Heritability, gain, and C effects in rooting of western hemlock cuttings

1984 ◽  
Vol 14 (5) ◽  
pp. 628-638 ◽  
Author(s):  
G. Sam Foster ◽  
Robert K. Campbell ◽  
W. Thomas Adams
Keyword(s):  
Genetic Gain ◽  
Clonal Selection ◽  
Genetic Correlations ◽  
Morphological Characteristics ◽  
Western Hemlock ◽  
Clonal Variation ◽  
Potential Bias ◽  
Correlated Responses

Analysis of clonal variation for five rooting traits of western hemlock (Tsugaheterophylla (Raf.) Sarg.) clones demonstrated that clonal variation was due to both genetic and C effects (i.e., physiological or morphological characteristics unique to the ortet because of its specific environment). The potential bias to genotypic values of clones owing to C effects was significant, but heritability and gain estimates were only slightly biased. The five rooting traits were highly heritable (H2 = 0.87–0.92), and predicted genetic gain from clonal selection was substantial. Genetic correlations between pairs of traits were generally high (0.66−0.99); therefore, when selecting for any one trait, correlated responses can be expected in other traits.

scholarly journals Multiple Propagation Effects on Genetic Estimates of Rooting for Western Hemlock

1992 ◽  
Vol 117 (4) ◽  
pp. 651-655 ◽  
Author(s):  
Cecil T. Pounders ◽  
G. Sam Foster
Keyword(s):  
Root System ◽  
Genetic Gain ◽  
Clonal Selection ◽  
Western Hemlock ◽  
Clonal Variation ◽  
System Quality ◽  
Rooted Cuttings ◽  
Selection Procedures ◽  
Propagation Effects ◽  
Highly Correlated

Analysis of clonal variation for two rooting traits of western hemlock [Tsuga heteterophylla (Raf.) Sarg.] clones indicated that realized genetic gain would be improved by more effective partitioning and reduction of environmental differences associated with clones. Interactions between clones and multiple propagation dates were significant, but clone rank changes between dates were minor. Number of meted cuttings per plot (RC) and number of main roots per cutting (MR) were more highly correlated genetically (1.06) than phenotypically (0.36). Broad-sense heritabilitiesHx2 = 0.62 and Hx2 = 0.79 for RC and MR, respectively) and predicted genetic gain from clonal selection were moderately high. Both the percentage of rooted cuttings and root system quality could be rapidly improved by the clonal selection procedures used.

Clonal selection prospects in western hemlock combining rooting traits with juvenile height growth

1985 ◽  
Vol 15 (3) ◽  
pp. 488-493 ◽  
Author(s):  
G. Sam Foster ◽  
Robert K. Campbell ◽  
W. Thomas Adams
Keyword(s):  
Environmental Effect ◽  
Clonal Selection ◽  
Selection Index ◽  
Genetic Correlations ◽  
Height Growth ◽  
Western Hemlock ◽  
Rooted Cuttings ◽  
Unique Type ◽  
Genetic Components ◽  
Economic Weights

Variation in 1st-year height (HT) of western hemlock (Tsugaheterophylla (Raf.) Sarg.) rooted cuttings was partitioned into environmental and genetic components. C effects, a unique type of environmental effect, was highly significant and made up 8% of the total variation. Much of the variation (21%) resulted from genetic control of HT, producing a broad-sense heritability of 0.81. As reported in a previous paper, initial rooting ability of the rooted cuttings affected the 1st-year height growth of the trees. Genetic correlations between HT and the five rooting traits ranged from 0.37 to 0.59. Using a selection index (assuming 33% selection intensity) containing both HT and a rooting trait (VOL) would result in gains of 8–10% for HT and 20–34% for VOL, depending on relative economic weights for the two traits.

Field performance, C effects, and their relationship to initial rooting ability for western hemlock clones

1993 ◽  
Vol 23 (9) ◽  
pp. 1947-1952 ◽  
Author(s):  
A.D. Paul ◽  
G.S. Foster ◽  
D.T. Lester
Keyword(s):  
Clonal Selection ◽  
Genetic Correlations ◽  
Broad Sense ◽  
Total Variance ◽  
Western Hemlock ◽  
Regression Equations ◽  
Indirect Measure ◽  
Environmental Correlations ◽  
Rooting Ability ◽  
Initial Root

