title: Determining the Composition of Lignins in Different Tissues of Silver Birch.
abstract: Quantitative and qualitative lignin analyses were carried out on material from the trunks of silver birch (Betula pendula Roth) trees. Two types of material were analyzed. First, whole birch trunk pieces were cryosectioned into cork cambium, non-conductive phloem, the cambial zone (conductive phloem, cambium and differentiating xylem), lignified xylem and the previous year's xylem; material that would show differences in lignin amount and quality. Second, clonal material from one natural birch population was analyzed to show variations between individuals and between the lignin analysis methods. The different tissues showed marked differences in lignin amount and the syringyl:guaiacyl (S/G) ratio. In the non-conductive phloem tissue containing sclereids, the S/G ratio was very low, and typical for phloem fibers and in the newly-formed xylem, as well as in the previous year's xylem, the ratio lay between five and seven, typical for broadleaf tree xylem. Clonal material consisting of 88 stems was used to calculate the S/G ratios from the thioacidolysis and CuO methods, which correlated positively with an R² value of 0.43. Comparisons of the methods indicate clearly that the CuO method is a good alternative to study the monomeric composition and S/G ratio of wood lignins.
authors.affiliation: Department of Biosciences, Division of Plant Biology, P.O. Box 65, University of Helsinki, FI-00014 Helsinki, Finland. kurt.fagerstedt@helsinki.fi.
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Fagerstedt
authors.affiliation: Natural Resources Institute Finland, Jokiniemenkuja 1, Fi-01300 Vantaa, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Saranpää
authors.affiliation: Natural Resources Institute Finland, Jokiniemenkuja 1, Fi-01300 Vantaa, Finland. tarja.tapanila@luke.fi.
authors.forename: Tarja
authors.initials: T
authors.lastname: Tapanila
authors.affiliation: Department of Biosciences, Division of Plant Biology, P.O. Box 65, University of Helsinki, FI-00014 Helsinki, Finland. juha.immanen@helsinki.fi.|Institute of Biotechnology, P.O. Box 65, Helsinki University, FI-00014 Helsinki, Finland. juha.immanen@helsinki.fi.
authors.forename: Juha
authors.initials: J
authors.lastname: Immanen
authors.affiliation: Department of Biosciences, Division of Plant Biology, P.O. Box 65, University of Helsinki, FI-00014 Helsinki, Finland. juan.alonsoserra@helsinki.fi.
authors.forename: Juan Antonio Alonso
authors.initials: JA
authors.lastname: Serra
authors.affiliation: Natural Resources Institute Finland, Jokiniemenkuja 1, Fi-01300 Vantaa, Finland. kaisa.nieminen@luke.fi.
authors.forename: Kaisa
authors.initials: K
authors.lastname: Nieminen
keywords: Betula pendula; acetyl bromide; cupric oxide; lignin analysis methods; phloem; thioacidolysis; xylem