Conifer Families Research Articles

Chemical Composition of the Hydrosol and the Essential Oil of Three Different Species of the Pinaceae Family : Picea glauca (Moench) Voss., Picea mariana (Mill.) B.S.P., and Abies balsamea (L.) Mill.

The chemical composition of the oils and hydrosols collected from wild plantations of three species of the Pinaceae family of conifers in the Grondines region of the province of Quebec, Canada, were determined by GC-FID and GC-MS analyses. The components obtained from the hydrosol of Picea glauca (Moench) Voss., (White Spruce) were mainly monoterpene alcohols, aldehydes and ketones. The major compound by far was camphor (65 %) with borneol (10 %) as an important minor constituent. In contrast, the essential oil was composed mainly of β-pinene (20 %) and camphor (20 %) followed by α-pinene (12 %) and bornyl acetate (12 %). Bornyl acetate (34.2 %) was the main compound identified in the Picea mariana (Mill.) B.S.P., (Black Spruce) oil and monoterpenes, mainly α-pinene (12.9 %) and camphene (16.4 %), constituted at least 45 % of the oil. On the contrary, due to their very low water solubility, monoterpene hydrocarbons were barely present in the hydrosol in which alcohols were the main components. They were oc-terpineol and borneol (each ˜14 %), terpinen-4-ol and camphene hydrate (each ˜6 %) as well as several aliphatic alcohols (cis-3-hexen-1-ol - 6.5 %). Bornyl acetate was also a significant component (7.8 %). Monoterpenes were the main components of the essential oil of Abies balsamea (L.) Mill. (Canadian Fir oil). They were β-pinene (33.5 %), Δ3-carene (14 %), oc-pinene (11.3 %) as well as limonene and β-phellandrene (each ˜7 %). Bornyl acetate was also a significant component (10 %). α-terpineol (˜41 %) was by far the main component observed in the hydrosol followed by borneol (6.4 %). Of particular interest was the presence of maltol (˜15 %). To our knowledge, this is the first report on the hydrosol composition obtained from a coniferous tree.

497 Reproductive anatomy of the conifer family Cheirolepidiaceae

497 Reproductive anatomy of the conifer family Cheirolepidiaceae

Cloning and Characterization of WOX4 Gene from Vitis vinifera L. Involved in Stem Cell Regulation

Abstract Wuschel-related homeobox (WOX) genes play essential, specific, and sometimes redundant roles in plant embryo development, shoot and root meristem maintenance, and plant development. Though much information was quickly gained with members of the WOX gene family of Arabidopsis, monocotyledonous crops, and gymnospermous conifers, little is known about perennial woody plants. In this study, we isolated the first WOX gene family member from grape (Vitis vinifera L. cv. Cabernet Sauvignon), and named it VvWOX4 based on its characteristic domains and phylogenetic analysis. The identity of VvWOX4 was validated by MALDI-TOF MS and Western blot with polyclonal antibody against Arabidopsis thaliana Wuschel. Functional analysis showed that VvWOX4 markedly increased shoot primordia structures when overexpressed under CaMV 35S promoter in tobacco. A different expression pattern was found for VvVOX4 compared with AtWUCHEL and its expression was detected in unique organs of grapevines. Besides the expression in the vegetative shoot apical meristem (SAM) of grape shoot tips, VvWOX4 is expressed in dormant winter buds, inflorescence, young leaves, and tendril tips, but not in root tips. In young leaves, the expression of VvWOX4 is strongly upregulated by wounding, and also by plant growth regulators such as 2 mg L −1 2,4-D, 1 mg L −1 NAA and 1 mg L −1 BAP treatments, while downregulation was monitored by 1 mg L −1 IBA treatment, and there was no response to 0.5 mg L −1 GA3 treatment. Together, our results revealed the first member of grape WOX gene family and indicated different roles and regulation of VvWOX4 in the perennial woody crop grapevine.

Morphological and functional stasis in mycorrhizal root nodules as exhibited by a Triassic conifer.

