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Summary: The genus Ektaphelenchoides is a diverse group of nematodes; they are either inhabitants of trees or present in the rhizosphere of economical plants. Members of the genus have ecological relevance in terms of being associated with insects and predators of other nematodes. In the present study, a new Ektaphelenchoides species, E. factum n. sp., is described and illustrated. The new species was isolated from a log sample of Pinus taeda imported from the USA. It is characterised by the lateral field with three incisures, stylet distinctly tripartite. Females having a vulval flap, the anus and rectum indistinct, and the tail (posterior part of body) filiform. Males having arcuate and 21.5 (19.4-22.9) μ m long spicules, the lamina of the spicule is smoothly curved to distal end, condylus well developed with a broadly rounded tip, rostrum triangular with finely rounded tip and cucullus absent, tail arcuate and conical with terminus bearing a sharply pointed mucron. The new species is different from other Ektaphelenchoides species in having a vulval flap. Molecular characterisation and phylogenetic studies also supported its unique status. In addition, a Chinese native population of E. pini , detected in Pinus koraiensis branches from Liaoning province, P.R. China, is described. [ABSTRACT FROM AUTHOR]

The regeneration of Korean pine (Pinus koraiensis Sieb. et Zucc.) is a core issue for restoration from secondary to primary forests in northeastern China. However, Korean pine exhibits limited recruitment within its own canopy in primary forests, but demonstrates excellent regeneration in secondary forests. Until now, the mechanisms underlying this phenomenon have not been satisfactorily explained. Hence, we conducted studies in both primary and secondary forests to investigate whether light availability during the non-growing season determines the fate of regeneration. In spring and autumn, understory light availability in the secondary forest was significantly better than that in the primary forest. The biomass and non-structural carbohydrate (NSC) concentrations of natural pine seedlings were considerably greater in the secondary forests compared to primary forests. The carbohydrate concentrations increased during spring and autumn and decreased in summer. In the manipulation experiment, the biomass of seedlings was positively correlated with the organ NSCs in spring, while the survival rates were correlated with NSCs in autumn. The light availability during the spring and autumn seasons may have a crucial role in the regeneration of Korean pine seedlings. This finding may support our practical management approach for the transformation of secondary forests into Korean pine forests. [ABSTRACT FROM AUTHOR]

Data on the status of two natural populations of the rare, endemic medicinal species Alangium platanifolium known from the Russian Federation is provided in this article. Information about one of them is reported for the first time. Geobotanical descriptions of the phytocenoses are presented. In southern Primorskii krai, A. platanifolium has been noted to grow in the shrub layer of coniferous/broad-leaved forest with Pinus koraiensis and Abies holophylla. It has also been found that the area of the population discovered 20 years ago has expanded tenfold and now amounts to 10 ha. The new locality of A. platanifolium covers an area of 0.25 ha. The total number of A. platanifolium is more than 700 of various-age plants. The data obtained extends the current knowledge of the distribution and life state of A. platanifolium and indicates the fact of the growth of subtropical elements in phytocenoses of the Russian Federation. [ABSTRACT FROM AUTHOR]

Gremmenia abietis (Dearn.) Crous (syn: Phacidium abietis) was originally described in North America to accommodate the species associated with snow blight of Abies and Pseudotsuga spp. In Japan, this species was first observed on the dead needles on Abies sachalinensis and Picea jezoensis var. jezoensis in 1969. However, the identity of Japanese species was unclear due to the lack of molecular data and the absence of anamorph description. In this study, we collected fresh specimens from various conifer species (A. sachalinensis, A. veitchii, Pic. jezoensis var. jezoensis, Pic. jezoensis var. hondoensis, Pinus koraiensis, and Pin. pumila) in Japan and revised the taxonomy based on morphological and phylogenetic analyses. Phylogenetic analyses based on nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS), nuc 28S rDNA (28S), and RNA polymerase II second largest subunit (RPB2) regions indicated that the species belongs to Phacidiaceae. Conidiomata formed in vitro produced pyriform, hyaline conidia without mucoid appendage, which distinguished the species from phylogenetically related genera. Consequently, we established Chionobium takahashii to accommodate the snow blight fungus in Japan. Further phylogenetic analyses also indicated that C. takahashii includes several distinct clades corresponding to the host genera (Abies, Picea, Pinus). Morphological differences among those clades were unclear, suggesting that C. takahashii may contain host-specific cryptic species. [ABSTRACT FROM AUTHOR]

To study the ultrasonic -assisted extraction (UAE) process of oil and proanthocyanidins from Pinus koraiensis seed scales, a single-factor analysis experiment was conducted with oil and proanthocyanidins yield as response values. The Box-Behnken response surface optimization method was applied to determine the optimal process conditions, which were as follows: 67% ethanol aqueous solution, liquid material ratio of 10 ∶ 1 mL/ g, tea saponin mass concentration of 0. 3%, power of 100 W, time of 20 min, water bath temperature of 50 ℃, expected yield of 21. 24% and 3. 03 mg / g respectively, actual yield of 20. 86% and 2. 98 mg / g, relative error of 1. 79% and 2. 97%. Comparison analysis revealed that UAE reached equilibrium in a relatively short time. UAE treatment increased the specific surface area of the seed powder in the solution. The order of DPPH and ABTS + free radical scavenging activities for oil and proanthocyanidins was proanthocyanidins, Ve and oil, indicating that Pinus koraiensis seed scales oil and proanthocyanidins possess good antioxidant capabilities. The use of tea saponin as an inducer for UAE extraction of oil and proanthocyanidins from Pinus koraiensis seed scales demonstrated advantages. These research findings provide a theoretical basis for the in-depth development of Pinus koraiensis seed scales. [ABSTRACT FROM AUTHOR]

In this paper, data obtained by scanning 10 artificial Korean pine forests based on Terrestrial Laser Scanning (TLS), were combined with field survey data to construct tree height curve model, height to crown base prediction model and crown contact height prediction model, and a simultaneous equation system was established. First, from the five kinds of tree height curve models selected, two models with better fitting effects were selected as the candidate models of the simultaneous equations. Then one model with good fitting effect and high applicability from the five height to crown base models was selected as base model, and the stand factors (mean DBH of stand, stand basal area, ratio of height to diameter, mean DBH of dominant trees and mean height of dominant trees) were introduced into the basic model by means of re-parameterization and optimal subset regression, the model with better fitting effect was selected as the alternative model of height to crown base model. The same method was used to select alternative crown contact height model with good fitting effect. Finally, the tree height curve model, alternative height to crown base model and alternative crown contact height model were combined in pairs to establish simultaneous equations. Through seemingly unrelated regression estimation, the best equations were selected by the goodness of fit and the test results, and the simultaneous equations were evaluated. When the optimal simultaneous equation was used to estimate the tree height, the decision coefficient R² = 0. 896, and the root mean square error RMSE= 0. 612 m; when the equations was used to estimate the height to crown, R² = 0. 575, RMSE = 0. 850 m; when the equations was used to estimate the crown contact height, R² = 0. 719, RMSE= 0. 791 m, and all kinds of inspection indexes were good. On the whole, the equation system had better fitting accuracy and test effect for tree height, height to crown and crown contact height, and can solve the internal correlation problem of tree height, height to crown and crown contact height, which provided the basis for further study of crown structure and dynamic changes of Korean pine. [ABSTRACT FROM AUTHOR]

In this study, we utilized the remarkable capabilities of Bacillus subtilis ls-45 during the fermentation process to generate pine nut peptide. Through gene sequencing, we confirmed the proficiency of Bacillus subtilis ls-45 in producing protease, thereby serving as a valuable enzymatic source for protein hydrolysis. Our investigation focused on examining the variations in amino acid types and quantities between enzymatic pine nut protein peptide (EPP) and fermented pine nut protein polypeptide (FPP). Furthermore, we conducted a comprehensive assessment of the in vitro antioxidant activities of EPP and FPP, encompassing measurements of their Hydroxyl radical scavenging rate, Total reducing capacity, Superoxide anion scavenging rate, and ABTS+ radical scavenging rate. Notably, FPP exhibited superior antioxidant capacity compared to EPP. By employing semi-inhibitory mass concentration (IC50) analysis, we determined that FPP displayed enhanced efficacy in neutralizing hazardous free radicals when compared to EPP. [ABSTRACT FROM AUTHOR]

