• Journal of Life Science
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• v.16 no.5
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• pp.866-869
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• 2006

The inhibitory effect of pine needle (Pinus densiflora S.) on potato polyphenol oxidase (PPO) was investigated. The addition of the pine needle extract exhibited a higher inhibitory effect on the potato polyphenol oxidase activity than that of the citric acid or potassium sorbate. The enzyme activity was strongly inhibited in a pH range of 7.0-8.0. When the incubation time of reaction mixture was increased, the potato polyphenol oxidase activity was markedly inhibited. The pine needle extract inhibited the potato polyphenol oxidase non-competitively. And also the pine needle extract subjected to a heat treatment at $100^{\circ}C$ for 10 min or to an acid treatment at pH 2.0, 3.0, and 4.0 for 3 hours still retained inhibitory effect on potato polyphenol oxidase.

• Mycobiology
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• v.40 no.4
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• pp.231-235
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• 2012

Fungal endophytes are microfungi that live in plants without causing apparent symptoms of infection. This study was conducted to identify endophytic fungi isolated from leaves of coniferous trees in Bohyeon Mountain of Korea. We collected leaves of two species of coniferous trees, Pinus densiflora and Pinus koraiensis, from 11 sites in the study area. A total 58 isolates were obtained and identified using molecular and morphological characteristics. Four species of endophytic fungi were isolated from P. densiflora: Lophodermium conigenum, Leotiomycetes sp., Septoria pini-thunbergii, and Polyporales sp., while two fungal species were isolated from P. koraiensis: Eurotiomycetes sp. and Rhytismataceae sp. The most frequently isolated species were L. conigenum and S. pini-thunbergii.

• Journal of Korea Foresty Energy
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• v.18 no.2
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• pp.92-99
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• 1999

This study was carried out to understand the primary production of biomass, vertical biomass distribution in the stand and the difference of biomass production for part of the trees by stand density for natural Pinus densiflora forest at Mt. Baekdoo located in northeastern China. The primary production of biomass was estimated by the layers of trees, shrubs, herbs for five density classes. For the biomass estimation of the Pinus densiflora trees in stern, stembark and the above-ground tree, the regression model of logW = a + blog(D$^2$H) + c(D$^2$H) was adapted for all of the density classes where W is dry weight, D$_1$ diameter at breast height, and H, tree height. For the biomass estimation in branch and needle, and the needle area, the regression model of logW=a+blogD+cD was adapted for all of the density classes. With increasing stand density the biomass of trees increased but that of shrubs and herbs decreased. Net primary production of biomass in parts of the tree also increased with increasing stand density. However the percentage of the needle biomass among the total biomass in the above-ground tree decreased with increasing stand density. Consequently, primary production rate of biomass in the above-ground tree increased. The primary production of biomass for each part of the trees in natural Pinus densiflora natural forests showed in descending order : stern, needle, branch, and stembark regardless of stand density.

• The Korean Journal of Ecology
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• v.20 no.5
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• pp.315-321
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• 1997

Peroxidase activities and isozyme patte군 of the pine needles (Pinus densiflora) were examined and compared in the coastal regions of Anmyum-Do(Choongnam, Taean-Gun) and inland regions of Shinchang-Myun(Choongnam, Asan-City). The pine needle peroxidase from Anmyum-Do showed approximately three times higher specfic activity than Shinchang pine needle peroxidase. The pine needle extracts of Anmyun-Do and Shinchang contained three anionic isoperoxidases, named A1, A2 and A3, when subjected to starch gel electrophoresis at pH 7.0. Cjationic isoperoxidases could not be found in both extracts., However, there existed unique isoperoxidase An only from the extracts of Anmyun-Do pine needles under the salinary environment. Moreover, the specific activities of catalase and glucose-6-phosphate dehydrogenase from Anmyun-Do, known for the inducible enzymes under the stress condition, were about 1.8 times higher than those of Shinchang pine needles. However, the specific activities of other enzymes did not show great differences between the two regions. Considering the above results of the higher specific activity of peroxidase and the unique expression of isoperoxidase An, pine needle peroxidase might involve in the defence mechanism against the salinary stress of Anmyun-Do.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.377-384
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• 2009

Three-year-old seedlings of susceptible Pinus densiflora and resistant Pinus x rigitaeda were each inoculated with the pinewood nematode, Bursaphelenchus xylophilus, to compare disease development. Needle dehydration was evident on seedlings of P. densiflora by 20 days after inoculation, 10 days earlier than this symptom was observed on P. ${\times}$ rigitaeda. Xylem drying was more frequent in seedlings of P. densiflora than in that of P. ${\times}$ rigitaeda between 20 and 60 days after inoculation. No significant differences were found between P. densiflora and P. ${\times}$ rigitaeda for stem water content or for stem and leaf relative water content in current-year branches after nematode inoculation, but the average number of B. xylophilus recovered from stems differed significantly between the two groups. The number of B. xylophilus recovered from stems was negatively correlated with the stem water content and with stem and leaf relative water content. By the time the experiment was terminated at 60 days after inoculation, all 3 of the last group of P. densiflora seedlings had died, but 2 of the 3 remaining P. ${\times}$ rigitaeda hybrid seedlings were still alive. Additional studies are needed to further explore the specific mechanisms preventing nematode multiplication in the seedlings of resistant P. ${\times}$ rigitaeda.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.97-102
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• 1995

