• Journal of Korean Society of Forest Science
• /
• v.98 no.1
• /
• pp.115-124
• /
• 2009

New strain needs to maintain desirable characteristics for long term when it was bred, but in lapse of time it degenerates into a bad condition. Therefore the influence of temperature on the viability and survival rates of Lentinula edodes strains were examined after cryopreservation. Also, liquid nitrogen preservation for L. edodes has been proved to be one of the most reliable method. However, a mechanical damage of strain is inevitable during cryopreservation of the fungus because the fungus is very sensitive to stress of cooling rate in the freezing process. So we tried to find out state change of L. edodes with a programmable freezer. L. edodes strains were preserved at $-20^{\circ}C$, $-80^{\circ}C$ and $-196^{\circ}C$ for 50 days. At $-20^{\circ}C$, its mycelial growth became extinct. When thawed, the growth of mycelia which were preserved at $-80^{\circ}C$ was fastest. Attempts were made to investigate viability of L. edodes strains after freezing at $-80^{\circ}C$ and $-196^{\circ}C$, respectively. As the result, more than 90% showed high survival rate of strains tested at $-80^{\circ}C$ and $-196^{\circ}C$. Mycelial growth between apical and basal parts of colony after freezing preservation for 50 days was compared. At apical and basal parts, the survival rates showed 100% at $-80^{\circ}C$, but 98% and 94% at $-196^{\circ}C$, respectively. We confirmed that the ice crystal formation temperatures of L. edodes strains were $-6.0^{\circ}C$ for Sanlim 1, $-5.5^{\circ}C$ for the Sanlim 2, $-4.0^{\circ}C$ for the Sanlim 3 and $-15.5^{\circ}C$ for the Sanzo 302. These results indicated that L. edodes strains showed completely different responses to the ice crystal formation. We knew the fact that even the same species, especially L. edodes, they displayed completely different responses to the same freezing condition. Also, this has nothing to do with the connection between temperature type and freezing point. And a protocol was tried to minimize state change of L. edodes strains using programmable freezer when they are frozen, but it was not effective on them.

• Korean Journal of Plant Resources
• /
• v.23 no.4
• /
• pp.368-373
• /
• 2010

Juniperus chinensis var. sargentii Henry is a short and creeping evergreen shrub which reaches about 60 cm in height and only occurs in the northeast Asia and in the top of high mountains over the Korea. The Korea Forest Service protects it strictly by law since J. chinensis var. sargentii is an eccentric plant and possibly may be exterminated soon in Korea. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of J. chinensis var. sargentii. The rooting responses of branch cuttings, obtained from hard(May) and semi-hard wood shoots (August) to four growth regulators, namely, IAA, IBA, NAA and Rooton(exceptionally powder method) applied at various concentrations(0, 100, 200, 500, 1000 and 2000 $mgL^{-1}$) were examined in mixed soil media. Rooting rate showed significant difference between cutting times, among kinds and among concentrations of growth regulators. The optimum cutting time was April to May in hardwood cutting. The application of IBA 1000 $mgL^{-1}$(rooting rate : 36.4%) was most effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was 30.4%. Root characteristics such as number, length and diameter of root were not significantly affected by kinds and concentrations of growth regulators in hardwood cutting.

• Journal of Forest and Environmental Science
• /
• v.34 no.5
• /
• pp.412-417
• /
• 2018

Agroforestry is emerged as climate smart agriculture system and known to help in maintaining soil nutrient sustainability but its rate of expansion is still not appreciable. The present paper incorporates the different species under various agroforestry practices its density, growth and growing stock. The most dominated agroforestry practices in Bilaspur district identified as boundary tree based agri- silviculture (32%) followed with inside field tree based agri-silviculture (21%). Agri-horti-silvicultural system found merely in 5% farmer's field while silvo-pastoral practice in 8% fields. The result depicts that the most prevailing agroforestry tree species in non-forest area of Bilaspur comprises Acacia nilotica 36%, Butea monosperma 22%, Albizia spp 16%, Terminalia arjuna 7%, Azadirachta indica 3.5% and other species 15.5%. More than 90% farmer allows tree species growing naturally in their fields mainly for fuel wood, timber and as source of additional income as these species need not require special attention and care, while only 5% farmer's has adopted Tectona grandis, Dalbergia sissoo etc commercially for higher future return. The paper also discusses the constraints on agroforestry for enabling development of agroforestry in future.

