The Evolution of Avian Breeding Systems J. David Ligon

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 531-532
Keyword(s):  
Breeding Systems

Analysis of the effectiveness of Landrace families pigs breeding systems

2017 ◽  
Vol 1 (68) ◽  
pp. 153-157
Author(s):  
Natalia Lyashenko ◽  
◽  
Alexander Jarmoc ◽  
Maria Galicheva ◽  
Irina Tletseruk ◽  
...  
Keyword(s):  
Breeding Systems

scholarly journals DNA Polymorphism in Lycopersicon and Crossing-Over per Physical Length

Genetics ◽  
1998 ◽  
Vol 150 (4) ◽  
pp. 1585-1593 ◽  
Author(s):  
Wolfgang Stephan ◽  
Charles H Langley
Keyword(s):  
Dna Sequence ◽  
Dna Polymorphism ◽  
Sequence Polymorphism ◽  
Breeding Systems ◽  
Crossing Over ◽  
Physical Length ◽  
Interspecific Divergence ◽  
Dna Sequence Polymorphism ◽  
Outcrossing Species ◽  
Genomic Regions

Abstract Surveys in Drosophila have consistently found reduced levels of DNA sequence polymorphism in genomic regions experiencing low crossing-over per physical length, while these same regions exhibit normal amounts of interspecific divergence. Here we show that for 36 loci across the genomes of eight Lycopersicon species, naturally occurring DNA polymorphism (scaled by locus-specific divergence between species) is positively correlated with the density of crossing-over per physical length. Large between-species differences in the amount of DNA sequence polymorphism reflect breeding systems: selfing species show much less within-species polymorphism than outcrossing species. The strongest association of expected heterozygosity with crossing-over is found in species with intermediate levels of average nucleotide diversity. All of these observations appear to be in qualitative agreement with the hitchhiking effects caused by the fixation of advantageous mutations and/or “background selection” against deleterious mutations.

scholarly journals The role of historical factors and natural selection in the evolution of breeding systems of Oxalis alpina in the Sonoran desert ‘Sky Islands’

2010 ◽  
Vol 23 (10) ◽  
pp. 2163-2175 ◽  
Author(s):  
J. PÉREZ-ALQUICIRA ◽  
F. E. MOLINA-FREANER ◽  
D. PIÑERO ◽  
S. G. WELLER ◽  
E. MARTÍNEZ-MEYER ◽  
...  
Keyword(s):  
Natural Selection ◽  
Sonoran Desert ◽  
Breeding Systems ◽  
Sky Islands ◽  
Historical Factors

A simulation study of open nucleus and closed nucleus breeding systems in a sheep population

1995 ◽  
Vol 60 (1) ◽  
pp. 117-124 ◽  
Author(s):  
J. A. Roden
Keyword(s):  
Genetic Gain ◽  
Live Weight ◽  
Breeding Systems ◽  
Breeding Value ◽  
Linear Unbiased Prediction ◽  
Sheep Population ◽  
Best Linear Unbiased ◽  
Nucleus Breeding ◽  
Open Nucleus ◽  
Selection Of

AbstractStochastic simulation was used to compare the results of alternative breeding systems in a sheep population divided into 10 flocks of 120 ewes. The breeding systems compared were selection within closed flocks (CF), a closed nucleus system (CNS), an open nucleus system (ONS) and open nucleus systems with the selection of nucleus replacements being restricted to either nucleus born males (ONSRm) or nucleus born females (ONSRf). Selection was for a best linear unbiased prediction of breeding value for lamb live weight which had a heritability of 0·17. The open nucleus breeding systems (ONS, ONSRm, ONSRf) resulted in higher rates of genetic gain, more predictable selection responses and lower rates of inbreeding than either the closed nucleus system (CNS) or selection within closed flocks (CF). Initial genetic differences between flocks resulted in higher rates of genetic gain in the nucleus breeding systems due to the use of between flock genetic variance. In the ONS system up to 25% of nucleus sires and approximately 50% of nucleus dams were born in base flocks. Nevertheless if selection of either nucleus sires or dams was restricted to nucleus born animals there was very little change in genetic gain or rate of inbreeding.

Use of space as an indicator of social behavior and breeding systems in the gymnotiform electric fish Brachyhypopomus pinnicaudatus

2008 ◽  
Vol 83 (4) ◽  
pp. 379-389 ◽  
Author(s):  
Manuela Miranda ◽  
Ana C. Silva ◽  
Philip K. Stoddard
Keyword(s):  
Social Behavior ◽  
Electric Fish ◽  
Breeding Systems ◽  
Use Of Space ◽  
Brachyhypopomus Pinnicaudatus

Breeding Systems and Compatibility in Glyceria

Nature ◽  
1955 ◽  
Vol 175 (4456) ◽  
pp. 561-562 ◽  
Author(s):  
MARTIN BORRILL
Keyword(s):  
Breeding Systems

scholarly journals Growth performance and wood structure of wavy grain sycamore maple (Acer pseudoplatanus L.) in a progeny trial

2021 ◽  
Vol 78 (1) ◽  
Author(s):  
Mona Quambusch ◽  
Cornelia Bäucker ◽  
Volker Haag ◽  
Andreas Meier-Dinkel ◽  
Heike Liesebach
Keyword(s):  
Growth Performance ◽  
Vegetative Propagation ◽  
Seed Orchard ◽  
Breeding Systems ◽  
Acer Pseudoplatanus ◽  
Wood Structure ◽  
Progeny Trial ◽  
Plus Tree ◽  
Sycamore Maple ◽  
Figure Type

Abstract • Key message Wavy grain, a rare figure type of wood, leads to highly priced timber in Acer pseudoplatanus L. The influence of this trait on growth performance and its causes are not known. Analyzed wavy and straight grain sycamore maple progenies show comparable growth performance in a field trial. Stability of wavy grain after vegetative propagation is confirmed and genetic inheritance indicated. • Context Wavy grain is a rare figure type of wood resulting from undulating fiber growth that leads to a decorative and highly priced timber in Acer pseudoplatanus L. with top positions on auction sales. Nevertheless, neither the influence of this trait on growth performance is known, nor have the causes been disentangled. • Aims Our objectives were to find out if wavy grain figure influences growth parameters essential for log quality and to gain insight into the causes of wavy grain by the analysis of a progeny trial and a seed orchard. • Methods In a progeny trial with 30-year-old F-1-offspring from selected wavy grained and straight grained trees, trunk diameter, tree height, and trunk shape were evaluated. Additionally, 21 trees of the trial and selected plus tree-grafts of a seed orchard were felled and analyzed for occurrence and intensity of wavy grain structure. • Results No effect of the wavy and straight grain parentage on growth was observed in the progeny trial. Of the felled trees, over 30% showed evidence of wavy grain compared to rare occurrence in natural stands. Wood structure analysis of plus tree scions confirmed the stability of wavy grain after vegetative propagation. • Conclusion Wavy grain seems to be genetically inherited, and there seems to be no statistically significant difference in commercially relevant traits in the progeny. This highlights the value of including wavy grain as a desired attribute in breeding systems of maple.

The relative importance of hummingbirds as pollinators in two bromeliads with contrasting floral specializations and breeding systems

2018 ◽  
Author(s):  
Amanda Ferreira Pinto Magalhães ◽  
Pietro Kiyoshi Maruyama ◽  
Luísa Alícida Fernandes Tavares ◽  
Rodrigo Lemes Martins
Keyword(s):  
Breeding Systems ◽  
Relative Importance
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