The significance of lenticels for successful<Emphasis Type="Italic"> Pityogenes chalcographus</Emphasis> (Coleoptera: Scolytidae) invasion of Norway spruce trees [<Emphasis Type="Italic">Picea abies</Emphasis> (Pinaceae)]

In this study we tested whether Pityogenes chalcographus L. beetles preferably infest their host tree, Picea abies (L.) Karst., through lenticels or not. In a second step the resin canal system, which is important for defence against bark beetles, was investigated under lenticels and under lenticel-free periderm. Beetle colonisation tests on breeding logs resulted in 93.2% successful invasions through lenticels, 4.2% through lenticel-free periderm, 1.2% through wounds, and 1.4% near branches (n=1,606). Three main reasons why beetles invade preferable sites are discussed, taking the function of lenticels to supply gas exchange of the interior tissues into consideration. First, attractive volatiles are more easily detectable over the lenticels, and this could be a stimulus for the bark beetles to invade their hosts through these structures. Secondly, the very loosely arranged tissues of the lenticel and bigger intercellular spaces in the cortex and secondary phloem under the lenticel permit the beetles easier movement towards the vascular cambium. Thirdly, the total resin canal area of both primary and secondary canals and the number of secondary resin canals were reduced under lenticels. A higher resin canal density beneath lenticels would constitute a barrier to gas movement.     

The course of resin canals in the shoots of conifers

Resin canal patterns in the Pinaceae differ significantly from those in other conifers. In this paper, Pinus type, Picea type and Larix type are defined.Pinus has the Pinus type pattern, in spite of the possession of a system of peripheral canals in some members. The patterns inAbies, Picea, Cedrus, Keteleeria andPseudotsuga are varied. Both Pinus and Picea types are usually observed, although many other types are also seen in these five genera.Larix andPseudolarix have the Larix type pattern, andTsuga has a modified Torreya type pattern. From the data obtained in the present series of studies (Suzuki, 1979a, b), two main evolutional trends of resin canal patterns are suggested. In the Pinaceae, the patterns probably evolved from the complicated type to the simple type. In the other families, they evolved from the simple type to the complicated type. Moreover, it is to be considered likely that the patterns have evolved independently in each family. Patterns of resin canals are very similar to the primary vascular patterns. The similarity is probably not fundamental, but superficial, because most of the conifer species, of which resin canal patterns are varied, have but a single type of the primary vascular system.     

Needle morphological evidence of the homoploid hybrid origin of Pinus densata based on analysis of artificial hybrids and the putative parents,Pinus tabuliformis and Pinus yunnanensis

Genetic analyses indicate that Pinus densata is a natural homoploid hybrid originating from Pinus tabuliformis and Pinus yunnanensis. Needle morphological and anatomical features show relative species stability and can be used to identify coniferous species. Comparative analyses of these needle characteristics and phenotypic differences between the artificial hybrids, P. densata, and parental species can be used to determine the genetic and phenotypic evolutionary consequences of natural hybridization. Twelve artificial hybrid families, the two parental species, and P. densata were seeded in a high‐altitude habitat in Linzhi, Tibet. The needles of artificial hybrids and the three pine species were collected, and 24 needle morphological and anatomical traits were analyzed. Based on these results, variations in 10 needle traits among artificial hybrid families and 22 traits among species and artificial hybrids were predicted and found to be under moderate genetic control. Nineteen needle traits in artificial hybrids were similar to those in P. densata and between the two parental species, P. tabuliformis and P. yunnanensis. The ratio of plants with three needle clusters in artificial hybrids was 22.92%, which was very similar to P. densata. The eight needle traits (needle length, the mean number of stomata in sections 2 mm in length of the convex and flat sides of the needle, mean stomatal density, mesophyll/vascular bundle area ratio, mesophyll/resin canal area ratio, mesophyll/(resin canals and vascular bundles) area ratio, vascular bundle/resin canal area ratio) relative to physiological adaptability were similar to the artificial hybrids and P. densata. The similar needle features between the artificial hybrids and P. densata could be used to verify the homoploid hybrid origin of P. densata and helps to better understand of the hybridization roles in adaptation and speciation in plants.     

