Comparing gain and optimum test size from progeny testing and phenotypic selection in Pinus sylvestris

2007 ◽  
Vol 37 (7) ◽  
pp. 1227-1235 ◽  
Author(s):  
Björn Hannrup ◽  
Gunnar Jansson ◽  
Öje Danell
Keyword(s):  
Pinus Sylvestris ◽  
Genetic Parameters ◽  
Phenotypic Selection ◽  
Tree Breeding ◽  
Optimum Number ◽  
Progeny Testing ◽  
Southern Sweden ◽  
Family Selection ◽  
Investment Level ◽  
Optimum Balance

The profit from tree breeding is dependent on the amount of money invested and how these resources are spent, particularly in the testing of selection candidates. Simulations of within-family selection were used to find the optimum balance among the number of candidates, progenies per candidate, and test sites for a given investment level and to compare the profit from progeny testing and phenotypic selection. The simulations were based on genetic parameters estimated from 66 Pinus sylvestris L. progeny trials in southern Sweden and on compilations of breeding costs. For progeny testing the optimum number of candidates and test sites increased with increasing investment level, whereas the number of progenies per candidate and site decreased and stabilized at ca. 10 individuals. The maximum annual profit for the phenotypic selection was higher and occurred at a lower investment level than for progeny testing. Among the two alternatives of progeny testing studied, the intensive alternative with practices to stimulate early flowering showed a higher maximum annual profit than the base alternative.

Balanced forest tree improvement can be enhanced by selecting among many parents but maintaining balance among grandparents

2008 ◽  
Vol 38 (11) ◽  
pp. 2797-2803 ◽  
Author(s):  
Dag Lindgren ◽  
Darius Danusevičius ◽  
Ola Rosvall
Keyword(s):  
Genetic Gain ◽  
Phenotypic Selection ◽  
Tree Breeding ◽  
Breeding Population ◽  
Forest Tree ◽  
Selection Strategy ◽  
Family Selection ◽  
Parent Selection ◽  
Tree Breeding Program ◽  
Balanced Tree

A model for a balanced tree breeding program that considers genetic gain and cost was used to assess the benefits of increasing the breeding population to allow for a component of among-parent selection while maintaining an equal contribution among grandparents, rather than relaying on within-family selection with an equal parental representation. The scenario used in this study had characteristics similar to those of the phenotypic selection strategy for Scots pine ( Pinus sylvestris L.) in Sweden. The results showed that investments in a greater number of parents and families to allow for among-parent selection resulted in a markedly higher genetic gain. The among-parent selection component increased the genetic gain by as much as 70% in a scenario with a high budget and no family creation costs and by as much as 20% in a scenario with a low budget and high family creation costs.

Genetics and breeding of Sitka spruce

1987 ◽  
Vol 93 (1-2) ◽  
pp. 41-50
Author(s):  
Roy Faulkner
Keyword(s):  
Phenotypic Selection ◽  
Sitka Spruce ◽  
Interspecific Hybridisation ◽  
Family Selection ◽  
Short Term ◽  
Improvement Programme ◽  
Important Trait ◽  
Clonal Testing ◽  
Selection For ◽  
Old Trees

SynopsisSitka spruce is a monoecious, wind-pollinated, cross-fertilising species showing wide genetic variation which suggests heterozygosity for many alleles and natural selection against self-fertilisation. Phenotypic selection for the important trait of vigour is ineffective, so testing progenies of selected individuals and clonal testing is an essential and time-consuming part of any improvement programme. Old trees can be vegetatively propagated by grafting and very young trees by rooted cuttings.The British tree improvement programme is based, in the short term, on the use of seed collected from superior plantation trees of desirable origins; in the mid term on seed derived from clonal orchards based on mixtures of clones previously tested for superiority in family tests; and in the longer term on highly superior seed or clones derived from a system of recurrent mating with family selection. Three populations are being developed. There is a small interspecific hybridisation programme.

Patterns of genetic parameters for height in field genetic tests of Picea abies and Pinus sylvestris in Sweden

2011 ◽  
Vol 7 (6) ◽  
pp. 1099-1111 ◽  
Author(s):  
Johan Kroon ◽  
Tore Ericsson ◽  
Gunnar Jansson ◽  
Bengt Andersson
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Genetic Parameters ◽  
Genetic Tests

Optimum Group Size in Progeny Testing and Family Selection

Biometrics ◽  
1957 ◽  
Vol 13 (4) ◽  
pp. 442 ◽  
Author(s):  
Alan Robertson
Keyword(s):  
Group Size ◽  
Progeny Testing ◽  
Family Selection

Can we breed Merino sheep with softer, whiter, more photostable wool?

2010 ◽  
Vol 50 (12) ◽  
pp. 1089 ◽  
Author(s):  
S. Hatcher ◽  
P. I. Hynd ◽  
K. J. Thornberry ◽  
S. Gabb
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Phenotypic Selection ◽  
Quality Traits ◽  
Current Generation ◽  
Merino Sheep ◽  
Initial Cohort ◽  
Selection For

Genetic parameters (heritability, phenotypic and genetic correlations) were estimated for a range of visual and measured wool traits recorded from the 2008 shearing of the initial cohort of Merino progeny born into the Sheep CRC’s Information Nucleus Flock. The aim of this initial analysis was to determine the feasibility of selectively breeding Merino sheep for softer, whiter, more photostable wool and to quantify the likely impact on other wool production and quality traits. The estimates of heritability were high for handle and clean colour (0.86 and 0.70, respectively) and moderate for photostability (0.18), with some evidence of maternal effects for both handle and photostability. The phenotypic correlations between handle and clean colour and between handle and photostability were close to zero, indicating that achieving the ‘triple’ objective of softer, whiter, more photostable wool in the current generation through phenotypic selection alone would be difficult. There was evidence of an antagonistic relationship between handle and photostability (–0.36), such that genetic selection for softer wool will produce less photostable wool that will yellow on exposure to UV irradiation. However genetic selection for whiter wool is complementary to photostability and will result in whiter wool that is less likely to yellow. Genetic selection to improve handle, colour and photostability can be achieved with few detrimental effects on other visual and measured wool traits, particularly if they are included in an appropriate selection index.