Mycorrhizal root nodules occur in the conifer families Araucariaceae, Podocarpaceae, and Sciadopityaceae. Although the fossil record of these families can be traced back into the early Mesozoic, the oldest fossil evidence of root nodules previously came from the Cretaceous. Here we report on cellularly preserved root nodules of the early conifer Notophytum from Middle Triassic permineralized peat of Antarctica. These fossil root nodules contain fungal arbuscules, hyphal coils, and vesicles in their cortex. Numerous glomoid-type spores are found in the peat matrix surrounding the nodules. This discovery indicates that mutualistic associations between conifer root nodules and arbuscular mycorrhizal fungi date back to at least the early Mesozoic, the period during which most of the modern conifer families first appeared. Notophytum root nodules predate the next known appearance of this association by 100 million years, indicating that this specialized form of mycorrhizal symbiosis has ancient origins.

Root suckering in a Triassic conifer from Antarctica: Paleoecological and evolutionary implications

Although root suckering and other types of sprouting are well studied in extant woody plants, little is known about the distribution of these traits at a macroevolutionary scale. Anatomically preserved fossil plants represent an excellent but understudied source of information of the distribution of sprouting behavior through time and across taxa. A block of silicified peat collected in the Middle Triassic Fremouw Formation at the Fremouw Peak locality, Central Transantarctic Mountains, Antarctica, contains a group of anatomically preserved roots of the fossil conifer Notophytum krauselii that bear young shoots. The specimen was prepared using the standard acetate peel technique and studied in reflected and transmitted light. Young sucker shoots bearing well-preserved leaves are produced in groups in some areas of the Notophytum roots. The production of root suckers in Notophytum indicates that some of the trees growing in polar forests during the Triassic could respond to environmental stresses by regenerating their vegetative structures and had the potential to reproduce vegetatively. The specimens also represent the first anatomical evidence of root suckering in any fossil seed plant, and its occurrence in an early putative podocarp supports the idea that this trait might be ancestral in at least some extant conifer families.

Leaf evolution in Southern Hemisphere conifers tracks the angiosperm ecological radiation.

The angiosperm radiation has been linked to sharp declines in gymnosperm diversity and the virtual elimination of conifers from the tropics. The conifer family Podocarpaceae stands as an exception with highest species diversity in wet equatorial forests. It has been hypothesized that efficient light harvesting by the highly flattened leaves of several podocarp genera facilitates persistence with canopy-forming angiosperms, and the angiosperm ecological radiation may have preferentially favoured the diversification of these lineages. To test these ideas, we develop a molecular phylogeny for Podocarpaceae using Bayesian-relaxed clock methods incorporating fossil time constraints. We find several independent origins of flattened foliage types, and that these lineages have diversified predominantly through the Cenozoic and therefore among canopy-forming angiosperms. The onset of sustained foliage flattening podocarp diversification is coincident with a declining diversification rate of scale/needle-leaved lineages and also with ecological and climatic transformations linked to angiosperm foliar evolution. We demonstrate that climatic range evolution is contingent on the underlying state for leaf morphology. Taken together, our findings imply that as angiosperms came to dominate most terrestrial ecosystems, competitive interactions at the foliar level have profoundly shaped podocarp geography and as a consequence, rates of lineage diversification.

Deep simple morphophysiological dormancy in seeds of the basal taxad Cephalotaxus

AbstractAlthough mature seeds of the monogeneric conifer family Cephalotaxaceae sensu stricto have underdeveloped embryos, no definitive studies have been done to classify dormancy in this family. Our primary purpose was to determine the kind of dormancy in seeds of Cephalotaxus wilsoniana and to put the results into a broad phylogenetic context for gymnosperms. The species is of horticultural and medicinal value, and information is needed on how to propagate it efficiently from seeds. Embryo growth and germination were monitored for seeds at warm, cold and warm plus cold temperatures, and germination was monitored for seeds subjected to: (1) cold → warm → cold → warm; and (2) warm → cold → warm → cold → warm temperature sequences. The effects of gibberellic acids GA3 and GA4 were tested on radicle emergence in ungerminated seeds and on shoot emergence in root-emerged seeds. Germination was promoted by ≥ 36 weeks of warm stratification followed by ≥ 8 weeks of cold stratification, but only if seeds were returned to high temperatures. The underdeveloped embryo must increase in length by >120% before the radicle emerges. Neither GA3 nor GA4 was effective in promoting radicle emergence; however, both plant growth regulators increased rate (but not percentage) of shoot emergence in root-emerged seeds. We conclude that seeds of C. wilsoniana have the deep simple level of morphophysiological dormancy (MPD), C1b-C3-B1b; thus, warm stratification followed by cold stratification and then warm-temperature incubation are required for germination. In gymnosperms, MPD is known in cycads, Ginkgo and now in three families of conifers.

