Endbericht zum Forschungsprogramm Terpene in Nadeln und Zweigen von Picea abies (L.) Karst

An 13 Standorten in Slowenien wurden Nadeln von $\underline{Picea}$ $\underline{abies}$ (L.) Karst. mittels Gaschromatographie auf ihren Gehalt an Mono- und Sesquiterpenen untersucht. Ziel des Versuches war es, eine mögliche Korrelation der Terpene mit dem Schwefelgehalt der Nadeln festzustellen. Zusätzlich wurde die Terpenverteilung innerhalb einer Einzelfichte bestimmt, um mehr Information über die naturliche Variabilität innerhalb eines Baumes sowie über mögliche die Terpensynthese beeinflussende Faktoren zu erhalten. Die untersuchten Nadeln enthielten zwischen 1 und 2,5 mg Terpene/g Frischgewicht. Hauptkomponenten im Terpenspektrum waren Limonen, Camphen, Myrcen, $\alpha$-pinen und Bornylacetat. Ein Zusammenhang zwischen dem Gehalt an Monoterpenen und der Schwefelbelastung eines Baumes ist nicht zu erkennen, auch ergibt sich keine Korrelation zwischen der Hohenlage der Standorte und dem Terpengehalt. Innerhalb eines Baumes sinkt der Terpengehalt in den Nadeln von der Krone zur Basis ab, wobei der Abfall vom 2. zum 4. Wirtel besonders stark ist. Zwischen den beiden seiten (Sonnen-, Schattenseite) der Fichte konnte kein signifikanter Unterschied festgestellt werden. Daneben besteht, wie auch im ersten Versuch, kein signifikanter Unterschied zwischen den beiden untersuchten Nadeljahrgängen

δ13C values of CO2 from soil respiration on sites with crops of C3 and C4 type of photosynthesis.

Based on the differential discrimination between 13CO2 and 12CO2 during photosynthetic CO2 fixation by C3 and C4 plants, the relative contribution of organic soil material of varying age can be checked by measuring the δ13C value of CO2 evolved during soil respiration. The CO2 from a soil cropped only with C3 plants for at least 7 years showed a δ13C value very close to that of C3 plant tissue. Correspondingly, a soil bearing the C4 plant maize for at least 6 years had a δ13C value for the respiratory CO2 quite near to that of a typical C4 plant. A soil cropped with maize in the year of study only showed intermediate δ13C values, with a tendency towards C4. With soil standardised for cultivation and cropping, a quantification of the part that fresh organic matter and especially the last year plant residues play in soil respiration, can be achieved

Influence of needle loss, yellowing and mineral content on monoterpenes in the needles of <em>Picea abies</em> (L.) Karst.

Monoterpenes in needles of Picea abies (L.) Karst. were studied to reveal whether or not the symptoms of forest decline observed in three mountain regions of South Germany (Bavaria) - needle loss and needle yellowing - are related to changes in the amounts of all or individual terpenes. The nutrient supply of the needles was examined in addition to the terpene concentrations, since the disease symptom montane yellowing is often associated with mineral deficiency. At two of the eight locations, trees exhibited Mg-deficiency, at one location K-deficiency was observed, and at another location the S-content of the needles indicated SO2-pollution. Using various statistical methods of analysis, no correlation was observed between the mineral element content of the needles, the percentage of needle loss and either the absolute or percentile terpene amounts stored within the needles. This finding is independent of needle age, date of sampling and terpene pattern. Concerning needle yellowing, the data show a tendency towards a reduction of the terpene concentrations in needles originating from branches with partly yellow needles compared to needles from exclusively green-needled branches. In spite of the fact that only 2-year-old and older needles show the disease symptom of yellowing, the terpene level is reduced even in still green, juvenile and 1-year-old needles. No terpene was found to be an indicator for early recognition of injury

Patterns of monoterpenes stored in the needles of <em>Picea abies</em> (L.) Karst. from several locations in mountainous regions of southern Germany.

