Mapping Quantitative Traits for Physical and Chemical Wood Properties in Loblolly Pine, 1999 Pulping Conference Proceedings

Mitchell Sewell & Daniel Bassoni

Institute of Forest Genetics

USDA Forest Service

Robert Megraw & Nicholas Wheeler

Weyerhaeuser Company

Carolyn Elam & Mark Davis

National Renewable Energy Laboratory

Department of Energy

Gerald Tuskan

Oak Ridge National Laboratory

Department of Energy

David Neale

Institute of Forest Genetics

USDA Forest Service

Wood property traits for loblolly pine (Pinus taeda L.) were analyzed for the presence of quantitative trait loci (QTLs) in a three-generation pedigree. Physical wood property traits include wood specific gravity (wsg) and microfibril angle (mfa). Chemical wood property traits include the percentage of cellulose, galactans, mannans, lignin and xylans. Both early- and latewood were analyzed for each trait. An interval mapping approach designed for an outbred pedigree was used to estimate the number of QTLs, the magnitude of QTL effects and their genomic position. Nine unique QTLs were detected for wsg, five for mfa and five for the wood chemistry traits. The wsg QTLs were specific to either earlywood or latewood, whereas each mfa QTL was detected for both early- and latewood. A preliminary analysis was performed for each of the wood chemistry traits. Comparisons of the effects and genomic location of QTLs from these preliminary results, in conjunction with a strong phenotypic correlation among each of these traits, suggest that these traits are highly correlated. These wood chemistry traits are collectively referred to as the cell wall chemistry (cwc) trait.