Quantitative trait locus (QTL) analysis of wood quality traits in Eucalyptus nitens

Abstract

To identify the chromosomal regions affecting wood quality traits, we conducted a genome-wide quantitative trait locus (QTL) analysis of wood quality traits in Eucalyptus nitens. This information is important to exploit the full potential of the impending Eucalyptus genome sequence. A three generational mapping population consisting of 296 progeny trees was used to identify QTL associated with several wood quality traits in E. nitens. Thirty-six QTL positions for cellulose content, pulp yield, lignin content, density, and microfibril angle (MFA) were identified across different linkage groups. On linkage groups (LG)2 and 8, cellulose QTL cluster with pulp yield and extractives QTL while on LG4 and 10 cellulose and pulp yield QTLs cluster together. Similarly, on LG4, 5, and 6 QTL for lignin traits were clustered together. At two positions, QTL for MFA, a physical trait related to wood stiffness, were clustered with QTL for lignin traits. Several cell wall candidate genes were co-located to QTL positions affecting different traits. Comparative QTL analysis with Eucalyptus globulus revealed two common QTL regions for cellulose and pulp yield. The QTL positions identified in this study provide a resource for identifying wood quality genes using the impending Eucalyptus genome sequence. Candidate genes identified in this study through co-location to QTL regions may be useful in association studies.

Progress in Myrtaceae genetics and genomics: Eucalyptus as the pivotal genus

“…Recent QTL studies, however, have reported a substantially larger number of QTLs for wood quality traits whose effects estimated rarely exceed 5%. Thumma et al (2010) detected 36 QTLs for cellulose content, pulp yield, lignin content, density, and microfibril angle (MFA) in E. nitens. Gion et al (2011) described a total of 117 QTLs for a number of wood and end-use related traits, including chemical, technological, physical, mechanical and anatomical properties.…”

Network-based integration of systems genetics data reveals pathways associated with lignocellulosic biomass accumulation and processing

“…The characterization of natural genetic perturbations segregating in phenotypically wild-type individuals offers an attractive alternative tool to study properties that emerge from permissible genetic variation (11,13). With the availability of high-throughput genotyping and high-resolution linkage maps in Populus (14,15) and Eucalyptus (16)(17)(18)(19), genetic approaches such as quantitative trait locus (QTL) (14,20,21) and LD-based association mapping (22)(23)(24)(25) are becoming feasible to…”

Oxidative stress proteins as an indicator of a low quality of eucalyptus clones for the pulp and paper industry

“…In another study, the high yield of pulp and cellulose content was associated with the low content of extractives and total lignin (Poke et al, 2006). For Eucalyptus nitens, Kube et al (2001) found a high negative genetic correlation between extractive content and cellulose, which was the same correlation found by Thumma et al (2010) in the study of wood quality with QTLs for the same species. Together, these studies suggest that selection to increase the yield of pulp or cellulose content would probably result in the reduction of lignin and extractive content, which is a favorable for the production of wood for the pulp industry (Poke et al, 2006).…”