As genetic diversity is an important cause of variation in needle monoterpenes of conifers, the tree-to-tree variation was studied for Picea abies (L.) Karst. at eight different locations in three mountainous regions of southern Germany (Bavaria). The tree-to-tree variation, expressed by the coefficients of variation, is high, ranging between 50% and 70%. The maximum concentrations per tree are up to 10 times higher than the minimum ones. The trees from all locations show similar patterns of variation, which is significant when investigating the influence of external parameters like air pollution or infestation by pathogens. By means of cluster analysis five types of terpene patterns were clearly revealed. Two main groups were distinguished by their proportion of myrcene, and they are further divided into subgroups. The patterns are stable throughout different needle ages and dates of sampling. Apart from one location, there is no obvious geographical arrangement of the five patterns. The fact that no relationship exists between the genotypical classification and the total concentrations agrees well with the hypothesis that most of the variability based on the relative amounts is due to genetic variation, whereas the variation based on the absolute amounts reflects environmental factors

Seasonal variation in the monoterpenes in needles of <em>Picea abies</em> (L.) Karst.

This investigation was conducted to obtain information about the fluctuations in composition and amount of needle monoterpenes during the development of spruce needles. Studies conducted with two Norway spruce clones clearly revealed the existence of fluctuations. In juvenile needles, the amounts of the oxygenated terpenes increase constantly with age during the first 2 months of needle growth. The hydrocarbon terpenes dominate within the first weeks, some of them even showing a very distinct first maximum within the first 3 weeks after bud burst. All terpenes, including the oxygenated ones, have a maximum in June/July, which favours the hypothesis of a substitution of the hydrocarbons later on. There are significant changes even in mature needles of Norway spruce. The terpene level of 1-year-old needles of the clonal trees increased from spring to early summer and then dropped again towards winter. In addition, fluctuations in mature needles were shown for a set of ten wild trees. Needles of the same age class, which emerged in 1986, were sampled 4 times from 1986 to 1988. The needle terpene concentrations of the 1 -year-old needles were considerably lower in spring at the time of bud burst than in autumn. The terpene level of older needles thus seems to be influenced by biosynthetic and catabolic activities

Influence of various factors on quantitative composition of leaf monoterpenes of <em>Picea abies</em> (L.) Karst.

The extractable monoterpenes from needles of two groups of trees - 4-year-old clonal and 20-year-old wild trees - were studied with respect to the influence of individual constitution, needle age, whorl position, and position on branch. Leaf terpene amounts from clonal trees are significantly affected by age and position of the whorl, whereas position on the branch is of minor importance. Developing needles of clonal trees are most strongly affected by age and whorl position and they differ markedly from mature needles in quantitative terpene composition. Wild trees exhibit a very high variation from tree to tree, which obscures the influence of needle age and position. For this reason meaningful tree leaf terpene data will only be derived if large samples of needles of different ages are collected from distinct positions. When comparing different trees, needles should be selected that not only have the same state of development, but also originate from identical positions and have been subjected to the same light treatment

Biochemical response of Norway spruce (<em>Picea abies </em>(L.) Karst.) towards 14-month exposure to ozone and acid mist: Part I - effects on polyphenol and monoterpene metabolism.

Three-year-old clonal Picea abies (L.) Karst. plants, grown either on a sandy (No. 1) or on a calcareous (No. 2) soil, were treated with ozone (100 &mu;g m-3 and peaks of up to 360 &mu;g m-3) and acid mist (pH 3.0) over two vegetation periods. Needles of the current (1987) and previous (1986) year were analysed at the end of the experiment for biosynthetic enzymes and in vivo activity of the phenylpropanoid pathway, for products of polyphenol metabolism (clones 11 and 14), and for mono- and sesquiterpenes (clones 14 and 16). 1. Polyphenol metabolism. The activity of cinnamyl alcohol dehydrogenase, an enzyme of the lignin pathway, was increased by the treatment by up to 83% in the needles of both age classes. Chalcone synthase was measured in mature tree material for the first time. This enzyme, as well as phenylalanine ammonia-lyase activities and the content of catechin, astringin, isorhapontin, picein and p-hydroxyacetophenone, exhibited no significant treatment-dependent differences. However, soil and age-class dependent differences occurred. Pulse-labelling experiments with L[U-14 C]phenylalanine and [2-14 C]acetate were carried out at four different stages of shoot development and showed label incorporation into (+)-catechin and proanthocyanidins. There was no effect of the ozone and acid mist treatment. 2. Monoterpenes. The content of needle terpenes was generally diminished by the ozone and acid mist treatment. Other factors tested, such as clone, needle age and soil, exerted a highly significant influence on the content of most of the needle monoterpenes