Genetic variances among clonally propagated populations of tamarack and the implications for clonal forestry

1987 ◽  
Vol 17 (10) ◽  
pp. 1175-1180 ◽  
Author(s):  
Y. S. Park ◽  
D. P. Fowler
Keyword(s):  
New Brunswick ◽  
Clonal Propagation ◽  
Tree Improvement ◽  
Clonal Forestry ◽  
Additive Variance ◽  
Genetic Variances ◽  
Clonal Variance

Genetic variances of three tamarack (Larixlaricina (Du Roi) K. Koch.) populations in central New Brunswick were examined using vegetatively propagated materials. The component of variance due to clones within families was large for both 5-year height and survival and was partitioned into additive and nonadditive genetic variances. About 85% of the clonal variance for height was additive for the AFES and CANAAN populations but was only 18% for the NORTON population. For survival, the proportion of nonadditive variance was larger than additive variance for the AFES and CANAAN populations, whereas for the Norton population it was negligible. The possibility of clonal propagation and selection is explored as a tree improvement –reforestation option and a strategy is discussed.

Commercialization potential of somatic embryogenesis in black spruce tree improvement

1994 ◽  
Vol 70 (5) ◽  
pp. 593-598 ◽  
Author(s):  
G. W. Adams ◽  
M. G. Doiron ◽  
Y. S. Park ◽  
J. M. Bonga ◽  
P. J. Charest
Keyword(s):  
Somatic Embryogenesis ◽  
Clonal Propagation ◽  
Black Spruce ◽  
Tree Improvement ◽  
Embryogenic Tissue ◽  
Improvement Program ◽  
Mature Embryos ◽  
Somatic Plants ◽  
Number Of Individuals ◽  
Potential Tool

The somatic embryogenesis process was evaluated as a potential tool for operational vegetative propagation using individuals from families currently used in the J.D. Irving, Ltd. black spruce tree improvement program. Most families were responsive although the number of individuals within families capable of producing embryogenic tissue (ET) varied greatly (1–70%). Seventy-four percent of the ET clones produced mature embryos and most of these germinated. Greenhouse survival was initially low (11%) but improved in subsequent experiments to 45% as growing regimes were refined. Demonstration plantings of the resulting somatic plants were established at two sites in New Brunswick. A total of 206 clones were cryopreserved. The potential for integrating somatic embryogenesis techniques into tree improvement and stock production programs is discussed. Key words: tree improvement, somatic embryogenesis, clonal propagation, black spruce, biotechnology

ADDITIVE BY ADDITIVE VARIANCE WITH INBREEDING AND LINKAGE

Genetics ◽  
1984 ◽  
Vol 108 (2) ◽  
pp. 487-500
Author(s):  
C Clark Cockerham
Keyword(s):  
Quantitative Trait ◽  
Selection Response ◽  
Relative Effect ◽  
Identity By Descent ◽  
Additive Variance ◽  
Genetic Variances ◽  
Additive Component ◽  
Self Fertilization ◽  
Explicit Expressions

ABSTRACT Two-locus coancestries, which provide the coefficients of the additive by additive component in the variance and covariance of relatives for a quantitative trait, were formulated generally in terms of two-locus probabilities of identity by descent for combinations of parental and recombinant gametes. Explicit expressions, with linkage, were developed for all relatives of self-fertilization, for selfed and outbred relatives and for full and half sibs from unrelated inbred parents. The relative effect of linkage on the two-locus coancestry decreases rapidly as inbreeding and relatedness of the relatives increase. It was concluded that the error caused by ignoring linkage would probably be small in the estimation of genetic variances or in the projection of selection response with self-fertilization.

scholarly journals The status and potential of using controlled parentage in operational reforestation in New Brunswick

1998 ◽  
Vol 74 (2) ◽  
pp. 190-194 ◽  
Author(s):  
G. W. Adams ◽  
K. J. Tosh
Keyword(s):  
New Brunswick ◽  
Black Spruce ◽  
Seed Orchard ◽  
Tree Improvement ◽  
Breeding Programs ◽  
Future Challenges ◽  
The Status ◽  
Vegetative Multiplication ◽  
Improvement Programs ◽  
Initial Research

Tree improvement programs began in New Brunswick in the 1970s, and, by the early 1990s, most of the seed used in reforestation was from seed orchards. Initial research such as fertilizer trials and other flower induction methods focussed on increasing seed orchard yields. Trials have also been established to investigate parental contribution to seed orchard production. As the New Brunswick Tree Improvement Council breeding programs advance into the second generation, two new approaches have been developed to capture genetic gain more efficiently. The use of controlled breeding followed by vegetative multiplication of black spruce has been adopted operationally by J.D. Irving, Limited, and a jack pine meadow orchard has been established by the New Brunswick Department of Natural Resources and Energy. This paper presents an overview of these programs and the future challenges of using controlled parentage in operational reforestation stock production.