The stomatal CO2 proxy does not saturate at high atmospheric CO2 concentrations: evidence from stomatal index responses of Araucariaceae conifers

The inverse relationship between the number of stomata on a leaf surface and the atmospheric carbon dioxide concentration ([CO(2)]) in which the leaf developed allows plants to optimise water-use efficiency (WUE), but it also permits the use of fossil plants as proxies of palaeoatmospheric [CO(2)]. The ancient conifer family Araucariaceae is often represented in fossil floras and may act as a suitable proxy of palaeo-[CO(2)], yet little is known regarding the stomatal index (SI) responses of extant Araucariaceae to [CO(2)]. Four Araucaria species (Araucaria columnaris, A. heterophylla, A. angustifolia and A. bidwillii) and Agathis australis displayed no significant relationship in SI to [CO(2)] below current ambient levels (~380 ppm). However, representatives of the three extant genera within the Araucariaceae (A. bidwillii, A. australis and Wollemia nobilis) all exhibited significant reductions in SI when grown in atmospheres of elevated [CO(2)] (1,500 ppm). Stomatal conductance was reduced and WUE increased when grown under elevated [CO(2)]. Stomatal pore length did not increase alongside reduced stomatal density (SD) and SI in the three araucariacean conifers when grown at elevated [CO(2)]. These pronounced SD and SI reductions occur at higher [CO(2)] levels than in other species with more recent evolutionary origins, and may reflect an evolutionary legacy of the Araucariaceae in the high [CO(2)] world of the Mesozoic Era. Araucariacean conifers may therefore be suitable stomatal proxies of palaeo-[CO(2)] during periods of "greenhouse" climates and high [CO(2)] in the Earth's history.

AGAMOUS subfamily MADS-box genes and the evolution of seed cone morphology in Cupressaceae and Taxodiaceae

In this comparative developmental genetics study, we test hypotheses based on fossil and morphological data on reproductive organ morphology and evolution in conifers--specifically, the ovule-bearing organ in Cupressaceae and Taxodiaceae. Genes homologous to the Arabidopsis gene AGAMOUS are expressed in ovuliferous scales of spruces (Picea) throughout development. Previous studies have shown that the AGAMOUS subfamily of MADS-box genes predates the split between angiosperms and gymnosperms, and that these genes have in part conserved functions in reproductive development among seed plants, especially in the specification of identity of the ovule-bearing organs. These data indicate that their expression in conifer families other than Pinaceae might be used as markers for organs homologous to the Pinaceae ovuliferous scale. Here we have isolated putative AGAMOUS orthologs from Cupressaceae and Taxodiaceae and analyzed their expression pattern in seed cones to test for the presence of morphological homologs of ovuliferous scales. Our results were not congruent with the hypothesis that the tooth of the Cryptomeria seed cone is homologous to the Picea ovuliferous scale. Likewise, the hypothesis that the bracts of Thujopsis and Juniperus contain fused ovuliferous scales was not supported. However, we found expression of AGAMOUS homologs in the sterile bracts of Cupressaceae seed cones at late developmental stages. This expression probably represents a novel gene function in these conifer families, since no corresponding expression has been identified in Pinaceae. Our study suggests that the evolutionary history of modern conifer cones is more diverse than previously thought.