Rooted cuttings from 30 clones of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were established in a field trial in northwest Oregon. A secondary cloning approach was used to partition C effects variance from genetic variance. Clonal variance in total height was significant at 1 (HT1) and 5 (HT5) years and represented 9.2% and 10.6% of the total variance at the two ages, respectively. C effects variance (among primary ramets within clones) was nonsignificant and represented 2.4% and 0% of the total variance at the two ages, respectively. Broad-sense heritabilities of HT1 and HT5 were relatively low, being 0.10 and 0.13, respectively. When calculated on a clone-mean basis, the broad-sense heritabilities increased substantially, reaching 0.53 and 0.61 for HT1 and HT5, respectively. Phenotypic correlations paired between the rooting traits and either HT1 or HT5 were low and not significant. Genetic correlations were 0.42 and 0.29 between an indirect measure of initial root system volume (VOL) and HT1 or HT5, respectively. The genetic correlations between rooting ability and HT1 or HT5 were 0.61 and 0.69, respectively. No genetic correlation existed between length of the longest initial root and field height. Environmental correlations between initial rooting traits and field height were essentially zero. Of the three initial rooting traits tested via regression analysis, VOL served as the only significant predictor or either HT1 or HT5, although the R2 values were less than 0.03, hence, the regression equations were of no practical value. Based on these results, clonal selection of western hemlock for increased early height growth should be aided by indirect selection for clonal rooting ability via a multiple trait selection.

Genetic control of liability to infection with Nematospiroides dubius in mice: direct and correlated responses to selection of mice for faecal parasite egg count

Parasitology ◽  
1983 ◽  
Vol 87 (1) ◽  
pp. 113-127 ◽  
Author(s):  
P. J. Brindley ◽  
C. Dobson
Keyword(s):  
Genetic Control ◽  
Primary Infection ◽  
Genetic Correlations ◽  
Strong Positive Correlation ◽  
Correlated Responses ◽  
Antibody Titres ◽  
Refractory State ◽  
Selection Limit ◽  
Nematospiroides Dubius ◽  
Positive Correlations

SUMMARYMice selected as liable (L) and refractory (R) over 10 generations voided significantly more and less Nematospiroides dubius eggs compared with randomly mated (Rd) mice after primary infection with 100 larvae. Strong positive correlation was found between the numbers of N. dubius eggs in mouse faeces and the numbers of adult N. dubius recovered from mice culled from the R, Rd and L colonies. Selection limit based on a faecal e.p.g. was reached in the L mice after 9 generations whereas the faecal N. dubius e.p.g. voided by the R mice continued to decline throughout selection. In contrast, no change in worm numbers was found in L or R mice after 6 generations. The refractory state of the trait, liability to infection with N. dubius, was inherited as a dominant character with a realized heritability value of ~ 0∣2. Differential correlated responses from N. dubius infectivity compared with N. dubius fecundity and growth indicated murine genetic control of this trait by 2 major genetic units. In general, there were negative phenotypic and genetic correlations between the faecal N. dubius e.p.g. of mice and murine morphological conformation, but positive correlations between the faecal N. dubius e.p.g. of selected mice and establishment, growth and fecundity of N. dubius populations in these mice. There was little correlation between the faecal N. dubius e.p.g. after primary infection and anti-N. dubius antibody titres and parasite female/male sex-ratio.

Clonal variation in shoot respiration and tree growth of Eucalyptus hybrids

2007 ◽  
Vol 37 (8) ◽  
pp. 1404-1413 ◽  
Author(s):  
Andrew N. Callister ◽  
Peter K. Ades ◽  
Stefan K. Arndt ◽  
Mark A. Adams
Keyword(s):  
Respiration Rate ◽  
Tree Growth ◽  
Isothermal Calorimetry ◽  
Intraclass Correlation ◽  
Genetic Correlations ◽  
Volume Growth ◽  
Eucalyptus Camaldulensis ◽  
Tree Size ◽  
Balance Model ◽  
Clonal Variation

Respiration rate and efficiency in growing tissues are major determinants of plant growth. We measured apical shoot respiration and tree growth in 3-year-old clones of Eucalyptus camaldulensis Dehnhardt × Eucalyptus grandis W. Hill ex Maid. and Eucalyptus camaldulensis × Eucalyptus globulus Labill. Respiration was measured by isothermal calorimetry and the oxidation state of newly formed biomass was determined by elemental analysis. We found that the enthalpy change due to conversion of carbon substrate to biomass was too small for determining specific growth rate by an enthalpy balance model of respiration and growth. Negative phenotypic correlations were significant between respiration rate and basal area, height, volume, and volume growth. Genetic correlations between respiration rate and tree size or growth were mostly significant and estimates ranged from –0.55 to –1.02. Repeatability of the clone means was around 0.80 for respiration rate, 0.71–0.91 for summer growth, and in excess of 0.80 for tree size traits. The intraclass correlation for clones (within families) was 0.33 for rate of CO2 evolution and 0.45 for rate of metabolic heat evolution. Our results suggest considerable potential for altering respiration rate in breeding populations by selection, although the mechanisms linking respiration with growth require further investigation.