Background: Early selection in tree breeding could be achieved by addressing the longevity of tree improvement activities. Genetic parameter changes and age–age correlations are essential for determining the optimal timing of early selection. Practical tracking of genetic parameters of Pinus koraiensis, a major timber species with economic and ecological value, has become feasible as its progeny testing has entered the mid-term age in Korea. However, research on the age−age correlation of P. koraiensis as progeny trials approach rotation age is limited. This study aimed to investigate genetic parameter trends and age−age correlations in P. koraiensis progeny. P. koraiensis progeny were assessed at two sites using a linear mixed-effects model with two-dimensional spatial autoregressive structure. Height, diameter, and volume growth were measured in 11 assessments over 40 years. Results: Genetic parameters, such as height and diameter, showed different patterns of change. The heritability ranged for the three growth traits in 0.083–0.710, 0.288–0.781, and 0.299–0.755 across the sites and age. Height heritability and its coefficient of variance decreased, whereas the diameter and volume estimates remained relatively constant. Correlations with Age 40 for phenotypic, genetic, and rank of breeding values ranged between 0.16 and 0.92, 0.594 and 0.988, and 0.412 and 0.965, respectively. These correlations generally increased as the age approached Age 40, with particularly high levels observed at Age 26 and Age 30. Conclusion: The observed genetic trends in P. koraiensis progeny testing offer valuable insights for early and precise selection. Notably, selecting superior genotypes at Ages 26–30 is supported by discernible genetic gains and robust correlations. Future research should integrate unbalanced data for selecting mother trees or families and conduct a comprehensive economic analysis of early selection to validate its practical benefits. [ABSTRACT FROM AUTHOR]

In this paper, we consider the long-term sustainability of the northeast Korean pine. We propose a class of natural Korean pine population system with time delay and diffusion term. First, by analyzing the roots distribution of the characteristic equation, we study the stability of the model system with diffusion terms and prove the occurrence of Hopf bifurcation. Second, we introduce lactation time delay into a population model with a diffusion term, based on stability theory of ordinary differential equation, norm form methods and center manifold theorem, the stability of bifurcating periodic solutions and the relevant formula for the direction of Hopf bifurcation are given. Finally, some numerical simulations are given. [ABSTRACT FROM AUTHOR]

Pinus koraiensis, an economically and ecologically vital five-needle pine species, was surveyed for female and male strobilus production variation among 52 clones over five years in a seed orchard in Gangwon province of South Korea. We estimated heritability, effective population size and gene diversity, calculated maleness index, and drew parental balance curves for the strobilus production annually. Results demonstrated marked variation in female and male strobilus production among clones and years, particularly in male strobilus production. The maleness indices indicated a considerable deviation from sexual balance. Parental balance curves revealed that the top 20% of the most fertile clones contributed significantly to the total strobilus production. High heritability values underscored the substantial genetic influence on strobilus production. The gene diversity of orchard parents (GDp) was set as one (GDp = 1) considering panmictic situations, and then loss of gene diversity in the female gametes (GDf) was relatively estimated to be ranged from 0.096 (loss = 1 − GDf = 1 − 0.904, 9.6% in 2017) to 0.017 (= 1 − 0.983, 1.7% in 2020). We emphasize the importance of the effective number of parents as a crucial parameter for informing seed orchard management decisions. [ABSTRACT FROM AUTHOR]

The occurrence, frequency, and severity of drought are accelerating due to global warming. Understanding the vulnerability of plantation forests to climate change, particularly to drought events, is critical to revealing the underlying mechanisms of tree resilience, recovery, and acclimation, which are important for plantation management. How the stand age affects the climate sensitivity of tree growth, as well as the direction, magnitude, and duration of the drought legacy, in plantation forests in northeast China is still unclear. In this study, we used MODIS-derived NDVI time series with gridded climate data from 2000 to 2020 to fill this knowledge gap. The selected plantation forests were dominated by four coniferous species: Korean pine (Pinus koraiensis), Scots pine (Pinus sylvestris), Japanese larch (Larix kaempferi), and Dahurian larch (Larix gmelinii). The results show that the climate sensitivity of tree growth differed among species and age groups. The growth of Korean pine and Scots pine was mostly dependent upon precipitation, while the growth of Japanese larch and Dahurian larch was determined primarily by temperature. Old Japanese larch (21–40 years) and Dahurian larch trees (31–60 years) were more sensitive to temperature and precipitation than young conspecifics, whereas old Korean pine (41–60 years) and Scots pine (31–60 years) were less sensitive to precipitation and temperature than young conspecifics. Furthermore, the legacy of drought lasted one year for Korean pine, Japanese larch, and Dahurian larch and over three years for Scots pine. Old trees were more severely affected by drought, particularly Scots pine and Dahurian larch. The findings of the study can help improve plantation forest management for better adaptation to future climate change. [ABSTRACT FROM AUTHOR]

Terahertz time-domain spectroscopy (THz–TDS) and hyperspectral technology were used for wood recognition. As wood is a valuable national resource, it is essential to utilize it efficiently and reasonably by classifying the species of wood. To accomplish this, ten distinct species of wood, including five types of softwood (Pinus sylvestris, Pinus tabulaeformis, Pinus massoniana, Larix gmelinii, and Pinus koraiensis) and five types of hardwood (Xylosma racemosum, Populus davidiana, Fraxinus rhynchophylla, Betula platyphylla, and Tilia tuan Szyszyl), were selected as experimental samples. Four hundred groups of data for terahertz absorption coefficient spectra and four hundred groups of hyperspectral data were acquired using THz–TDS and hyperspectral technology, respectively, and then examined for their spectral features. Three spectral preprocessing techniques, including the Savitsky– Golay smoothing algorithm, standard normal variable transformation, and multivariate scattering correction, were employed to preprocess the spectrum. Support vector machine recognition models were then created to compare and analyze the effects of recognition. The results demonstrated that both THz–TDS and hyperspectral approaches could successfully identify five different species of hardwood from various families and genera, with the highest accuracy rates of 92 and 94%, respectively. THz–TDS achieved a 92% recognition rate for five different species of softwood from the same family, indicating good recognition effects, while hyperspectral technology did not achieve such results. [ABSTRACT FROM AUTHOR]

Auricularia auricula polysaccharides used in Pinus koraiensis polyphenol encapsulation and delivery under weightlessness are rarely reported. In this study, an anionic polysaccharide fragment named AAP Iα with a molecular weight of 133.304 kDa was isolated and purified to construct a polyphenol encapsulation system. Nanoparticles named NPs-PP loaded with a rough surface for Pinus koraiensis polyphenol (PP) delivery were fabricated by AAP Iα and ε-poly-L-lysine (ε-PL). SEM and the DLS tracking method were used to observe continuous changes in AAP Iα, ε-PL and PP on the nanoparticles' rough surface assembly, as well as the dispersion and stability. Hydrophilic, monodisperse and highly negative charged nanoparticles can be formed at AAP Iα 0.8 mg/mL, ε-PL 20 μg/mL and PP 80 μg/mL. FT-IR was used to determine their electrostatic interactions. Release kinetic studies showed that nanoparticles had an ideal gastrointestinal delivery effect. NPs-PP loaded were assembled through electrostatic interactions between polyelectrolytes after hydrogen bonding formation in PP-AAP Iα and PP-ε-PL, respectively. Colon adhesion properties and PP delivery in vivo of nanoparticles showed that NPs-PP loaded had high adhesion efficiency to the colonic mucosa under simulated microgravity and could enhance PP bioavailability. These results suggest that AAP Iα can be used in PP encapsulation and delivery under microgravity in astronaut food additives. [ABSTRACT FROM AUTHOR]