Terpenoid and morphological variability of Pinus quadrifolia and its natural hybridization with Pinus monophylla in Northern Baja California and adjoining United States

Mono- and sesquiterpenoids from wood of P. quadrifolia and that of the southwestern form of P. monophylla were analysed by GLC. Concurrently the number of needles per fascicle, the number of resin canals, and the number of abaxial and adaxial stomatal rows towards the tip, in the middle, and towards the base of the needles were determined. The data covered 90 trees from 8 pure populations from southernmost California and northern Baja California and 21 trees from a mixed stand in Baja California.α-Pinene, mycene, α-amorphene, γ-muurolene, germacrene D, and to a very minor extent camphene, β-pinene, limonene, β-phellandrene and β-ylangene percentages could be used for species identification. The number of needles per fascicle, the number of resin canals, and the number of abaxial stomatal rows afforded appreciably sharper identification, however. Statistical treatment of chemical and morphological data from pure stands did not give evidence for introgression of the two species. A definite intermediacy, rather limited in extent, could be demonstrated for the mixed stand, however.     

Changes of monoterpene concentrations in needles of pollution-injured Picea abies exhibiting montane yellowing

Terpenes were analyzed in needles of pollution injured Picea abies (L.) Karst. of the Southern Black Forest (SW Germany) showing symptoms of montane yellowing. Compared to a set of healthy trees, a set of injured trees showed increased terpene hydrocarbon concentrations relative to needle fresh weight. This difference was even more pronounced when the terpene concentrations of green, healthy and yellowing, injured needles from the same internode of individual injured trees were compared. Increased terpene concentrations were observed in the basal parts of injured needles, while their distal parts exhibited a loss of terpenes. In addition, an alteration in the pattern of terpene occurrence was observable. Most striking was the changed ratio of α-pinene to β -pinene. with marked increase of the latter, in injured needles. As indicated by ultratrace analysis of isolated mesophyll. vascular tissue and resin ducts of the needles, mono- and sesquiterpenes were found exclusively in resin ducts. The other tissues were virtually free of terpenes. Isolated resin from a single resin duct contained all terpenes (monoterpene hydrocarbons, alcohols and ketones, and sesquiterpene hydrocarbons) that are typical for the needle. An individual response to air pollution of each separate short resin duct in the needle may be deduced.     

奥硝唑用于感染根管消毒的细菌学研究

目的　观察和探讨新型抗厌氧菌药物奥硝唑消毒感染根管的抗菌效果。方法　选择感染根管患牙98颗,常规根管预备后,随机分为试验组(奥硝唑组)和对照组(甲醛甲酚组)各4 9颗。分别在根管预备前、预备后及封药后进行根管内细菌标本采样、培养、分离与鉴定,测定根管内细菌变化及检出情况,并观察封药后临床症状和体征的变化。结果　2组封药后,根管内细菌数量及检出率均较封药前明显降低( P<0 .0 5 ) ,根管内细菌数量及检出率比较,差异无显著性( P>0 .0 5 ) ,奥硝唑的近期临床疗效优于甲醛甲酚。结论　奥硝唑是一种较安全、有效的根管消毒药物     

The course of resin canals in the shoots of conifers

The course of resin canals in stem cortex and the continuity between resin canals in leaves and those in stem cortex were investigated. The present paper is the first of three parts of the investigation. In this paper, fundamental features of resin canals and actual resin canal patterns in the Taxaceae, Cephalotaxaceae and Podocarpaceae are reported. From the observation of serial transections of shoots, composite diagrams and three-dimensional models of resin canal patterns are drawn. Central canals, if present, run vertically in stem cortex and sometimes divide, end blindly or unite each other. The distance between two adjacent central canals fluctuates rhythmically in connection with the vascular supply from the stem to leaves. The resin canal patterns of the families are classified into four types. Those ofTaxus, Nothotaxus and three species ofDacrydium belong to the Taxus type, those ofTorreya andCephalotaxus to the Torreya type, those ofDacrydium elatum, Podocarpus alpinus, P. elatus, P. elongatus andP. neriifolius to the Dacrydium type, those ofP. macrophyllus, P. nagi andP. koordersii to the Podocarpus type.     

