Erik W. Andersson 
,
Kostas A. Spanos,
Timothy J. Mullin,
Dag Lindgren
Phenotypic selection compared to restricted combined index selection for many generations
Andersson E. W., Spanos K. A., Mullin T. J., Lindgren D. (1998). Phenotypic selection compared to restricted combined index selection for many generations. Silva Fennica vol. 32 no. 2 article id 689. https://doi.org/10.14214/sf.689
Abstract
A breeding population has been subjected to repeated selection and crossing by simulation. Unrestricted phenotypic selection and restricted combined index selection were compared at the same effective number for five generations. Results show that phenotypic selection often achieves the gain and diversity possible to achieve by combined index selection but the relative efficiency is different for different family sizes and heritabilities. When phenotypic selection was compared with restricted combined index method at low heritabilities, both methods performed almost equally in terms of gain at the same effective number in small family sizes, although in large families, phenotypic selection was less efficient. At high heritabilities phenotypic selection was as efficient as combined index selection. Phenotypic selection was more efficient in conserving additive variance than combined index selection over five generations compared at the same gain and effective number. The introduction of a dominance component to the total variance had little effect. An increased breeding population size by a factor of ten resulted in an increased additive gain by app. 15%. The conclusion is that even though combined index selection is superior in identifying and extracting the potential for breeding achievements, it is generally not performing better than mass selection when compared at the same effective population size in small families.
Keywords
genetic diversity;
heritability;
status number;
phenotypic selection;
index selection
-
Andersson,
Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden
E-mail
erik.andersson@genfys.slu.se
- Spanos, N.AG.RE.F.-Forest Research Institute, 57006 Vassilika, Thessaloniki, Greece E-mail kas@nn.gr
- Mullin, Genesis Forest Science Canada Inc., C.P. 64 Succursale Haute-Ville, Québec, QC G1R 4M8 Canada E-mail tjm@nn.ca
- Lindgren, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden E-mail dl@nn.se
Received 15 May 1997 Accepted 8 May 1998 Published 31 December 1998
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