The antibacterial activity and mechanism of Pinus densiflora extracts against Escherichia coli and Staphylococcus aureus were investigated. The growth inhibition tests of paper diffusion and optical density exhibited that the extracts have potent antibacterial potentials against foodborne pathogens. The measurement of membrane fluidity by fluorescence polarization has indicated that one of the antibacterial mechanisms involves the disruption of membrane integrity resulting in an increase in the membrane fluidity in both of E. coli and S. aureus. The alteration of fatty acid composition was accompanied by the disturbance of membranes thus shifting the proportion of saturated verses unsaturated fatty acids or trans fatty acids from 1.27:1 to 1.35:1 in E. coli and 1.47:1 to 2.31:1 in S. aureus, most likely to compensate for the increased membrane fluidity by means of a higher proportion of saturated fatty acids which is known to render rigidity in membranes. Realtime q-PCR (polymerase chain reaction) analysis of fatty acid synthetic genes and bacterial stress genes revealed that there was minimal influence of P. densiflora extracts on fatty acid genes except for fab I and the stress rpos in E. coli, and relatively greater impact on fatty acid genes and the stress sigB in S. aureus. [ABSTRACT FROM AUTHOR]

In the quest to combat infections attributable to antibiotic-resistant superbacteria, an essential oil derived from the needles of Pinus koraiensis Sieb. et Zucc. (PKEO) has emerged as a promising solution. In this study, we demonstrate that PKEO can be used to inhibit the growth, glucose metabolite acidogenicity, and biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA). Quantitative PCR analysis provided direct evidence that PKEO reduces the mRNA expression of the accessory gene regulator A (agrA) and staphylococcal accessory regulator A (sarA), thereby indicating its inhibitory effect on pathogenic regulatory genes. Chromatographic analyses of PKEO identified terpene hydrocarbons as prominent essential oil constituents. These compounds, notably α-pinene, limonene, and β-caryophyllene, have been established to have antimicrobial properties. Our findings indicate that an oil derived from P. koraiensis can effectively combat antibiotic-resistant strains by disrupting the pathogenicity regulatory system, thereby establishing PKEO as a promising candidate for the treatment of MRSA infections. [ABSTRACT FROM AUTHOR]

A smart thinning operation refers to an advanced method of selecting and cutting trees to be thinned based on digitally captured forest information. In smart thinning operations, workers use the coordinates of individual trees to navigate to the target trees for thinning. However, it is difficult to accurately locate individual trees in a forest stand covered with a canopy, necessitating a precise real-time positioning system that can be used in the forest. Therefore, this study aimed to evaluate the applicability of the global navigation satellite system real-time kinematic (GNSS-RTK) device in a forest stand through analysis of its positioning accuracy within the forest environment and evaluation of the operational range of the single-baseline RTK based on analysis of the positioning precision and radio signal strength index (RSSI) change with increasing distance from the base station. The results showed that the root mean square error (RMSE) of the horizontal positioning error was highly accurate, with an average of 0.26 m in Larix kaempferi stands and 0.48 m in Pinus koraiensis stands. The RSSI decreased to a minimum of −103.3 dBm within 1 km of distance from the base station; however, this had no significant impact on the horizontal positioning precision. The conclusion is that the GNSS-RTK is suitable for use in smart thinning operations. [ABSTRACT FROM AUTHOR]

Natural waxes have demonstrated exceptional potential as oil gels for saturated and trans fatty acids, but their application has been limited by issues such as temperature sensitivity, lack of stability and durability, and compatibility. In this study, three types of wax (Beeswax (BW), Rice bran wax (RBW), and Carnauba wax (CW)) were combined with calcium hydroxide to produce calcified wax. The calcified Korean pine seed oil gel obtained by heating and stirring with Korean pine seed oil is responsive to temperature and has environmental adaptability. The effects of critical gel concentration, temperature regulation, texture properties, microstructure, oil-holding capacity, and FT-IR on the quality parameters of oil gel were investigated. Additionally, an in vitro digestion model was developed to comprehend the decomposition rate of fat during gel structure digestion and transportation. The results demonstrated a close correlation between the critical gelation concentration and calcium ion content. Furthermore, after calcification, the hardness followed the order BW > CW > RBW. Moreover, there was an approximate 10 °C increase in wax melting point. Conversely, BW:Ca exhibited the lowest oil leakage. The microstructures revealed that the oil gels formed post-wax calcification exhibited similar fractal dimension (Db) values (<7 μm), and the intermolecular forces were characterized by van der Waals forces, which were consistent with those observed in the non-calcified group. In conjunction with the vitro digestion simulation, our findings demonstrated that RBW and CW oil gels gradually released 20%, 35%, and 35% of free fatty acids (FFA) within the initial 30 min of intestinal digestion. Importantly, the FFA release rate was significantly attenuated, thereby providing a foundation for developing wax-based gel processed foods that facilitate gentle energy release benefits for healthy weight management. [ABSTRACT FROM AUTHOR]

Using mean earlywood density data from Pinus koraiensis cores, we reconstructed the April–June mean minimum temperature from 1797 to 2015 for the Changbai Mountains. The reconstruction explained 52.6% of the actual mean minimum temperature variance during 1901–2015. After smoothing with an 11‐year moving average, we identified three major cold periods (1797–1875, 1881–1899, and 1903–1946) and three major warm periods (1876–1880, 1900–1902, and 1947–2015) in the reconstructed series. Spatial correlation showed that the reconstruction contained climatic signals for a large area including most of northeast China, especially the Bohai Rim region and the eastern side of the Mongolian Plateau. A comparison between the newly reconstructed temperature series for the surrounding areas reveals similar variations, particularly in the warming trend during the second half of the 20th century. The driving factors of the mean minimum temperature were influenced mainly by the interaction of solar activity and large‐scale atmospheric‐oceanic variability. The reconstructed series provides a basis for understanding past climate change in the Changbai Mountains and for predicting future climate change trends in Northeast China. [ABSTRACT FROM AUTHOR]

The size of the leaf area can have a profound impact on the growth and life activities of the tree, and then it is related to the change of the biomass of the tree and the development trend of the forest ecology. The research on leaf area can play a key role in the correlation analysis of trees. Based on the analytical wood data of 48 Korean pine plantations in Heilongjiang Province and the leaf area data measured by the drainage method, a basic linear regression model was established, and then random effect parameters were introduced to construct a mixed effect regression model to improve the fitting effect and prediction accuracy. When random effects at the tree level were added, the optimal mixed effect model obtained contained three random effect parameters, namely logarithm of branch base diameter(lnBD), logarithm of branch length (lnSL), and tree height logarithm(lnHT). The R ² a was 0. 86, the MAE was 0. 342 8, and the RMSE was 0. 484 1. The statistical indicators were better than the basic linear model that only included fixed effects. The comprehensive analysis showed that the model can better describe the leaf area of Korean pine branches. Then, based on the model, the crown leaf area of the Korean pine tree was calculated and a mixed effect prediction model was obtained. The mixed model R ² a was 0. 83 and the RMSE was 0. 442 9. Through the test results, it can be seen that the model can predict the crown and leaf area of Korean pine trees better, and provide a better guiding direction for the future management of artificial Korean pine in this area. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the anti-amnestic property of Korean red pine bark extract (KRPBE) on TMT-induced cognitive decline in ICR mice. As a result of looking at behavioral function, the consumption of KRPBE improved the spatial work ability, short-term learning, and memory ability by Y-maze, passive avoidance, and Morris water maze tests. KRPBE suppressed antioxidant system damage by assessing the SOD activity, reduced GSH content, and MDA levels in brain tissue. In addition, it had a protective effect on cholinergic and synaptic systems by regulating ACh levels, AChE activity, and protein expression levels of ChAT, AChE, SYP, and PSD-95. Also, the KRPBE ameliorated TMT-induced mitochondrial damage by regulating the ROS content, MMP, and ATP levels. Treatment with KRPBE suppressed Aβ accumulation and phosphorylation of tau and reduced the expression level of BAX/BCl-2 ratio and caspase 3, improving oxidative stress-induced apoptosis. Moreover, treatment with KRPBE improved cognitive dysfunction by regulating the neuro-inflammatory protein expression levels of p-JNK, p-Akt, p-IκB-α, COX-2, and IL-1β. Based on these results, the extract of Korean red pine bark, which is discarded as a byproduct of forestry, might be used as an eco-friendly material for functional foods or pharmaceuticals by having an anti-amnesia effect on cognitive impairment. [ABSTRACT FROM AUTHOR]