Estimated Phenotypic and Genetic Parameters Based on data from the Swedish Pig Progeny Testing Stations

1980 ◽  
Vol 30 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Nils Lundeheim ◽  
Kjell Johansson ◽  
Kjell Andersson
Keyword(s):  
Genetic Parameters ◽  
Progeny Testing

scholarly journals Genetic parameters, phenotypic, genotypic and environmental correlations and genetic variability on sunflower in the Brazilian Savannah

2017 ◽  
Vol 47 (8) ◽  
Author(s):  
Ellen Grippi Lira ◽  
Renato Fernando Amabile ◽  
Marcelo Fagioli ◽  
Ana Paula Leite Montalvão
Keyword(s):  
Genetic Variability ◽  
Genetic Parameters ◽  
Environmental Control ◽  
Genetic Correlations ◽  
Phenotypic Selection ◽  
Phenotypic Variance ◽  
Environmental Correlations ◽  
High Genetic Variability ◽  
Brazilian Savannah ◽  
Main Component

ABSTRACT: Sunflower (Helianthus annuus L.) is an annual crop that stands out for its production of high quality oil and for an efficient selection, being necessary to estimate the components of genetic and phenotypic variance. This study aimed to estimate genetic parameters, phenotypic, genotypic and environmental correlations and genetic variability on sunflower in the Brazilian Savannah, evaluating the characters grain yield (YIELD), days to start flowering (DFL) based on flowering date in R5, chapter length (CL), weight of a thousand achenes (WTA), plant height (H) and oil content (OilC) of 16 sunflower genotypes. The experiment was conducted at Embrapa Cerrados, Planaltina, DF, situated at 15º 35’ 30”S latitude, 47º 42’ 30”W longitude and 1.007m above sea level, in soil classified as dystroferric Oxisol. The experimental design used was a complete randomized block with four replicates. The nature for the effects of genotypes and blocks was fixed. Except for the character chapter length, genetic variance was the main component of the phenotypic variance among the genotypes, indicating high genetic variability and experimental efficiency with proper environmental control. In absolute terms, the genetic correlations were superior to phenotypic and environmental. The high values reported for heritability and selective accuracy indicated efficiency of phenotypic selection. Results showed high genetic variability among genotypes, which may contribute to the genetic improvement of sunflower.

scholarly journals Towards new seed orchard designs in Germany – A review

2021 ◽  
Vol 70 (1) ◽  
pp. 84-98
Author(s):  
Heike Liesebach ◽  
Katharina Liepe ◽  
Cornelia Bäucker
Keyword(s):  
Native Species ◽  
Random Mating ◽  
Seed Orchard ◽  
Tree Breeding ◽  
Progeny Testing ◽  
Acer Pseudoplatanus ◽  
Seed Orchards ◽  
Breeding Populations ◽  
Estimated Breeding Values ◽  
Species Specific

Abstract New first and 1.5 generation seed orchards are to be created in Germany based on recently assembled breeding populations of Acer pseudoplatanus, Larix sp., Picea abies, Pinus sylvestris, Pseudotsuga menziesii, and Quercus sp. To justify the high expenses in time and cost for orchard establishment and maintenance, planning should make use of consolidated knowledge and experience of both the national and international scientific community. Here, we briefly describe advances in genetic gains achieved through tree breeding, and resume population genetic aspects and design considerations to draw conclusions for clonal composition and spatial design of the new orchards. We conclude that to avoid outbreeding depression separate orchards are required for each breeding zone. The zones are species-specific and defined by ecological and climatic aspects. A minimum of 60-80 clones per orchard is recommended for native tree species with high proportions of natural regeneration in forest practice. This would allow future selective thinning based on estimated breeding values from progeny testing. It would also permit the transfer of seed orchard progenies into a naturally regenerating forest stands without the risk of a genetic bottleneck. Lower clone numbers are appropriate for non-native species and hybrids. It is important to strictly avoid inbreeding depression, achieved by using only one clone per progeny or population, from which the plus trees were selected. Further, the spatial layout should promote random mating by optimizing the neighbourhood of each clone. With all of these considerations taken into account, we expect superior quality traits and at least 10-15 % more volume from the new seed orchards.

Estimation of genetic parameters for temperament and ease of milking assessed on a linear scale in friesian holstein heifers

1991 ◽  
Vol 1991 ◽  
pp. 167-167
Author(s):  
H J Bellamy ◽  
G J T Swanson
Keyword(s):  
Artificial Insemination ◽  
Genetic Parameters ◽  
Assessment Method ◽  
Progeny Testing ◽  
Linear Scale ◽  
Testing Scheme ◽  
Milk Marketing ◽  
Estimation Of Genetic Parameters

Following the introduction of the linear assessment method of evaluating conformation within the Dairy Progeny Testing Scheme run by the Artificial Insemination Organisation (now Genus) of the Milk Marketing Board in 1983 three new traits were included in 1985 and 1986. The new traits were Temperament, Ease of Milking and Fore Udder Angle. In addition information was collected on the number of hours since milked when the classification was carried out.The objective of this study was to establish whether the variation in linear scores was significantly affected by the number of hours since milked and also to estimate the phenotypic and genetic parameters for the new trails, in particular Temperament and Ease of Milking.

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