Douglas fir, Pseudotsuga

Dihydroflavonol 4-reductase (DFR EC 1.1.1.219) is a member of the short-chain dehydrogenase/reductase family and catalyzes the stereospecific conversion of (+)-(2R,3R)-dihydroflavonols to the corresponding (2R,3S,4S) flavan-3,4-cw-diols (leucoanthocyanidins), with NADPH as a required cofactor. The enzyme activity was first identified in cell suspension cultures of Douglas fir (Pseudotsuga menziesii) and was shown to be related to the accumulation of flavan-3-ols and proanthocyanidins [96]. Leucoanthocyanidins and DFR were later shown to be required for anthocyanidin formation by complementation of Matthiola incana mutants blocked between dihydroflavonol and anthocyanidin biosynthesis [97, 98], DFR has been purified to apparent homogeneity and biochemically analyzed from flower buds of Dahlia variabilis [99]. DFR was shown to accept different substrates depending on the plant species from which it was isolated (reviewed in 100). 

Marques, R., and J. Ranger. 1997. Nutrient dynamics in a chronosequence of Douglas fir (Pseudotsuga menziesii (Mirb,) Franco) stands in the Beaujolais Mounts (France). Forest Ecology and Management 91 255—277. 

Newton, M. and D.S. Preest (1988). Growth and water relations of Douglas-fir (Pseudotsuga menziesii) seedlings under different weed regimes. Weed Sci., 36 653-662. 

Douglas fir (Pseudotsuga menziesii) was chipped and screened to a relatively homogeneous chip size of approx 3 x 3 x 0.3 cm. The chips were initially impregnated with 4.5% (w/w) gaseous S02 and then steam exploded in a 1-L steam gun in batches of 50 g of dry chips at 195°C for 4.5 min, as previously described by Boussaid et al. (14). The steam-exploded wood samples of each batch were collected, combined, washed, and finally defibrillated on a refiner to produce a homogeneous feedstock. 

This paper is a report on preliminary studies evaluating the suitability of bark extracts from four West Coast softwood species as bonding agents for particleboard. The barks investigated include white fir (Abies concolor), ponderosa pine (Pinus ponderosa), Douglas fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) ... 

Medium-hard Douglas fir Pseudotsuga Wood, cones Lumber, paper, decoration... 

To determine the distribution of lignin from bromine analysis, it is essential to know the reactivity of bromine toward lignin in different morphological regions. For black spruce (Picea mariana), Douglas-fir (Pseudotsuga menziesii) and loblolly pine (Pinus taeda), the lignin in the secondary wall of tracheids is 1.7... 

Table 4.4.1 gives the distribution of lignin in Douglas-fir (Pseudotsuga menziesii) earlywood tracheids (Saka and Thomas 1982). The overall lignin content (W) of the earlywood portion is 0.285 gig). The Klason and acid-soluble lignin determinations should be made on wood taken near the location from which the sections are collected for EDXA measurements. 

Vertical and horizontal resin ducts are natural and constant features of four domestic genera pines Finns), spruces Picea), larches Larix), and Douglas-fir Pseudotsuga). Resin ducts also develop as a response to injury or trauma in other genera, as well as in the four listed above (2). Horizontal resin ducts are contained in special multiseriate rays, called fusiform rays because of their spindle shape in tangential view (Figure 14B). 

Larch wood Larix occidentalis) Decomposed Douglas-fir Pseudotsuga menzeisii) Ponderosa pine Pinus ponderosa) Aspen... 

Figure 1.5. Indistinct growth ring boundaries Figure 1.6. Very distinct growth ring boundaries in the wood of Dacrydium cupressinwn. x in the wood of Douglas fir, Pseudotsuga 45. menziesii. x 60.

Douglas Fir Pseudotsuga men-zies (Mirb.) Franco P. apterus lh instar larvae Topical ++ 8S... 

Douglas fir Pseudotsuga sp. (FP-H-11) Chaco Canyon, New Mexico Softwood 1127... 

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