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Abundant gymnosperm pollen grains associated with the oedemerid beetle Darwinylus marcosi Peris, 2016 were found in Early Cretaceous amber from Spain. This discovery provides confirmatory evidence for a pollination mutualism during the mid Mesozoic for the family Oedemeridae (Coleoptera), which today is known to pollinate only angiosperms. As a result, this new record documents a lateral host-plant transfer from an earlier gymnosperm to a later angiosperm, indicating that pollination of the latter is a derived condition within Oedemeridae. This new fossil record exemplifies one of the 4 ecological-evolutionary pollinator cohorts now known to have existed during the global shift from a gymnosperm to an angiosperm dominated global flora. Currently, all direct evidence for pollination during the 35 million-year interval of the mid Cretaceous gymnosperm-to-angiosperm transition entails recognition of gymnosperm pollen grains on insect mouthparts and other body contact surfaces, while analogous records involving angiosperms are lacking. The gathering evidence indicates that angiosperm pollination was preceded by at least 4 gymnosperm pollination modes that served as a functional and ecological prelude to the rise and expansion of angiosperms.

Essential nutrients and metals have been quantified in stems of many tree species to understand the role of stems as storage and source organs. Little is known about stored stem resources of cycad tree species. Cycas micronesica tissue was collected from apical and basal axial regions of stems; and pith, vascular, and cortex tissues were separated into three radial regions. Leaves were also sampled to provide a comparison to stems. Minerals and metals were quantified in all tissues. Minerals and metals varied greatly among the six stem sections. Phosphorus varied more among the three radial sections than the other macronutrients, and zinc and nickel varied more than the other micronutrients. Stem carbon was less than and stem calcium was greater than expected, based on what is currently known tree stem concentrations in the literature. Elemental concentrations were generally greater than those previously reported for coniferous gymnosperm trees. Moreover, the stem concentrations were high in relation to leaf concentrations, when compared to published angiosperm and conifer data. The results indicated that the addition of more cycad species to the literature will improve our understanding of gymnosperm versus angiosperm stem nutrient relations, and that the non-woody cycad stem contains copious essential plant nutrients that can be mobilized and deployed to sinks when needed.

The embryos of Ginkgo biloba L. are generally reported to undergo after-ripening and be underdeveloped at the time of dispersal, which suggests that the seeds have morphological dormancy (MD) or morphological physiological dormancy (MPD). The aim of this work is to determine whether embryos of a G. biloba population are well-developed at the time of seed dispersal, and whether the seeds are dormant or not. From 8 September, which was the 140th day after flowering (140 DAF), seeds were collected separately from trees (T) and the ground (G) every 10 days until 7 December (230 DAF), resulting in a total of 10 samples. The changes in vertical diameter, transverse diameter, fresh weight, water content, and embryo length during seed development were measured. Simultaneously, the effects of different temperatures (15, 25, 30, and 35 °C) on seed germination, dormancy, and germination characteristics of G. biloba seeds were studied. Results showed that the embryos of G. biloba seeds were well developed and had no morphological dormancy. On 18 September (150 DAF), embryos were visible with a length of 2.5 mm. On 7 December (230 DAF), at the time of seed dispersal, their length was 17.1 mm. The germination percentage of the isolated embryos and seeds increased as the delay in seed collection increased, but there was no significant difference between T and G (p > 0.05). On 7 December (230 DAF), the germination of the isolated embryos reached 98%, indicating that the embryos were nondormant. Without pretreatment, seed germination was 82.57% within four weeks at 25 °C. Furthermore, the germination test at different temperatures showed the highest germination percentage at 30 °C (84.82%). Obviously, the G. biloba seeds were nondormant. The mean germination time (MGT) of the seeds at 30 and 35 °C was significantly lower than that of the seeds at 15 and 25 °C, and the speed of germination (SG) was significantly higher than that of the seeds at 15 and 25 °C. Although there was no significant difference in the seed-germination percentage between 30 and 35 °C, a portion of the seeds (9.5%) rotted at 35 °C. Therefore, 30 °C was the most favorable germination temperature for G. biloba seeds. This is the first study that reports G. biloba seeds with no dormancy.

