Author(s)

Ilze Irbe, Guna Noldt, Uldis Grinfelds, Anrijs Verovkins, Aris Jansons, Gerald Koch

Johann Heinrich von Thunen-Institute (vTI)/Federal Research Institute for Rural Areas, Forestry and Fisheries Institute of Wood Technology and Wood Biology (HTB), Hamburg, Germany.
Latvian State Forest Research Institute “Silava”, Salaspils, Latvia.
Latvian State Institute of Wood Chemistry (LS IWC), Riga, Latvia.

Genetic variation of ten Norway spruce (Picea abies (L.) Karst.) clones regarding their decay resistance against brown rot fungi, as well as physical and chemical properties of clones were investigated. 31- year-old spruce clones: 26, 31, A10, A15, A7, B10, B15, B6, V7, V9 were selected across Latvia. The stem diameters of spruce clones varied between 13.0 and 20.9 cm. The wood density of clones ranged from 361 to 443 kg/m³. Klason lignin content, depending on the clone, was between 27.0%-28.9%. Cellular UV microspectrophotometry of the non-infected tracheids displayed the typical lignin distribution with highest absorbance values in the cell corners (abs_{280 nm} 0.80) and compound middle lamellae (abs_{280 nm} 0.48), while secondary wall showed lower lignin absorbance values (abs_{280 nm}0.29 - 0.35). The deposition of phenolic extractives in ray parenchyma and epithelial cells of resin canals were emphasized by a significantly higher UV-absorbance (abs_{280 nm} 0.68 to 0.78) when compared to the cell wall associated lignin. The content of acetone-soluble extractives of spruce clones varied between 1.1% - 1.8%. The x-value (natural durability) for all spruce clones after exposure to C. puteana and P. placentawas >0.90 (durability class 5, not durable). Most of clones after degradation by G. trabeum had x-value > 0.90 with exception of clones B15 and V9 that showed x-value ≤ 0.90 (durability class 4, slightly durable). Natural durability of spruce clones did not correlate with stem diameter, density, content of lignin and extractives.

Norway Spruce Clones; Natural Durability; Brown Rot; Lignin; Extractives; Density; UV Microspectrophotometry

Irbe, I. , Noldt, G. , Grinfelds, U. , Verovkins, A. , Jansons, A. and Koch, G. (2012) Genetic variation of Norway spruce clones regarding their natural durability, physical and chemical properties. Advances in Bioscience and Biotechnology, 3, 1104-1112. doi: 10.4236/abb.2012.38135.