scholarly journals Multi-Level Genetic Variation and Selection Strategy of Neolamarckia cadamba in Successive Years

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1455
Author(s):  
Qingmin Que ◽  
Chunmei Li ◽  
Buye Li ◽  
Huiyun Song ◽  
Pei Li ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Tree Species ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Wood Products ◽  
Early Selection ◽  
Selection Efficiency ◽  
Age Related ◽  
Multi Level ◽  
Variation And Selection

Neolamarckia cadamba (Roxb.) Bosser is a tropical evergreen broadleaf tree species that could play an important role in meeting the increasing demand for wood products. However, multi-level genetic variation and selection efficiency for growth traits in N. cadamba is poorly characterized. We therefore investigated the efficiency of early selection in N. cadamba by monitoring the height (HT), diameter at breast height (DBH), and tree volume (V) in 39 half-sib families from 11 provenances at ages 2, 3, 4, 5, and 6 years in a progeny test. Age-related trends in growth rate, genetic parameters in multi-level, efficiency of early selection, and realized gain in multi-level for growth traits were analyzed. The result showed that genetic variation among families within provenances was higher than that among provenances. The estimated individual heritability values for the growth traits ranged from 0.05 to 0.26, indicating that the variation of growth traits in N. cadamba was subject to weak or intermediate genetic control. The age–age genetic correlations for growth traits were always positive and high (0.51–0.99), and the relationships between the genetic/phenotypic correlations and the logarithm of the age ratio (LAR) were described well by linear models (R2 > 0.85, except the fitting coefficient of genetic correlation and LAR for HT was 0.35). On the basis of an early selection efficiency analysis, we found that it is the best time to perform early selection for N. cadamba at age 5 before half-rotation, and the selection efficiencies were 157.28%, 151.56%, and 127.08% for V, DBH, and HT, respectively. Higher realized gain can be obtained by selecting superior trees from superior families. These results can be expected to provide theoretical guidance and materials for breeding programs in N. cadamba and can even be a reference for breeding strategies of other fast-growing tree species.

Genetic evaluation of crossbred lamb production. 4. Genetic parameters for first-cross animal performance

2007 ◽  
Vol 58 (8) ◽  
pp. 839 ◽  
Author(s):  
V. M. Ingham ◽  
N. M. Fogarty ◽  
A. R. Gilmour ◽  
R. A. Afolayan ◽  
L. J. Cummins ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Meat Quality ◽  
Mixed Models ◽  
Fixed Effects ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Quality Traits ◽  
Meat Quality Traits ◽  
Lamb Growth

The study estimated heritability for lamb growth and carcass performance, hogget ewe wool production, and worm egg count among crossbred progeny of maternal breed sires, as well as the genetic and phenotypic correlations among the traits. The data were from crossbred progeny of 91 sires from maternal breeds including Border Leicester, East Friesian, Finnsheep, Coopworth, White Suffolk, Corriedale, and Booroola Leicester. The sires were mated to Merino ewes at 3 sites over 3 years (and also Corriedale ewes at one site), with 3 common sires used at each site and year to provide genetic links. These sheep comprised part of the national maternal sire central progeny test program (MCPT) to evaluate the genetic variation for economically important production traits in progeny of maternal and dual-purpose (meat and wool) sires and the scope for genetic improvement. The matings resulted in 7846 first-cross lambs born, with 2964 wether lambs slaughtered at an average age of 214 days, and wool data from 2795 hogget ewes. Data were analysed using univariate mixed models containing fixed effects for site, year, sex and type of birth and rearing, dam source and sire breed, and random terms for sire and dam effects. Heritabilities and genetic correlations were estimated based on variances from progeny of 70 sires by fitting the same mixed models using a REML procedure in univariate and multivariate analyses. Estimates of heritability were low for lamb growth traits (0.07–0.29), meat colour and meat pH (0.10–0.23), and faecal worm egg count (0.10), moderate for carcass fat and muscle traits (0.32–0.47), and moderate to high for wool traits (0.36–0.55). Estimates of direct genetic correlations among liveweights at various ages were high and positive (0.41–0.77) and those between liveweights and most carcass and meat quality traits were small and varied in sign. Liveweights were moderately to highly positively correlated with most wool traits, except fibre diameter (–0.28–0.08). The study indicates that there is genetic variation for wool, growth, carcass, and meat quality traits, as well as for faecal worm egg count, with scope for selection within Australian maternal sire breeds of sheep.