• Journal of the Korea Furniture Society
• /
• v.22 no.3
• /
• pp.230-238
• /
• 2011

Consumers' expenditure is getting larger on children due to their parents' compensation for increase of double-income family life and decrease of birth rate caused by high economic growth. Increase of demand on children items in the market leads the necessity of development of furniture for children. This study is aimed to design children chairs that meet the environment for children. In this study, the age of children is defined to be 5~7 years old. In order to investigate what causes environment change, this study covers roughly change of environment, change of learning program and use of environment-friendly material. In such scope, we drew out the factors that the chairs for children shall be equipped with. Case studies were done through such drawn factors. The scope of the furniture for children is limited to the chairs for children among the ones made in either Korea or overseas. As a result, we could draw out such keyword of the furniture as storage, mobility, environment-friendly, object style image, preferred color, functionality and safety, based on which we could plan the design and make the final result through high frequency round molding manufacturing process.

• Journal of the Korean Wood Science and Technology
• /
• v.29 no.2
• /
• pp.140-145
• /
• 2001

Antimicrobial and antioxidative activities on heartwood extractives of domestic species were investigated to develop a natural fungicide or preservative. Six flavanones including pinostrobin, eriodictyol, naringenin, pinocembrin, taxifolin and verecundin were isolated from Prunus sargentii which has been selected due to its high antimicrobial and antioxidative activities among the tested species. According to the results of antifungal test, pinocembrin was evaluated as the highest antifungal compound among the test compounds, which showed 80% of hyphal growth inhibition rate. Antifungal activity of pinocembrin was similar to hinokitiol(${\beta}$-thujaplicin), strong antimicrobial compound isolated from Thujopsis dolabrata. Naringenin followed pinocembrin in its antifungal activity. However, verecundin did not show any antifungal activity. No compound was effective in antibacterial activities. As a result of the measurement of free radical scavenging activity, antioxidative activities of taxifolin and eriodictyol were 2 times that of ${\alpha}$-tocopherol, and antioxidative index of these compounds were even superior to that of ${\alpha}$-tocopherol. In this regard, it could inferred that high antifungal and antioxidative activities of extractives of P. sargentii were derived from pinocembrin, taxifolin and eriodictyol, respectively.

• Applied Chemistry for Engineering
• /
• v.33 no.4
• /
• pp.373-380
• /
• 2022

In this study, Chung's equations 1, 2, and 3 were extended to standardize smoke safety rating evaluation in case of fire, and Chung's equations-V, smoke performance index-V, and smoke growth index-V were calculated. Five types of wood were selected and their smoke indices were measured using the cone calorimeter method according to ISO 5660-1. The smoke risk was graded by the smoke risk index-VI according to Chung's equation-VI. Smoke risk index-VI increased in the order of PMMA (1) ≈ maple (1.01) < ash (1.57) < needle fir (4.98) < paulownia (46.15) < western red cedar (106.26). It was predicted that maple and ash had the lowest smoke risk, and paulownia and western red cedar had the highest. The five samples' CO mean production rate (COP_mean) was 0.0009~0.0024 g/s, indicating that these woods were incompletely burned than the polymethyl methacrylate (PMMA) reference material. Regarding the smoke properties of the chosen woods, the smoke performance index-V (SPI-V) increased as the bulk density increased, and the smoke risk index-VI (SRI-VI) decreased.