Shifting functional roles and the evolution of conifer pollen-producing and seed-producing cones

Exploring patterns in the evolution of seed plant reproductive morphology within a functional context offers a framework in which to identify and evaluate factors that potentially drive reproductive evolution. Conifers are a particularly useful group for studies of this kind because they have a long geologic history and their reproductive organs are borne on separate structures with discrete functions. Multivariate analysis of morphological data collected from pollen-producing and seed-producing cones of Paleozoic, Mesozoic, and extant conifer species shows that seed cones underwent a significant expansion of morphological diversity that began during the Early-Middle Jurassic and has continued into the present day. In contrast, pollen cones show significantly lower levels of morphological diversity and exhibit similar basic morphologies throughout conifer evolutionary history. The increase in seed cone diversity through time is primarily the result of two novel structural and organizational features that evolved independently in different conifer families during the Mesozoic: robust, tightly packed cones in members of Araucariaceae, Cupressaceae sensu lato, and Pinaceae, and highly reduced, fleshy cones or solitary seeds in Podocarpaceae, Taxaceae, and some members of Cupressaceae sensu stricto. In extant conifers, these cone morphologies are associated with species that have strong interactions with vertebrate seed predators, seed dispersers, or a combination of both. This suggests that increases in the strength and complexity of biotic interactions in the Jurassic and Cretaceous were a primary driver of conifer reproductive evolution, and that patterns of character evolution relate to the increasing importance of cone tissue in seed protection and seed dispersal through time.

Characterizing Modern and Fossil Gymnosperm Exudates Using Micro-Fourier Transform Infrared Spectroscopy

Infrared absorption spectra of exudates from 65 species of gymnosperms were measured using micro–Fourier transform infrared (FTIR) spectroscopy. On the basis of the infrared spectra, three compositionally distinct groups of exudates can be distinguished: resins, volatile-rich resins, and gums. Resins and volatile-rich resins are mainly composed of terpenoids, whereas gums are polysaccharides. Resins and volatile-rich resins are restricted to conifers (Pinophyta). Gums, on the other hand, are produced by some conifer families including Araucariaceae and Podocarpaceae; nonconifer gymnosperms including Ginkgo (Ginkgophyta), cycads (Cycadophyta), and Welwitschia (Gnetophyta); and angiosperms. Using spectral band ratios, conifer resins can be subdivided quantitatively into two distinct resin types that reflect compositional differences in their terpenoid constituents and broadly parallel different conifer families. The first type of resin (pinaceous resin) is produced by members of Pinaceae and consists mainly of diterpenes that are based on abietane/pimarane skeletal structures. The second type (cupressaceous resin) is associated with members of the Cupressaceae, Sciadopityaceae, Araucariaceae, and Podocarpaceae and consists mainly of diterpenes that are based on the labdanoid structures. Variability within the resin spectra correlates with the number of free hydroxyl groups, and it can be used to assess the degree of resin polymerization. Volatile-rich resins are found exclusively within Pinaceae, reflecting a generally higher abundance of volatile mono- and sesquiterpenoids in resins of this family. The results of the FTIR spectroscopy have direct implications for the assessment of the fossil potential and the chemotaxonomic interpretation of modern and fossil gymnosperm exudates.

Comparative Chloroplast Genomes of Pinaceae: Insights into the Mechanism of Diversified Genomic Organizations

Pinaceae, the largest family of conifers, has diversified organizations of chloroplast genomes (cpDNAs) with the two typical inverted repeats (IRs) highly reduced. To unravel the mechanism of this genomic diversification, we examined the cpDNA organizations from 53 species of the ten Pinaceous genera, including those of Larix decidua (122,474 bp), Picea morrisonicola (124,168 bp), and Pseudotsuga wilsoniana (122,513 bp), which were firstly elucidated. The results uncovered four distinct cpDNA forms (A−C and P) that are due to rearrangements of two ∼20 and ∼21 kb specific fragments. The C form was documented for the first time and the A form might be the most ancestral one. In addition, only the individuals of Ps. macrocarpa and Ps. wilsoniana were detected to have isomeric cpDNA forms. Three types (types 1−3) of Pinaceae-specific repeats situated nearby the rearranged fragments were found to be syntenic. We hypothesize that type 1 (949 ± 343 bp) and type 3 (608 ± 73 bp) repeats are substrates for homologous recombination (HR), whereas type 2 repeats are likely inactive for HR because of their relatively short sizes (151 ± 30 bp). Conversions among the four distinct forms may be achieved by HR and mediated by type 1 or 3 repeats, thus resulting in increased diversity of cpDNA organizations. We propose that in the Pinaceae cpDNAs, the reduced IRs have lost HR activity, then decreasing the diversity of cpDNA organizations, but the specific repeats that the evolution endowed Pinaceae complement the reduced IRs and increase the diversity of cpDNA organizations.