Genetics of wood stiffness and its component traits inPinus radiata

2006 ◽  
Vol 36 (5) ◽  
pp. 1165-1178 ◽  
Author(s):  
Heidi S Dungey ◽  
A Colin Matheson ◽  
Dominic Kain ◽  
Robert Evans
Keyword(s):  
New Zealand ◽  
Genetic Correlations ◽  
Microfibril Angle ◽  
Early Selection ◽  
Stiffness Modulus ◽  
Wood Stiffness ◽  
South Wales ◽  
Age Related ◽  
Component Traits ◽  
Selection For

The potential for breeding Pinus radiata D. Don to improve wood stiffness (modulus of elasticity, MoE) was examined by obtaining pith-to-bark cores from trees at breast height in two independent genetic trials. The effectiveness of early selection for stiffness and indirect selection on the component traits, microfibril angle (MfA) and wood density, was determined as well as the age-related changes in the genetic variation of these traits. The first trial comprised 50 open-pollinated families in the central North Island, New Zealand. The second trial comprised 20 control-pollinated families in New South Wales, Australia. The genetic control of MfA, density, and MoE was found to be high in the corewood and moderate in the outerwood. Estimated genetic correlations suggested that early selection for most traits would be successful but could be carried out slightly earlier at the New Zealand site than at the Australian site. To maximize gain in the corewood, selection for MoE and MfA would be most effective around rings 4-8. There were no adverse correlations between MoE and MfA or density, implying that selection for MoE would also improve MfA and density.

scholarly journals Age-related Trends in Genetic Parameters for Jack Pine and Their Implications for Early Selection

2007 ◽  
Vol 56 (1-6) ◽  
pp. 242-252 ◽  
Author(s):  
Y. H. Weng ◽  
K. J. Tosh ◽  
Y. S. Park ◽  
M. S. Fullarton
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
Jack Pine ◽  
Single Site ◽  
Early Selection ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Age Related ◽  
Different Ages ◽  
Rotation Age

Abstract Trends in genetic parameters for height growth of jack pine (Pinus banksiana Lamb.) were examined over three series of family tests throughout New Brunswick. Data were analyzed for each site and across sites within each series. Although individual narrow sense heritability estimates from single-site analyses varied substantially from site to site and showed no consistent age-related pattern, the estimates from across-site analyses showed an increasing trend to age 20. Similar as individual narrow sense heritability, the coefficient of additive genetic variance estimated from single site showed more variation than those estimated from across site analyses. Age-age (type-a) genetic correlations for height were high and could be well predicted by a LAR2 model, where LAR is the natural logarithm of the ratio between two ages at assessment. Type-b genetic correlations were high and of similar magnitude at different ages. Genetic correlations between height at different ages and volume at one-half rotation age were generally high. Taking the volume at one-half rotation age as the target trait, the selection for target trait from early selection at ages 5~7 could be more efficient per year than direct selection.

scholarly journals Early Selection for Improving Volume Growth in Coastal Douglas-fir Breeding Programs

2012 ◽  
Vol 61 (1-6) ◽  
pp. 186-198 ◽  
Author(s):  
T. Z. Ye ◽  
K. J. S. Jayawickrama
Keyword(s):  
Growth Traits ◽  
Genetic Correlations ◽  
Volume Growth ◽  
Selection Criterion ◽  
Growth Increment ◽  
Douglas Fir ◽  
Early Selection ◽  
Family Selection ◽  
Total Growth ◽  
Age Trends

