Korean Pine Seeds Research Articles

Korean pine, Pinus koraiensis Sieb. et Zucc.: seed quality and soil conditions for growth at the Verkhneussuriysky Forest Station (Primorsky Krai, Russia)

This publication presents research results on Korean pine seed quality and soil conditions at the Verkhneussuriysky Forest Station of the Federal Scientifi c Center of Biodiversity FEB RAS. The purpose of research is selecting plus trees based on seed productivity. High seed quality depended on favorable soil conditions for tree growth: soils with thicker horizons rich in organic matter, with high soil enzymatic activity contributing to the transfer of elements into more accessible forms for plant nutrition. Tree No.7 had very large cones with a large number of seeds, while the empty seed yield was 42%. We believe that the 1000-kernel weight does not always refl ect the seed quality. The soil conditions under that tree were extremely unfavorable for a high quality crop. The following conditions contributed to an effi cient harvest of Korean pine seeds: higher content of mobile phosphorus in the AU horizon (tree No.4), and favorable acid/alkaline conditions for brown soil formation (Cambisols). Brown soils have high catalase enzyme activity due to abundant plant residues in the AU horizon and strong content of organic carbon, which indicates high biological activity in their surface horizons. Studying changes in optical parameters of soils within the phytogenic fi elds of model trees allowed to establish the mutual correlation between the organic carbon content and the integral refl ection of soils (R). This will allow us to use the indicator P to indicate the state of soil fertility in forest ecosystems in further research. Data showed that seed quality depends on favorable growth conditions and the location of the tree.

Evaluating the Legacy Effects of the Historical Predatory Seed Harvesting on the Species Composition and Structure of the Mixed Korean Pine and Broadleaf Forest from a Landscape Perspective

Adequate seed provenance is an important guarantee for the restoration of the mixed Korean pine (Pinus koraiensis) and broadleaf forest (MKPBF). However, the commercial harvest exclusion in natural forests has led to a sharp decline in economic income from timber. Given the economic value of Korean pine seeds, predatory seed harvesting (PSH) has become increasingly serious in the past 20 years and has significantly reduced the seed and seedling bank, which might seriously threaten the restoration and sustainable management of the MKPBF. How the historical PSH has affected the future of the MKPBF is unclear at the landscape scale. In this study, we quantified the effects of seed harvesting at the landscape scale by a forest landscape model LANDIS PRO, and then assessed the legacy effects of the historical PSH on the composition and structure of the MKPBF in the Xiaoxing’an Mountains, Northeast China. Our results showed that the historical PSH decreased the Korean pine basal area of all age cohorts, with an average decrease of 0.06 to 0.19 m2 ha−1 but insignificantly altered the age structure diversity of Korean pine throughout the simulation. Our results indicated that the historical PSH remarkably decreased the dominance of Korean pine by 11.1%, but significantly increased the dominance of spruce (Picea koraiensis and Picea jezoensis) and fir (Abies nephrolepis) by 3.8% and 4.5%, respectively, and had an insignificant effect on the other tree species over the simulation. We found that the historical PSH evidently changed the succession trajectories of the disturbed stands, which would result in the transition from the succession pattern dominated by Korean pine to that dominated by spruce and fir. The historical PSH decreased the importance value of Korean pine by 12.2% on average but increased it by 5.1% and 6.0% for spruce and fir, respectively, and resulted in an average 33.2% increase in the dissimilarity index compared with the initial state during the whole simulation period. Future forest management should strictly limit the intensity and rotation of seed harvesting to protect the seed provenance of Korean pine and consider how to ensure the recovery and sustainable management of the MKPBF through direct seeding or seedling planting.

