Inheritance of aluminium tolerance in Phalaris aquatica L

1986 ◽  
Vol 37 (4) ◽  
pp. 397 ◽  
Author(s):  
RA Culvenor ◽  
RN Oram ◽  
JT Wood
Keyword(s):  
Genetic Correlation ◽  
Breeding Population ◽  
Solution Culture ◽  
Aluminium Tolerance ◽  
Staining Procedure ◽  
Highly Sensitive ◽  
Sib Families ◽  
Heritability Estimates ◽  
The Difference ◽  
Further Development

The inheritance of aluminium tolerance in P. aquatica was investigated in solution culture, and correlations with other screening systems were determined. In the Israeli cultivar, Noy, the difference between the highly sensitive and moderately tolerant classes, which had been resolved in earlier experiments, can be largely explained by a two-gene hypothesis in which tolerance requires at least one dominant allele at each locus. Modifiers of these genes may also be involved. Assuming that the extensive continuous variation within the moderately tolerant class is polygenic, a quantitative inheritance study was conducted in a population of half-sib families in a diverse breeding population, the sensitive class being eliminated on performance in solution. Heritability estimates for relative root extension in solution ranged from 0.48 to 0.75, and estimated response to selection was high. However, heritability estimates for shoot growth of the same plants on a field site high in aluminium were low and non-significant (0.07-0.26). The highest estimate of genetic correlation between solution and field was not significant at 0.56. Variability in soil aluminium concentrations appeared to be a major cause of these low values. Prior screening of the population using a haematoxylin root-staining procedure gave a significant genetic correlation with solution responses (0.48). However, the technique requires further development for screening phalaris. In breeding for improved tolerance, the highly sensitive class could be eliminated by test crossing potential parents with homozygous sensitive plants. Several generations of selection could then be imposed, which, on the basis of genetic parameters estimated from solution screening, should yield a population appreciably more aluminium-tolerant than existing cultivars.

Heritabilities and genetic and phenotypic correlations for height and diameter in coastal Douglas-fir

1982 ◽  
Vol 12 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Francis C. Yeh ◽  
Chris Heaman
Keyword(s):  
Genetic Correlation ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Growing Season ◽  
Breeding Population ◽  
Douglas Fir ◽  
Single Tree ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Factorial crosses of 22 seed trees and 4 pollen parents from a breeding population of 445 coastal Douglas-firs were tested at two sites. Analyses of heights and diameters after the sixth growing season indicated only the significance of additive genetic variance. The single tree heritability estimates for height and diameter were 0.10 ± 0.07 and 0.12 ± 0.08, respectively. The genetic correlation between height and diameter was 0.81 ± 0.64.

Relative sensitivity of 18 full-sib families of Pinustaeda to O3

1982 ◽  
Vol 12 (2) ◽  
pp. 203-209 ◽  
Author(s):  
L. W. Kress ◽  
J. M. Skelly ◽  
K. H. Hinkelmann
Keyword(s):  
Loblolly Pine ◽  
Significant Variation ◽  
Relative Sensitivity ◽  
Air Pollutant ◽  
Symptom Expression ◽  
Foliar Symptom ◽  
Sib Families ◽  
The Difference ◽  
Old Trees ◽  
Further Development

Seedlings of 18 full-sib families of loblolly pine (Pinustaeda L.) were screened for sensitivity to 0.10, 0.15, 0.20, or 0.25 ppm O3 in 8-h exposures. Primary needles of newly germinated seedlings and secondary needles of 1-year-old trees were exposed when the needle ages were 3–4 and 8–12 weeks, respectively. Significant variation in foliar symptom expression was noted among families, and was nearly identical for both primary and secondary needles. Family 6-13 × 2-8 was the most sensitive in eight of nine treatments, and was significantly more sensitive than the remaining 17 families in five of nine treatments. In all cases, family 6-13 × 2-8 sustained greater injury than the families involving parent tree 504 (three families) and the difference was significant in eight of nine treatments. The data suggest that it may be feasible to use sensitive and insensitive families of loblolly pine as air pollutant bioindicators, although considerable further development is necessary. The finding that sensitivity and tolerance may be heritable warrants further study.

