Species Of Pseudotsuga Research Articles

Chemometric analysis of monoterpenes and sesquiterpenes of conifers.

Volatile organic compounds (VOCs) and essential oils of conifers are widely used in the pharmaceutical industry. This work aimed to analyze the VOCs of 30 conifer species representing the Pinaceae and Cupressaceae families. Samples were collected from arboreta in Hungary, and their chemical composition was determined by gas chromatography (SPME-GC/MS); then, chemometric analyses were performed using multivariate methods to identify characteristic VOCs of conifers. Here, we present results for monoterpene and sesquiterpene profiles of the examined conifer samples. The most abundant compounds detected were α-pinene, bornyl acetate, limonene, β-pinene, β-caryophyllene, β-myrcene, δ-3-carene, and β-phellandrene. The results showed that the following volatiles were characteristic of the conifer groups: sabinene (RRT=6.0) for the cupressoid group (which includes the Cupressaceae species), longifolene (RRT=15.0) and β-pinene (RRT=6.1) were characteristic of the pinoid group (including Picea, Pinus, and Pseudotsuga species), and camphene (RRT=5.5) and bornyl acetate (RRT=12.6) were characteristic of the abietoid group (including Abies, Cedrus, and Tsuga species). Our results on VOCs in the Pinaceae and Cupressaceae families contribute to the elucidation of biodiversity patterns of conifer species and, in addition, may support the industrial application of terpenes.

A new species of Pseudotsuga (Pinaceae) from the lower Miocene of Lesvos, Greece, and its palaeogeographical and palaeoclimatic implications

Pseudotsuga Carrière is commonly known as Douglas-fir, a minor genus attributed to Pinaceae. Four extant species are included in this genus, with dispersed distribution in East Asia and western North America. Pseudotsuga possesses a number of fossil records of needled leaves, seed cones, and seeds. Nevertheless, few reliable fossil wood of this genus has been specifically investigated. Here, we describe some anatomically well-preserved petrified fossil wood from the lower Miocene of Lesvos Island, Greece, as Pseudotsuga lesvosensis n. sp. The studied fossil wood remains are characterized by the presence of normal axial and radial resin canals, piceoid cross-field pitting, along with distinctive helical thickenings in cell walls consistent with Pseudotsuga. The present fossil conifer further enriches the species diversity of the Miocene Petrified Forest in Lesvos. The first report of Pseudotsuga lesvosensis from the southern Europe in this study extends the tempo-spatial distribution patterns of Pseudotsuga and contributes to further understanding of its origin and evolutionary history. The occurrence of P. lesvosensis fossil wood, as well as other palaeontological macrofloral composition evidence, indicates a humid warm temperate to subtropical climatic condition during the early Miocene within the Lesvos, which differs significantly from the current Mediterranean climate.

The Potential Global Distribution of Sirex juvencus (Hymenoptera: Siricidae) under Near Current and Future Climatic Conditions as Predicted by the Maximum Entropy Model.

Simple SummaryThe difference in the potential distribution of Sirex juvencus (Hymenoptera: Siricidae) under current and future climatic conditions is dependent on environmental factors such as temperature and precipitation, which can affect survival. In this study, we investigated the impact of climate change on the distribution and spread of an invasive insect pest species of forestry, S. juvencus. This wood wasp drills holes on a tree trunk or branch with ovipositor and then deposits eggs inside the hole, along with a wood-rotting fungus which helps its larva to digest the host plant. We analyzed the current distribution data from Asia, Europe, and North America with the maximum entropy model and revealed that the species might increase its distribution area as ambient temperature increases and precipitation (moisture) declines. There is also evidence to show that the species will spread more in moderately suitable areas. The species can also co-infest hosts along with other Sirex species of wood wasp, making its potential impact highly significant.Wood wasp species in the genus Sirex are known pests of forestry. They cause significant economic losses due to their impacts on plant health and wood quality. S. juvencus (Hymenoptera: Siricidae), widely distributed in Asia, Europe, and North America, is known to negatively impact forestry, infesting Picea, Pinus, Larix, Abies, Cupressus, and Pseudotsuga species. This pest destroys plants by depositing eggs, mucus, and its obligate mutualistic fungus, Amylostereum areolatum. Its obligate mutualistic fungus is to provide nutrition for S. juvencus larva. Despite its extensive distribution range, little is known about which environmental variables significantly impact current and future distribution patterns of S. juvencus for pest control and monitoring. Here we used the maximum entropy model in conjunction with occurrence points of S. juvencus and environmental variables to predict the current and future global potential distribution of S. juvencus. We used the jackknife method and Pearson’s correlation analysis to select the environmental variables that influence the geographic distribution of S. juvencus, which resulted in the inclusion of the monthly average maximum temperature in February, the max temperature of warmest month, monthly average minimum temperature in July, monthly total precipitation in June, precipitation of the driest month, monthly total precipitation in September, and the temperature annual range. Temperature and precipitation are mainly likely to drive the distribution enabled by its obligate mutualistic fungus and the potential to co-infect with other Sirex species. The high temperature and low humidity influence S. juvencus eggs and larvae directly and indirectly via fungus-growth, which enables the larvae to survive. Furthermore, S. juvencus may increase its distribution to moderately suitable areas due to competition or dependency on other Sirex species during the infestation. Under the future climatic conditions, the highly suitable area increased by 32.79%, while the moderately suitable area, low suitable area, and unsuitable area increased by 28.14%, 3.30%, and 2.15%. Under climate changes, S. juvencus may spread in previously unsuitable areas rapidly.