Seed size varies tremendously in plants and its evolution is influenced by multiple ecological and biological factors that are difficult to disentangle. In this study, we focus on understanding the role of seed dispersal by animals in the evolution of seed size in conifers, the most diverse extant nonflowering seed plant group., Relationships among seed size, dispersal syndrome, climate and cone morphology were analyzed across conifers using quantitative models of character evolution and phylogenetic regression techniques., Dispersal syndrome is a more consistent predictor of seed size within major extant conifer clades than climate. Seeds are generally larger in animal-dispersed than wind-dispersed species, and particular cone morphologies are consistently associated with specific ranges in seed size., Seed size and cone morphology evolve in a correlated manner in many animal-dispersed conifers, following a trade-off that minimizes the total size of the dispersal unit. These relationships are also present in other nonflowering seed plant groups, and have been important in the evolution of seeds and cones at least over the Cenozoic and perhaps over much of the later Mesozoic. [ABSTRACT FROM AUTHOR]

Decomposing leaf litter is a large supply of energy and nutrients for soil microorganisms. How long decaying leaves continue to fuel anaerobic microbial activity in wetland ecosystems is poorly understood. Here, we compare leaf litter from 15 tree species with different growth forms (angiosperms and gymnosperms, deciduous, and longer life span), using litterbags positioned for up to 4 years in a forested peatland in New York State. Periodically, we incubated partially decayed residue per species with fresh soil to assess its ability to fuel microbial methane (CH) production and concomitant anaerobic carbon dioxide (CO) production. Decay rates varied by leaf type: deciduous angiosperm > evergreen gymnosperm > deciduous gymnosperm. Decay rates were slower in leaf litter with a large concentration of lignin. Soil with residue of leaves decomposed for 338 days had greater rates of CH production (5.8 µmol g dry mass d) than less decomposed (<0.42 µmol g dry mass d) or more decomposed (2.1 µmol g dry mass d) leaf residue. Species-driven differences in their ability to fuel CH production were evident throughout the study, whereas concomitant rates of CO production were more similar among species and declined with degree of decomposition. Methane production rates exhibited a positive correlation with pectin and the rate of pectin decomposition. This link between leaf litter decay rates, biochemical components in leaves, and microorganisms producing greenhouse gases should improve predictions of CH production in wetlands. [ABSTRACT FROM AUTHOR]

A reference genome sequence for Pseudotsuga menziesii var. menziesii (Mirb.) Franco (Coastal Douglas-fir) is reported, thus providing a reference sequence for a third genus of the family Pinaceae. The contiguity and quality of the genome assembly far exceeds that of other conifer reference genome sequences (contig N50 = 44,136 bp and scaffold N50 = 340,704 bp). Incremental improvements in sequencing and assembly technologies are in part responsible for the higher quality reference genome, but it may also be due to a slightly lower exact repeat content in Douglas-fir vs. pine and spruce. Comparative genome annotation with angiosperm species reveals gene-family expansion and contraction in Douglas-fir and other conifers which may account for some of the major morphological and physiological differences between the two major plant groups. Notable differences in the size of the NDH-complex gene family and genes underlying the functional basis of shade tolerance/intolerance were observed. This reference genome sequence not only provides an important resource for Douglas-fir breeders and geneticists but also sheds additional light on the evolutionary processes that have led to the divergence of modern angiosperms from the more ancient gymnosperms. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY: The hydraulics of xylem has been widely studied in numerous species and organ types. However, comparatively little is known about how phloem and xylem are hydraulically coupled or about many of the basic structural properties of phloem (such as conducting cell numbers and conductive areas), which nevertheless have direct bearing on understanding phloem loading and unloading. METHODS: Using a combination of light, epifluorescence, confocal, and transmission electron microscopy, we quantified the hydraulic architecture of Ginkgo biloba leaf laminae and examined the scaling relationships between phloem and xylem in five fully mature leaves. KEY RESULTS: The conductive areas and lengths of sieve cells and tracheids increase basipetally toward the petiole in a manner that is consistent with Münch's pressure flow hypothesis for phloem transport. This trend holds true for individual veins, the sum of conductive areas across all veins at any distance from the petiole, and for individual sieve cells and tracheids. Further, the conductive areas of phloem and xylem are isometrically correlated across the entire vasculature of the leaf lamina. The data for conducting cell areas do not conform with the predictions of the hydraulic models of da Vinci and Murray. CONCLUSIONS: The scaling of Ginkgo lamina hydraulics complies with that observed in leaves of other gymnosperms and most angiosperms and is inconsistent with theoretical models that assume that the volume of transported incompressible fluids is conserved. [ABSTRACT FROM AUTHOR]