An analysis of pre-weaning deaths in rabbits with special emphasis on enteritis and pneumonia. II. Genetic sources of variation

1967 ◽  
Vol 9 (1) ◽  
pp. 93-97 ◽  
Author(s):  
W. C. Rollins ◽  
R. B. Casady
Keyword(s):  
Genetic Correlation ◽  
Death Rate ◽  
Genetic Effects ◽  
Experiment Station ◽  
Sources Of Variation ◽  
Heritability Estimates ◽  
The Difference ◽  
Additive Genetic Effects ◽  
The U.S

Heritability estimates of death from enteritis or pneumonia, the two major causes of pre-weaning death at the U.S. Rabbit Experiment Station, Fontana, California, have been estimated. The data consisted of 15,329 observations made at the station from 1946 to 1961.From birth to 14 days of age the death rate over the years increased from 0·2 to 6·1% During the period from 15 days to 56 days of age (weaning) the enteritis death rate was quite constant over the years (7·5%) while that of enteritis or pneumonia increased from 8·3% to 13·2%.Heritability of death from enteritis or pneumonia for the period 15 to 56 days of age was estimated on the basis of paternal half sib analysis to be 0·12 ± 0·02. Based on an analysis of differences between dams within sires the corresponding estimate was 0·58 ± 0·05. The difference between the two estimates was attributed to maternal and non-additive genetic effects.The genetic correlation between the two diseases under discussion was estimated to be 0·66 and 0middot;57 on the basis of differences among sires and among dams within sires respectively.Breeding plans are suggested on the basis of the parameters estimated.

scholarly journals Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Parameter Estimates ◽  
Sampling Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

scholarly journals Three Social Classroom Applications to Improve Student Attitudes

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Alf Inge Wang ◽  
Aleksander Aanesl. Elvemo ◽  
Vegard Gamnes
Keyword(s):  
Social Interaction ◽  
Software Architecture ◽  
Student Attitudes ◽  
Activity Level ◽  
Difficulty Level ◽  
Technical Quality ◽  
Digital Devices ◽  
Highly Sensitive ◽  
The Difference

The paper presents results of a quasiexperiment where the three social classroom applications Post-It, WordCloud, and Categorizer were used in software architecture lectures. Post-It and WordCloud are applications that allow students to brainstorm or give comments related to a given topic. Categorizer is a puzzle game where the students are asked to place a number of terms in one of two correct categories. The three applications are multimodal HTML5 applications that enable students to interact in a classroom using their own digital devices, and the teacher’s laptop is used to display progress and results on the large screen. The focus of this study was to evaluate how the difference of these applications and how their integration into the lecture affected the students’ motivation, engagement, thinking, activity level, social interaction, creativity, enjoyment, attention, and learning. In addition, the study evaluated the usability and the technical quality of the applications. The results of the experiment show that the way such applications are integrated into a lecture highly affects the students’ attitude. The experiment also showed that the game-based application was on average better received among the students and that the students’ attitude was highly sensitive to the difficulty level of the game.

An analysis of the variation in the lean tissue distribution of sheep

1982 ◽  
Vol 34 (3) ◽  
pp. 257-264 ◽  
Author(s):  
B. T. Wolf
Keyword(s):  
Tissue Distribution ◽  
Genetic Correlation ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Maximum Difference ◽  
Lean Tissue ◽  
Heritability Estimates ◽  
The Relationship ◽  
Daily Gain ◽  
Sire Breed

ABSTRACTThe distribution of lean tissue between eight standard joints was examined in 956 crossbred lambs slaughtered at constant live weights of either 35 or 40 kg. The sire breeds used were the Dorset Down, Ile-de-France, Oldenburg, Oxford, Suffolk and Texel. Sire breed did not have a significant effect on the proportion of total carcass lean found in the higher-priced joints but did show significant differences in the proportion of total carcass lean found in individual joints, with a maximum difference of 7·7 g total lean per kg joint being recorded. Similarly, small but significant effects due to ewe age (1 to 3 years), rearing type (single, twin, triplet), sex (male castrate, female) and weight of total lean were reported for the proportion of total carcass lean found in different joints.Heritability estimates ranged from 0·07 (s.e. 008) to 0·65 (s.e. 0·16) for the proportion of total lean in the best-end neck and higher-priced joints respectively. Phenotypic standard deviations of 5·8g/kg and 17·9g/kg were reported for the proportion of total lean found in the best-end neck and the higher-priced joints respectively. The genetic correlations between the proportion of total lean in each of the higher-priced joints and the proportion of total lean in the higher-priced joints combined were positive. A genetic correlation of 017 (s.e. 0·20) was found for the relationship between average daily gain from birth to slaughter and the proportion of total lean in the higher-priced joints.