This study aims to explore the effects of adding various amounts of nitrogen on the photosynthesis characteristics of 4 tree species and the diversity in adaptability to nitrogen treatment among different tree species. A nitrogen addition experiment was established with 3 nitrogen addition levels in Kaiyuan Forestry Center, Shulan City, Jilin Province. The levels of N treatment were no nitrogen (0kg.hm- 2. a - 1), low nitrogen 50kg hm- 2. a- 1 ), high nitrogen (100kg hm- 2.a- 1) . 4 afforestation tree species (Pinus koraiensis, Juglans mandshurica, Fraxinus mandshurica, and Phellodendron amurense) were selected to determine the photosynthetic parameters, stomatal behavior parameters, and spectral reflectance indices, with one-way analysis of variance and least significant difference method conducted to analyze the significance of differences among the 4 tree species and the photosynthetic physiological change of different nitrogen treatments. Pinus koraiensis and Phellodendron amurense had a higher net photosynthetic rate than J. mandshurica and F. mandshurica at no nitrogen treatment (P < 0.05), showing a relative competitive advantage. Nitrogen treatments inhibited the photosynthetic capacity of Pinus koraiensis and the relative chlorophyll content, stomatal conductivity, and transpiration rate of J. mandshurica and F. mandshurica were increased at high nitrogen treatment (P < 0.05) . Furthermore, the photochemical reflectance index of J. mandshurica and Phellodendron amurense was decreased with nitrogen treatments (P < 0.05), indicating that these treatments triggered the photoprotection mechanism. Phellodendron amurense, which belonged to the strong positive species, was most suitable for artificial regeneration on bare land. Meanwhile, due to its shade tolerance, F. mandshurica was relatively inferior in full sunlight. The photosynthetic capacity of J. mandshurica and F. mandshurica could be enhanced by applying nitrogen fertilizer. In contrast, the photosynthetic capacity of Pinus koraiensis would be inhibited, considering its sensitivity to nitrogen, if nitrogen fertilizer was applied. [ABSTRACT FROM AUTHOR]

In order to study the effects of autumn fertilization on the growth and flowering of Pinus koraiensis grafted seedlings with different rootstock types, three kinds of Korean pine grafted seedlings with different rootstock types (Pinus sylvestris var. mongolica, P. koraiensis, P. armandii) were selected as the research objects. Four autumn nitrogen application levels (0, 0. 5, 1. 0, 1. 5g / plant) were set up to determine and analyze the growth, physiology and flowering response of three kinds of Korean pine grafted seedlings to autumn fertilization. The results showed that: nitrogen application in autumn could significantly increase the accumulation of chlorophyll, nitrogen and soluble protein in the scion at the end of the growing season of Korean pine grafted seedlings, promote the growth of the scion in the next growing season, and increase the flowering plant rate and total flowering number. Different types of rootstock grafted seedlings had different responses to autumn fertilization. When the rootstock type was P. sylvestris var. mongolica and P. koraiensis, the optimal autumn nitrogen application rate was at a medium nitrogen level (1. 0 g / plant). When the rootstock type was P. armandii, the optimal autumn nitrogen application rate was at a high nitrogen level (1. 5 g / plant). Under the same medium nitrogen treatment conditions, autumn fertilization had a more significant promoting effect on the flowering ability of the scions of P. sylvestris var. mongolica grafted with P. koraiensis seedlings in the following year, and a more significant promoting effect on the growth of the scions of P. koraiensis grafted with P. koraiensis seedlings in the following year. The phenomenon of overwintering death occurred in P. armandii grafted with P. koraiens seedlings, and autumn fertilization could reduce the overwintering death rate of seedlings by 34. 45%. [ABSTRACT FROM AUTHOR]

The northward expansion of Bursaphelenchus xylophilus has caused devastating disasters in the northeastern region, posing a significant threat to Pinus koraiensis, which is the major component species of the top ecological community of the Northeast China forest area. This study aims to enrich the molecular mechanism of the interaction between P. koraiensis and B. xylophilus, thus laying a theoretical foundation for the breeding of disease-tolerant P. koraiensis. The disease tolerance of 20 families of P. koraiensis to B. xylophilus was identified by artificial inoculation and different families of P. koraiensis were divided into three categories: tolerant, susceptible and high-susceptible. The RNA of tolerant and high-susceptible P. koraiensis was extracted for transcriptome sequencing. The α-terpineol synthase gene (Pk-αts) related to disease tolerance was screened and cloned. The expression level of Pk-αts in 4 tolerant, 2 susceptible, and 4 high-susceptible P. koraiensis was randomly detected by RT-qPCR, and the relative tolerance index of these 10 P. koraiensis families was calculated. The correlation between Pk-αts expression level and the relative tolerance index of P. koraiensis was analyzed. The results showed that after inoculating B. xylophilus for 20 days, only a few needles of tolerant P. koraiensis turned yellow, with an average relative tolerance index of 0. 88, while high-susceptible P. koraiensis showed partial needle redness, with an average relative tolerance index of 0. 09. Transcriptome sequencing identified 1 770 genes that were up-regulated in tolerant P. koraiensis and had no change or down-regulated in high-susceptible P. koraiensis. The relative expression of Pk-αts in tolerant P. koraiensis was 2. 83, which was extremely significant, but the relative expression in high-susceptible P. koraiensis was -1. 27. The cloned Pk-αts gene was 1 230 bp in length, encoding a protein composed of 409 amino acids, with an isoelectric point of 5. 55 and a relative molecular weight of 47. 60 ku. After comparison, it had the highest homology with the α-terpineol synthase gene and contained conserved motifs such as DDxxD and RRx8W of plant monoterpene synthases and Terpene_synth domain, which were consistent with the structural characteristics of monoterpene synthases. RT-qPCR detection showed that the expression of the Pk-αts gene was upregulated (the average expression level is 1. 39) in tolerant P. koraiensis, while it was unchanged or downregulated in susceptible and high -susceptible P. koraiensis, indicating that the upregulation of the Pk-αts gene expression was synchronized with the temporal and spatial of P. koraiensis tolerance to in the early stage of B. xylophilus infection. The expression level of Pk-αts was positively correlated with the relative tolerance index of P. koraiensis (Pearson's coefficient was 0. 911, P< 0. 01), indicating that the up-regulated expression of the Pk-αts gene improved the disease tolerance of P. koraiensis. In summary, different families of P. koraiensis have different tolerance to B. xylophilus, and some P. koraiensis have certain disease tolerance. The up-regulated expression of Pk-αts gene alleviates disease symptoms and helps to improve the disease tolerance of P. koraiensis to B. xylophilus. The Pk-αts gene can be used as a detection target for identifying tolerance of P. koraiensis to B. xylophilus, which is helpful for the breeding of tolerant P. koraiensis. [ABSTRACT FROM AUTHOR]

Under the background of global nitrogen deposition, temperate forest ecosystems are suffering increasing threats, and species diversity is gradually decreasing. In this study, nitrogen addition experiments were conducted on Korean pine (Pinus koraiensis) plantations in Northeast China to explore the effect of long‐term nitrogen addition on herb species diversity to test the following hypothesis: long‐term nitrogen addition further reduced plant species diversity by affecting plant growth, which may be due to soil acidification caused by excessive nitrogen addition. Experimental nitrogen addition was conducted from 2014 to 2021, and the nitrogen treatment levels were as follows: N0 (control treatment, 0/(kg N ha−1 year−1)), N20 (low nitrogen treatment, 20/(kg N ha−1 year−1)), N40 (medium nitrogen treatment, 40/(kg N ha−1 year−1)) and N80 (high nitrogen treatment, 80/(kg N ha−1 year−1)). A herb community survey was conducted in the region from 2015 to 2021. The results showed that long‐term nitrogen addition decreased soil pH, changed the species and composition of herbaceous plants, and decreased the species diversity of understory herbaceous plants. With the increase in nitrogen application years, middle‐ and high‐nitrogen treatments significantly reduced the diversity of early‐spring flowering herbs and early‐spring foliating herbs, and their diversity decreased with the decrease in soil pH, indicating that soil acidification caused by long‐term nitrogen addition may lead to the decrease of plant diversity. However, for early‐spring growing herbs, adequate nitrogen addition may promote their growth. Our results show that plants have evolved different life‐history strategies based on their adaptation mechanisms to the environment, and different life‐history strategies have different responses to long‐term nitrogen addition. However, for most plants, long‐term nitrogen application will have a negative impact on the growth and diversity of herbs in temperate forests. [ABSTRACT FROM AUTHOR]