Rodent-mediated seed dispersal of Korean pine in forest gaps: The importance of fine-scale spatial heterogeneity of understory vegetation

During the restoration of secondary forests in Northeast China, it is critically important to promote seed recruitment of Korean pine (Pinus koraiensis), which is highly dependent on rodents and significantly affected by spatially heterogeneous understory vegetation of forest gaps. Understanding the link between understory microhabitats and rodent-mediated seed dispersal, including post-dispersal seed predation and scatter-hoarding seed escaped predation, is essential to improve seed survival. Previous studies have focused on their qualitative relationships by roughly classifying understory vegetation characteristics, which cannot precisely predict regeneration direction. Quantifying the spatial heterogeneity of understory vegetation parameters (e.g., canopy cover, CC; gap fraction, GF) using terrestrial laser scanning (TSL) provides a vital way to determine quantitative relationships. In this study, we collected point cloud data in forest gaps with three sizes and six within-gap positions through TSL to quantify the understory microhabitats using CC and GF and integrated these parameters with spatial site data of Korean pine seeds scatter-hoarding and post-dispersal predation by rodents. The results showed that the influence of the within-gap position on the understory microhabitats was insignificant, and the spatial site selection of post-dispersal seed predation and seed storage was concentrated in the range of 0–22 m away from the seed station, irrelevant to the gap size. Considering the risk of predation by enemies and seed pilferage by competitors in forest gaps, rodents scatter-hoarded or post-dispersal predated seeds in the CC range of 0.2–0.3, and post-dispersal predated seeds less often in the CC range > 0.8. The ratio of post-dispersal seed predation to scatter-hoarding escaped predation firstly increased and then decreased along with the increase in CC and GF. Therefore, the spatial heterogeneity in understory microhabitats caused by gap treatment had an uncertain effect on rodent-mediated seed dispersal, depending on the relative ratio of post-dispersal seed predation to seed scatter-hoarding.

Change in seed dormancy status controls seasonal timing of seed germination in Korean pine (Pinus koraiensis)

AbstractSeed dormancy ensures seedling establishment in the favorable season in a seasonally changing environment. Korean pine (Pinus koraiensis Sieb. et Zucc.) seeds have morphophysiological dormancy after dispersal in autumn. A small fraction of seeds germinates in the first spring, but most seeds germinate in the second spring following dispersal. It is not clear how dormancy status changes and thus drives germination characteristic. Fresh Korean pine seeds were buried between litterfall and soil in Fenglin National Nature Reserves, Heilongjiang Province, northeastern China, in middle October 2018 and regularly exhumed. Field germination percentage, embryo growth, seed viability and laboratory germination percentage of exhumed seeds were determined. The physiological dormancy part of morphophysiological dormancy was gradually released during the first winter, but reinduced in the first summer following dispersal. The reinduced physiological dormancy was broken again in the second autumn and winter. The morphological dormancy part of morphophysiological dormancy was slowly released over the first summer but rapidly broken during the second early and middle autumn. In the second spring, Korean pine seeds completely escaped from morphophysiological dormancy. The physiological dormancy part of morphophysiological dormancy was completely released, but the morphological dormancy part was still maintained, leading to very low germination in the first spring in the field. Relief of morphophysiological dormancy enables a high percentage of seeds to germinate at relatively low temperature (alternating day/night temperature above 10/5 °C) in the second spring. Korean pine provides an example of the change in dormancy status of seeds with morphophysiological dormancy.

Effects of active molecules of Korean pine seed on rodent health and implications for forest regeneration

After maturation, Korean pine (Pinus koraiensis Siebold & Zucc.) seeds often cannot disperse to reach a suitable germination site. It is therefore difficult to naturally regenerate by itself and relies on animal dispersal. Squirrels hoard pine seeds as winter food and Korean pine seeds stored for overwintering might become the source of regeneration of the species. From field observations, the pine seeds are the food preference for squirrels during autumn in the Lesser Khingan Mountains in Northeast China. Such preference by squirrels has been attributed to high seed energy content and the ease of seed storage. However, it may also be expected from nutritional aspects that a coevolutionary relationship between squirrels and Korean pine species could be partially explained by the effect of active seed components and their physiological regulatory effects on squirrels. To test this hypothesis, control experiments were carried out to examine the modulatory effects of Korean pine nut oil (PNO) on intestinal microbiota, inflammatory profile and oxidative stress in mice. The results showed that, compared with mice fed a high-fat diet, PNO significantly improved the physical and the healthy state of mice. Histological analysis of the liver and epididymal fat tissue showed that PNO alleviated liver and adipocyte lesions, and inflammation caused by high-fat diets. PNO also significantly decreased atherosclerotic index and ameliorate serum lipid accumulation to prevent cardiovascular disease, which effect the positive control SG group. Moreover, PNO elevated superoxide dismutase and glutathione peroxidase enzyme activities and reduced malondialdehyde levels in the serum. 16S rRNA sequencing showed that PNO restored intestinal microbiota composition, significantly increasing the relative abundance of Lactobacillus and Akkermansia bacteria. These results suggest that Korean pine seeds not only provide adequate fat, protein and energy for squirrels, but also promote physical health and improve body immunity.