Growth characteristics of Sakhalin spruce (Picea glehnii) planted on the northern Japanese hillsides exposed to strong winds

Sakhalin spruce (Picea glehnii), a native species typically found in northern Japan, has been used in reforestation on hillsides exposed to strong winds. In the reforestation areas, there are south-facing (S-slope) and northwest-facing slopes (NW-slope). Climatic conditions are contrasting between the two slopes, with shallower snow cover on the S-slopes. We compared growth responses of the spruce to micro-environment between the S- and NW-slopes through soil nutrients, needle longevity, water status, photosynthesis, and nutrients in the needles. These parameters were measured in needles exposed above the snow in winter and in lower needles protected by snow cover. High-position needles suffered from drought stress, especially in winter, and needles were shed early in the year on both slopes. Low-position needles did not suffer from drought stress, and maintained a high photosynthetic rate on both slopes. However, needle longevity was reduced on the S-slope, and concentrations of nitrogen, phosphorus, and potassium in the needles decreased with needle age. Soil nutrient concentrations were low on the S-slope, which suggests that the needles on the S-slope may remobilize nutrients from aged needles to younger needles prior to shedding. This characteristic is probably an adaptation in Sakhalin spruce to poor soil conditions.     

Alterations of the resin canal system of <Emphasis Type="Italic">Pinus pinaster</Emphasis> seedlings after fertilization of a healthy and of a <Emphasis Type="Italic">Hylobius abietis</Emphasis> attacked stand

Changes in resource availability and biotic and abiotic stress may alter the defensive mechanisms of pine trees. The effect of fertilisation on the resin canal structure of Pinus pinaster seedlings established in two trials in NW Spain, one attacked by Hylobius abietis and the other non-attacked, was studied. The leaders of 50 plants were destructively sampled and the resin canal density, the canal area and its relative conductive area in the phloem and xylem were assessed. Experimentally increased nutrient availability significantly decreased resin canal density in the phloem of the seedlings in the two analysed trials, where unfertilised seedlings presented up to 30% more resin canal density than the fertilised seedlings (mean value ± SEM = 0.32 ± 0.02 resin canals mm⁻² in the fertilised plants versus 0.45 ± 0.04 resin canals mm⁻² in the control plants). Fertilisation had no effect on the resin canal system in the xylem, but significantly increased tracheid size. Significant differences of resin canals among sites were observed mainly in the xylem; the resin canal density was 1.7-fold greater in the attacked site than in the non-attacked site. The similar structure of phloem resin canals in both sites supports that phloem resin canals are constitutive mechanisms of defence in P. pinaster, whereas xylem resin canals would be constitutive mechanisms but also inducible mechanisms of resistance following the attack of pine weevils or bark beetles. XM and LS equally contributed to this paper.     

Monoterpenoid and morphological differentiation within Pinus cembroides

Wood of Pinus cembroides from 232 trees sampled in 23 localities throughout its range in the United States and Mexico has been analysed for monoterpenes. With a few exceptions the trees of the continental populations from the state of Hidalgo northward produced α-pinene as the main monoterpene. The majority of trees of the southern populations (subsp. orizabensis) from the state of Puebla and adjoining regions of the neighboring Veracruz and Tlaxcala produced 3-carene in appreciable amounts. The population from Baja California (subsp. lagunae) produced monoterpenes of the sabinene family (thujene, sabinene, γ-terpinene, terpinolene and $\text{p-}\text{cymene}$) as the main constituents. The variations in morphological characters, including number of needles per fascicle, number of stomatal rows in needles, number of resin canals in needles, as well as other characters of the internal needle morphology, needle length and thickness, needle retention, thickness of seed shells, bark and cone characteristics, rate of growth and cotyledon number either paralleled or did not contradict the chemical variations. The evolution of the southern populations (subsp. orizabensis) into a separate group most likely resulted from geographic separation and climatic differences, while the evolutionary separation of the Baja California trees (subsp. lagunae) was connected with northwestern movement of the California coastal region from Miocene onward and the formation of Sierra Madre Occidental resulting in separation of this population from the mainland populations by the gap of the Gulf of California and the coastal mountain ranges.     