Lipid-rich Pinus koraiensis seed kernels are highly regarded for their nutritional and health benefits. To ascertain the molecular mechanism of lipid synthesis, we conducted widely targeted metabolomic profiling together with a transcriptome analysis of the kernels in P. koraiensis cones at various developmental stages. The findings reveal that 148 different types of lipid metabolites, or 29.6% of total metabolites, are present in kernels. Among those metabolites, the concentrations of linoleic acid, palmitic acid, and α-linolenic acid were higher, and they steadily rose as the kernels developed. An additional 10 hub genes implicated in kernel lipid synthesis were discovered using weighted gene co-expression network analysis (WGCNA), gene interaction network analysis, oil body biosynthesis, and transcriptome analysis. This study used lipid metabolome and transcriptome analyses to investigate the mechanisms of key regulatory genes and lipid synthesis molecules during kernel development, which served as a solid foundation for future research on lipid metabolism and the creation of P. koraiensis kernel food. [ABSTRACT FROM AUTHOR]

Root nitrogen (N)-uptake rate and uptake preference, and their association with root morphological and chemical traits are important to characterize root N-acquisition strategies of trees. However, how the root N-acquisition strategy varies with tree age, especially for those species that coexist at a common site, remains unknown. In this study, a field isotopic hydroponic method was used to determine the uptake rate and contribution of NH4+, NO3− and glycine, for three coexisting ectomycorrhizal coniferous species [ Pinus koraiensis (Korean pine), Picea koraiensis (Korean spruce) and Abies nephrolepis (smelly fir)] at three age classes (young, middle-aged and mature) in a temperate forest. Concurrently, root morphological and chemical traits, as well as mycorrhizal colonization rate were determined. Our results show that the root uptake rate of total N and NH4+ gradually decreased across all three species with increasing tree age. The three species at all age classes preferred NH4+, except for middle-aged Korean spruce and mature smelly fir, which preferred glycine. In contrast, all three species showed the lowest acquisition of NO3−. According to the conceptual framework of 'root economics space', only a 'collaboration' gradient (i.e. dimension of root diameter vs specific root length or area) was identified for each species, in which root N-uptake rate loaded heavily on the side of 'do-it-yourself' (i.e. foraging N more by roots). Young trees of all species tended to exhibit the 'do-it-yourself' strategy for N uptake, and mature trees had an 'outsourcing' strategy (i.e. foraging N by a mycorrhizal partner), whereas middle-aged trees showed a balanced strategy. These findings suggest that shifts of root N-acquisition strategy with tree age in these species are mainly mediated by root traits along the 'collaboration' gradient, which advances our understanding of belowground competition, species coexistence and N cycling in temperate forests. [ABSTRACT FROM AUTHOR]

A continuous record of paleogeographic events in southeastern Primorye has been restored based on the data from the deposits of Gniloe Lake, located on the northern coast of Nakhodka Bay, starting from 3240 cal BP. In total, five warming periods were identified: 3240–2500, 1865–1650, 1330–840, and 730–625 cal BP, and from the second half of the 17th century to the present; four periods of cooling: 2500–1865, 1650–1330, 840–730, and 625–320 cal BP; six wet periods: 3240–2500, 1865–1650, 1480–1330, 1060–840, 730–625 cal BP, and the last 280 years; and five dry periods: 2500–1865, 1650–1480, 1330–1060, 840–730, and 625–210 cal BP. According to palynological analysis, the expansion of Pinus koraiensis and dark coniferous species occurred during the second phase of the Mid-Subatlantic cooling of 1480–1330 cal BP. Over the last 150 years, the most significant changes have been associated with the anthropogenic transformation of landscapes as a result of urbanization. The area of forests and their species composition have decreased. At present, shrub thickets have occupied areas of the deforested oak forests. Based on the results of diatom analysis, seven stages of development of Gniloe Lake were established. There was a shallow semi-open lagoon at a sea level 1–1.5 m higher than the present-day one about 3240 cal BP. Cooling and a decrease in humidity about 2500 cal BP led to the formation of a slightly saline half-closed lagoon. Shallowing of the lagoon about 2000 cal BP ago was due to a decrease in the sea level. Finally, the lagoon separated from the sea about 1450 cal BP. The transformation of the lagoon into a fresh lake occurred around 1080 cal BP. During the period of cooling 838–733 cal BP the shallowing of the lake began, which continued in the Little Ice Age. The increase of the lake level associated with moderate warming and an increase in humidity began at 210 cal BP. Traces of three catastrophic events were recorded in the sediments of Gniloe Lake: a high-level storm about 3000 cal BP and 2 tsunamis around 2000 and 1560 cal BP. [ABSTRACT FROM AUTHOR]

Phellodendron amurense is national second-class protected plant. The quantitative analysis on the niche characteristics of dominant tree populations in broad-leaved mixed forest of Phellodendron amurense can provide theoretical basis for the protection of Phellodendron amurense and maintaining species diversity. Based on the 9 th national forest inventory in Jilin Province, the Phellodendron amurense broad-leaved mixed forest community in Changbai Mountain was investigated and the methods of importance value, Levins niche width, Shannon-Wiener niche width and Pianka niche overlap were used to analyze the niche characteristics of dominant tree populations in this region. The results showed that, there were 25 broad-leaved species, accounting for 96. 15% of the total, and the important value of Phellodendron amurense in the broad-leaved mixed forest was the largest. The Levins and Shannon-Wiener niche width indices were basically the same in order. The species with the largest niche width was Phellodendron amurense, followed by Juglans mandshurica. The niche overlap value of species such as Phellodendron amurense with Butula costata, Juglans mandshurica and Ulmus laciniata was large. The niche width and niche overlap degree showed obvious consistency. However, the niche width and niche overlap of some species were opposite, such as Carpinus turczaninowii vs. Quercus dentata, Robinia pseudoacacia, and Tilia tuan, Phellodendron amurense vs. Pinus koraiensis, which was related to the ecological habits, habitat characteristics and spatial distribution of the tree species. [ABSTRACT FROM AUTHOR]

Wood biomass is an alternative to fossil fuels. However, biomass use has several limitations. Torrefaction, in which reduction conditions prevail to overcome these limitations, has been suggested. Here, torrefaction using different wood chips (Liriodendron tulipifera, Populus canadensis, Pinus rigida, and Pinus koraiensis) was conducted under oxygen-rich and oxygen-lean conditions to determine the effects of oxygen. Torrefaction was conducted at 230–310 °C for 1 h. A mass yield difference of 3.53–20.02% p (percentage point) was observed between oxygen-lean and oxygen-rich conditions. The calorific value increased by a maximum of 50.95% and 48.48% under oxygen-rich and oxygen-lean conditions, respectively. Decarbonization (DC), dehydrogenation (DH), and deoxygenation (DO) occurred in the following order because of dehydration and devolatilization during biomass torrefaction: DO > DH > DC. The calorific value of the torrefied biomass increased linearly with the extent of all three processes. The combustibility index and volatile ignitability were calculated based on proximate composition to suggest the optimal conditions for replacing anthracite and bituminous coal. This study provides suggestions for stable operation in a standard boiler design. [ABSTRACT FROM AUTHOR]