An Improved Multi-Level Set C-V Model for Grading of Korean Pine Seeds

An improved multi-level set C-V model for non-destructive grading of Korean pine seeds is presented in this paper. On the basis of improved Ostu and rough segmentation results of expansion operation, the improved C-V model is used to extract the target contour of Korean pine seeds; the characteristic parameters of fruit length and maximum transverse diameter are extracted by mathematical morphology method, and polynomial fitting is carried out with the actual measured values to construct a mathematical model with better quality; according to the extracted characteristic parameters, a comprehensive evaluation and grading standard for Korean pine seeds is established. The experimental results show that this method can achieve simultaneous classification of multiple Korean pine seeds, and the average accuracy of classification can be up to 97.2%.

Modelling the cone yields of Korean pine

Korean pine is the most important plantation tree species in northeast China. Besides timber, it produces edible seeds. Economic comparisons between alternative management schedules of Korean pine plantations require information on tree growth but also on seed yields since Korean pine seeds generate significant economic returns. This study developed models for the cone yields of Korean pine. Data were collected from 24 permanent sample plots during 2004–2018. Model types suitable for modelling count data with a high proportion of zero counts, namely zero-inflated and hurdle models, were tested as alternatives to those types of Poisson and negative binomial models that did not include a sub-model for the excess of zeros. Correlations between observations collected from the same plot and tree were taken into account by fitting mixed-effects models. There was much annual variation in seed production, which was modelled by using indicator variables for different years. The other predictors of the cone models were tree diameter at the breast height, stand basal area, competitive position of the tree in the stand (basal area in larger trees) and site index. It was concluded that the best model types for predicting cone yields in simulation and optimization studies were negative binomial hurdle model and Poisson hurdle model. The same models were evaluated to be the most recommendable also in cases where probabilistic predictions are needed, for instance in stochastic optimization.

The temperature and length for the release of primary and induction of secondary physiological dormancy in Korean pine (Pinus koraiensis Sieb. et Zucc.) seeds

Primary physiological dormancy and secondary physiological dormancy of Korean pine seeds restrict the regeneration of broad-leaved Korean pine (Pinus koraiensis) mixed forest. Dry and imbibed seeds were stratified at 1 °C and 5 °C for 1, 2, 4 and 6 months. Germination percentage, mean germination time (MGT) and germination rate index (GRI) were measured to determine the optimal low temperature and its duration for the release of primary physiological dormancy. Once primary physiological dormancy was released through cold stratification, seeds were stored in an environment in which the temperature progressively increased from 5 to 25 °C. After one month of storage at each storage temperature, the germination percentage, MGT and GRI were measured to determine the threshold temperature for the induction of secondary physiological dormancy. Both dry and imbibed seeds not only exhibited a high germination percentage (approximately 80%) but also germinated rapidly (MGT and GRI were 17 days and 2.36, respectively) after 6 months of storage at either 1 °C or 5 °C. The germination percentage of cold stratified seeds gradually decreased from 78% (5 °C) to 72% (10 °C), 55% (15 °C), 10% (20 °C) and 8% (25 °C). The results of this study suggest that stratifying seeds at 1 °C or 5 °C for 6 months releases primary physiological dormancy. The induction of secondary physiological dormancy occurs at temperatures above 15 °C.