Morpho-anatomical traits of Pinus peuce needles from natural populations in Montenegro and Serbia

Variability of eight morpho-anatomical traits of two-year-old needles of the Macedonian pine (Pinus peuce Griseb.), collected from natural populations of Montenegro (Zeletin and Sjekirica) and Serbia (Mokra Gora), was investigated. The needles have two resin ducts of the external type (touching epidermis). The average values were as follows: 7.14 cm (needle length), 0.86 mm (needle width), 0.66 mm (needle thickness), 13.32 μm (cuticle+epidermis thickness), 16.24 μm (height of hypodermal cells), 1.45 (number of hypodermis layers), 2 (number of resin ducts) and 52.45 μm (resin duct diameter). The most variable characters were needle width and needle thickness. PCA visualizes overlapping of three populations. Cluster analysis suggests that the Sjekirica population is more similar to the Mokra Gora population than to the geographically nearest population of Zeletin. Given results are discussed in relation to our previous investigations of this species based on terpenes and n-alkanes, where the population from Mt. Zeletin also exhibited differences compared to the population from other Balkan localities.     

Comparative Observations of Resin Canals in Secondary Xylem of Three Species of Normal and Dwarf Pines

The number size and morphology of resin canals in secondary xylem of three species of normal and dwarf pines, i. e. Pinus thunbergii, P. tabulaeformis and P. densiflora, were comparatively studied. It was found that the number of resin canals in dwarf pines was significantly greater than in normal pines, while the size of resin canals in dwarf pines was invariably smaller than in normal pines. In addition, the epithelial cells around the canals of dwarf pines extended laterally, which made the outline of resin canals aliform-like. These findings might indicate that the raviations of resin canals representing a special adaptation to the unfavourable growth conditions were also correlated with the trend of shortening and narrowing of dwarf pines.     

Development of the supraorbital and mandibular lateral line canals in the cichlid,Archocentrus nigrofasciatus

The development of two of the cranial lateral line canals is described in the cichlid, Archocentrus nigrofasciatus. Four stages of canal morphogenesis are defined based on histological analysis of the supraorbital and mandibular canals. "Canal enclosure" and "canal ossification" are defined as two discrete stages in lateral line canal development, which differ in duration, an observation that has interesting implications for the ontogeny of lateral line function. Canal diameter in the vicinity of individual neuromasts begins to increase before ossification of the canal roof in each canal segment; this increase in canal diameter is accompanied by an increase in canal neuromast size. The mandibular canal generally develops later than the supraorbital canal in this species, but in both of these canals development of the different canal segments contained within a single dermal bone is asynchronous. These observations suggest that a dynamic process requiring integration and interaction among different tissues, in both space and time, underlies the development of the cranial lateral line canal system. The supraorbital and mandibular canals appear to demonstrate a "one-component" pattern of development in Archocentrus nigrofasciatus, where the walls of each canal segment grow up from the underlying dermal bone and then fuse to form the bony canal roof. This is contrary to numerous published reports that describe a "two-component" pattern of development in teleosts where the bony canal ossifies separately and then fuses with an underlying dermal bone. A survey of the literature in which lateral line canal development is described using histological analysis suggests that the occurrence of two different patterns of canal morphogenesis ("one-component" and "two-component") may be due to phylogenetic variation in the pattern of the development of the lateral line canals.     

Stomatal frequency adjustment of four conifer species to historical changes in atmospheric CO2

The species-specific inverse relation between atmospheric CO(2) concentration and stomatal frequency for many woody angiosperm species is being used increasingly with fossil leaves to reconstruct past atmospheric CO(2) levels. To extend our limited knowledge of the responsiveness of conifer needles to CO(2) fluctuations, the stomatal frequency response of four native North American conifer species (Tsuga heterophylla, Picea glauca, Picea mariana, and Larix laricina) to a range of historical CO(2) mixing ratios (290 to 370 ppmV) was analyzed. Because of the specific mode of leaf development and the subsequent stomatal patterning in conifer needles, the stomatal index of these species was not affected by CO(2). In contrast, a new measure of stomatal frequency, based on the number of stomata per millimeter of needle length, decreased significantly with increasing CO(2). For Tsuga heterophylla, the stomatal frequency response to CO(2) changes in the last century is validated through assessment of the influence of other biological and environmental variables. Because of their sensitive response to CO(2), combined with a high preservation capacity, fossil needles of Tsuga heterophylla, Picea glauca, P. mariana, and Larix laricina have great potential for detecting and quantifying past atmospheric CO(2) fluctuations.     