Response to selection in Australian Merino sheep. III. Single character selection for high and low values of wool weight and its components

1970 ◽  
Vol 21 (6) ◽  
pp. 955 ◽  
Author(s):  
HN Turner ◽  
MG Brooker ◽  
CHS Dolling
Keyword(s):  
Body Weight ◽  
Unit Area ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Initial Response ◽  
Skin Area ◽  
Correlated Responses ◽  
Fibre Number ◽  
Selection For ◽  
Staple Length

Direct and correlated responses are reported for 10 traits in eight pairs of lines under selection for high and low values of single characteristics : clean wool weight per head, clean wool weight per unit skin area (measured only in the groups under selection for it), body weight, wrinkle score, fibre number per unit skin area (adjusted for body weight), fibre diameter, staple length, and percentage clean yield. All groups showed overall divergence in the character under selection, though response was not always symmetrical, and in two cases (long staple and low fibre number) there was no continuing response after the initial response to extreme selection of the base parents. In all except one case, whenever previous estimates of genetic correlation were at the level of 0.2 or higher, correlated responses were in the predicted direction, though not always symmetrical in magnitude. The exception was a previously reported negative correlation between fibre number and staple length, which was not exhibited under selection for either character. Where two characters of a pair were under selection, reciprocal responses agreed in sign; magnitude will be examined in a later paper. Wool per unit area was shown to have a greater influence on clean wool weight than that of surface area, with staple length on this occasion being the most important component of wool per unit area. Reasons for an apparent decrease in the relative importance of fibre number are discussed. Three other points of importance in sheep breeding are again emphasized by these results : 1. Crimp in several pairs of groups was a poor indicator of fibre diameter. 2. Increases in clean wool weight were associated with falls in crimp number, even though fibre diameter actually became finer; diameter, not crimp, should therefore be used as a guide to wool quality. 3. The absence of genetic correlations DL and NL indicates that selection can be for high N (fibre number) with high L (staple length) and low D (fibre diameter) -in other words, a desirable fleece -with no impeding genetic correlations.

Multitrait and repeatability estimates of random effects on litter size in sheep

2002 ◽  
Vol 74 (2) ◽  
pp. 209-216 ◽  
Author(s):  
C. Hagger
Keyword(s):  
Litter Size ◽  
Random Effects ◽  
Genetic Gain ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Parameter Estimates ◽  
Data Sets ◽  
Phenotypic Variance ◽  
The Third ◽  
Meat Sheep

AbstractFive data sets with records of first, second and third lambings of the White Alpine sheep (WAS1, WAS2), the Brown-Headed Meat sheep (BFS), the Black-Brown Mountain sheep (SBS) and the Valais Black-Nose sheep (SNS) of Switzerland were used to estimate phenotypic and genetic parameters for litter size using a multitrait and a repeatability model by the REML method. The sets contained litter information from 26 274, 25 165, 18 913, 14 953 and 21 726 ewes, respectively. Average numbers of litters per ewe were between 2·09 and 2·31. Average litter sizes at birth were between 1·36 and 1·57 lambs in first, between 1·52 and 1·75 in second and, between 1·56 and 1·86 in third parities. Multitrait estimates of heritability for size of first litters were 0·164, 0·157, 0·117, 0·223 and 0·116 for the WAS1, WAS2, BFS, SBS and SNS data, respectively. The corresponding estimates were 0·176, 0·165, 0·140, 0·208 and 0·134 for second and, 0·141, 0·155, 0·121, 0·145 and 0·107 for third litters. The systematic increase in phenotypic variances from first to third litter within data sets favoured the multivariate over the repeatability approach. Genetic correlations between size of the first three litters were, with one exception, above 0·927. Random flock ✕ year and sire of litter effects contributed between 2·2% and 13·2% and between 0·7% and 4·7% to the phenotypic variance of the traits, respectively. Residuals contributed between 70·6% and 84·2% to this parameter, estimates for the third litter were always highest. Heritability estimates from the repeatability model were smaller than the smallest multivariate estimates. Expected genetic gain in litter size from selection on the multitrait model was equal to the achieved response from the repeatability approach.

scholarly journals Bayesian genetic parameters for body weight and survival of Nile tilapia farmed in Brazil

2011 ◽  
Vol 46 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Alexandra Inês Santos ◽  
Ricardo Pereira Ribeiro ◽  
Lauro Vargas ◽  
Freddy Mora ◽  
Luiz Alexandre Filho ◽  
...  
Keyword(s):  
Genetic Gain ◽  
Nile Tilapia ◽  
Genetic Parameters ◽  
Positive Impact ◽  
Genetic Correlations ◽  
Breeding Population ◽  
Linear Threshold ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Impact On Survival ◽  
Credible Intervals