Roles of abscisic acid and gibberellins in maintaining primary and secondary dormancy of Korean pine seeds

Primary dormancy of seeds of Korean pine (Pinus koraiensis Sieb. et Zucc.) after dispersal in the autumn and the induction of secondary dormancy the first summer following seed dispersal limit the regeneration of mixed broadleaved Korean pine forests in Northeast China. This study was to determine how changes in the levels of abscisic acid (ABA) and gibberellic acid (GA) maintain primary and secondary dormancy of Korean pine seeds under germination conditions. We transferred seeds with one of five primary dormancy states or three secondary dormancy states to germination conditions and measured changes in the levels of ABA, GA1+3 (GA1 and GA3) and GA4+7 (GA4 and GA7) in the seed coat, megagametophyte and embryo during incubation. Seed coat ABA levels in primary dormant seeds (PDS) and ABA levels in various parts of secondary dormant seeds (SDS) gradually declined during incubation but were still higher than in seeds for which dormancy was progressively released. GA4+7 and GA1+3 levels in embryos greatly decreased 35% and 24%, respectively, during incubation of SDS, and thus, the ratio of ABA to GA4+7 in embryos and megagametophytes significantly increased. The ratio of ABA to GA1+3 in various parts of SDS increased slightly during incubation. In contrast, in seeds for which secondary dormancy was already released, GA4+7 and GA1+3 levels in the embryo, GA4+7/ABA ratio in the embryo and seed coat, and the GA1+3/ABA in the embryo and megagametophyte significantly increased during incubation. There was no trend in the changes in the levels of ABA, GA4+7 or GA1+3 in embryos and megagametophytes of PDS or the levels of GA4+7 or GA1+3 in megagametophytes of SDS during incubation. The results suggest that high ABA levels in the seed coat maintain primary dormancy of Korean pine seeds. Maintenance of secondary dormancy involves a reduction of GA4+7, GA1+3, GA4+7/ABA, and GA1+3/ABA and the retention of high ABA levels.

Seed coat and aging conditions affect germination and physiological changes of aging Korean pine seeds

ABSTRACTThe study was conducted to obtain information on possible seed aging during the long-term storage period of Korean pine seeds with thick impermeable seed coat. The seeds were artificially aged at 18, 24, 37 and 45°C for 35 days. Germinations percentages (GP) of aged seeds were highest on 25 days at 18°C, 15 days at 24°C and 10 days at 37°C. The seeds exposed at 45°C have completely lost their germinability after 5 days of aging. From 5 days of aging, mean germination times (MGT) were lower than control seed. The electrical conductivity on 10 days at 45°C reached 1.5–2.5 times its control seed, and had a positive correlation with the GP and a negative correlation with the MGT. The K+ was the most in leaching solution, and K+ and Mg2+ showed a high negative correlation between GP and MGT. The ratio of K+/Na+ had a higher correlation with seed vigor. The malondialdehyde (MDA) increased to 21 times of control seeds at 45°C after 35 days of aging, and had a negative correlation with GP and MGT. The antioxidant enzymes showed different sensitivity to aging, depending on storage conditions and enzyme species. Ascorbate peroxidase showed the highest correlation with germination following glutathion reductase and Catalase. In conclusion, the seed aging had an effect initially to increase the GP and reduce the MGT. However, as aging treatment continued, the seeds eventually lost vitality due to an increase in physiological damages.

Short-term acute nitrogen deposition alters the interaction between Korean pine seeds and food hoarding rodents

Although the environmental impacts of nitrogen (N) deposition have been well studied, how nitrogen deposition affects the interaction between seeds and food hoarding animals has never been investigated. In this study, N was added twice as NH4NO3 to Korean pines Pinus koraiensis in order to explore the impacts of N deposition on seed traits and food-hoarding behaviors of small rodents in the northeastern deciduous forests in China. Pine cones were collected to measure seed traits and to test food-hoarding behaviors of small rodents both in the field and in semi-natural enclosures. Our results showed that short-term N addition significantly enhanced the ratio of seed meat to seed coats and the concentrations of crude protein. Moreover, seed volatile compounds were significantly altered by N addition, resulting in lower emission of α-pinene but higher emissions of D-limonene. Consequently, nitrogen addition increased seed scatter-hoarding by both Tamias sibiricus and Apodemus peninsulae in enclosures. Field experiments showed the consistent results that small rodents preferred to scatter-hoard seeds with N addition over the control. To our knowledge, this is the first study showing that nitrogen deposition shapes the interaction between seeds and food-hoarding animals through altering the physical and chemical traits of seeds.