scholarly journals The Psychology of Creativity: A Discussion Between Creative Potential and Its Realization

2015 ◽  
Vol 2 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Jacek Gralewski
Keyword(s):  
Social Psychology ◽  
Creative Activity ◽  
Creative Potential ◽  
Social Conditioning ◽  
Creativity Research ◽  
The Social ◽  
The Difference ◽  
Further Development ◽  
Different Levels ◽  
Psychology Of Creativity

AbstractThis text is devoted to a discussion of current achievements in the psychology of creativity, as well as to the further development of the field. It is concerned with a criticism of former and current theses in the field of the psychology of creativity discussed by Glăveanu (2014). The arguments presented indicate that, despite Glăveanu’s (2014) proposition, the psychology of creativity is not in crisis. It is pointed out that the difference in views between supporters of the social psychology approach to creativity and psychology researchers oriented towards the study of creative potential on how to conduct creativity research, stems from a concentration on different levels of creativity, and not necessarily from an ineffective theory of creativity. As a consequence of these different perceptions of creativity at its particular levels, determining the prime standard of creative potential is not sufficient to understand the social conditioning of creative activity and the social assessment of creativity, and vice versa.

scholarly journals An Accidental Genetic Epidemiologist

2020 ◽  
Vol 21 (1) ◽  
pp. 15-36
Author(s):  
Robert C. Elston
Keyword(s):  
Statistical Analysis ◽  
Association Analysis ◽  
Genetic Epidemiology ◽  
Early Life ◽  
Method Development ◽  
Paternity Testing ◽  
Linkage And Association Analysis ◽  
Computer Package ◽  
Heritability Estimates ◽  
Further Development

I briefly describe my early life and how, through a series of serendipitous events, I became a genetic epidemiologist. I discuss how the Elston–Stewart algorithm was discovered and its contribution to segregation, linkage, and association analysis. New linkage findings and paternity testing resulted from having a genotyping lab. The different meanings of interaction—statistical and biological—are clarified. The computer package S.A.G.E. (Statistical Analysis for Genetic Epidemiology), based on extensive method development over two decades, was conceived in 1986, flourished for 20 years, and is now freely available for use and further development. Finally, I describe methods to estimate and test hypotheses about familial correlations, and point out that the liability model often used to estimate disease heritability estimates the heritability of that liability, rather than of the disease itself, and so can be highly dependent on the assumed distribution of that liability.

Horseshoe crabs as potential sentinel species for coastal health: juvenile haemolymph quality and relationship to habitat conditions

2018 ◽  
Vol 69 (6) ◽  
pp. 894 ◽  
Author(s):  
Billy K. Y. Kwan ◽  
Virginia K. Y. Un ◽  
S. G. Cheung ◽  
Paul K. S. Shin
Keyword(s):  
Horseshoe Crab ◽  
Anthropogenic Activities ◽  
Monitoring Program ◽  
Significant Negative Correlation ◽  
Sentinel Species ◽  
Crab Species ◽  
Horseshoe Crabs ◽  
The Difference ◽  
Lead Nickel ◽  
Further Development

As an interface between terrestrial and marine environments, coastal and estuarine areas are particularly prone to various pollution stresses. Identification of sentinel species is, therefore, essential to provide precautionary information on coastal health conditions. Given their significant ecological roles in estuarine ecosystems, horseshoe crabs are a potential species to indicate the general health status of coastal habitats. The present study demonstrated that the changes in haemolymph composition pattern of two Asian juvenile horseshoe crab species (Tachypleus tridentatus and Carcinoscorpius rotundicauda) are sensitive to reflect heavy metal (lead, nickel and iron) and nutrient (nitrate and ammonia) concentrations of intertidal sediments. In particular, a significant negative correlation was found for the amebocyte viability and ratio of granular–spherical to granular–flattened and degranulated dendritic-like morphological states of amebocytes in juvenile haemolymph with nitrate and lead concentrations respectively. There were also significantly higher concentrations of haemolymph haemocyanin and plasma protein in juvenile C. rotundicauda than in T. tridentatus on the same shore, possibly being related to the difference in foraging habitats of these two horseshoe crab species. Such non-lethal sampling of haemolymph from juvenile horseshoe crabs can be useful for a further development of the monitoring program in assessing potential environmental impacts by anthropogenic activities.

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