Genetic variation in quantitative traits and selective breeding in fish and shellfish

Aquaculture ◽  
1983 ◽  
Vol 33 (1-4) ◽  
pp. 51-72 ◽  
Author(s):  
Trygve Gjedrem
Keyword(s):  
Genetic Variation ◽  
Quantitative Traits ◽  
Selective Breeding ◽  
Fish And Shellfish

scholarly journals HSP90 affects the expression of genetic variation and developmental stability in quantitative traits

2008 ◽  
Vol 105 (8) ◽  
pp. 2963-2968 ◽  
Author(s):  
T. A. Sangster ◽  
N. Salathia ◽  
S. Undurraga ◽  
R. Milo ◽  
K. Schellenberg ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Quantitative Traits ◽  
Developmental Stability

Components of Genetic Variation Associated with Second and Third Chromosome Gene Arrangements in Drosophila melanogaster

Genetics ◽  
1987 ◽  
Vol 116 (1) ◽  
pp. 87-97
Author(s):  
James A Ferrari
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Low Temperature ◽  
Interaction Effect ◽  
Quantitative Traits ◽  
Development Time ◽  
Gene Arrangement ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Chromosome Gene

ABSTRACT The effects of naturally occuring combinations of second and third chromosome gene arrangements of Drosophila melanogaster on two quantitative traits were partitioned into parameters of additive, dominance and interaction components of genetic variation. Development time and preadult survival of the gene arrangement genotypes were measured under four experimental conditions. Gene arrangement effects, when significant, were predominantly additive under all conditions. Experimental conditions, however, did influence gene arrangement effects. A second chromosome effect on development time was detected when amount of food or temperature was reduced, but not under optimal conditions. A third chromosome additive effect on development was observed under all experimental conditions. A consistent interaction effect between second and third chromosome gene arrangements was detected only at low temperature. Gene arrangement effects on survival were not as consistent as for development time, but also depended on experimental conditions.

scholarly journals Quantitative and molecular genetic variation in sympatric populations of Medicago laciniata and M. truncatula (Fabaceae): relationships with eco-geographical factors

2007 ◽  
Vol 89 (2) ◽  
pp. 107-122 ◽  
Author(s):  
MOUNAWER BADRI ◽  
HOUCINE ILAHI ◽  
THIERRY HUGUET ◽  
MOHAMED ELARBI AOUANI
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Local Adaptation ◽  
Quantitative Traits ◽  
Gene Diversity ◽  
Sympatric Populations ◽  
Widespread Species ◽  
Geographical Factors ◽  
Significant Difference ◽  
Selection For

SummaryMedicago laciniata is restricted to south of the Mediterranean basin and it extends in Tunisia from the inferior semi-arid to Saharan stages, whereas M. truncatula is a widespread species in such areas. The genetic variability in four Tunisian sympatric populations of M. laciniata and M. truncatula was analysed using 19 quantitative traits and 20 microsatellites. We investigated the amplification transferability of 52 microsatellites developed in M. truncatula to M. laciniata. Results indicate that about 78·85% of used markers are valuable genetic markers for M. laciniata. M. laciniata displayed significantly lower quantitative differentiation among populations (QST=0·12) than did M. truncatula (QST=0·45). However, high molecular differentiations, with no significant difference, were observed in M. laciniata (FST=0·48) and M. truncatula (FST=0·47). Several quantitative traits exhibited significantly smaller QST than FST for M. laciniata, consistent with constraining selection. For M. truncatula, the majority of traits displayed no statistical difference in the level of QST and FST. Furthermore, these traits are significantly associated with eco-geographical factors, consistent with selection for local adaptation rather than genetic drift. In both species, there was no significant correlation between genetic variation at quantitative traits and molecular markers. The site-of-origin explains about 5·85% and 11·27% of total quantitative genetic variability among populations of M. laciniata and M. truncatula, respectively. Established correlations between quantitative traits and eco-geographical factors were generally more moderate for M. laciniata than for M. truncatula, suggesting that the two species exhibit different genetic bases of local adaptation to varying environmental conditions. Nevertheless, no consistent patterns of associations were found between gene diversity (He) and environmental factors in either species.