Identification of a novel sugar compound from Korean pine seeds

Sugar derivatives are critically important in nutritional, pharmaceutical, and some non-food industries. Amino sugars are more important as essential components of many drugs, antibiotics, and biopolymers. Hence, a novel amino sugar compound is worthy of investigation for identification and production. A novel amino sugar compound was identified from crude extracts of Korean pine seed embryos. This new compound was isolated from extracts using traditional purification steps. The pure compound was white in color with a melting point of 145°C. HPLC, TLC, FT-IR, and NMR analyses of the compound indicated a trisaccharide form of amino mannose that was polymerized with β-(1→2) glycosidic bonding. Computer-aided NMR spectral analysis of the trisaccharide of 2-dehydro-2-mannosamine exhibited a 96% match with the 13C-NMR spectrum of the new compound.

Comparison of methods for extracting high-throughput sequencing RNA from Korean pine seeds

Korean pine (Pinus koraiensis Sieb. et Zucc.) is an ecologically and economically important tree species in East Asia. Molecular studies of seed development of this species are limited due to the lack of effective RNA extraction protocols. This study aimed to obtain an effective method to extract high-quality RNA from Korean pine seeds. The TRIzol kit and CTAB methods were used to extract the total RNA from Korean pine seeds at different developmental stages. The bands of RNA extracted by CTAB were not clear, whereas the bands of RNA extracted by the TRIzol kit were brighter and clearer, indicating higher quality and integrity of the RNA products extracted by the TRIzol kit. The 28S rRNA band was approximately 1.5- to 2-fold brighter than the 18S rRNA band on the agarose gel electrophoresis. The absorbance value A 260/280 was 1.8–2.0, and the absorbance value A 260/230 was >1.9. The Bioanalyzer RNA integrity results showed that the RNA integrity number of the RNA extracted using the TRIzol kit was acceptable for high-throughput sequencing. Therefore, the total RNA extracted using the TRIzol kit method can be used for high-throughput sequencing and other molecular biology experiments.

Evaluation of regeneration potential of Pinus koraiensis in mixed pine-hardwood forests in the Xiao Xing’an Mountains, China

Large scale harvest of Korean pine (Pinus koraiensis) seeds as a food product in the mixed Korean pine-hardwood forest of northeastern China poses a serious threat to the sustainability and restoration of this endangered regional ecosystem. Seed collection over past decades greatly reduced the seed bank and subsequent seedling and sapling recruitment, and impacting a wide array of granivorous animals that rely on the pine seeds. We surveyed Korean pine seeds, including solid seeds (SS), insect consumed seeds (ICS) and other (animal) consumed (OCS) kernels, of the seed bank (forest floor and the top 10 cm of mineral soil), the seedlings and saplings from 1 m2 sample plots in five forest types in Liangshui Nature Reserve (LNR) of the southern Xiao Xing’an Mountains in northeastern China to provide accurate information for assessing the Korean pine regeneration potential. The average number of pine seeds in the seed bank were 11.2 seeds/m2, 9.1 seeds/m2, 4.6 seeds/m2, 1.1 seeds/m2, and 0.2 seeds/m2 in Korean pine-basswood forest, mixed Korean pine-hardwood forest, mixed conifer-hardwood forest, white birch forests, and oak forests, respectively. In the first three forest types, percentages of SS (potentially viable seeds) were 11.2%, 3.5% and 27.8%, respectively. The percentages of ICS (not viable seeds) were consistent at around 35%. The higher but variable percentages of OCS (not viable seeds) indicated high seed predation in these forests. Compared with other studies, we recorded higher percentages of seed damage, probably due to our survey approach and the increased depth of seed bank sampled in our study. Depletion of pine seeds in the seed bank greatly reduced seedling and sapling recruitment. Densities of pine seedlings varied from about 180 trees/ha in the mixed Korean pine-hardwood forest to about 5,400 trees/ha in the mixed conifer-hardwood forests and showed a high degree of spatial variation. Saplings were rare in the mixed Korean pine-hardwood forest, but ranged in the thousands in other forests. Large scale pine seed harvest has seriously threatened the sustainability of the mixed Korean pine-hardwood forest ecosystem. Scaling down the seed harvest or supplemental planting of pine saplings are urgently needed to maintain the health of the existing Korean pine forests and to restore this endangered ecosystem.