The purpose of this study was to investigate the effect of artificial acid rain(pH2.0, 3.0. 4.0 and 5.0) adjusted by natural rain fall and control group by pH6.5 on the change in needle chlorophyll fluorescence of Pinus densiflora and Pinus thunbergii. This study was performed from May, 1994 to August, 1994, during which 20ml of artificial acid rain was used once a week. The results are as follows : In the first treatment of artificial acid rain the measured indexes of fluorescence have increased in pH4.0 and pH5.0 treatments and decreased in pH2.0 and pH3.0 in comparison with those of the control group. As the treatment of artificial acid rain was processed the fluorescence indexes of both Pinus densiflora and Pinus thunbergii have decreased as the degree of acidity increased higher and that of Pinus densiflora has decreased more significantly than Pinus thunbergii. The measurement of change in the numerical indexes of fluorescence was proved to be a very effective criterion to make an early decision of damage of the vegetation by acid rain.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.349-352
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• 2002

The effects of Mn on growth and nutrient status of Pinus densiflora seedlings grown in a nutrient culture solution were investigated. Mn concentrations was added as manganese chloride at 0, 30 and 60ppm to the nutrient culture solution. The 2-year-old seedlings were transplanted into the solution maintained at pH 4.0, and grown for 90 days in a greenhouse. The Mn treatment induced a significant reduction in the dry weight growth of the seedlings. The relative growth rate(RGR) and net assimilation rate(NAR) of the seedlings decreased with increasing Mn concentrations in the nutrient culture solutions. For the nutrient status of the seedlings, Ca and Mg content in trunk and root was least in 60ppm Mn treatment, and Mn content in needle was about 3 times more than in root. Also the net photosynthetic rate of the seedlings was significantly lower both in 30ppm and 60ppm Mn treatment compared to them in 0ppm. This result suggests that the reductions in the RGR and NAR of the seedlings may be resulted from the inhibition of net photosynthesis by the mixed effect of lower nutrient uptake of roots and excess accumulation of Mn in needle.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.424-430
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• 1990

The variation of needle, cone and seed characteristics and of allelic frequency in isoenzyme, ADH, ME and PGI, according to different resin duct index in Pinus densiflora, Pinus thunbergii and their hybrids was analyzed. The results obtained were as follows : 1. With increase of number of resin ducts, morphological characteristics such as needle length, needle sheath length, cone size, seed size, seed wing size, 1000 seeds weight, etc. tended to he increased, while number of stomata row in needle to be decreased. 2. As the results of discriminant analysis for the morphological characteristics of needle, cone and seed, most individuals are generally coincided with number of resin duct mostly in Pinus densiflora were not. 3. According to the canonical discriminant function obtained from the morphological characteristics in Pinus densiflora, Pinus thunbergii and their hybrids including introgressive hybrid, the resin duct index, 1000 seeds weight, cone size and neelde sheath length characterized fairly their species. 4. With increase of resin duct index, hybrid index tended to be higher. The results obtained from the discriminant analysis and the hybrid index were nearly same each other. 5. With increase of number of resin duct, the allelic frequencies for isoenzyme, ADH-$B_2$, ME-$A_2$ and PGI-$B_1$. $B_2$ tended to increase but those of ADH-$B_3$, ME-$A_4$, and PGI-$B_3$, to decrease. It is thought that this increase of frequency for the former four isoenzymes was resulted in introgressive gene flow from Pinus thunbergii to Pines densiflora and accordingly the frequency of latter three isoenzymes tended to decrease.

• The Korean Journal of Mycology
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• v.43 no.2
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• pp.133-136
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• 2015

We investigated endophytic fungi diversity of two Pinaceae species (Pinus densiflora, Pinus rigida) and one Cupressaceae species (Juniperus rigida) on Mt. Seodae, Korea. In total, 34 isolates were obtained from 19 host plants and identified according to internal transcribed spacer (ITS) region. As a result, they were placed in 13 taxa. Among them, 52.9% belonged to Leotiomycetes, 32.3% belonged to Sordariomycetes, 5.8% belonged to Agaricomycetes, and 3.0% for isolates belonged to either Eurotiomycetes, Dothideomycetes or Ustilaginomycetes. In particular, Lophodermium growing in pine would be an especially important instance of biodiversity for endophytes, suggesting that further study examining its ecological function in the environment is critical.

• Journal of Forest and Environmental Science
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• v.38 no.1
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• pp.48-54
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• 2022

This study was conducted to examine litter inputs and litter decomposition rates following thinning, which is among the most important forest management activities that enhance the beneficial functions in Korean forests. Litter inputs and litter decomposition rates following a 2-year elapse from thinning in Pinus densiflora and following a 7-year elapse from thinning in Quercus variabilis stands were measured for 2 years from 16 sites in three regions (Sancheong-gun, Uiryeong-gun, and Jinju-si) in Gyeongsangnam-do, Korea. Annual needle litter inputs in P. densiflora stands were significantly decreased following thinning, whereas annual broadleaved leaf litter inputs in Q. variabilis stands were not significantly different between thinned and unthinned treatments. The annual mean total litter inputs in both tree species were significantly lower in the thinned (P. densiflora: 3,653 kg ha^-1 year^-1; Q. variabilis: 4,963 kg ha^-1 year^-1) compared to the unthinned stands (P. densiflora: 5,138 kg ha^-1 year^-1; Q. variabilis: 5,997 kg ha^-1 year^-1) during the study period. The mass loss rates from decomposing needle litter in P. densiflora stands were significantly lower (p<0.05) in the thinned stands than in the unthinned stands for two sampling dates of the eight included in the study, whereas the decomposition rates from decomposing leaf litter in Q. variabilis stands were not affected by thinning. The results indicate that thinning effects on total litter inputs remained clear following a 2-year elapse from thinning in P. densiflora stands and following a 7-year elapse from thinning in Q. variabilis stands.