【Objective】 The study aimed to explore the effects of different soil layers and tending and thinning intensities on soil fungi under Pinus koraiensis plantation in Liaodong mountain area. 【Method】 Illunima-Miseq high-throughput sequencing technology was used to determine the soil surface layer (0-10 cm) and subsurface layer (10-20 cm) of different thinning degrees. 【Result】 A total of 572 932 high-quality ITS sequences were obtained, which could be divided into 9329 OTUs on the basis of 97% sequence similarity; The dominant phyla included Basidiomycota, Ascomycota, Mortierellomycota, Rozellomycota, Mucoromycota, Chytridiomycota, Glomeromycota and the phyla with unclear classification. The top 10 dominant bacterial genera were Sebacina, Mortierella, Russula, Suillus, Geminibasidium, Leucoagaricus, Tylospora, Amanita, Delastria, Tricholoma; The abundance of fungi on the surface layer was higher than that on the subsurface layer; The richness of soil fungal population with different thinning intensities showed the extreme intensity area ＞ the weak intensity area ＞ the control group ＞ the intensity area ＞ the medium area; The results of variance analysis showed that there was no significant difference in relative abundance between different soil layers and different thinning intensities at the gate level. At the genus level, there were significant differences in the relative abundance of Leucoagaricus and Tylospora in the two soil layers, and there were significant differences in the relative abundance of Leucoagaricus, Amanita and Tricholoma in different thinning intensities; The species composition of fungi in the surface layer and subsurface layer, the extremely strong and weak regions and the control group were similar, and the similarity between the extremely strong and weak regions and the control group was higher than that in the moderate and strong regions. 【Conclusion】 In P.koraiensis plantation in Liaodong mountain area, thinning intensity and soil layer can affect the richness, diversity and species composition of soil fungi under the forest to a certain extent. [ABSTRACT FROM AUTHOR]

Kolibacia squamulata Gebler (Coleoptera: Trogossitidae) was recorded in China as a result of a study of the natural enemies of Monochamus saltuarius Gebler (Coleoptera: Cerambycidae), the vector of the Bursaphelenchus xylophilus Steiner & Buhner (Nematoda: Aphelenchoididae). Diagnostic illustrations are provided, and the biology, habitat preferences, and distribution of K. squamulata are reviewed. This species was found in northeast China, in the Pinus koraiensis forest in Tangtu Township, Fushun County, Fushun City, Liaoning Province, China, in 2021. [ABSTRACT FROM AUTHOR]

Korean pine is an economically essential afforestation species limited by the unreasonable collection of cones, indiscriminate use of chemical pesticides and pest damage. This study aimed to determine whether spraying bacterial or fungal solutions affected insect pests, cone development, and the seed quality of Korean pine Pinus koraiensis Sieb. et Zucc. The experiment was conducted in a forest plantation in Linkou County (Heilongjiang, China) in 2019. Four fungal strains and one bacterial strain were applied during the flowering phase of Korean pine. The results after a year and a half of study indicated that a high concentration of Bacillus thuringiensis 223176 promoted cone development, increased seed weight, and reduced the proportion of damaged cones. Under this treatment, there were 15.873% damaged cones; the seed weight reached 0.829 g, and there were 82.738% fully developed cones. Trees treated with the second most effective strain, Beauveria bassiana 122077, had 30.556% damaged cones and an average seed weight of 0.810 g. Leucanicillium antillanum 01 performed the worst in this study. The seed weight was only 0.775 g, and the damaged and fully developed cones were 52.444 and 41.773%, respectively. In summary, spraying bacterial or fungal solutions during the flowering stage of Korean pine positively impacted seed quality and effectively decreased damage by the lepidopteran species that feed on the cones and seeds in this study. [ABSTRACT FROM AUTHOR]

Crown width (CW) is an important individual tree variable commonly used to assess tree vigor and the production efficiency of stands. However, our understanding of the effects of climate and the combined effects of climate with competition on the variation of CW remains unknown. Therefore, this study developed CW models by nonlinear mixed-effects (NLME) to explore these effects. Data were obtained from Korean pine (Pinus koraiensis Siebold and Zucc.) plantations in five forestry agencies in northeastern China. The results showed that stand basal area (BA), height to crown base (HCB), isothermality (BIO3), and annual precipitation (BIO12) were significantly related to the variations of CW. CW increased with increasing BIO12, while decreased with increasing BA, HCB, and BIO3. The hierarchical partitioning (HP) analysis showed that the relative importance of BIO3 was larger than BA, HCB, and BIO12. In addition, we found that competition altered the variations of CW responses to climate. Competition, tree size, and climate CW model (CC-CWM) performed the best performance in model fitting and prediction accuracy. Therefore, CC-CWM was selected to predict CW under future climate change. By comparing the eleven sampling methods with eighteen sample sizes, it was reasonable to select six medium-trees to estimate the random effect parameters. Our study provides evidence of the effects of climate and the combined effects of competition and climate on the variations of CW, potentially useful for the development of rational and scientific forest management decisions under future climate changes. [ABSTRACT FROM AUTHOR]

The fertilization process is a critical step in plant reproduction. However, the mechanism of action and mode of regulation of the fertilization process in gymnosperms remain unclear. In this study, we investigated the molecular regulatory networks involved in the fertilization process in Korean pine ovules through anatomical observation, physiological and biochemical assays, and transcriptome sequencing technology. The morphological and physiological results indicated that fertilization proceeds through the demise of the proteinaceous vacuole, egg cell division, and pollen tube elongation. Auxin, cytokinin, soluble sugar, and soluble starch contents begin to decline upon fertilization. Transcriptomic data analysis revealed a large number of differentially expressed genes at different times before and after fertilization. These genes were primarily involved in pathways associated with plant hormone signal transduction, protein processing in the endoplasmic reticulum, fructose metabolism, and mannose metabolism. The expression levels of several key genes were further confirmed by qRT-PCR. These findings represent an important step towards understanding the mechanisms underlying morphological changes in the Korean pine ovule during fertilization, and the physiological and transcriptional analyses lay a foundation for in-depth studies of the molecular regulatory network of the Korean pine fertilization process. [ABSTRACT FROM AUTHOR]

The primary purpose of this study was to delineate the most significant factors in the wood impregnation process. For this, the authors prepared larch (Larix kaempferi) and Korean pine (Pinus koraiensis) wood and used alkaline copper quaternary as an impregnation solution. The chamber temperature was adjusted to 25, 50, and 80 °C, and the pressure was adjusted to 100, 200, and 300 psi. The impregnation process was maintained for up to 90 min. Multiple regression analysis was used to investigate the effects of temperature, time, and pressure in terms of amount of solution impregnated during the process. Factors affecting the amount of solution impregnated were as follows: the effect of pressure was greater than that of time, which was greater than that of temperature. Therefore, pressure was the most critical factor in the wood impregnation process. [ABSTRACT FROM AUTHOR]

This study aimed to investigate how pre-steaming affects the drying times, final moisture contents (final MCs), and prevention of checking during the high-temperature and low-humidity drying process of boxed-heartwood Korean red pine (Pinus densiflora S. et Z.) and Douglas-fir (Pseudotsuga menziesii) with 20 × 20 cm and with 30 × 30 cm cross sections. Although average final MCs of the larger cross sections were slightly higher than those of smaller cross sections, all were over-dried between 3.3% and 8.1% MC, compared to the in-use moisture content for outdoor building materials. All the pre-steamed samples were only slightly defected by surface checks of 5 mm or less in width. The sample timbers with the 20 × 20 cm cross-sectional size were slightly defected by internal checking, whereas those with the 30 × 30 cm cross-sectional size were severely defected. However, there was no clear impact of pre-steaming time on the prevention of internal checking. [ABSTRACT FROM AUTHOR]

Statistical analysis of data on the area of planted area and the number of asexual lines ( family lines) in Heilongjiang Province forest tree seed bases over 50 years of collection areas, seed orchards, and offspring forests was conducted to provide technical support for scientific management and sustainable development of the seed bases. The results showed that the area and the number of preserved resources of the forest tree seed base in Heilongjiang Province were the largest in the 1980s, and the broad-leaved species grew faster after 2010. The area and number of coniferous species occupied an absolute advantage, with Pinus koraiensis Sieb. et Zucc., Larix gmelinii (Rupr. ) Kuzen. and Pinus sylvestris var. mongolica accounting for more than 86% of the established area and more than 88% of the number of preserved resources. There were 1 270. 17 hm 2 of various types of seed orchards built, containing 17 859 asexual lines; 342. 46 hm 2 of offspring forests, with less area built for other species except Pinus sylvestris var. mongolica, and the number of parents measured was not rich enough, with only 10 127 lines; 151. 37 hm 2 of collection area, with 8 805 asexual lines preserved, more than twice less than the seed orchards. It is suggested to increase the establishment of broad-leaved species and other new demand species; vigorously carry out the determination of offspring and increase the collection of germplasm resources of different traits in different areas. [ABSTRACT FROM AUTHOR]