참나무림내 천연발생한 잣나무 치수의 지상부 현존량 및 양분분포

잣나무는 우리나라의 대표적인 조림수종으로서 종자가 비산하지 못하고 조류나 설치류등의 동물에 의해 운반, 산포됨으로써 잣나무 인공조림지 주변 산림의 하층에 잣나무 치수가 천연 발생하게 된다. 조사 임분 내에서는 직경급, 수고급별 분포에서 역 J자형을 나타내는 음수의 잣나무가 상층의 참나무림에 의해 낮은 광환경과 토양의 비옥도가 낮은 조건하에서 생육하고 있다. 조사 임분은 비교적 온도가 높고 건조한 남서사면이지만 상층의 참나무림 임관에 의해 완화되며, 따라서 잣나무 종자의 발아나 치수를 보호하는 미세 입지환경을 제공 할 수 있을 것으로 생각된다. 잣나무 치수의 전체 현존량은 잣나무 인공림에 비해 높았으며 참나무림 하부의 낮은 광 환경에서도 적응하는 것으로 생각된다. 각 기관별 질소와 인의 농도는 인공 잣나무림 및 혼효하는 참나무림의 각 기관별 농도보다 낮았으며 양분량도 현존량에비해 상대적으로 적었다. 이들 양분은 일반적으로 식물의 성장에 필요한 주요 성분이므로 잣나무와 활엽수 혼효림의 시업에 있어서 지조부는 임상에 존치 시키는 것이 유리할 것으로 판단된다. The occurrence of Korean pine (Pinus koraiensis) advance growth has been noticed in the deciduous oak forest being adjacent to the mature Korean pine plantation. the korean pine seedlings in the forest were regenerated naturally from harvested and transported Korean pine seeds and cones by rodents, mainly red squirrels. Mongolian oak (Quercus bariabilis), which formed dominant overstory, had close-to-normal distributions of height, diameter and age classes. Korean pine, which dominated the understory, had the reverse J-shaped height, diameter and age distributions that are expected of a shade tolerant species. Growing in the summer shade of the oak, Korean pine seedling had slow, but steady height growth during the past four decades. Total biomass of Korean pine seedling ranged from <TEX>$2,835-8,541kg\;ha^{-1}$</TEX> and biomass allocation of Korean pine seedling was follows : stem (with bark) > foliage > branches > roots. Korean pine seedlings allocated more biomass to foliage and branches compare to planted Korean pine. The smaller root/shoot ratio of Korean pine seedling in the site is to believed to be result of competition for light. Contents of N and K for Korean pine seedling were greatest in foliage follow by branches, stem ad roots, while content of P was greater in the order of foliage > roots > stem > branches.

Human–wildlife competition for Korean pine seeds: vertebrate responses and implications for mixed forests on Changbai Mountain, China

Introduction Korean pine (Pinus koraiensis) is a dominant tree species in the cold temperate mixed forest zone in eastern Eurasia. Its seeds are food sources for wildlife but have become an important and marketable part of the economy for local communities.

The effects of hoarding habitat selection of Eurasian red squirrels ( Sciurus vulgaris) on natural regeneration of the Korean pines

