeding of self-pollinated plants. There is no clear superiority from one index to another although some show one or more negative aspects, such as favoring the selection of a top performing plant from an inferior family in detriment of an excellent plant from a superior family

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