• Journal of Korean Society of Forest Science
• /
• v.102 no.3
• /
• pp.372-381
• /
• 2013

The leaf growth and physiological characteristics of Forsythia saxatilis were investigated under different relative light intensities (RLI) and fertilization levels in order to find out the optimum environmental conditions for in-situ restoration. RLI and fertilization were four levels (30%, 43%, 63% of full sun and full sun) and three levels (non-fertilization, 2 times and 3 times of average forest soil in Korea), respectively. According to the increase of fertilization level under all RLI, leaf area increased and leaf dry weight and the ratio of leaf dry weight to leaf area decreased. As the fertilization level increased, photosynthetic pigment contents such as chlorophyll a, b and carotenoid under all RLI decreased. And pigment contents were the highest under full sun in the same fertilization level. Foliar nitrogen content under fertilization was higher than that under non-fertilization, and chlorophyll/nitrogen ratio decreased with the increase of fertilization level under all RLI. The increase of photosynthetic rate was observed with the increase of fertilization level at 63% of RLI and full sun, and dark respiration rate under fertilization was lower than under non-fertilization. Apparent quantum yield was lower at non-fertilization than that of fertilization, and it was highest at 63% of RLI under the same fertilization level. In conclusion, leaf growth and physiological characteristics of F. saxatilis could be improved under higher light conditions and fertilization.

• The Korean Journal of Mycology
• /
• v.36 no.1
• /
• pp.36-40
• /
• 2008

Studies were processed to confirm the differences of productivity according to sawdust size and effect of additives for sawdust cultivation of shiitake. In results of investigation until shiitake mycelia fully spread on surface of sawdust medium, mycelial growth in treatment of sawdust size $3{\sim}5\;mm$ with $CaCO_3$ and $KNO_3$, and treatment of sawdust sizw $3{\sim}5\;mm$ without $CaCO_3$ and $KNO_3$ was the fastest. And, in investigation of rate of weight reduction, treatment of sawdust size below 1 mm without $CaCO_3$ and $KNO_3$ was the highest. The tendency of fruiting was somewhat different according to treatments. In case of sawdust size below 1 mm with $CaCO_3$ and $KNO_3$, yield produced from 1st to 2nd flushing period was over 80%. However, in case of sawdust size below 1 mm plus $5{\sim}7\;mm$ without $CaCO_3$ and $KNO_3$, yield produced from 3rd to 4th flushing period was more than it from 1st to 2nd flushing period and rate of yield produced from 1st to 2nd flushing period to total yield was 34%. Results of investigation on productivity, yield and the number of fruit-bodies were remarkably different according to treatments. Sawdust size $3{\sim}5\;mm$ with $CaCO_3$ and $KNO_3$, whose total yield and the number of fruit-bodies were 568 g and 67, respectively, was the highest. And, total yield of medium of sawdust size below 1 mm plus $2{\sim}3\;mm$ without $CaCO_3$ and $KNO_3$ was lowest as 227 g and the number of fruit-bodies of medium of sawdust size below 1 mm plus $5{\sim}7\;mm$ without $CaCO_3$ and $KNO_3$ was lowest as 24. In investigation on amount of fruit-bodies over 10 g, medium of sawdust size $3{\sim}5\;mm$ with $CaCO_3$ and $KNO_3$ was highest as 397 g.