A Functional Analysis of Podocarp Ecology

Viewed in terms of species diversity, the Southern Hemisphere conifer family Podocarpaceae is equivalent to its northern sister the Pinaceae. However, despite their similar age and common heritage these two families diverge strongly in morphology, physiology, and ecology. Both Pinaceae and Podocarpaceae are successful families of vascular plants, and in both cases this success has been built upon contrasting and rather canalized adaptive differentiation. Pinaceae thrive in virtually all Northern Hemisphere forest environments where freezing limits the success of evergreen angiosperm competitors. In contrast, the Podocarpaceae are most successful in the tropics, where they compete directly with broad-leaved angiosperms, usually in montane rainforest. This chapter discusses some of the key adaptations that have enabled tropical Podocarpaceae to remain competitive during the rise of angiosperms. I also examine the hydraulic �Achilles heel� that limits all members of the Podocarpaceae to a mesic rainfall envelope.

Organization, anatomy, and fungal endophytes of a Triassic conifer embryo

Much is known about the Paleozoic conifers and the conifers assignable to extant families that appear in the Jurassic; however, relatively little is known about the transitional conifers of the early Mesozoic, especially the Voltziales. To better understand the evolution of this group, we aim to increase knowledge of voltzialean anatomy and morphology. A fossil embryo of the group is described in this study. • Several permineralized seeds, one containing a well-preserved embryo, were collected from the early Middle Triassic Fremouw Peak locality in the Central Transantarctic Mountains. Samples were prepared using the standard acetate peel technique and studied in transmitted light. • The embryo belongs to Parasciadopitys aequata, a member of the Voltziales. The embryo and megagametophyte tissues are exquisitely preserved. The embryo is colonized by two distinct fungi. Sporocarps of the fungi are found in the megagametophyte and in the space between the megagametophyte and nucellus. The additions of embryo and megagametophyte characters to the description of P. aequata have made it one of the most completely known fossil taxa reproductively. • Preservation of fossil embryos, although rare, can expand the array of characters available in tracing the evolutionary history of plants. The embryo of P. aequata shares similarities with embryos of other extinct and extant conifer families. The association of the embryo with Combresomyces cornifer and Mycocarpon asterineum increases our understanding of the roles of microorganisms in Triassic ecosystems.

Characterization of Plant Exudates by Principal-Component and Cluster Analyses with Nuclear Magnetic Resonance Variables

Principal-component and cluster analyses have been applied to nuclear magnetic resonance data for exudates derived from both conifers and angiosperms in order to classify these materials on the basis of molecular structure. The method succeeds in distinguishing resins produced by the conifer families Araucariaceae, Cupressaceae, and Pinaceae from each other and from resins produced by the angiosperm family Fabaceae. Other exudate types, including gums, gum resins, and kinos, also are distinguished from each other and from the resins.

Pollen and spores from the Tendaguru Beds, Upper Jurassic and Lower Cretaceous of southeast Tanzania: palynostratigraphical and paleoecological implications