AbstractMeasurements on growth traits up to 41 years of age from 68 progeny sites in eight first-generation breeding zones of coastal Douglas-fir (Pseudotsuga menziesii [MIRB.] FRANCO var. menziesii) in the US Pacific Northwest were used to investigate age trends of genetic parameters and to determine optimum age of selection. Heritabilities and age-age genetic correlations were estimated using univariate or bivariate mixed model analyses. Heritability estimates tended to increase with age for both total growth and growth increment traits. The estimates showed different age trends among breeding zones, but the differences were generally small. Age-age genetic correlations for total growth traits fitted Lambeth’s model surprisingly well, despite the data being collected from multiple breeding zones. Using rotation-age (i.e., 50yr) volume as the selection criterion, the greatest correlated gains per year were achieved by making family selection at juvenile ages (i.e., 9 for height, 13 for diameter, and 11 for volume). Similar results were obtained for within-family selection except that the optimum ages of selection were 2~4 years later than that from family selection, i.e., 11 for height, 15 for diameter and volume. Early selection on total height was always more efficient and had earlier optimum ages than on other growth traits. The optimum ages of early family selection on total growth were 4~11 years earlier than on the corresponding growth increment traits. It was also evident that the optimum ages of selection occurred later for slow-growth trials than for fast-growing trials.

scholarly journals Genetic Variation Among and Within Populations in Swedish Species of Sorbus aucuparia L. and Prunus padus L. Assessed in a Nursery Trial

2005 ◽  
Vol 54 (1-6) ◽  
pp. 1-8 ◽  
Author(s):  
V. Baliuckas ◽  
T. Lagerström ◽  
L. Norell ◽  
G. Eriksson
Keyword(s):  
Genetic Variation ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Population Variation ◽  
Sorbus Aucuparia ◽  
Population Effect ◽  
Prunus Padus ◽  
Bud Flushing ◽  
Over Time ◽  
Leaf Colouring

Abstract Seedlings originating from open-pollinated offspring of six and four populations of Prunus padus and Sorbus aucuparia, respectively, were studied with respect to phenology and growth traits for 3-4 years in a nursery. There were no replications at the population levels since the experiments should be converted to seedling seed orchards. Therefore, a special statistical model for analysis of the population effect was developed making use of neighbour performances. This model was also used for derivation of heritabilities. The heritabilities for phenology traits were in many cases high in P. padus, > 0.40, while they varied in the range 0.07-0.62 in S. aucuparia. The population effect was significant for all growth rhythm traits in P. padus and for a majority of traits in S. aucuparia. In both species the heritability for height decreased over time. Only bud flushing in P. padus indicated a relationship with population latitudinal origin in some cases. The genetic correlations between bud flushing different years were relatively strong in both species while the corresponding correlations for leaf colouring were moderate in P. padus and weak in S. aucuparia. In conclusion, the observed structure suggests that the pattern of seed dispersal may have an influence on the among- and within-population variation.

Efficiency of early selection for rotation-aged growth and wood density traits in Pinus radiata

2005 ◽  
Vol 35 (8) ◽  
pp. 2019-2029 ◽  
Author(s):  
Li Li ◽  
Harry X Wu
Keyword(s):  
Pinus Radiata ◽  
Growth Traits ◽  
Growth Ring ◽  
Genetic Correlations ◽  
Ring Width ◽  
Early Selection ◽  
Breast Height ◽  
Growth Ring Width ◽  
Cambial Age ◽  
Heritability Estimates

