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Genetic dissection of quantitative traits in Scots pine

Abrahamsson, Sara (2011). Genetic dissection of quantitative traits in Scots pine. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2011:77
ISBN 978-91-576-7621-4
[Doctoral thesis]

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The phenotypic expressions of Scots pine, have been extensively studied over the years, but the gene regulation behind the traits has only just begun to be elucidated. The overall aim of this thesis was to start dissecting the genetics behind a number of adaptive traits in Scots pine and examine how they are influenced by relatedness using different molecular tools.

In a full-sib family of Scots pine the genetic variation in autumn frost hardiness and height growth was revelead by measuring open-pollinated offspring. A significant genetic variation for both traits was found, a prerequisite to identify quantitative trait loci (QTL). A conceptual statistical model in the Bayesian framework for identifying QTLs in dynamic traits i.e. traits that vary over time, was developed and applied in a QTL study based on a full-sib family of 250 trees. A set of 160 AFLPs were utilized. QTLs for three latent traits were identified: one for the slope (growth) and two for the quadratic term (growth cessation).
As a tool to identify candidate genes for the study of quantitative adaptive traits, gene regulation under continuous red (cR) and far-red (cFR) light was studied in hypocotyls from open-pollinated seeds from a natural population in northern Sweden using microarray technology. The gene expression patterns for the light response pathway in Scots pine under cFR show clear differences from those of angiosperms, wherein we observed up-regulation of cryptochrome1. This gene has, therefore, become a strong candidate gene that deserves further studies to elucidate the genetics behind Scots pine adaptation.

Not knowing the genetic relationship and inbreeding of trees, and how it influences the phenotypic expression, can lead to over- or underestimation of additive genetic values resulting in biased heritability estimates. A natural population of Scots pine, earlier identified as being highly inbreed, was used to investigate the influence of inbreeding by the correlation between heterozygosity and propotion of sound seed (PSS), average seed weight and proportion of rare alleles (PRA). Heterozygosity fitness correlation (HFC) was found positive for PSS and negative for PRA most likely due to recessive deleterious alleles purged in homozygotes. The study provided evidence that, as predicted by theory, inbreeding enhances HFC in a species with high outbreeding rate and high number of lethal equivalents as Scots pine.

Authors/Creators:Abrahamsson, Sara
Title:Genetic dissection of quantitative traits in Scots pine
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2011
Number of Pages:66
IAbrahamsson S, Nilsson J-E, Wu H, García-Gil MR and Andersson B (2011) Inheritance of height growth and autumn cold hardiness based on two generations of full-sib and half-sib families of Pinus sylvestris. Scandinavian Journal of Forestry (Submitted manuscript)
IISillanpää MJ, Pikkuhookana P, Abrahamsson S, Knürr T, Fries A, Lerceteau E, Waldmann P and García-Gil MR (2011) Simultaneous estimation of multiple quantitative trait loci and growth curve parameters through hierarchical Bayesian modeling. Heredity doi:10.1038/hdy.2011.56
IIIRanade S, Abrahamsson S, Niemi J, and García-Gil MR. Pinus taeda microarray as a tool for candidate gene identification for local red/far-red light adaptive response in Pinus sylvestris (Submitted manuscript)
IVAbrahamsson S, Hallander J and García-Gil MR The general effect model explains the weak heterozygosity-fitness correlation (HFC) in an inbred Scots pine population (Submitted manuscript)
Place of Publication:Umeå
Publisher:Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-7621-4
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F62 Plant physiology - Growth and development
Agrovoc terms:pinus sylvestris, quantitative trait loci, genes, inbreeding, cold tolerance, microsatellites, genetic markers
Keywords:heterozygosity fitness correlation, inbreeding, molecular markers, microsatellite, QTL, cold hardiness, height, AFLP, microarray, Light quality
Permanent URL:
ID Code:8329
Department:(S) > Dept. of Forest Genetics and Plant Physiology
External funders:Föreningen Skogsträdsförädling and Knowledge Foundation
Deposited By: Sara Abrahamsson
Deposited On:16 Sep 2011 12:08
Metadata Last Modified:02 Dec 2014 10:47

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