Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 71 for “"Genetic Correlations"”.
-
Investigating Damage, Genetic Correlations, and Natural Selection to Understand Multiple Plant Defenses in Passiflora incarnata
… investment in multiple defenses. Alternatively, genetic correlations between defenses could lead to their joint expression, even if possessing both defenses is non-adaptive. Plants may produce multiple defenses if putative resistance traits do not reduce damage, forcing plants to rely on …
-
Inheritance and Genetic Correlations of Certain Traits in Modified Endosperm Texture Opaque-2 Maize (Zea Mays L.)
… o2 and six modified o2 lines, and xenia effects, genetic variance components, and genetic correlations were determined in a modified population Synthetic Disease Oil o2o2. Variance components were estimated from analyses of S(,1) and S(,2)/S(,1) families and S(,1) progeny means. Plant height, 100 …
-
Genetic Parameters and Genetic Trends of Female Fertility in Icelandic Dairy Cattle
… by calving interval, has been included in the genetic evaluation of Icelandic dairy cattle since 1993. In spite of this an unfavourable genetic trend is seen and, recent implementation of test-day models for the genetic evaluation of milk production has changed the premise of using calving …
-
Genetic Analysis of Sheep Discrete Reproductive Traits Using Simulation and Field Data
… of restricted maximum likelihood (REML) in genetic analyses of categorical data was evaluated using simulation and field data. Four genetic models were used to simulate underlying phenotypic variates, which were derived as the sum of additive genetic and environmental effects (Model 1A and …
-
Genetic evaluation of ewe productivity and its component traits in Katahdin and Polypay sheep
… objectives of this dissertation were to evaluate genetic influences on ewe productivity, its growth and reproductive components, and measures indicative of accelerated lambing performance. Genetic parameters were estimated for total weight of litter weaned per ewe lambing (TW) and its components, …
-
Logistic growth curve parameter estimates for scrotal circumference and relationships with female reproduction in crossbred sheep
… to estimate variance components for additive genetic, ewe, and litter effects in group two Jambs. Heritability estimates for wt at birth to 150 d ranged from .14 to .42. Heritabilities for sc and sc scaled to the 1/3 power of body weight (rsc) ranged from .09 to .57 and from .13 to .55, …
-
Genotype by environment interaction for Holstein milk yield and fitness traits between Saudi Arabia and the United States
(Co)variance components and genetic parameters for Holstein first and all lactations mature equivalent milk and reproductive traits in the first four lactations were estimated by multiple-trait animal model using Method R procedures. The objectives of this study were to determine if genotype by …
-
Microevolutionary processes in natural populations of the waterstrider Aquarius remigis
… be optimal, but evolution may be constrained by genetics, the adaptive landscape, development, and functional limitations. Optimal body size is determined by the net effect of selection acting throughout the life history of the organism. Body size is correlated between the sexes, and sexual size …
-
Selection to improve spring fertility in a crossbred sheep population
… 5 years; 63 sires and 420 dams were represented. Genetic parameters were estimated by restricted maximum likelihood (REML) using various animal models. Heritability estimates for spring fertility ranged from .07 to .11. Litter size heritability was .05 for fall lambing and .10 for all lambings. …
-
Application of molecular markers to early generation testing in maize breeding
… (Zea mays L.) inbreds. Even though the expected genetic correlations between testcross performance in different generations is high, non-genetic effects reduce the effectiveness of early-generation testing. This experiment was conducted to determine the usefulness of molecular marker information …
-
Correlated responses and parameter changes in a bidirectional selection experiment for body weight in chickens
… and estimates of realized heritabilities, 3. Genetic correlations between the selected and unselected traits, 4. Phenotypic and environmental correlations between selected and unselected traits, and 5. The prediction of correlated responses. The realized heritabilities of unselected traits …
-
Factors affecting the phenologies of life history traits in two summer annual plant species
… phenologies, and the heritable basis of and genetic correlations among life history and morphological traits.
-
Genetic Parameters of Foal Inspection Scores in the International Sporthorse Registry and Oldenburg Registry North America
… North America were used for statistical and genetic analysis. Scored traits include type and conformation (TC), athletic ability of movement (AM), overall development as related to age (OD), and total score (TS) calculated as a weighted average of TC, AM, and OD. Premium status (PS) was …
-
Genetics, immunoresponsiveness, and disease resistance in chickens
… traits in lines HA and LA were due to genetic correlations with antibody response. These genetic correlations were generally negative and are suggestive of differential allocation of resources. Phenotypic correlations were generally very small. Changes in allelic frequencies at …
-
GENETIC PARAMETERS FOR HEAT AND SALINITY STRESS TOLERANCE IN NORTHERN GULF OF MEXICO EASTERN OYSTER, CRASSOSTREA VIRGINICA
… (h<sup>2</sup>) of tolerance traits and genetic correlations were estimated using linear mixed models. Heritability of heat stress tolerance in seed was low and did not differ significantly from zero (0.216±0.199). Heat stress tolerance in adults and condition index in juveniles were both …
-
Estimation of genetic parameters for development of alternative selection criteria for increased litter size in Rambouillet sheep
… needed to estimate heritabilities of and genetic correlations among litter size, ovulation rate, scrotal circumference and body weight in Rambouillet sheep were estimated using REML (Restricted Maximum Likelihood) via an EM (Expectation-Maximization) type algorithm. Data were obtained from …
-
Genetic evaluation of a linear trait description
… overall and regional age adjustment factors. Genetic parameters were estimated. Heritabilities ranged from .40 for stature to .14 for fore udder. Standard errors ranged from .039 for stature to .018 for fore udder. Genetic correlations ranged from +.75 between teats and udder support to -.61 …
-
Genetic Variability, Correlations and Selection Response for Kernel Traits in Two Modified Endosperm Opaque-2 Maize Populations
To determine the genetics of endosperm modification and the relationships with other traits in opaque-2 (o(,2)) maize (Zea mays L.), an investigation was conducted to estimate genetic variation, correlations and responses to S(,1) family selection for kernel traits in two modified endosperm o(,2) …
-
Estimates of genetic and phenotypic parameters in Columbia and Columbia X Southdale sheep
… and yearling ages as well as the phenotypic and genetic correlations among these traits. Information was acquired concerning the effects of year of birth, age of dam, type of birth and rearing, sex, breed, and station on the weanling and yearling traits considered. Data were available on 2442 …
-
Line characterization and evaluation of genetic parameters of serum cholesterol levels, activity, feed intake, growth and body moisture in selected and unselected lines of laboratory mice
… control (C). Heritability (h²), phenotypic and genetic correlations of SCL, activity, growth, and body moisture content were estimated for 466 sire-son pairs of mice from an unselected line. Blood samples were obtained by sinus orbital bleeding at 35 and 70 days of age in the line …
Page 1 of 4