Articles containing the keyword 'monoterpenes'

Variation of monoterpene composition of Pinus sylvestris L. was studied in Southern, Central and Northern Finland using data from both natural stands and plus trees. The natural stands were analysed using different techniques and for fewer terpenes than the plus trees.

There were large differences between areas in the proportion of 3-carene in trees from natural stands, as has been discussed by previous authors. The proportion of 3-carene is bimodally distributed and believed to be controlled by a single gene with large effect. For this reason, we stratified our samples into high carene (>10%) and low carene (<10%) groups. Univariate analysis did not reveal any additional differences between natural populations in different zones for components other than 3-carene. In plus trees, several components showed significant differences, but the proportion of 3-carene did not differ between areas. Multivariate discrimination analysis did not distinguish between areas for natural stands. However, for the plus trees discriminant analysis allowed us to discriminate between the zones relatively efficiently. The proportion of correct classification was greater than 64% using the best methods. The central zone was most distinct, and 80% of its trees were correctly classified. Broad generalizations are not possible due to the limitations imposed by our data. Our analysis of phenotypic variation does not support the suggestion that plus trees selected from the north represent a southern type.

The PDF includes an abstract in Finnish.

• Muona, E-mail: om@mm.unknown
• Hiltunen, E-mail: rh@mm.unknown
• Morén, E-mail: em@mm.unknown
• Shaw, E-mail: ds@mm.unknown

The monoterpene composition of the needle oil of Pinus oocarpa Schiede ex Schltdl. and Pinus caribaea Morelet growing in Zambia were studied by means of GC-MS. P. oocarpa needle samples were taken from 29 trees representing different clones in a seed orchard and from 43 trees in a commercial plantation in 1980. The P. caribaea needle samples were collected from 17 clones in a seed orchard.

Nine compounds were positively identified in the monoterpene fraction of P. oocarpa and eight in that of P. caribaea. The amounts of these compounds showed marked tree-to-tree variation and the sample trees were screened into distinct groups on the basis of the variation. The results give a basis for selection in favour of pest resistance and turpentine yield.

The PDF includes a summary in Finnish.

• Löyttyniemi, E-mail: kl@mm.unknown
• Hiltunen, E-mail: rh@mm.unknown
• Löyttyniemi, E-mail: rl@mm.unknown
• Räisänen, E-mail: sr@mm.unknown

The development of Scots pine (Pinus sylvestris L.) seedlings and damage caused by Hylobius abietis L. (Coleoptera, Curculionidae) were studied during a three-year period. Olfactory responses of H. abietis was studied in laboratory with several volatile oils isolated from different kinds of P. sylvestris seedlings. Resistance of seedlings against H. Abietis was evaluated in terms of their monoterpene composition. Three aspects of resistance (preference, antibiosis and tolerance) were evaluated separately. Seedling chemotype was found to be associated with these aspects of host resistance on only minor scale. Discussion was attached to a further search for host resistance arising from other properties and constituents of oleoresin. Height growth of the seedlings recovering from weevil damage was 86–91% compared to healthy seedlings.

The PDF includes a summary in English.

• Selander, E-mail: js@mm.unknown
• Kalo, E-mail: pk@mm.unknown

Monoterpene hydrocarbon contents of needles in Scots pine (Pinus sylvestris L.) plants both damaged and untouched by the moose (Alces alces L.) were compared in the study. The material was collected in an 8-year-old plantation in Central Finland. Needle samples were taken from the topmost shoot whorl of the plants in the middle of April, 1976. Only minor differences were found between the plant groups. Thus, terpenes in pine presumably play no important role in the browsing preference by moose.

The PDF includes a summary in Finnish.

• Löyttyniemi, E-mail: kl@mm.unknown
• Hiltunen, E-mail: rh@mm.unknown