Las coníferas de la Reserva de la Biosfera "La Michilía", Durango, México

Se realizó una revisión taxonómica de las coníferas de la Reserva de la Biosfera "La Michilía", en el sureste del estado de Durango. Dos familias con trece taxa incluyendo los infraespecíficos son reconocidos. La familia Cupressaceae es representada por los géneros Juniperus y Cupressus con dos especies y una variedad para el primer caso y una sola especie para el segundo. De la familia Pinaceae sobresale el género Pinus con nueve especies y una variedad y para Pseudotsuga una sola especie. Se incluyen claves dicotómicas, descripciones, distribución de los taxa y especímenes de referencia para la determinación de las especies.

Rhizopogon togasawariana sp. nov., the first report of Rhizopogon associated with an Asian species of Pseudotsuga

Rhizopogon subgenus Villosuli are the only members of the genus known to form an ectomycorrhizal relationship exclusively with Pseudotsuga. The specificity of this host relationship is unusual in that Rhizopogon is broadly associated with several tree genera within the Pinaceae and relationships with a host genus are typically distributed across Rhizopogon subgenera. Naturally occurring specimens of R. subg. Villosuli have been described only from North American collections, and the unique host relationship with Pseudotsuga is demonstrated only for Rhizopogon associated with P. menziesii (Douglas-fir), the dominant species of Pseudotsuga in North America. Species of Pseudotsuga are naturally distributed around the northern Pacific Rim, and Rhizopogon associates of other Pseudotsuga spp. are not yet described. Here we present the results of field sampling conducted in P. japonica forests throughout the Japanese archipelago and describe Rhizopogon togasawariana sp. nov., which occurs in ectomycorrhizal association with P. japonica. Placement of this new species within R. subg. Villosuli is supported by morphological and molecular phylogenetic analysis, and its implications to Pseudotsuga-Rhizopogon biogeography are discussed.

Revisiting the host effect on ectomycorrhizal fungal communities: implications from host–fungal associations in relict Pseudotsuga japonica forests

Host identity is among the most important factors in structuring ectomycorrhizal (ECM) fungal communities. Both host-fungal coevolution and host shifts can account for the observed host effect, but their relative significance in ECM fungal communities is not well understood. To investigate these two host-related mechanisms, we used relict forests of Pseudotsuga japonica, which is an endangered endemic species in Japan. As with other Asian Pseudotsuga species, P. japonica has been isolated from North American Pseudotsuga spp. since the Oligocene and has evolved independently as a warm-temperate species. We collected 100 soil samples from four major localities in which P. japonica was mixed with other conifers and broadleaf trees. ECM tips in the soil samples were subjected to molecular analyses to identify both ECM fungi and host species. While 136 ECM fungal species were identified in total, their communities were significantly different between host groups, confirming the existence of the host effect on ECM fungal communities. None of the 68 ECM fungal species found on P. japonica belonged to Pseudotsuga-specific lineages (e.g., Rhizopogon and Suillus subgroups) that are common in North America. Most of ECM fungi on P. japonica were shared with other host fungi or phylogenetically close to known ECM fungi on other hosts in Asia. These results suggest that after migrating, Pseudotsuga-specific fungal lineages may have become extinct in small isolated populations in Japan. Instead, most of the ECM fungal symbionts on P. japonica likely originated from host shifts in the region.