Taxus spp. are ancient gymnosperms that produce a unique secondary metabolite, namely, taxol, an anticancer drug. JAZ proteins are key regulators of the JA signaling pathway, which control taxol biosynthesis. However, the JAZ proteins of Taxus spp. are poorly studied. In this work, nine JAZ genes from Taxus chinensis were identified using our previous transcriptome data and named as TcJAZ1–TcJAZ9 . Of these nine TcJAZ proteins, eight contain Jas and TIFY domains, and the Jas domain of TcJAZ6 is incomplete. Most TcJAZs and PsJAZs are not related to AtJAZs and OsJAZs. Phylogenetic analysis divided all JAZ proteins from Arabidopsis thaliana , Oryza sativa , Picea sitchensis , and T. chinensis into eight subgroups; gymnosperms JAZs were classified into subgroups V–VIII, and angiosperm JAZs were categorized into subgroups I–V. Three motifs of subgroups VI–VIII were identified in gymnosperm JAZs, indicating that gymnosperm JAZ proteins exhibit a different evolutionary process from those of angiosperms. The expression patterns of nine TcJAZs showed that TcJAZ2/3/8 was a key regulator, indicating their important roles in T. chinensis . Results revealed that gymnosperm JAZs differ from angiosperm JAZs in terms of molecular structure. Three novel conserved motifs were found in TcJAZs and PsJAZs. This study provides a basis for research on JA regulatory system in Taxus spp. and for elucidating the significance of JA signaling pathway to land plants. [ABSTRACT FROM AUTHOR]

PREMISE OF THE STUDY:: The Bahamas archipelago is formed by young, tectonically stable carbonate banks that harbor direct geological evidence of global ice‐volume changes. We sought to detect signatures of major changes on gene flow patterns and reconstruct the phylogeographic history of the monophyletic Zamia pumila complex across the Bahamas. METHODS:: Nuclear molecular markers with both high and low mutation rates were used to capture two different time scale signatures and test several gene flow and demographic hypotheses. KEY RESULTS:: Single‐copy nuclear genes unveiled apparent ancestral admixture on Andros, suggesting a significant role of this island as main hub of diversity of the archipelago. We detected demographic and spatial expansion of the Zamia pumila complex on both paleo‐provinces around the Piacenzian (Pliocene)/Gelasian (Pleistocene). Populations evidenced signatures of different migration models that have occurred at two different times. Populations on Long Island (Z. lucayana) may either represent a secondary colonization of the Bahamas by Zamia or a rapid and early‐divergence event of at least one population on the Bahamas. CONCLUSIONS:: Despite changes in migration patterns with global climate, expected heterozygosity with both marker systems remains within the range reported for cycads, but with significant levels of increased inbreeding detected by the microsatellites. This finding is likely associated with reduced gene flow between and within paleo‐provinces, accompanied by genetic drift, as rising seas enforced isolation. Our study highlights the importance of the maintenance of the predominant direction of genetic exchange and the role of overseas dispersion among the islands during climate oscillations. [ABSTRACT FROM AUTHOR]