Seven-year-old Pinus koraiensis from a Hegang clone nut orchard was used as the experimental material to determine the contents of chlorophyll, soluble sugar and endogenous hormones during the fertilization experiment of N, P and K from June 2019 to mid-June in the 2021, the effects of fertilization on physiology and endogenous hormones of Pinus koraiensis clones were studied. The results showed that the contents of chlorophyll a, chlorophyll b and total chlorophyll of Pinus koraiensis clones were significantly increased by fertilization, and the contents of N and P fertilizer were the highest, which were 39. 55%, 14. 68% and 28. 52% higher than those of the control, respectively. The response of chlorophyll content of different clones to fertilization was different. The chlorophyll content of HG18, HG16, HG9 was significantly higher than that of control after N, P application. After fertilization, ABA(Abscisic acid) content was significantly higher than that of the control, and N fertilizer treatment increased by 152. 2%, while GA3(Gibberellic acid 3) and IAA(Indole aceticacid) contents were significantly lower than that of the control. The response of GA3, IAA and ABA contents of different clones to fertilization was different, the GA3 and IAA contents of HG50 and HG40 were significantly increased after fertilization, while the ABA contents of HG25 and HG24 were significantly increased. After fertilization, chlorophyll content was negatively correlated with GAs(Gibberellic acids content) and positively correlated with ABA, while soluble sugar content was positively correlated with GA3 . In conclusion, fertilization increased ABA content and decreased GA3 and IAA content, which had an effect on increasing chlorophyll content and decreasing soluble sugar accumulation in plants. [ABSTRACT FROM AUTHOR]

Background: Korean pine nuts (Semen Pinus koraiensis (P. koraiensis)) have been a valuable ingredient in Korean cuisine since ancient times, and the classical literature on traditional medicine states that pine nuts can moisturize skin. Aims: To confirm the therapeutic efficacy of the ethanol extract of these pine nuts in an animal contact dermatitis (CD) model. Materials and Methods: Korean pine nuts were extracted using 70% ethanol, and the crude extract obtained was condensed and lyophilized to produce EEPK (the 70% ethanol extract of P. koraiensis). A DNFB (1-fluoro-2,4-dinitrofluorobenzene)-induced BALB/c mouse model of CD was used to investigate the effects of EEPK on skin symptoms, histopathological abnormalities, and cytokine secretion in inflamed tissues. Results: EEPK reduced skin color changes, lesion severities, and dorsal skin thickening and inhibited epidermis hyperplasia and immune cell infiltration into inflamed tissues. In addition, EEPK suppressed the productions of tumor necrosis factor-α, interferon-γ, interleukin-6, and monocyte chemoattractant protein-1 but did not affect body weights or spleen/body weight ratios. Conclusion: P. koraiensis has potential as a therapeutic agent for CD and as a treatment for inflammatory skin disease management products. Furthermore, the mechanism underlying its therapeutic effects differs from that of corticosteroids. [ABSTRACT FROM AUTHOR]

Exogenous glutathione (GSH) promotes the proliferation of embryogenic callus (EC) cells in Korean pine in the course of somatic embryogenesis, and reactive oxygen species (ROS) may play an important role in regulating the proliferation of EC cells by exogenous GSH. However, the concrete metabolic response of ROS is unclear. In this study, two cell lines of Korean pine with high proliferative potential 001#-001 (F, Fast proliferative potential cell line is abbreviated as F) and low proliferative potential 001#-010 (S, Slow proliferative potential cell line is abbreviated as S) were used as test materials. The responses of ROS-related enzymes and substances to exogenous GSH and L-Buthionine-sulfoximine (BSO) were investigated in EC cells. The results showed that the exogenous addition of GSH increased the number of early somatic embryogenesis (SEs) in EC cells of both F and S cell lines, decreased the amount of cell death in both cell lines. Exogenous addition of GSH promoted cell division in both cell lines, increased intracellular superoxide dismutase (SOD) and catalase (CAT) activities, inhibited intracellular hydrogen peroxide (H2O2), malondialdehyde (MDA) and nitric oxide (NO) production, and increased NO/ROS ratio. In conclusion, the exogenous GSH promoting the proliferation of Korean pine EC cells, the activity of intracellular antioxidant enzymes was enhanced, the ROS level was reduced, and the resistance of cells to stress was enhanced. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are obtained herein by green synthesis using plant extracts instead of chemical reagents. However, the AgNPs fabricated via green synthesis are prone to aggregation, and their reproducible formations are difficult owing to the lack of capping ability in the extract. Although such aggregations of AgNPs are also observed in chemical synthesis, the phenomenon is more severe in green synthesis. In this study, we used Pinus koraiensis pinecone extract as a new green-synthetic agent along with 1 mM AgNO 3 and diatomite (DE) as the biosilica surface to prepare AgNPs stably. Scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis confirmed that the AgNPs were formed on DE by green synthesis with a size of 27 nm; they were non-aggregated and well-dispersed on the DE surface. The AgNP-coated DE composite (AgNPs/DE) showed antibacterial activity that could kill > 99% of E. coli and S. aureus within one hour. Further, the AgNPs/DE with antimicrobial activity can be used up to five times repeatedly. The use of DE in the green synthesis of nanoparticles can thus provide advantages such as adequate dispersion and enhanced ability of the AgNPs. The results obtained herein support the environmentally friendly strategy of preparation and application of AgNPs. [Display omitted] • Green synthesis of silica nanoparticle (AgNPs) by pinecone extract was done on diatomite (DE) to yield DE/AgNPs. • In AgNPs/DE composite, the formed AgNPs are well dispersed on diatomite surface. • AgNPs/DE composite showed good antibacterial activity for gram-positive and gram–negative bacteria. • Antibacterial activity of AgNP can be re-used via AgNPs/DE composite. [ABSTRACT FROM AUTHOR]

Taking six kinds of arbors in Maoershan area of Heilongjiang Province as the research object, this paper provides theoretical data for forest fire prevention. The pyrolysis stage of holocellulose was studied by thermogravimetric analysis, the mechanism function was selected by Coats Redfern integral method, and the data were processed by Origin software to obtain the corresponding activation energy and frequency factor. The pyrolysis stage data of holocellulose were extracted, and the principal component analysis was carried out by SPSS software to rank the combustibility. The results showed that the pyrolysis process of 6 kinds of arbors’ trunk samples can be divided into water loss stage, holocellulose pyrolysis stage, lignin pyrolysis stage and carbonization stage. The descending order of activation energy in the pyrolysis stage of holocellulose in the branches and stems of 6 kinds of arbors was: Tilia amurensis Rupr., Pinus sylvestris var. mongolica Litv., Fraxinus mandshurica Rupr., Betula platyphylla Suk., Larix gmelinii Kuzen., Pinus koraiensis Sieb. et Zucc., The descending order of principal component analysis was: Tilia amurensis Rupr., Pinus koraiensis Sieb. et Zucc., Fraxinus mandshurica Rupr., Larix gmelinii Kuzen., Pinus sylvestris var. mongolica Litv., Betula platyphylla Suk. . The two orders were different, indicating that the flammability cannot be evaluated only from the micro point of view, but should be considered from many aspects. [ABSTRACT FROM AUTHOR]

Effects of steam explosion were investigated relative to impregnation of wood. Three types of softwoods [North American spruce (Picea orientalis), Korean pine (Pinus koraiensis), and Japanese larch (Larix kaempferi)] were prepared and subjected to steam explosion treatment. The crosssectional surfaces of the samples were observed with SEM, and their open-pore and closed-pore porosities were determined using a gas pycnometer. The softwoods were vacuum impregnated using ACQ-2 (Alkaline Copper Quaternary), a commercial preservative. After steam explosion treatment, the impregnation amount increased by 42.9% in the spruce and 155% in the Korean pine. However, there was no significant difference in the Japanese larch. The results from this study indicated that the steam explosion treatment helped to improve open-pore porosity by generating micro-cracks in the cell walls of softwoods, which improved the impregnation process. However, the degree of improvement in impregnation process differed by the species type. [ABSTRACT FROM AUTHOR]