Pseudotsuga tanaiiHuzioka from the earliest Miocene Shichiku Flora of northeast Japan: Systematics and ecological conditions

The earliest fossil record of the genus Pseudotsuga (Pinaceae) in Asia, Pseudotsuga tanaii Huzioka, was reexamined with additional materials of seeds, leaves, cones, and twigs from the earliest Miocene Shichiku Flora of the Joban area, northeast Japan. These specimens were restudied to better understand the relationship of these fossils with the extant and fossil species from Asia. Pseudotsuga tanaii not only shows characters common to the modern species in East Asia, but also yields similar characters seen in the American clade. Thus, it could be an ancestral taxon of the Asian clade, which appeared before the diversification of the East Asian species. In contrast to the extant Pseudotsuga species growing under warm-temperate climate conditions at middle to high elevations in the mountains, Pseudotsuga tanaii appears to have been associated with lowland vegetation growing at lake margins. Forest vegetation associated with the species is equivalent to the Mixed Northern Hardwood forest, which develops under cooler climatic conditions. The inferred habitat of Pseudotsuga tanaii and its age support the hypothesis based on molecular phylogeny and morphological analyses that the genus originated in the higher latitudes during the early Paleogene and migrated south following the climatic deterioration during the late Paleogene.

Fatty acid composition of Pinaceae as taxonomic markers.

Following our previous review on Pinus spp. seed fatty acid (FA) compositions, we recapitulate here the seed FA compositions of Larix (larch), Picea (spruce), and Pseudotsuga (Douglas fir) spp. Numerous seed FA compositions not described earlier are included. Approximately 40% of all Picea taxa and one-third of Larix taxa have been analyzed so far for their seed FA compositions. Qualitatively, the seed FA compositions in the three genera studied here are the same as in Pinus spp., including in particular the same delta5-olefinic acids. However, they display a considerably lower variability in Larix and Picea spp. than in Pinus spp. An assessment of geographical variations in the seed FA composition of P. abies was made, and intraspecific dissimilarities in this species were found to be of considerably smaller amplitude than interspecific dissimilarities among other Picea species. This observation supports the use of seed FA compositions as chemotaxonomic markers, as they practically do not depend on edaphic or climatic conditions. This also shows that Picea spp. are coherently united as a group by their seed FA compositions. This also holds for Larix spp. Despite a close resemblance between Picea and Larix spp. seed FA compositions, principal component analysis indicates that the minor differences in seed FA compositions between the two genera are sufficient to allow a clear-cut individualization of the two genera. In both cases, the main FA is linoleic acid (slightly less than one-half of total FA), followed by pinolenic (5,9,12-18:3) and oleic acids. A maximum of 34% of total delta5-olefinic acids is reached in L. sibirica seeds, which appears to be the highest value found in Pinaceae seed FA. This apparent limit is discussed in terms of regio- and stereospecific distribution of delta5-olefinic acids in seed triacylglycerols. Regarding the single species of Pseudotsuga analyzed so far (P. menziesii), its seed FA composition is quite distinct from that of the other two genera, and in particular, it contains 1.2% of 14-methylhexadecanoic (anteiso-17:0) acid. In the three genera studied here, as well as in most Pinus spp., the C18 delta5-olefinic acids (5,9-18:2 and 5,9,12-18:3 acids) are present in considerably higher amounts than the C20 delta5-olefinic acids (5,11-20:2 and 5,11,14-20:3 acids).

Internal transcribed spacer region evolution in Larix and Pseudotsuga (Pinaceae)

The nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region has been characterized in the sister genera Larix and Pseudotsuga (Pinaceae). Complete sequences were obtained for seven species of Larix from North America and Eurasia and five species of Pseudotsuga from western North America and eastern Asia. ITS region lengths ranged from 1759 to 1770 bp in Larix and from 1564 to 1571 bp in Pseudotsuga. In both genera, ITS1 is three times as long as the 5.8S plus ITS2 and contains subrepeats as observed in other genera of Pinaceae. Secondary structure models predicted that the subrepeats fold into terminal stem and loop domains. ITS polymorphism detected within individuals of Larix and Pseudotsuga suggests a slow rate of concerted evolution among nrDNA loci. Except for the placement of L. sibirica, phylogenetic analyses of the ITS region agreed with previously reported restriction site analyses of Larix and Pseudotsuga. The data were not consistent with phylogenetic hypotheses for Larix based primarily upon ovulate cone characters, failing to support a derivation of the North American L. laricina from a short-bracted Eurasian lineage. The phylogenetic hypothesis did not conflict with a stepping stone model of evolution for Pseudotsuga, but a basal lineage could not be inferred for either genus.