A total of 1097 cross-sectional wood disks from breast height were sampled from two rotation-aged (27 and 31 years from planting) genetic trials of radiata pine (Pinus radiata D. Don) in Australia to estimate the genetic correlation between early and rotation-aged growth and wood quality traits and the efficiency of early selection. Annual growth-ring width and density, diameter at breast height (DBH), and area-weighted density (AD) from 30 open-pollinated families were measured using X-ray densitometry. Genotype × site interactions were not significant for density and growth traits. Ring density increased steadily from the pith to cambial age 14, and then density had little change in the following years. For AD, the family and individual heritability estimates were about 0.60 and 0.30 after the first 2 years. For DBH, family and individual narrow-sense heritability estimates increased steadily after the first 4 years, and family heritability increased to 0.7 at a cambial age of 11 and had little change thereafter. Individual heritability estimate increased to 0.4 at cambial age 14 and was similar for the later ages. Beyond a cambial age of 5 years, there were strong negative genetic correlations of around –0.80 between AD and DBH. Age–age genetic correlations for AD were high and reached 0.80 and above after cambial age 3. Age–age genetic correlations for DBH were similar to AD, except the first two years. The most efficient early selection year was between ages 4 and 6 years after planting for AD, and between ages 8 and 11 years for DBH.

scholarly journals 211 Changes in genetic parameters of fitness and growth traits under genomic selection in pigs

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 41-41
Author(s):  
Jorge Hidalgo ◽  
Shogo Tsuruta ◽  
Daniela Lourenco ◽  
Yijian Huang ◽  
Kent Gray ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genomic Selection ◽  
Variance Components ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Data Set ◽  
Daily Gain ◽  
Over Time

Abstract Genomic selection increases intensity of selection and decreases generation interval. However, intensive selection reduces genetic variation and can strengthen undesirable genetic correlations. The purpose of this study was to investigate changes in genetic parameters of litter size (LS), number born alive (NBA), number born dead (NBD) and average daily gain (ADG) and weight at off-test (WT) in pigs over time. The data set contained 20,086 (LS), 21,230 (NBA), 21,230 (NBD), 144,717 (ADG) and 144,718 (WT) phenotypic records. Pedigree file included 369,776 animals born between 2001 and 2018, of which 39,038 were genotyped. Two trait models were evaluated (LS-ADG, LS-WT, NBA-ADG, NBA-WT, NBD-ADG and NBD-WT) using 3-year sliding subsets starting from 2010. Variance components and genetic parameters were estimated using GIBBS2F90 program. Computations were performed with (BLUP) or without (ssGBLUP) genotypes. For BLUP (ssGBLUP), the changes in heritability from 2010–2012 to 2015–2018 were 0.08 to 0.09 (0.08 to 0.06) for LS, 0.33 to 0.24 (0.37 to 0.16) for ADG, 0.11 to 0.07 (0.10 to 0.07) for NBD, and 0.32 to 0.24 (0.38 to 0.17) for WT. Differences were also observed for genetic correlations as they were -0.23 to -0.73 (-0.31 to -0.58) for LS-ADG, -0.24 to -0.74 (-0.31 to -0.50) for LS-WT, -0.33 to -0.65 (-0.41 to -0.53) for NBA-ADG, -0.35 to -0.66 (-0.42 to -0.45) for NBA-WT, 0.12 to 0.04 (0.12 to 0.16) for NBD-ADG, and 0.11 to 0.05 (0.11 to 0.22) for NBD-WT. Genomic selection in pigs reduced heritabilities and emphasized the antagonistic relationship that are under strong selection. Heritabilities estimated from ssGBLUP declined more than those by BLUP while changes in the genetic correlations were smaller and more gradual by ssGBLUP. Differences between ssGBLUP and BLUP could be caused by genomic pre-selection unaccounted for by BLUP.

scholarly journals JUVENILE-MATURE GENETIC CORRELATIONS IN Pinus taeda CLONES PROPAGATED VIA SOMATIC EMBRYOGENESIS

2016 ◽  
Vol 40 (2) ◽  
pp. 255-267
Author(s):  
Poliana Coqueiro Dias ◽  
Aloisio Xavier ◽  
Marcos Deon Vilela de Resende ◽  
Fabrício Antonio Biernaski ◽  
Regiane Abjaud Estopa ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Pinus Taeda ◽  
Genetic Correlations ◽  
Estimation Procedure ◽  
Early Selection ◽  
Selection Efficiency ◽  
Selection For ◽  
Rotation Age ◽  
High Selection ◽  
Selection Of