A NEW SPECIES OF PICEA BASED ON SILICIFIED SEED CONES FROM THE OLIGOCENE OF WASHINGTON

Picea eichhornii n. sp. is described from anatomically preserved seed cones. The fossils are from the Early Oligocene Jansen Creek Member of the Makah Fm. which is exposed along the northern shore of the Olympic Peninsula, Washington. The cones are at least 5.5 cm long and up to 3.5 cm in diameter. The cone axis is 4–6 mm in diameter and contains a pith made up of thick-walled parenchyma cells. Resin canals occur in a single ring in the secondary xylem in some specimens but are absent in others. The cortex is mostly parenchymatous and contains numerous large axial resin canals that branch to supply the bract and scale. Vascular traces to each scale and its subtending bract diverge separately from the vascular cylinder of the cone axis. The bract is tongue-shaped and keeled at its base. It is 5 mm wide and up to 9 mm long. The bract trace fades out before entering the bract base while two resin canals extend into the bract base. The ovuliferous scale is about 2.3 cm long and has a thin, probably papery, apex. Resin canals of the scale occur abaxial to the vascular tissue in the scale base, but some bend around the margins of the vascular strand to become adaxial outward. About 20 resin canals occur in the abaxial scale sclerenchyma, and this is the main anatomical feature that distinguishes these cones as a new species. There are less than 14 such canals in cones in a reference collection of 15 modern species and in the two fossil species known from anatomically preserved material. While the new species adds to our knowledge of the diversity of Cenozoic Picea, its affinities within the genus remain undetermined.     

Responses of Neodiprion sertifer (Hym., Diprionidae) larvae to variation in needle resin acid concentration in Scots pine

Summary We have studied how differences in needle resin acid concentrations between two clones of Scots pine influenced larval survival, larval developmental time, and cocoon weight in Neodiprion sertifer. Larvae were reared under controlled conditions in the laboratory on needles showing a three-fold difference, in resin acid concentration. Larval developmental time was significantly longer for larvae fed needles high in resin acids. No significant differences were found in cocoon weight. Larvae fed needles high in resin acids suffered significantly higher mortality, most of which occurred, in the first two instars. Data on relative growth rate for last-instar larvae, based on a traditional growth efficiency experiment, did not show any negative effects of resin acids, indicating that a possible induction takes place during early instars. Observations on the feeding behaviour of last-instar larvae, the high consumption of bark tissue (with high concentrations of resin acids) by larvae fed needles low in resin acids and preference for needle tissues high in resin acids, indicate that these larvae might actively search for tissues rich in resin acids. We conclude that the physiology and behaviour of N. sertifer has been shaped, in part, by the conflict between the negative effects of resin acids, primarily in early instars (longer developmental time with a corresponding increase in exposure to natural enemies and an increase in direct mortality), and the positive effect of resin acids in later instars (a need for resin acids for use in its own predator defence secretion).     

枫香亚科植物茎初生结构中树脂道发生发育的研究

经研究表明枫香亚科植物 (苏合香 L iquidambar orientalis,阿丁枫 Alitangiqia chinesis,枫香L iquidamformosana)茎的初生结构中树脂道的发生方式均为裂生型 ,树脂道的发育经历 :(1)原始细胞分裂阶段 ;(2 )胞间道发生阶段 ;(3)胞间道扩张阶段 ;(4 )树脂道成熟阶段 ;(5)树脂道老化阶段。枫香亚科与壳菜果亚科相比 ,两亚科树脂道自然发生阶段相同 ,但发生方式有别 ,分布区域有异同点。     

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

Summary 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.     

Ultrastructural diversity in the pore canal systems of amphipod crustaceans

Transmission electron microscopy was used to analyze the structure and organization of the intracuticular pore canal system in 34 species of amphipod crustaceans. Pore canals were detectable in all species, including those that, from scanning electron microscopy, had been considered to lack them. Canal structure ranges from simple transcuticular passages of uniform diameter to more elaborate systems with distal canal dilatations variously equipped with electron dense collars, tubular filaments, single or multiple channels leading to the surface and transverse partitions separating canal contents of different electron densities. Considerable branching between tubular elements of the canal system is evident in many species. In most species the canals communicate with the outsidevia epicuticular channels. Even in those species in which this communication was not established, their epicuticle generally contains abundant cavities with external pores. Although some consistency in structure and organization is present among a few groups of taxonomically related species, pore canal characteristics generally could not be correlated with habitat or life style. It is suggested that the structural and organizational variety present reflects a considerable array of functions among amphipod pore canal systems.