Summary During the mid-Cretaceous, angiosperms diversified from several nondiverse lineages to their current global domination [ 1 ], replacing earlier gymnosperm lineages [ 2 ]. Several hypotheses explain this extensive radiation [ 3 ], one of which involves proliferation of insect pollinator associations in the transition from gymnosperm to angiosperm dominance. However, most evidence supports gymnosperm–insect pollinator associations, buttressed by direct evidence of pollen on insect bodies, currently established for four groups: Thysanoptera (thrips), Neuroptera (lacewings), Diptera (flies), and now Coleoptera (beetles). Each group represents a distinctive pollination mode linked to a unique mouthpart type and feeding guild [ 4–9 ]. Extensive indirect evidence, based on specialized head and mouthpart morphology, is present for one of these pollinator types, the long-proboscid pollination mode [ 10 ], representing minimally ten family-level lineages of Neuroptera, Mecoptera (scorpionflies), and Diptera [ 8, 10, 11 ]. A recurring feature uniting these pollinator modes is host associations with ginkgoalean, cycad, conifer, and bennettitalean gymnosperms. Pollinator lineages bearing these pollination modes were categorized into four evolutionary cohorts during the 35-million-year-long angiosperm radiation, each defined by its host-plant associations (gymnosperm or angiosperm) and evolutionary pattern (extinction, continuation, or origination) during this interval [ 12 ]. Here, we provide the first direct evidence for one cohort, exemplified by the beetle Darwinylus marcosi , family Oedemeridae (false blister beetles), that had an earlier gymnosperm (most likely cycad) host association, later transitioning onto angiosperms [ 13 ]. This association constitutes one of four patterns explaining the plateau of family-level plant lineages generally and pollinating insects specifically during the mid-Cretaceous angiosperm radiation [ 12 ]. [ABSTRACT FROM AUTHOR]

Mesophyll conductance is thought to be an important photosynthetic limitation in gymnosperms, but they currently constitute the most understudied plant group in regard to the extent to which photosynthesis and intrinsic water use efficiency are limited by mesophyll conductance. A comprehensive analysis of leaf gas exchange, photosynthetic limitations, mesophyll conductance (calculated by three methods previously used for across-species comparisons), and the underlying ultra-anatomical, morphological and chemical traits in 11 gymnosperm species varying in evolutionary history was performed to gain insight into the evolution of structural and physiological controls on photosynthesis at the lower return end of the leaf economics spectrum. Two primitive herbaceous species were included in order to provide greater evolutionary context. Low mesophyll conductance was the main limiting factor of photosynthesis in the majority of species. The strongest sources of limitation were extremely thick mesophyll cell walls, high chloroplast thickness and variation in chloroplast shape and size, and the low exposed surface area of chloroplasts per unit leaf area. In gymnosperms, the negative relationship between net assimilation per mass and leaf mass per area reflected an increased mesophyll cell wall thickness, whereas the easy-to-measure integrative trait of leaf mass per area failed to predict the underlying ultrastructural traits limiting mesophyll conductance. [ABSTRACT FROM AUTHOR]

The endosymbiotic theory states that plastids are derived from a single cyanobacterial ancestor that possessed a cell wall. Peptidoglycan (PG), the main component of the bacteria cell wall, gradually degraded during plastid evolution. PG-synthesizing Mur genes have been found to be retained in the genomes of basal streptophyte plants, although many of them have been lost from the genomes of angiosperms. The enzyme encoded by bacterial MurE genes catalyzes the formation of the UDP-N-acetylmuramic acid (UDPMurNAc) tripeptide in bacterial PG biosynthesis. Knockout of the MurE gene in the moss Physcomitrella patens resulted in defects of chloroplast division, whereas T-DNA-tagged mutants of Arabidopsis thaliana for MurE revealed inhibition of chloroplast development but not of plastid division, suggesting that AtMurE is functionally divergent from the bacterial and moss MurE proteins. Here, we could identify 10 homologs of bacterial Mur genes, including MurE, in the recently sequenced genomes of Picea abies and Pinus taeda, suggesting the retention of the plastid PG system in gymnosperms. To investigate the function of gymnosperm MurE, we isolated an ortholog of MurE from the larch, Larix gmelinii (LgMurE) and confirmed its presence as a single copy per genome, as well as its abundant expression in the leaves of larch seedlings. Analysis with a fusion protein combining green fluorescent protein and LgMurE suggested that it localizes in chloroplasts. Cross-species complementation assay with MurE mutants of A. thaliana and P. patens showed that the expression of LgMurE cDNA completely rescued the albefaction defects in A. thaliana but did not rescue the macrochloroplast phenotype in P. patens. The evolution of plastid PG and the mechanism behind the functional divergence of MurE genes are discussed in the context of information about plant genomes at different evolutionary stages. [ABSTRACT FROM AUTHOR]