Comprehensive study of sections of mares in the Bolshaya Ussurka River basin has allowed highlighting climate changes over the past 2900 years. Reconstructions are based on the data of botanical, diatom, and palynological analyses and radiocarbon dating. The moisture content changed most significantly. Periods of prolonged droughts, which coincided with the weakening of the summer monsoon, were established. A long dry period continued from about 2900 up to 1360 yr BP. Dry conditions did not exclude floods caused by heavy rain caused by the passage of typhoons or deep cyclones. The Medieval Warm Period and Little Ice Age were humid and characterized by increased cyclogenesis. There were short-term fluctuations in humidity: droughts about 530–460 yr BP ago, then conditions became more humid about 400 yr BP and especially about 330–260 yr BP ago. The age ranges of periods with different flood activity and paleo-fires were determined. Events were correlated with data on regional and global events. A different response of mountain and bog landscapes to short-period climatic changes has been established. The role of the Korean pine in forest vegetation changed significantly; its distribution is controlled by changes in the hydroclimatic conditions. The optimum environments for the development of Korean pine forests were 780–530 yr BP ago. The role of Korean pine decreased during dry phases and after fires. The most variable vegetation of the mares was during the Little Ice Age. Modern anthropogenic changes in landscapes are also recorded in the sections. The scale of floods has significantly increased under human impact. [ABSTRACT FROM AUTHOR]

In the large-scale breeding of conifers, cultivating embryogenic cells with good proliferative capacity is crucial in the process of somatic embryogenesis. In the same cultural environment, the proliferative capacity of different cell lines is significantly different. To reveal the regulatory mechanism of proliferation in woody plant cell lines with different proliferative potential, we used Korean pine cell lines with high proliferative potential 001#–001 (Fast) and low proliferative potential 001#–010 (Slow) for analysis. A total of 17 glutathione-related differentially expressed genes was identified between F and S cell lines. A total of 893 metabolites was obtained from the two cell lines in the metabolomic studies. A total of nine metabolites related to glutathione was significantly upregulated in the F cell line compared with the S cell line. The combined analyses revealed that intracellular glutathione might be the key positive regulator mediating the difference in proliferative capacity between F and S cell lines. The qRT-PCR assay validated 11 differentially expressed genes related to glutathione metabolism. Exogenous glutathione and its synthase inhibitor L-buthionine-sulfoximine treatment assay demonstrated the positive role of glutathione in the proliferation of Korean pine embryogenic cells. [ABSTRACT FROM AUTHOR]

Korean pine (Pinus koraiensis Sieb. et Zucc.), as the main tree species in northeast China, has important economic and ecological values. Currently, supplementary light has been widely used in plant cultivation projects. However, the studies about different supplementary light sources on the growth and development of Korean pine are few. In this study, the one with no supplementary light was used as the control, and two kinds of light sources were set up: light-emitting diode (LED) and incandescent lamp, to supplement light treatment of Korean pine. The spectrum and intensity of these two light sources were different. The results showed that the growth and physiological–biochemical indicators were significantly different under different supplementary light treatments. The biomass of supplementary light treatment was significantly lower than the control. Compared with the control, IAA and GA were lower, and JA, ABA, ZT, and ETH were higher under supplementary light conditions. Photosynthetic parameters in supplementary light conditions were significantly lower than the control. Supplemental light induces chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid accumulation. From RNA-seq data, differentially expressed genes (DEGs) were observed in all the comparison groups, and there were 487 common DEGs. The expression levels of DEGs encoding transcription factors were also changed. According to GO and KEGG analysis, the plant hormone signal transduction, circadian rhythm-plant, and flavonoid biosynthesis pathways were the most enriched. These results provided a theoretical basis for the response of Korean pine to different supplementary lights. [ABSTRACT FROM AUTHOR]

The embryogenesis capacity of conifer callus is not only highly genotype-dependent, but also gradually lost after long-term proliferation. These problems have seriously limited the commercialization of conifer somatic embryogenesis (SE) technology. In this study, the responsive SE cell line (R-EC), the blocked SE cell line (B-EC), and the loss of SE cell line (L-EC) were studied. The morphological, physiological, transcriptomic, and metabolomic profiles of these three types of cells were analyzed. We found that R-EC had higher water content, total sugar content, and putrescine (Put) content, as well as lower superoxide dismutase (SOD) activity and H2O2 content compared to B-EC and L-EC. A total of 2566, 13,768, and 13,900 differentially expressed genes (DEGs) and 219, 253, and 341 differentially expressed metabolites (DEMs) were found in the comparisons of R-EC versus B-EC, R-EC versus B-EC, and B-EC versus L-EC, respectively. These DEGs and DEMs were mainly found to be involved in plant signal transduction, starch and sugar metabolism, phenylpropane metabolism, and flavonoid metabolism. We found that the AUX1 and AUX/IAA families of genes were significantly up-regulated after the long-term proliferation of callus, resulting in higher auxin content. Most phenylpropane and flavonoid metabolites, which act as antioxidants to protect cells from damage, were found to be significantly up-regulated in R-EC. [ABSTRACT FROM AUTHOR]

Effects of roasting treatment on functional properties and structure of pine kernel protein from two grafted species: Pinus koraiensis (PK) and Pinus sylvestris var. (PKS) were evaluated by analysis of SDS‐PAGE, FTIR, fluorescence spectrum, solubility, emulsifying properties, etc. The results showed that roasting improved functional properties of PK and PKS. Structure analysis elucidated that conformational changes of tertiary structure, occurrence of unfolded protein structure, and enhancement in α‐helix and random coil structures. For PK, solubility, emulsifying and oil holding capacity (OHC) were the highest at 150°C, 20 min. PKS had the highest emulsification and OHC at 150°C, 10 min. The improvements in functional properties of PK and PKS should be attributed to the influence of intramolecular intergroup forces on secondary and tertiary structures, which resulted in higher surface charges and reduced turbidity. This study provided a reference for moderating quality properties of two kinds pine kernel. Novelty impact statement: Two kinds of nuts protein from grafted pine were comparatively studied for functionalities at different roasting parameters. Proteins from grafted pine nuts had different reaction schema to the combination of temperature and time. 150°C, 10 or 20 min were the optimum roasting conditions for improving functional properties of pine kernel protein. [ABSTRACT FROM AUTHOR]

Understanding how assimilated carbon (C) is allocated in forest ecosystems is crucial for process-based models and accurate prediction of global C cycling. We tracked the fate of recently assimilated C of Korean pine (Pinus koraiensis) and birch (Betula platyphylla) among various C pools in a temperate forest for 27 days using the 13CO2 pulse labeling approach. Birch had low carbon use efficiency (CUE) and allocated 66.9% of the recently assimilated C to metabolism and respiration, and had faster turnover rate of recently assimilated C in the labile pool of leaves and soil compared to pine. Pine had high CUE and allocated 12.3% of the recently assimilated C to metabolism and respiration. Our study showed that pine, as the dominate species of the climax stage, has a more conservative strategy of C use than the pioneer species birch, which may be one of the underlying mechanisms of higher soil carbon sequestration in pine forests compared to birch forests. [ABSTRACT FROM AUTHOR]

Light is one of the most important environmental cues that affects plant development and regulates its behavior. Light stress directly inhibits physiological responses and plant tissue development and even induces mortality in plants. Korean pine (Pinus koraiensis) is an evergreen conifer species widely planted in northeast China that has important economic and ecological value. However, the effects of light stress on the growth and development of Korean pine are still unclear. In this study, the effects of different shading conditions on physiological indices, molecular mechanisms and metabolites of Korean pine were explored. The results showed that auxin, gibberellin and abscisic acid were significantly increased under all shading conditions compared with the control. The contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid also increased as the shading degree increased. Moreover, a total of 8556, 3751 and 6990 differentially expressed genes (DEGs) were found between the control and HS (heavy shade), control and LS (light shade), LS vs. HS, respectively. Notably, most DEGs were assigned to pathways of phytohormone signaling, photosynthesis, carotenoid and flavonoid biosynthesis under light stress. The transcription factors MYB-related, AP2-ERF and bHLH specifically increased expression during light stress. A total of 911 metabolites were identified, and 243 differentially accumulated metabolites (DAMs) were detected, among which flavonoid biosynthesis (naringenin chalcone, dihydrokaempferol and kaempferol) metabolites were significantly different under light stress. These results will provide a theoretical basis for the response of P. koraiensis to different light stresses. [ABSTRACT FROM AUTHOR]