Evolutionary relationships of Douglas-fir and its relatives (genus Pseudotsuga) from DNA restriction fragment analysis

We used restriction fragment analysis of chloroplast, nuclear, and mitochondrial DNA to study phylogeny in the genus Pseudotsuga. Total genomic DNA from one outgroup (Larix occidentalis Nutt.) and five Pseudotsuga species from Japan, mainland China, Taiwan, and North America were digested with 20 restriction enzymes, blotted, and probed up to 17 times with cloned DNA fragments. A total of 38 shared fragment characters were subjected to Wagner parsimony analysis coupled with bootstrapping to evaluate statistical significance of the phylogenetic trees. The complex patterns that we observed for actin gene fragments were evaluated via a Fitch–Margoliash distance-matrix analysis. Both parsimony and distance-matrix analyses indicated that relationships among species in the genus coincide with their current geographic distribution; genetic similarity declines with migration distance around the Pacific Rim. The Asian and North American species form well-differentiated and statistically significant monophyletic groups. Pseudotsuga japonica is the Asian species closest to the North American species. Affinities to the outgroup Larix occidentalis suggest that Pseudotsuga originated in North America and then migrated into Asia. Key words: parsimony, phylogeny, biogeography, conifer, Pinaceae.

Range-wide patterns of allozyme variation in Douglas-fir (Pseudotsugamenziesii)

Seeds from 104 geographical locations throughout the range of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were analyzed at 20 enzyme loci to determine patterns of genetic variation and to make phylogenetic inferences. On average, the populations were polymorphic at 37% of the loci (range 5.0–65.0). Mean expected heterozygosity was 0.137 (range 0.021–0.239). Of the total genie diversity (HT = 0.182) observed, 24% was due to differentiation among populations. One Mexican population was genetically distinct from the rest of the species, which suggests the possibility of additional Pseudotsuga species in Mexico. The rest of the populations clustered into two groups corresponding to the recognized coastal and interior varieties. In addition, the interior variety separated into northern and southern subgroups near 44° latitude. Transition zones between the varieties were found to be narrower and more abrupt than has been suggested previously. Populations within the coastal variety and the northern interior subgroup averaged higher expected heterozygosity than the southern interior subgroup, but in the southern interior subgroup, populations were much more highly differentiated. Allozyme variation followed a latitudinal cline in the interior variety, but only weak geographical patterning was observed in the coastal variety. In general, genetic diversity decreased towards the periphery of the species range. Range-wide patterns of allozyme variation were similar to those in terpene studies, with the major exception that the Sierra Nevada seed sources in this study were closely aligned with the coastal variety rather than with the interior variety. Range-wide patterns of genetic variation in Douglas-fir largely reflect the evolutionary history of the species as revealed by paleobotanical studies.

The effects of soil and atmospheric drought on photosynthesis and stomatal control of gas exchange in three coniferous species

The responses of steady‐state CO2 assimilation rate (A), transpiration rate (E), and stomatal conductance (gs) to changes in leaf‐to‐air vapour pressure difference (δW) on one hand and to increasing soil drought on the other hand were examined in 2‐year‐old seedlings of Pseudotsuga menziesii, Pseudotsuga macrocarpa and Cedrus atlantica. Analysing the data through A vs intercellular CO2 molar fraction (ci) graphs, we could determine stomatal and mesophyll contributions to changes in A as δW or soil drought were increased. Increasing soil drought affected gs and mesophyll photosynthesis independently, since clearly distinct predawn leaf water potential (ψp) regions appeared in which either stomatal or mesophyll effects prevailed for explaining the changes in A. The two Pseudotsuga species exhibited a large ψP range (between ca ‐0.8 and ‐1.5 to ‐1.9 MPa) in which only stomata were responsible for the decrease in A. A dramatic decline in mesophyll photosynthesis was noticed starting from values as high as ‐1.2 MPa (C. atlantica), ‐1.5 MPa (P. macrocarpa) and ‐1.9 MPa (P. menziesii). Increasing ΔW at high soil water content led to a sharp decline in A primarily due to an alteration of mesophyll photosynthesis. Stomatal conductance for CO2 diffusion was affected in a lesser extent and in close correlation with the changes in mesophyll photosynthesis, which could suggest the existence of a functional linkage between mesophyll photosynthesis and stomata. Surprisingly, the drought resistant P. macrocarpa exhibited the least conservative water use efficiency in response to the two types of drought. In this species drought adaptation seems to be mainly due to its high root growth and soil prospection ability.

Chemotaxonomy of the genus Abies—I. : Survey of the terpenes present in the Abies balsams

Terpenes of the balsams of seventeen Abies and three Pseudotsuga species and varieties were analyzed by gas-liquid chromatography. The differences in composition found indicate that this method can be used for distinguishing between some closely related species, although substantiation will have to be made through further population studies.

Fatty Acids in Pollen of Some Coniferous Species

Fatty acids in pollen of five coniferous species were isolated and analyzed by gas-liquid chromatography. It was found that 0.76 to 0.89 percent of the dry weight of pollen was fatty acid in three species of Pseudotsuga and 1.25 to 1.33 percent in two species of Pinus. Major components in Pseudotsuga were oleic, palmitic, and linoleic acids, whereas in Pinus they were linolenic, oleic, palmitic, and stearic acids.