We investigated molecular distributions and stable carbon isotopic compositions (δ 13 C) of sedimentary n -alkanes (C 15 C 35 ) in the riverbank and marine surface sediments to trace natural and anthropogenic organic carbon (OC) sources in the eastern Yellow Sea which is a river dominated marginal sea. Molecular distributions of n -alkanes are overall dominated by odd-carbon-numbered high molecular weight n -C 27 , n -C 29 , and n -C 31 . The δ 13 C signatures of n -C 27 , n -C 29 , and n -C 31 indicate a large contribution of C 3 gymnosperms as the main source of n -alkanes, with the values of −29.5 ± 1.3‰, −30.3 ± 2.0‰, and −30.0 ± 1.7‰, respectively. However, the contribution of thermally matured petroleum-derived OC to the sedimentary OC pool is also evident, especially in the southern part of the study area as shown by the low carbon preference index (CPI 25-33 , <1) and natural n -alkanes ratio (NAR, <−0.6) values. Notably, the even-carbon-numbered long-chain n -C 28 and n -C 30 in this area have higher δ 13 C values (−26.2 ± 1.5‰ and −26.5 ± 1.9‰, respectively) than the odd-carbon-numbered long-chain n -C 29 and n -C 31 (−28.4 ± 2.7‰ and −28.4 ± 2.4‰, respectively), confirming two different sources of long-chain n -alkanes. Hence, our results highlight a possible influence of petroleum-induced OC on benthic food webs in this ecosystem. However, the relative proportions of the natural and petroleum-derived OC sources are not calculated due to the lack of biogeochemical end-member data in the study area. Hence, more works are needed to constrain the end-member values of the organic material supplied from the rivers to the eastern Yellow Sea and thus to better understand the source and depositional process of sedimentary OC in the eastern Yellow Sea. [ABSTRACT FROM AUTHOR]

Premise of research. Despite their importance for understanding plant evolution and plant-environmental interactions through geological time, fossil roots have always received less attention than aerial parts. In the case of the lignophytes (i.e., progymnosperms and seed plants), the ability to form abundant secondary vascular tissues (secondary xylem and phloem) can, however, provide useful characters to compare isolated roots to stems from the same deposit to better understand the whole-plant structure and function of fossil plants. Methodology. We studied five permineralized lignophyte roots with well-preserved secondary xylem, and in two cases some secondary phloem, from the Early Carboniferous Lydiennes Formation of the Montagne Noire, France, using classical thin sections. Pivotal results. Analysis of the secondary vascular tissues of the roots allows us to distinguish three wood morphotypes that suggest affinities with at least three different types of stems previously reported in the Montagne Noire. One specimen is assigned to the arborescent seed plant Eristophyton; two are assigned to small, probably non-self-supporting seed plants belonging to either the Calamopityaceae or Lyginopitys; and two are assigned to the progymnosperms Protopitys or Stauroxylon. Conclusions. This study illustrates how the affinities of isolated permineralized lignophyte roots can be narrowed down by comparing their wood anatomy with that of stems from the same deposit. The diversity of stem organization seen in the Montagne Noire deposit typically illustrates the morpho-anatomical diversification of the lignophytes' vegetative body in the Early Carboniferous. This study is a first step toward adding the underground organs to our understanding of this diversification. [ABSTRACT FROM AUTHOR]

