Comprehensive genetic dissection of wood properties in a widely-grown tropical tree: Eucalyptus
1 CIRAD, Department of Biological System, Research Unit "Genetic improvement and adaptation of mediterranean and tropical plants" TA A-108/C, Campus International de Baillarguet, 34398 Montpellier Cedex, France
2 USBB - Institut du Pin, 351 cours de la libération, 33405 TALENCE Cedex, France
3 INRA, Unité d'Amélioration, Génétique et Physiologie Forestières, Olivet 45166, France
4 CIRAD, Department of Tropical Production system and Process Performance, Research Unit "Processing and promotion of Tropical Woods" 73 rue J-F Breton - TA B-40/16 - 34398 Montpellier Cedex 5, France
5 RAIZ - Forestry & Paper Research Institute, Qta S. Francisco, Apartado 15, Eixo, 3801-501 Aveiro, Portugal
6 CRDPI, BP 1291, Pointe Noire, République du Congo
7 UMR UPS/CNRS 5546, Pôle de Biotechnologies Végétales, 24 chemin de Borde Rouge, BP42617, Auzeville Tolosane, 31326 Castanet Tolosan, France
8 INRA, UMR 1202 BIOGECO, 69 route d'Arcachon, 33612 Cestas Cedex, France
BMC Genomics 2011, 12:301 doi:10.1186/1471-2164-12-301Published: 8 June 2011
Eucalyptus is an important genus in industrial plantations throughout the world and is grown for use as timber, pulp, paper and charcoal. Several breeding programmes have been launched worldwide to concomitantly improve growth performance and wood properties (WPs). In this study, an interspecific cross between Eucalyptus urophylla and E. grandis was used to identify major genomic regions (Quantitative Trait Loci, QTL) controlling the variability of WPs.
Linkage maps were generated for both parent species. A total of 117 QTLs were detected for a series of wood and end-use related traits, including chemical, technological, physical, mechanical and anatomical properties. The QTLs were mainly clustered into five linkage groups. In terms of distribution of QTL effects, our result agrees with the typical L-shape reported in most QTL studies, i.e. most WP QTLs had limited effects and only a few (13) had major effects (phenotypic variance explained > 15%). The co-locations of QTLs for different WPs as well as QTLs and candidate genes are discussed in terms of phenotypic correlations between traits, and of the function of the candidate genes. The major wood property QTL harbours a gene encoding a Cinnamoyl CoA reductase (CCR), a structural enzyme of the monolignol-specific biosynthesis pathway.
Given the number of traits analysed, this study provides a comprehensive understanding of the genetic architecture of wood properties in this Eucalyptus full-sib pedigree. At the dawn of Eucalyptus genome sequence, it will provide a framework to identify the nature of genes underlying these important quantitative traits.