Two informal sporomorph assemblage zones can be distinguished in the dinosaur-bearing Tendaguru Beds of southeast Tanzanian. The first zone, the Classopollis–Araucariacites–Shanbeipollenites Assemblage Zone, ranges from the Lower to the Upper Saurian Bed, and a mid-Oxfordian to Tithonian age is suggested based on the presence of Shanbeipollenites quadratus. The second zone, the Classopollis–Cicatricosisporites–Ruffordiaspora Assemblage Zone, is restricted in the Trigonia schwarzi Bed, which overlies the Upper Saurian Bed. The combined ranges of Cicatricosisporites hughesii, Ruffordiaspora australiensis and Trilobosporites obsitus would be consistent with a late Berriasian to Hauterivian age of this zone. This is refined further to late Valanginian to Hauterivian on the basis of already existing evidence from fauna and dinoflagellate cysts. From a phytogeographic point of view the Tendaguru locality belongs to the southern Gondwana Trisaccates Province because of the presence of trisaccate podocarpaceous pollen. The quantitative composition of the palynofloras is characterized by the dominance or abundance of pollen produced by the two conifer families Cheirolepidiaceae (Classopollis) and Araucariaceae (mainly Araucariacites). Pollen of Cheirolepidiaceae, typically xerophytic, drought-resistant, thermophilic plants, is dominant throughout the Tendaguru Beds except in parts of the Middle Saurian Bed where pollen of Araucariaceae, a presumably mesic group, becomes most abundant. Classopollis attains the highest degree of dominance in the shallow marine deposits associated with the saurian beds. This may be related to paleoecological and taphonomic factors, namely abundance of Classopollis-producing plants in low-lying coastal environments close to the lagoon-like depositional sites and transportational sorting of sporomorphs leading to a relative enrichment of small and/or anemophilous pollen. The abundance of Araucariacites in the Middle Saurian Bed suggests that araucarians existed in coastal plain environments that were stable enough to allow the growth of large trees. This open araucarian forest, which may have been a source of food for high-browsing dinosaurs, was situated landward of the cheirolepidiacean belt not far from the depositional sites. Pteridophytes and bryophytes were concentrated at moist places and around water bodies. Podocarpaceous conifers producing bisaccate and trisaccate pollen grew in local uplands, while gnetaleans related to Ephedra and Welwitschia may have been present in dry places. The palynological evidence is consistent with a seasonally dry, tropical to sub-tropical paleoclimate. Three new combinations, Equisetosporites certus (Bolkhovitina), Jugella caichigüensis (Volkheimer and Quattrocchio) and Trichotomosulcites microsaccatus (Couper), are proposed, and Jugella semistriata is described as a new species.

Organic matter from the Callovian (Middle Jurassic) deposits of Lithuania: Compositions, sources and depositional environments

Abstract This study presents the first organic geochemical and petrographical investigation of the Callovian deposits of the eastern part of the Central European Basin. It is shown that in both the terrigenous Papilė Formation (Lower Callovian) and shallow- to deeper-marine facies of the Papartinė and Skinija formations (Middle and Upper Callovian, respectively), terrestrial organic matter predominates. This is reflected by the carbon preference index values higher than 1.2 for all samples and in some cases higher than 2, as well as the occurrence of characteristic higher plant biomarkers like cadalene, dehydroabietane, simonellite and retene. Moreover, in the case of the Papilė Formation, sugiol – a natural product terpenoid produced by distinct conifer families, has been detected in clay sediments. The occurrence of such a biomolecule in the Middle Jurassic clays is reported for the first time. Its occurrence is probably connected with the presence of small wood debris in the clay sediments. In samples of the Papilė Formation, charcoal fragments co-occurring with unsubstituted polycyclic aromatic hydrocarbons were detected, indicating that wildfires took place during the Early Callovian of Lithuania and/or neighbouring areas. In the Middle and Upper marine Callovian sediments of Lithuania there is no evidence of anoxic conditions occurring in the water column. However, periodic anoxic or strongly dysoxic episodes may have occurred, most probably below the photic zone, during the deepest phase of the Late Callovian transgression, as is evidenced from pyrite framboid diameter distribution and general impoverishment of benthic fauna. Huminite reflectance ( R r ) values for the investigated area are in the range of 0.21–0.31%, suggesting the occurrence of immature organic matter. Such values indicate that these investigated deposits were close to the surface during their whole diagenetic history, and the thickness of younger cover did not exceed ca. 500 m. This is also supported by a biomarker analysis in which less thermally stable ββ -hopanes and hopenes significantly dominated.

Seed-cone scales from the upper Maastrichtian document the last occurrence in Europe of the Southern Hemisphere conifer family Araucariaceae

Stratigraphically well-documented seed-cone scales belonging to the conifer genus Araucaria have recently been collected from marine upper Maastrichtian (uppermost Cretaceous) limestones in the type area of the Maastrichtian Stage (NE Belgium, SE Netherlands). These fossils document the youngest known occurrences of the Monkey Puzzle family (Araucariaceae) in Europe, extending the last appearance datum (LAD) for Europe ‘upwards’ in time for c. 18 million years. The cone scales can barely be distinguished from those of the extant Araucaria heterophylla, today confined to Australia. Together with an equally close similarity to an Early Jurassic scale from North America, these finds illustrate the great antiquity and constancy of seed-cone morphology within Araucaria section Eutacta. Climate change and competition with angiosperms, rather than the impact of a large extraterrestrial body (Cretaceous/Paleocene boundary event), led to the demise of Araucaria in the Maastrichtian type area.