Tree improvement effects on tree size distributions forPicea glaucaandPicea marianain New Brunswick, Canada

2009 ◽  
Vol 25 (1) ◽  
pp. 10-20 ◽  
Author(s):  
Yuhui Weng ◽  
Yillsung Park ◽  
Dale Simpson ◽  
Kathy Tosh ◽  
Michelle Fullarton
Keyword(s):  
New Brunswick ◽  
Tree Improvement ◽  
Tree Size ◽  
Size Distributions

scholarly journals Porsild spruce in Canada – an update

2014 ◽  
Vol 90 (01) ◽  
pp. 105-107
Author(s):  
Rodney Arthur Savidge
Keyword(s):  
New Brunswick ◽  
Second Generation ◽  
Seed Orchard ◽  
Tree Improvement ◽  
Morphological Features ◽  
Common Component ◽  
New Developments ◽  
Engelmann Spruce ◽  
Wild Tree

Several new developments are noted since publication of “Porsild spruce in Canada” in The Forestry Chronicle in January 2013. Firstly, Porsild spruce has been found in northeastern Quebec. Secondly, although researchers were unaware of the fact until now, the Porsild spruce phenotype has been found to be a common component in the New Brunswick tree improvement program’s second-generation seed orchard in support of reforestation. Thirdly, a wild tree discovered in New Brunswick displays morphological features of Engelmann spruce and, based on observed similarities between Yukon Beringia Porsild spruce phenotypes and the accepted Engelmann spruce phenotype, it is possible that the New Brunswick Engelmann spruce tree was derived from the local Porsild spruce population.

Trends in variances and heritabilities with stand development of tropical pines

1996 ◽  
Vol 26 (8) ◽  
pp. 1473-1480 ◽  
Author(s):  
J. Vásquez ◽  
W.S. Dvorak
Keyword(s):  
Phenotypic Trait ◽  
Phenotypic Variance ◽  
Narrow Sense ◽  
Ontogenetic Changes ◽  
Narrow Sense Heritability ◽  
Additive Variance ◽  
Genetic Variances ◽  
Rate Of Increase ◽  
The Individual ◽  
Over Time

Phenotypic and additive genetic variances as well as narrow-sense heritability for cumulative height were determined from assessments of tropical pine (Pinuscaribaea Morelet, Pinuschiapensis (Mart.) Andresen, and Pinustecunumanii (Schw.) Eguiluz et Perry) trials established in South America and South Africa by the Central America and Mexico Coniferous Resources (CAMCORE) Cooperative. Cumulative stem height was analyzed from 1-, 3-, 5-, and 8-year data collected on open-pollinated families to determine additive genetic and phenotypic variances. Variances based on arithmetic as well as log-transformed values are presented. Phenotypic and genetic variances of log-transformed values decreased over time, probably reflecting the onset of intergenotypic competition. Absolute variances increased over time as the trials became older, but the rate of increase for phenotypic variance was greater than that for additive variance. Individual narrow-sense heritabiiities changed over time but without showing any definite trend by species. It appeared that variance trends reflected the varying ontogenetic changes during the development of the stands, which could be indicated by size of the trees rather than by their age. Breeding strategies in tropical pines should consider the increasing intensity of environmental effects as a stand matures, since they cause a decline of genetic variances at a higher rate than phenotypic variances. Furthermore, it is hypothesized that a phenotypic trait at a given ontogenetic stage of the individual is under temporal control of a set of genes that changes as the temporal environmental conditions change.

scholarly journals Significance of Linkage Disequilibrium and Epistasis on the Genetic Variances in Non-Inbred and Inbred Populations

2021 ◽  
Author(s):  
José Marcelo Soriano Viana ◽  
Antonio Augusto Franco Garcia
Keyword(s):  
Linkage Disequilibrium ◽  
Gene Networks ◽  
Current Knowledge ◽  
Genotypic Variance ◽  
Data Set ◽  
Additive Variance ◽  
Genetic Variances ◽  
Inbred Populations ◽  
The Impact ◽  
Epistatic Variance