scholarly journals Spontaneous mutations and the origin and maintenance of quantitative genetic variation

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Wen Huang ◽  
Richard F Lyman ◽  
Rachel A Lyman ◽  
Mary Anna Carbone ◽  
Susan T Harbison ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Quantitative Traits ◽  
Spontaneous Mutation ◽  
Natural Populations ◽  
Empirical Work ◽  
Stabilizing Selection ◽  
Spontaneous Mutation Rate ◽  
Evolutionary Forces ◽  
Quantitative Genetic

Mutation and natural selection shape the genetic variation in natural populations. Here, we directly estimated the spontaneous mutation rate by sequencing new Drosophila mutation accumulation lines maintained with minimal natural selection. We inferred strong stabilizing natural selection on quantitative traits because genetic variation among wild-derived inbred lines was much lower than predicted from a neutral model and the mutational effects were much larger than allelic effects of standing polymorphisms. Stabilizing selection could act directly on the traits, or indirectly from pleiotropic effects on fitness. However, our data are not consistent with simple models of mutation-stabilizing selection balance; therefore, further empirical work is needed to assess the balance of evolutionary forces responsible for quantitative genetic variation.

scholarly journals The effect of physical mutagenic factors on some quantitative traits in the generation of M2 Sesamum indicum L.

2020 ◽  
Author(s):  
A.A. Mogîlda ◽  
Keyword(s):  
Genetic Variation ◽  
Radiation Dose ◽  
Quantitative Traits ◽  
Physical Factor ◽  
Potential Method ◽  
Sesamum Indicum ◽  
Quantitative Parameters ◽  
Induced Mutagenesis ◽  
Agricultural Plants

Induced mutagenesis is considered an effective and potential method for generating genetic variation in agricultural plants. The paper presents data on the influence of this physical factor on the quantitative parameters in the M2 generation of sesame samples from Zaltsadovski, Kadet, Adaptovanii 2 at a dose of 200, 300, 400 and 500 Gy (Gray). According to the results obtained, the variability of some features was revealed, which varied depending on the sample and the applied radiation dose. The greatest changes in indicators compared to control were found in the genotypes Kadet at a dose of 300 Gy and Adaptovanii (200 Gy). The spectrum of morphobiological changes in plants will also be assessed in the M3 generation.

scholarly journals Molecular evaluations of thirty one clones of poplar based on RAPD and SSR molecular markers

Genetika ◽  
2014 ◽  
Vol 46 (3) ◽  
pp. 985-1001 ◽  
Author(s):  
M.K. Singh ◽  
N.B. Singh ◽  
S. Thakur ◽  
P.K. Naik
Keyword(s):  
Genetic Variation ◽  
Molecular Markers ◽  
Selective Breeding ◽  
Analysis Of Molecular Variance ◽  
Ssr Primers ◽  
The World ◽  
The Mean ◽  
Relationship Of ◽  
Management And Conservation ◽  
Selective Breeding Programme

Poplar is an important tree species valued all over the world for its wood importance. Despite limited knowledge of the levels of genetic diversity and relatedness, their cultivation as a source of plywood is widespread. In order to facilitate reasoned scientific decisions on its management and conservation and prepare for selective breeding programme, genetic analysis of 31 genotypes was performed using RAPD and SSR molecular markers. Twenty six RAPD primers and 14 SSR primers amplified a total of 236 and 85 scoreable bands of which 86.44% and 86.02% were polymorphic. The mean coefficient of gene differentiation (Gst) was 0.388 and 0.341 indicating that 61.2% and 65.9% of the genetic variation resided within the populations. Analysis of molecular variance (AMOVA) indicated that majority of genetic variation (94.6% using RAPD and 89% using SSR) occurred among genotypes, while the variation between the three groups (categorized as tall, medium and small plants height) was 5.4% (using RAPD and 11% (using SSR). The dendrogram obtained from NJ and STRUCTURE analysis revealed splitting of genotypes into four clusters with clear distinction between short, medium and tall height genotypes, indicated that genetic differentiations measure with respect to RAPD and SSR. However, both the markers were equally useful in providing some understanding about the genetic relationship of different genotypes of poplar that are important in the conservation and exploitation of poplar genetic resources.

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