Comparative Chloroplast Genomics Reveals the Evolution of Pinaceae Genera and Subfamilies

As the largest and the basal-most family of conifers, Pinaceae provides key insights into the evolutionary history of conifers. We present comparative chloroplast genomics and analysis of concatenated 49 chloroplast protein-coding genes common to 19 gymnosperms, including 15 species from 8 Pinaceous genera, to address the long-standing controversy about Pinaceae phylogeny. The complete cpDNAs of Cathaya argyrophylla and Cedrus deodara (Abitoideae) and draft cpDNAs of Larix decidua, Picea morrisonicola, and Pseudotsuga wilsoniana are reported. We found 21- and 42-kb inversions in congeneric species and different populations of Pinaceous species, which indicates that structural polymorphics may be common and ancient in Pinaceae. Our phylogenetic analyses reveal that Cedrus is clustered with Abies–Keteleeria rather than the basal-most genus of Pinaceae and that Cathaya is closer to Pinus than to Picea or Larix–Pseudotsuga. Topology and structural change tests and indel-distribution comparisons lend further evidence to our phylogenetic finding. Our molecular datings suggest that Pinaceae first evolved during Early Jurassic, and diversification of Pinaceous subfamilies and genera took place during Mid-Jurassic and Lower Cretaceous, respectively. Using different maximum-likelihood divergences as thresholds, we conclude that 2 (Abietoideae and Larix–Pseudotsuga–Piceae–Cathaya–Pinus), 4 (Cedrus, non-Cedrus Abietoideae, Larix–Pseudotsuga, and Piceae–Cathaya–Pinus), or 5 (Cedrus, non-Cedrus Abietoideae, Larix–Pseudotsuga, Picea, and Cathaya–Pinus) groups/subfamilies are more reasonable delimitations for Pinaceae. Specifically, our views on subfamilial classifications differ from previous studies in terms of the rank of Cedrus and with recognition of more than two subfamilies.

The petrographical and organic geochemical composition of coal from the East field, Bogovina Basin (Serbia)

A petrological and organic geochemical study was performed on coal samples from the East field deposit, Bogovina Basin, Serbia. Fourteen coal samples were collected from different parts of the Main and Upper coal seams from fresh, working faces in the underground subbituminous coal mine. The Lower Miocene (?) coal of the East field is a typical humic coal with huminite, liptinite and inertinite concentrations of up to 81.4 vol.%, 16.1 vol.% and 13.5 vol.%, respectively. Densinite is the most abundant maceral with variable amounts of ulminite and gelinite. Sporinite and liptodetrinite are the most common macerals of the liptinite group. Exsudatinite was detected in the lower part of the Lower coal seam. Inertodetrinite is the most abundant maceral of the inertinite group. The mineral matter consists mostly of clay minerals and carbonates. The mean random huminite reflectance (ulminite B) for the Main coal seam is 0.42 ± 0.04%Rr, and 0.41 ± 0.04%Rr for the Upper coal seam, which are typical for an immature to early mature stage of the organic matter. The distribution and abundance of n-alkanes and steranes indicates a significant contribution of epicuticular waxes from higher plants. High amount of phyllocladane-type diterpenoids (16α(H)-phyllocladane) suggests that coal forming plants were conifer families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Sciadopityaceae, and Phyllocladaceae, while a higher amount of pimarane and norpimarane suggests Pinaceae, Taxodiaceae, and Cupressaceae. The pristane/phytane (Pr/Ph) ratio implies variable anaerobic to oxic conditions during sedimentation. The distribution of the hopanes detected in the Bogovina East field coal indicates an immature to early mature stage of the organic matter, which is in agreement with huminite reflectance. The high coal sulphur contents from the East field are characteristic for slightly alkaline depositional environments generated by bentonite from the basement of the Main coal seam. The petrological observation and biomarker composition provide evidence for the generation of immature hydrocarbons which, most probably, originated from the resins and waxes of higher plants, mostly gymnosperms.