Abstract Detail

Physiological Section

Yelle, Daniel J. [1], Kretschmann, David [1], Ralph, John [2], Sweeney, Laura [1].

Detecting differences in growth ring, compression wood, and juvenile wood chemistry by chemometric analysis of 2D NMR spectra from wood cell walls.

This research investigates the cell wall chemistry of a single Pinus taeda L. tree throughout the secondary xylem. Previous chemical composition data from carbohydrate analysis and Klason lignin analysis from specific regions of the tree were statistically analysed to determine if cardinal direction, tree height, and growth ring position were significantly different in wood composition. With these data there was no clear evidence that wood composition directly correlated to the cardinal direction or tree height for either earlywood or latewood growth rings. Earlywood composition remained remarkably stable regardless of height and ring position; the most significant changes took place in the latewood bands. There was, however, an indication that those rings that have been identified as having compression wood corresponded to the latewood band. Here, we further investigate the differences in wood polymer structure between growth rings, compression wood, and juvenile wood of this single tree using wood cell wall dissolution, NMR spectroscopy, and chemometrics. The purpose of examining the structural chemistry throughout the tree is to characterize specific polymers at the molecular level that are responsible for certain tree physiological traits. The identical samples used for compositional analyses of the tree were dissolved and acetylated in situ for solution-state NMR analysis. The acquired NMR spectra of each sample were then analyzed using a multivariate approach, which allows detection of major and minor molecular changes between physiological tissues. Preliminary results suggest that the cell wall structural chemistry is considerably different at locations in the tree where there is high longitudinal shrinkage.  

1 - Forest Products Laboratory, U.S. Forest Service, 1 Gifford Pinchot Dr., Madison, WI, 53726, USA
2 - University of Wisconsin-Madison, Department of Biochemistry, Wisconsin Energy Institute, 1552 University Ave. , Madison, WI, 53726, USA

Keywords:
tree physiology
wood chemistry
growth rings
compression wood
juvenile wood
NMR spectroscopy
chemometrics.

Presentation Type: Oral Paper:Papers for Sections
Session: 42
Location: Pines South/Boise Centre
Date: Wednesday, July 30th, 2014
Time: 4:00 PM
Number: 42010
Abstract ID:881
Candidate for Awards:None