The objective of this study was to estimate genetic parameters for survival and weight of Nile tilapia (Oreochromis niloticus), farmed in cages and ponds in Brazil, and to predict genetic gain under different scenarios. Survival was recorded as a binary response (dead or alive), during harvest time in the 2008 grow-out period. Genetic parameters were estimated using a Bayesian mixed linear-threshold animal model via Gibbs sampling. The breeding population consisted of 2,912 individual fish, which were analyzed together with the pedigree of 5,394 fish. The heritabilities estimates, with 95% posterior credible intervals, for tagging weight, harvest weight and survival were 0.17 (0.09-0.27), 0.21 (0.12-0.32) and 0.32 (0.22-0.44), respectively. Credible intervals show a 95% probability that the true genetic correlations were in a favourable direction. The selection for weight has a positive impact on survival. Estimated genetic gain was high when selecting for harvest weight (5.07%), and indirect gain for tagging weight (2.17%) and survival (2.03%) were also considerable.

scholarly journals Estimates of genetic correlations and correlated responses to selection in cashew (Anacardium occidentale L.)

1998 ◽  
Vol 21 (3) ◽  
pp. 398-402 ◽  
Author(s):  
Diógenes Manoel Pedroza de Azevedo ◽  
João Ribeiro Crisóstomo ◽  
Francisco Célio Guedes Almeida ◽  
Adroaldo Guimarães Rossetti
Keyword(s):  
Genetic Variance ◽  
Genetic Correlations ◽  
Anacardium Occidentale ◽  
Correlated Responses ◽  
Population Means ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Variance Estimates ◽  
Good Possibility ◽  
East West

The present study estimates variances and genetic and phenotypic correlations for five traits in 27 progenies of cashew trees (Anacardium occidentale L.). Data were obtained from a trial conducted in 1992 at Pacajus, Ceará, experimental station of Embrapa Agroindústria Tropical. The characters studied were plant height (PH), North-South and East-West canopy spreads (NSS, EWS), and primary and secondary branch numbers (PBN, SBN). All genetic and phenotypic correlations presented positive and significant values. Selection to increase or decrease the average of any one of the five characteristics of cashew plants in the progenies studied affected the average of the others. The 16-month-old canopy spread can be predicted from NSS or EWS since correlations between them were high. Correlations between PH and SBN were low, indicating that there is a good possibility of obtaining smaller plants without causing drastic reductions in SBN. PH and SBN showed, respectively, the lowest and highest genetic variance estimates relative to the corresponding population means.

scholarly journals Clonal Variation in Lateral and Basal Rooting of Populus Irrigated with Landfill Leachate

2011 ◽  
Vol 60 (1-6) ◽  
pp. 35-44 ◽  
Author(s):  
R. S. Zalesny ◽  
J. A. Zalesny
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Landfill Leachate ◽  
Clonal Selection ◽  
Lateral Roots ◽  
Adventitious Rooting ◽  
Clonal Variation ◽  
Basal Roots ◽  
Root Growth Rate ◽  
Root Types

AbstractSuccessful establishment and productivity ofPopulusdepends upon adventitious rooting from: 1)lateral rootsthat develop from either preformed or induced primordia and 2)basal rootsthat differentiate from callus at the base of the cutting in response to wounding. Information is needed for phytotechnologies about the degree to whichPopulusadventitious rooting is controlled by effects of individual genotypes, waste waters used as alternative fertigation sources, and their interactions. Our objective was to irrigate twelvePopulusclones with well water (control) or municipal solid waste landfill leachate and to test for differences between initiation of lateral versus basal roots, as well as root growth rate and distributional trends for both root types. We evaluated number and length of lateral roots initiated from upper, middle, and lower thirds of the cutting, as well as basal callus roots. Overall, leachate irrigation affected lateral roots but not basal roots, and there was broad clonal variation between and within root types. On average, there were 129% more lateral than basal roots, which ranged from 3 to 27 (lateral) and 2 to 10 roots (basal). The percent advantage of number of roots from the middle portion of the cutting relative to other sections was 120% (upper), 193% (lower), and 24% (basal). Clones, treatments, and their interaction did not affect root growth rate, which ranged from 1.5 ± 0.6 to 3.4 ± 0.3 cm d−1, with a mean of 2.3 ± 0.2 cm d−1. These results contribute baseline information for clonal selection needed to establishPopulusfor phytotechnologies, energy, and fiber.

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