De novo mutation frequency in two Japanese tree species as a function of ambient radiation dose rate. [Display omitted] • Trees in contaminated areas following a nuclear accident were surveyed genetically. • De novo mutations (DNMs) were detected via RADseq, comparing parents and offspring. • Low-dose-rate radiation (up to 6.86 μGy h−1) did not affect the occurrence of DNMs. • Unknown factors other than low-dose-rate radiation had stronger effects on DNMs. • Haploid or phased reference genomes were effective for detecting DNMs. The impact of low-dose-rate radiation on genetics is largely unknown, particularly in natural environments. The Fukushima Dai-ich Nuclear Power Plant disaster resulted in the creation of contaminated natural lands. In this study, de novo mutations (DNMs) in germ line cells were surveyed from double-digest RADseq fragments in Japanese cedar and flowering cherry trees exposed to ambient dose rates ranging from 0.08 to 6.86 μGy h−1. These two species are among the most widely cultivated Japanese gymnosperm and angiosperm trees for forestry and horticultural purpose, respectively. For Japanese flowering cherry, open crossings were performed to produce seedlings, and only two candidate DNMs were detected from uncontaminated area. For Japanese cedar, the haploid megagametophytes were used as next generation samples. The use of megagametophytes from open crossing for next generation mutation screening had many advantages such as reducing exposure to radiation in contaminated areas because artificial crossings are not needed and the ease of data analysis owing to the haploid nature of megagametophytes. A direct comparison of the nucleotide sequences of parents and megagametophytes revealed an average of 1.4 candidate DNMs per megagametophyte sample (range: 0–40) after filtering procedures were optimized based on the validation of DNMs via Sanger sequencing. There was no relationship between the observed mutations and the ambient dose rate in the growing area or the concentration of 137Cs in cedar branches. The present results also suggest that mutation rates differ among lineages and that the growing environment has a relatively large influence on these mutation rates. These results suggested there was no significant increase in the mutation rate of the germplasm of Japanese cedar and flowering cherry trees growing in the contaminated areas. [ABSTRACT FROM AUTHOR]

The emergence of resistant pathogenic bacterial strains has threatened the human beings and already developed remedial measures. Based on the traditional herbal therapeutic history, present study is aimed to assess in vitro and in silico inhibition potential of leaves extracts of Pinus roxburghii and Cedrus deodara against human pathogenic bacteria Staphylococcus aureus, Salmonella typhi and Pseudomonas aeruginosa. Hexane, methanol and acetone extracts of both plants were evaluated against above mentioned bacterial strains employing agar well diffusion technique. While docking analyses were performed to analyze the interaction of vital bioactive compounds and bacterial virulence proteins to get an idea about potential candidates for drug discovery. Both plant extracts exhibited greater antibacterial activities against S. aureus as compared to S. typhi and P. aeruginosa. The activity of different extracts also portrayed the role of polarity of solvent and compound to be extracted in each solvent i.e., activity of hexane extract > methanol > acetone with some variations. MIC (minimum inhibitory concentration) values of P. roxburghii extracts were less than that of C. deodara against tested strains, while variation was observed in MBCs (minimum bactericidal concentrations). Furthermore, molecular docking of studied plants bioactive compounds and bacterial proteins showed strong interactions (binding affinity) i.e., taxifolin > nortrachelogenin > bisabolene > valencene > caryophyllene. Antibacterial efficiencies of P. roxburghii and C. deodara suggested their application as effective therapeutic agents against diseases caused by mentioned bacterial strains. In silico analysis suggests the isolation and usage of bioactive components as potential antibacterial agents/drugs after further experimentations on animals. [ABSTRACT FROM AUTHOR]

Forests, comprising 31% of the Earth's surface, play pivotal roles in regulating the carbon, water, and energy cycles. Despite being far less diverse than angiosperms, gymnosperms account for over 50% of the global woody biomass production. To sustain growth and development, gymnosperms have evolved the capacity to sense and respond to cyclical environmental signals, such as changes in photoperiod and seasonal temperature, which initiate growth (spring and summer) and dormancy (fall and winter). Cambium, the lateral meristem responsible for wood formation, is reactivated through a complex interplay among hormonal, genetic, and epigenetic factors. Temperature signals perceived in early spring induce the synthesis of several phytohormones, including auxins, cytokinins, and gibberellins, which in turn reactivate cambium cells. Additionally, microRNA-mediated genetic and epigenetic pathways modulate cambial function. As a result, the cambium becomes active during the summer, resulting in active secondary xylem (i.e., wood) production, and starts to become inactive in autumn. This review summarizes and discusses recent findings regarding the climatic, hormonal, genetic, and epigenetic regulation of wood formation in gymnosperm trees (i.e., conifers) in response to seasonal changes.