Abstract Background The influence of linkage disequilibrium (LD), epistasis, and inbreeding on the genotypic variance continues to be an important area of investigation in genetics and evolution. Although the current knowledge about biological pathways and gene networks imply that epistasis is important in determining quantitative traits, the empirical evidence for a range of species and traits is that the genetic variance is most additive. This is confirmed by some recent theoretical studies. However, because these investigations have assumed linkage equilibrium, only additive effects, or simplified assumptions for the two- and high-order epistatic effects, the objective of this investigation was to provide additional information about the impact of LD and epistasis on the genetic variances in non-inbred and inbred populations, using a simulated data set.Results The epistatic variance in generation 0 corresponded to 1 to 10% of the genotypic variance, with 30% of epistatic genes, but it corresponded to 5 to 45% assuming 100% of epistatic genes. After 10 generations of random cross or selfing the ratio epistatic variance/genotypic variance increased in the range of 15 to 1,079%. The epistatic variances are maximized assuming dominant epistasis, duplicate genes with cumulative effects, and non-epistatic gene interaction. A minimization occurs with complementary, recessive, and dominant and recessive epistasis. In non-inbred populations, the genetic covariances have negligible magnitude compared with the genetic variances. In inbred populations, excepting for duplicate epistasis, the sum of the epistatic covariances was in general negative and with magnitude higher than the non-additive variances, especially under 100% of epistatic genes.Conclusions The LD level for genes, even under a relatively low gene density, has a significant effect on the genetic variances in non-inbred and inbred populations. Assuming digenic epistasis, the additive variance is in general the most important component of the genotypic variance in non-inbred and inbred populations. The ratio epistatic variance/genotypic variance is proportional to the percentage of interacting genes and increases with random cross and selfing. In general, the additive x additive variance is the most important component of the epistatic variance. The maximization of the epistatic variance depends on the allele frequency, LD level, and epistasis type.

An economic analysis of black spruce breeding in New Brunswick

1986 ◽  
Vol 16 (3) ◽  
pp. 476-483 ◽  
Author(s):  
J. P. Cornelius ◽  
E. K. Morgenstern
Keyword(s):  
New Brunswick ◽  
Black Spruce ◽  
Tree Improvement ◽  
Internal Rate Of Return ◽  
Discount Rates ◽  
Family Selection ◽  
Breeding Programs ◽  
Program Efficiency ◽  
Wide Range ◽  
Plus Tree

A representative black spruce (Piceamariana (Mill.) B.S.P.) breeding program was formulated using information collected from New Brunswick Tree Improvement Council cooperators. This "base program" was subjected to program profitability and program efficiency analyses. Costs and revenues were computed for a range of real discount rates. The results showed that variation in discount rates did not greatly influence the break-even level of gross discounted revenue, which was fairly stable at around $100 000 for the base orchard of 5.2 ha. Projected gross discounted revenue ranged from about $100 000 at 4.5% discount rate to $36 at 16%. With the internal rate of return at 4.4%, it was concluded that black spruce breeding is probably an economic means of securing extra wood supplies. The program efficiency component concentrated on resource allocation between plus-tree and family selection. The results suggested that current strategies are close to optimum; for a wide range of numbers of familis selected within a constant budget, gross returns remained within about 10% of the maximum possible for each assumption set. It was concluded that current breeding programs should be continued, with present recommended strategies retained.

Casuarina junghuhniana (Casuarinaceae) in India

2010 ◽  
Vol 58 (2) ◽  
pp. 149 ◽  
Author(s):  
R. S. C. Jayaraj
Keyword(s):  
Special Reference ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Tree Improvement ◽  
Pulp And Paper ◽  
Casuarina Equisetifolia ◽  
Clonal Forestry ◽  
Pure Species ◽  
The World ◽  
Potential Use

Casuarina junghuhniana Miq., introduced into India in 1996, is gaining importance as an agroforestry species, with potential use in pulp and paper industry. Tree improvement of the species and attempts at clonal forestry are in progress. A hybrid of Casuarina equisetifolia L. and C. junghuhniana, introduced in 1951 from Thailand, is also planted in India, with the wrong identity as Casuarina junghuhniana. The present paper reviews the silviculture and tree improvement of the species, especially the attempts at introduction to various parts of the world by CSIRO, Australia, with special reference to India. The paper also attempts to resolve the confusion between the hybrid and the pure species, among the planting agencies in India.

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