Cone-cores discarded by Eurasian red squirrels were used to study the habitat selection of Korean pine-seeds hoarding, in forest patch Nos. 16 and 19 in Liangshui Nature Reserve, China. Ten transects with a total length of 15 km were uniformly set, and data from 343 valid samples were collected in a 369 hm 2 area. One hundred and eighty four were hoarding samples which were determined according to the cluster analysis based on the number of the cone-cores, while the other 159 were control samples. The principal component analysis, using 11 habitat factors, suggested that the distance from Korean pine forest, forest type, number of Korean pine seedlings, density and type of bush significantly influenced the habitat selection of hoarding by Eurasian red squirrels. The results of Bailey’s method indicated that the squirrels showed (1) preference for natural coniferous forest, natural fir and spruce forest and planted spruce forest; (2) avoidance of planted Korean pine forest and planted larch forest; and (3) random use of natural Korean pine forest. Moreover the distance from the Korean pines in the range of 150–600 m showed no effect on the habitat selection of hoarding by the Eurasian red squirrels. More than 50% of the cone-cores were discarded in either fringe or gap of the Korean pine forest with more cone-cores found at <300 m than at 300 m away (One-Way ANOVA; df = 3, 183, F = 5.76, p = 0.0009). This demonstrated that the Eurasian red squirrels could take the cone-cores out of the Korean pine forest. The density of bushes in samples of hoarding area was significantly lower than that in control samples (Kruskal–Wallis test; df = 1, χ 2 = 83.99, p < 0.0001). The number of the Korean pine seedlings in samples of hoarding area was significantly higher than that in the control samples (Kruskal–Wallis test; df = 1, χ 2 = 104.13, p < 0.0001). This illustrated that the hoarding habitat favoured the germination of the Korean pine seedlings. In conclusion the behavior of hoarding Korean pine seeds by the Eurasian red squirrels can promote the regeneration and dispersal of the Korean pines.

Isolation and characterization of a novel thermostable α-amylase from Korean pine seeds

Amylases have significant importance in broad industrial application including bio-ethanol production. Although amylases are widely distributed in microbes, plants and animals, it has been sought for new amylases from various sources with special industrial potential. In this study we firstly isolated and characterized a novel thermostable alpha-amylase from Korean pine seed. Enzyme was purified to homogeneity level with purification fold of 1286.1 using several techniques such as self-precipitation, (NH(4))(2)SO(4) fractionation, DEAE anion exchange and starch affinity chromatography. The purified alpha-amylase showed two bands in SDS-PAGE with molecular weight of 44 and 45 kDa. The apparent molecular weight of native enzyme was calculated to be 46.7 kDa. Internal peptide sequencing confirmed that the purified alpha-amylase was a novel enzyme. The optimum pH and temperature for enzyme activity were pH 4.5 and 65 degrees C, respectively. This enzyme was fully stable for 48h at 50 degrees C and retained 80% activity up to 96h. The K(m) and V(max) were 0.84 mg/ml and 3.71 micromol/min, respectively. On the basis of high thermal stability and a broad range of pH stability, the pine seed alpha-amylase showed a good prospect of industrial application.

New Method for Breaking Korean Pine Seed Dormancy

Pinus koraiensis (Korean pine) seeds possess deep dormancy caused by mechanical barrier and embryo immaturity. It usually takes 9-12 months of cold stratification to break the deep dormancy which is a main problem in nursery practice. This study was initiated to find an effective method to shorten the duration of stratification and to hasten seed germination. Thirty-one treatments were examined, focusing on the stratification period. Increased temperature in the presoaking process reduced the duration of required stratification at the low temperature and increased the rate of germination. The best method for breaking seed dormancy was pre-soaking seeds at a starting water temperature of 70°C, then at room temperature for 6 days, followed by 3 months of stratification at a constant temperature of 3°C.

EXTRACTION, ISOLATION AND IDENTIFICATION OF INHIBITORY SUBSTANCE IN PINUS KORAIENSIS SEEDS

A study has been made on the methods of extraction, isolation,purification and identifica-tion of the inhibitory substance in the Korean pine (Pinus Koraiensis Sieb. et Zucc) seeds.The different results of extracting with water and other organic solvents are compared in thispaper. By means of paper chromatography, thin layer chromatography, bioassay, colour reac-tion, gas chromatography and ultraviolet spectrophotometric determinations, it is proved thatthe main inhibitory substance in the Korean pine seeds is Abscisic Acid (ABA), thus pro-viding a theoretical basis for the study on breaking the dormancy of the seeds. In addition,changes in the content of ABA resulting from exposure to ultraviolet light for differentperiods are also examined and verified.