Sugar pine (Pinus lambertiana Douglas) is within the subgenus Strobus with an estimated genome size of 31 Gbp. Transcriptomic resources are of particular interest in conifers due to the challenges presented in their megagenomes for gene identification. In this study, we present the first comprehensive survey of the P. lambertiana transcriptome through deep sequencing of a variety of tissue types to generate more than 2.5 billion short reads. Third generation, long reads generated through PacBio Iso-Seq have been included for the first time in conifers to combat the challenges associated with de novo transcriptome assembly. A technology comparison is provided here to contribute to the otherwise scarce comparisons of second and third generation transcriptome sequencing approaches in plant species. In addition, the transcriptome reference was essential for gene model identification and quality assessment in the parallel project responsible for sequencing and assembly of the entire genome. In this study, the transcriptomic data were also used to address questions surrounding lineage-specific Dicer-like proteins in conifers. These proteins play a role in the control of transposable element proliferation and the related genome expansion in conifers. [ABSTRACT FROM AUTHOR]

Gnetaceae is a small, monotypic family of Gymnosperms with about 40 species of Gnetum of pantropical distribution. Of the three species found in the FLONA Carajás, G. leyboldii and G. schwackeanum occur in the forest, while only G. nodiflorum was recorded in canga. For Gnetum nodiflorum, a detailed morphological description, illustrations, distribution and morphological comments are presented. [ABSTRACT FROM AUTHOR]

The pollination drop (PD) is a sweet secretion produced by female cones of many gymnosperms whose main function is associated with the capture and transport of pollen to the nucellar surface of the ovule. Due to its high sugar content, PDs appear to be highly suitable for the attraction of animals that might act as potential pollinators for gymnosperms. In the present study, we evaluated the attraction of animals to female and male PDs (sugar-rich rewards) in plants of the Mediterranean shrub Ephedra fragilis in addition to their contribution to plant fitness. Animal exclusion experiments were conducted in Sa Dragonera Islet Natural Park (Western Mediterranean, Spain). In addition, a link between PD investment (PD concentration) and plant fitness was evaluated on plants of E. fragilis. Lizards and insects were the principal visitors to PDs offered by E. fragilis plants. Animals effectively contributed to plant fitness. Nevertheless, the fitness contribution was not as elevated as the contribution from wind pollination (~30 vs. 70 %, respectively). Increased plant investment on PDs significantly elevated fitness in plants of E. fragilis. The present study provides evidence that E. fragilis relies primarily on wind pollination, with pollination and fitness being supplemented by animal visitation. Additionally, besides its main role as pollen capture and germination, PDs act as a pollinator reward that benefits plant reproduction. [ABSTRACT FROM AUTHOR]

Mineralized wood collected from Late Pliocene strata near Gorbki village in the Transcarpathian region of Beregovo Kholmogor'e in southwestern Ukraine was anatomically studied and identified. The wood possesses distinctive anatomical features and has distinct growth rings with an abrupt transition from early- to late-wood. Wood consists of tracheids with 1–3 seriate, dominating bi-seriate, opposite pits on the radial walls and taxodioid cross-field pitting, indentures present. Rays are uni-seriate and 1 to 73 cells high. Ray parenchyma horizontal walls thin and smooth. Axial parenchyma distributed in early- and late-wood and is solitary and diffuse, with end walls nearly smooth or slightly nodular. The combination of features observed in the wood indicates it belongs to the conifer family Taxodiaceae and is most similar to modern Sequoia and assigned to the fossil genus Sequoioxylon. Comparison with species of Sequoioxylon show it is most similar to Sequoioxylon burejense, but ray tracheids were not found in our specimens. We describe the specimens here as Sequoioxylon cf. s. burejense noting this similarity. Extant Sequoia is distributed in the northern California coastal forest eco-region of northern California and southern Oregon in the United States where they usually grow in a unique environment with heavy seasonal precipitation (2500 mm annually), cool coastal air and fog drip. This study supplies magafossil evidence of Sequoioxylon as an element of the Late Pliocene forest community in Ukraine and indicates a climate with heavy seasonal precipitation and fog drip.