Plasticity of primary and secondary growth dynamics in Eucalyptushybrids: a quantitative genetics and QTL mapping perspective

BMC Plant Biology

Research Article

Jean-Marc Gion¹  Jérôme Bartholomé¹  Jean-Marc Bouvet²  Frédéric Salmon²  Philippe Vigneron³  Christophe Plomion⁴ 

[1] CIRAD, UMR AGAP, Cestas, F-33612, France;INRA, UMR BIOGECO, Cestas, F-33612, France;CIRAD, UMR AGAP, F-34398, Montpellier, France;CIRAD, UMR AGAP, Pointe Noire, Congo;CRDPI, BP 1291, Pointe Noire, Rep. of Congo;INRA, UMR BIOGECO, Cestas, F-33612, France;

关键词: Growth;    Growth modelling;    Plasticity;    QTL x E interaction;    Heritability;    Eucalyptus;   

DOI  :  10.1186/1471-2229-13-120

 received in 2013-04-29, accepted in 2013-08-14,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundThe genetic basis of growth traits has been widely studied in forest trees. Quantitative trait locus (QTL) studies have highlighted the presence of both stable and unstable genomic regions accounting for biomass production with respect to tree age and genetic background, but results remain scarce regarding the interplay between QTLs and the environment. In this study, our main objective was to dissect the genetic architecture of the growth trajectory with emphasis on genotype x environment interaction by measuring primary and secondary growth covering intervals connected with environmental variations.ResultsThree different trials with the same family of Eucalyptus urophylla x E. grandis hybrids (with different genotypes) were planted in the Republic of Congo, corresponding to two QTL mapping experiments and one clonal test. Height and radial growths were monitored at regular intervals from the seedling stage to five years old. The correlation between growth increments and an aridity index revealed that growth before two years old (r = 0.5; 0.69) was more responsive to changes in water availability than late growth (r = 0.39; 0.42) for both height and circumference. We found a regular increase in heritability with time for cumulative growth for both height [0.06 - 0.33] and circumference [0.06 - 0.38]. Heritabilities for incremental growth were more heterogeneous over time even if ranges of variation were similar (height [0-0.31]; circumference [0.19 to 0.48]). Within the trials, QTL analysis revealed collocations between primary and secondary growth QTLs as well as between early growth increments and final growth QTLs. Between trials, few common QTLs were detected highlighting a strong environmental effect on the genetic architecture of growth, validated by significant QTL x E interactions.ConclusionThese results suggest that early growth responses to water availability determine the genetic architecture of total growth at the mature stage and highlight the importance of considering growth as a composite trait (such as yields for annual plants) for a better understanding of its genetic bases.

【 授权许可】

Unknown   
© Bartholomé et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.