ABSTRACT This study aimed to estimate the genetic correlation among selection ages (juvenile - adult) and efficiency of early selection for the height, diameter, and volume traits of individuals from Pinus taeda families propagated via somatic embryogenesis. This study was carried out by genetic-statistical analysis, estimation procedure of variance (Reml), and prediction components of breeding values (Blup), using the Selegen-Reml/Blup software. Genetic correlations among juvenile ages and rotation age were performed by applying the linear model developed by Lambeth (1980). In accordance with results of the established model, the early selection can be performed in clones of Pinus taeda with high selection efficiency. Ages from 4 to 6 years old are enough to select Pinus taeda clones propagated via somatic embryogenesis for harvesting at 8 and 12 years old; and 6 to 10 years old are enough to select them for harvesting at 20 years old. On the basis of the genetic correlations estimates from the environments, the clones' selection of Pinus taeda propagated via somatic embryogenesis should be developed specifically for each environment. The clones' selection can be performed considering the diameter due to the high correlation between volume and diameter.

scholarly journals Novel insights into the genetic relationship between growth and disease resistance in Pacific salmon

2018 ◽  
Author(s):  
Agustin Barría ◽  
Andrea. B. Doeschl-Wilson ◽  
Jean P. Lhorente ◽  
Ross. D. Houston ◽  
José. M. Yáñez
Keyword(s):  
Genetic Variation ◽  
Disease Resistance ◽  
Survival Time ◽  
Genetic Relationship ◽  
Coho Salmon ◽  
Growth Traits ◽  
Bacterial Load ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Piscirickettsia Salmonis

AbstractBackgroundBreeding for disease resistance has become a highly desirable strategy for mitigating infectious disease problems in aquaculture. However, knowledge of the genetic relationship between resistance and other economically important traits, such as growth, is important to assess prior to including disease resistance into the breeding goal. Our study assessed the genetic correlations between growth and survival traits in a large bacterial infection challenge experiment. A population of 2,606 coho salmon individuals from 107 full-sibling families were challenged with the bacteria Piscirickettsia salmonis. Growth was measured as average daily gain prior (ADG0) and during (ADGi) the experimental infection and as harvest weight (HW). Resistance was measured as Survival time (ST) and binary survival (BS). Furthermore, individual measures of bacterial load (BL) were assessed as new resistance phenotypes and to provide an indication of genetic variation in tolerance in salmonid species.ResultsSignificant moderate heritabilities were estimated for ADG0 (0.30 ± 0.05), HW (0.38 ± 0.03), and for the survival traits ST (0.16 ± 0.03) and BS (0.18 ± 0.03). In contrast, heritabilities for ADGi and log-transformed BL were low (0.07 ± 0.02 (significant) and 0.04 ± 0.03, respectively), although these increased to moderate significant levels (0.20 ± 0.09 and 0.12 ± 0.05, respectively) when traits were assessed in survivors only. Significant and favorable genetic correlations were found between ADG0 and the growth traits ADGi (0.40 ± 0.16) and HW (0.64 ± 0.09), as well as with resistance as ST (0.43 ± 0.18), indicating that fish with higher genetic growth rate early on and prior to infection not only tend to maintain their genetic growth advantage until harvest, but also tend to grow faster and survive longer during infection. Furthermore, no robust unfavorable genetic correlations between ADG0 and any of the other traits considered in this study, in particular BL, was identified. Adding log BL as covariates into the models for growth under infection and survival provided an indication for genetic variation in tolerance.ConclusionsThese results suggest that selective breeding for early growth would be expected to simultaneously increase survival time and growth performance during an infection with Piscirickettsia salmonis after accounting for variation in bacterial load, and harvest weight in this coho salmon population, without negatively impacting on pathogen burden.

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