• 한국균학회소식:학술대회논문집
• /
• 2015.11a
• /
• pp.16-16
• /
• 2015

Ectomycorrhizal (ECM) mushrooms play a major role in plant growth promotion through symbiotic association with roots of forest trees. They also provide an economically important food resource to us and therefore they have been studied for their artificial cultivation for decades in Korea. We have secured bio-resources of ECM mushrooms from Korean forests and performed their physiological studies. To investigate the cultural characteristics, the fungi were cultured under different conditions (medium, temperature, pH of the medium, inorganic nitrogen source). More than 90% of total 160 strains grew on three solid media (potato dextrose agar, PDA; sabouraud dextrose agar, SDA; modified Melin-Norkrans medium, MMN). The rate of mycelial growth on malt extract agar (MEA) was lower than those of three media (PDA, SDA, MMN). None of the Tricholomataceae strains grew on MEA. Many strains of ECM mushrooms were able to grow at the temperature range of $15{\sim}25^{\circ}C$ on PDA, while they showed poor growth at $10^{\circ}C$ or $30^{\circ}C$. In particular, the growth rates of both Gomphaceae and Tricholomataceae were significantly lower at $10^{\circ}C$ than at $30^{\circ}C$. The optimal pH of many strains was pH 5.0 when they cultured in potato dextrose broth (PDB). Fifty-seven percent of tested strains grew well on medium containing ammonium source than nitrate source. Many strains of Tricholomataceae showed a notable growth on ammonium medium than nitrate medium. Twenty-three percent of strains preferred nitrate source than ammonium source for their mycelial growth. The production and activity of two enzymes (cellulase and laccase) by ECM fungi were also assayed on the enzyme screening media containing CMC or ABTS. Each strains exhibited different levels of enzymatic activities as well as enzyme production. The number of laccase-producing strains was less than that of cellulase-producing strains. We found that 77% of tested strains produced both cellulase and laccase, whereas 2% of strains did not produce any enzymes. The morphological characteristics of mycelial colony were also examined on four different solid media. Yellow was a dominant color in mycelial colony and followed by white and brown on all culture media. ECM mushrooms formed mycelial colonies with a single or multiple colors within a culture medium depending on the strains and culture media. The most common shape of mycelial colony was a circular form on all media tested. Other families except for Amanitaceae formed an irregular colony on MMN than PDA. All strains of Tricholomataceae did not form a filamentous colony on all media. The pigmentation of culture media by mycelial colonies was observed in more than 50% of strains tested on both PDA and SDA. The degree of pigmentation on PDA or SDA was higher than MMN and brown color was dominant than yellow color. The production of exudates from mycelial colony was higher on PDA than MMN. Brown exudates were mainly produced by many strains on PDA or SDA, whereas transparent exudates were mainly produced by strains on MMN. We observed the mycelial colonies with a single or multiple textures in just one culture plate. Wrinkled or uneven colony surfaces were remarkably observed in many strains on PDA or SDA, while an even colony surface was observed in many strains on MMN. Sixty percent of Tricholomaceae strains formed wrinkled surface on PDA. However, they did not form any wrinkle on MMN plate. Cottony texture was observed in mycelia colonies of many strains. Velvety texture was often observed in the mycelial colonies on SDA than PDA and accounted for 60% of Suillaceae strains on SDA.

• The Korean Journal of Mycology
• /
• v.44 no.3
• /
• pp.155-165
• /
• 2016

Domestic and international production of Tricholoma matsutake has decreased owing to matsutake forests being left alone, host plant disease, forest fires, climate change, and so on. In order to identify strains that are suitable for the production of T. matsutake-inoculated seedlings, Pinus densiflora seedlings were inoculated with T. matsutake after in vitro rooting and mycorrhization was examined in the roots of T. matsutake-inoculated seedlings after 6 months. The mycorrhization rate was greater than 80% for 5 strains (NIFoS 421, 434, 1681, 1984, and 2001) out of 19 total strains. Seven strains (NIFoS 434, 441, 561, 562, 1016, 1807, and 1812) showed shoot/root ratios of less than 3.0 and had a seedling shoot biomass of 2.0 to 4.8 times higher than that of the root. Eight strains (NIFoS 441, 561, 562, 1016, 1807, 1812, 1984, and 2001) stimulated increases in shoot volume and three stains (NIFoS 441, 562, and 1812) promoted the growth of root biomass by mycorrhizal formation. In conclusion, 4 strains (NIFoS 434, 561, 1984, and 2001) out of 19 total strains tested showed higher mycorrhization rates and seedling growth than those of the other strains. We expect that the use of these four strains may contribute to T. matsutake-inoculated seedling production.