Diterpene Resin Acids and Olefins in Calabrian Pine (Pinus nigra subsp. laricio (Poiret) Maire) Oleoresin: GC-MS Profiling of Major Diterpenoids in Different Plant Organs, Molecular Identification and Expression Analysis of Diterpene Synthase Genes

A quali-quantitative analysis of diterpenoid composition in tissues obtained from different organs of Pinus nigra subsp. laricio (Poiret) Maire (Calabrian pine) was carried out. Diterpene resin acids were the most abundant diterpenoids across all the examined tissues. The same nine diterpene resin acids were always found, with the abietane type prevailing on the pimarane type, although their quantitative distribution was found to be remarkably tissue-specific. The scrutiny of the available literature revealed species specificity as well. A phylogeny-based approach allowed us to isolate four cDNAs coding for diterpene synthases in Calabrian pine, each of which belonging to one of the four groups into which the d3 clade of the plants’ terpene synthases family can be divided. The deduced amino acid sequences allowed predicting that both monofunctional and bifunctional diterpene synthases are involved in the biosynthesis of diterpene resin acids in Calabrian pine. Transcript profiling revealed differential expression across the different tissues and was found to be consistent with the corresponding diterpenoid profiles. The isolation of the complete genomic sequences and the determination of their exon/intron structures allowed us to place the diterpene synthase genes from Calabrian pine on the background of current ideas on the functional evolution of diterpene synthases in Gymnosperms.

Basidiomycete diversity within Calabrian pine (Pinus brutia) ecosystems on the island of Cyprus

We are pleased to announce the posting of a new mycobiota on the Mycotaxon website: "Basidiomycete diversity within Calabrian pine (Pinus brutia) ecosystems on the island of Cyprus" by Michael Loizides. This brings to 146 the number of free access Fungae now available on http://www.mycotaxon.com/mycobiota/index.html

Vertical Crown Fuel Distributions in Natural Calabrian Pine (Pinus brutia Ten.) Stands

Calabrian pine (Pinus brutia Ten.) is the most widely distributed coniferous species in Turkey. Forests mostly composed of Calabrian pine constitute the most flammable forests in fire sensitive regions of the country. Especially, regenerated and immature stands of this species have the most fire-prone fuel type. This study evaluates the results of vertical crown fuel distribution and develops some crown fuel models to explain canopy fuel characteristics in natural Calabrian pine stands. A total of 35 trees were cut down and crown fuels were determined vertically. The highest crown fuel load was generally situated in the middle part of tree crown. The percentage of needles in each crown section increased gradually from the beginning of lower parts to the upper parts of tree crowns for three stand types. Total crown fuel loads were determined as 5.66 kg for regenerated stands, 11.57 kg for immature stands and 17.44 kg for middle age stands, respectively. Correlation and regression analyses were performed to determine the relationship between needles, branches, available fuels, total crown fuels and tree properties. The results of crown fuel distribution and the allometric equations developed in this study can be used to predict vertical fuel load at any height from ground to the top of Calabrian pine stands. The results of this study will contribute to the verification and evaluation of fuel load prediction models in use, and enhance the understanding of crown fire behavior mechanism in forest fires.

Profiling Volatile Terpenoids from Calabrian Pine Stands Infested by the Pine Processionary Moth

Terpenoids make up the biggest and most diversified class of chemical substances discovered in plants, encompassing over 40,000 individual compounds. In conifers, the production of terpenoids, either as oleoresin or emitted as volatile compounds, play an important role in the physical and chemical defence responses against pathogens and herbivores. In the present work, we examined, for the first time to the best of our knowledge, the terpenic defensive relations of Calabrian pine (Pinus nigra subsp. laricio (Poiret) Maire), facing the attack of the pine processionary moth (Thaumetopoea pityocampa (Denis and Schiffermüller, 1775)), brought about in the open on adult plant individuals growing at two distinct forest sites. Among the volatile terpenoids emitted from pine needles, bornyl acetate [(4,7,7-trimethyl-3-bicyclo[2.2.1]heptanyl) acetate] was the most frequently and selectively associated with the infestation, increasing during the period of most intense trophic activity of the caterpillars (defoliation), and decreasing thereafter. Although further work is needed to clarify whether the observed response reflects defence reactions and/or they are involved in communication among the infested plants and their biotic environment, the present results boost the currently growing interest in the isolation and characterization of plant secondary metabolites that can be used to control pests, pathogens, and weeds.

Effects of Recycled Fiber Fines on Hand Sheet Properties of Different Unbeaten and Beaten Pulps

In this study, 5, 10, and 15 % secondary fines of recycled pulp were added to unbeaten and beaten (28 ºSR) samples of recycled pulp, Turkish Calabrian pine (Pinus brutia Ten.) kraft pulp, and European aspen (Populus tremula L.) kraft pulp. The effects of the addition of fiber fines on hand sheets properties were evaluated. The addition of fiber fines to the unbeaten pulps improved the strength properties of hand sheets. The roughness of hand sheets was also decreased with the addition of fines. When fiber fines were added to the beaten pulps, the type of pulp strongly affected the paper strength properties. The strength properties of beaten pulps of Turkish Calabrian pine and European aspen were decreased with the addition of fiber fines, while the strength properties of beaten pulps of recycled pulp were increased. On the other hand, the air permeance of unbeaten and beaten samples was decreased with the addition of fiber fines. Consequently, the addition of fines to unbeaten and beaten pulps had a more pronounced effect on European aspen kraft pulp and recycled pulp than on Turkish Calabrian pine kraft pulp. Also, the strength of paper made of unbeaten recycled pulp with the addition of 15 % fines was higher than that of fines-free beaten recycled pulp.

Dependence of the sample estimates on the sample size

The paper provides data on the dependence of the sample indicators of the arithmetic mean, variance, asymmetry and excess of the length of the needles of European spruce (Picea rubra) and European larch (Larix decidua), the average length of a pair of needles of Scots pine (Pinus sylvestris) and Calabrian pine (Pinus brutia). The sizes of samples have been determined, which make it possible to obtain the values of the estimates of sample indicators that have stabilized around their general values. The data on the difference between the law of distribution of the length of the needles of coniferous plants from the normal one are confirmed. The possibility of using graphs of the dependence of sample indicators on sample sizes for the examination of scientific data is discussed.