• 환경생물
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• 제27권2호
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• pp.176-182
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• 2009

전나무의 천연갱신 형태를 임분의 특성과 연관하여 내설악 길골 총 30지역에서 조사하였다. 임학적 의미의 천연갱신은 주로 예전에 인공적 교란이 있었던 곳에서 나타나며 자연림의 특성이 강할수록 오히려 의미를 상실한다. 이것은 인공적 교란이 천연갱신에 더 나은 환경조건을 제공하기 때문으로 보인다. 이와는 달리 자연림에서 갱신단계는 인공림처럼 명확할 수 없고 잠시 나타났다 사라지는 상태이며 세대교체는 임분구조 변화의 일부라는 표현이 적합하다. 특히 patch dynamic이 임분구조를 결정하고 주 구성수종이 음수인 전나무 자연림에서는 인공림에서 사용되는 천연갱신 개념은 원천적으로 의미를 상실할 것으로 보인다.

• Journal of Forest and Environmental Science
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• 제38권2호
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• pp.90-101
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• 2022

The study aims to assess composition, diversity and population indices of natural regeneration of woody species in Jebel El Gerrie forest reserve, Blue Nile State, Sudan. We conducted field work between December 2018 and January 2019. We used random sampling to collect vegetation data in the forest where we made a total of 90 circular sample plots (radius 17.84 m) and distributed them proportionally to the area of each of the four density-based vegetation classes of the forest i.e. high density (C1), medium density (C2), low density (C3) and crop land (C4). In each sample plot we identified all regenerating tree species and counted their regeneration frequencies. We calculated ecological metrics of regeneration frequency, density, abundance, richness, evenness, diversity and importance value index (IVI) and drew abundance rank curve. Results revealed that out of fifteen mature tree species present, natural regeneration of 8 species, which belong to 6 families, was observed. The relatively most frequently naturally regenerating and abundant species were Anogeissus leiocarpa and Combretum hartmannianum. Richness, evenness and diversity of regenerating species were 1.33, 0.82 and 1.7, respectively. One-way ANOVA (α=0.05) of mean regeneration densities disclosed that there were significant differences (F_3,86=16.77, p=0.000) between C2 & C3 (p=0.000) and C2 & C4 (p=0.000). While regeneration of seven tree species were absent, two, two and four species were of good, poor and fair regeneration status, respectively. A comparison of mean density of natural regeneration with that of parent trees reflects a poor regeneration status of the forest. The study provides empirical results on the regeneration status of species and signifies the need for management interventions for species conservation and restoration, maintenance of biodiversity and sustainable production.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.246-250
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• 1991

Conditions for the production and regeneration in Lactobacillus bulgaricus protoplasts were investigated. Protoplasts of L bulgaricus strains were obtained by treatment with mutanolysin and lysozyme together in a protoplast forming buffer containing 0.02 M N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) (pH 7.0) and 0.5 M sucrose. High protoplast yield was obtained from cells cultured in the de Man, Rogosa and Sharpe(MRS) medium at the middle to late logarithmic growth phase. Regeneration was efficiently accomplished with a complex medium containing 1% sucrose, 20 mM $MgCl_2$, 5% gelatin, and 0.5% bovine serum albumin. The frequency of regeneration of protoplasts was 10~20% after 5 days of incubation at $30^{\circ}C$.

• Journal of Plant Biology
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• 제39권2호
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• pp.93-98
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• 1996

In order to enhance the system of potato transformation and further regeneration, potato was transformed using the Agrobacterium tumefaciens harboring $\beta$-glucuronidase (GUS) gene. We found that a series fo modified medium ttained 100% shoot regeneration within 5 weeks after the preincubated explants on stage I medium were infected with Agrobacterium. Callus appeared at the cut edges of stem segments on stage II medium, mainly at the basal parts. Some explants started to form shoots after two to three weeks on stage III medium containing kanamycin (50 mg/L). When transferred to MS medium containing 200 mg/L kanamycin, 81% of the transformed shoots formed roots at the cut edge of the plantlets. In contrast, untrasformed shoots never rooted and became yellowish after few weeks under the same conditions. Southern and northern analysis indicated in vitro shoot regeneration on the callus derived from the potato explants, which were incubated with Agrobacteria. The regeneration cycle was shortened after the transformatin and finally the transformation efficiency was highly enhanced.

• Journal of Ecology and Environment
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• 제29권1호
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• pp.17-22
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• 2006

Since the demands not only for value-added timber but the environmental functions of forests had been increased, native tree species has been, and is rapidly being replaced by foreign tree species in many parts of the world. However, the studies on population structure and regeneration characteristics of native tree species were not conducted enough. Regeneration of Kalopanax septemlobus growing among other hardwoods in natural forests is very difficult because of its low seed viability and germination rate. The study examined the distribution of mature trees of K. septemlobus and their regeneration pattern at the 1.12 ha study plot in natural deciduous broad-leaved forest of Mt. Jeombong. The density and mean DBH of K. septemlobus was 97 trees per ha and 32 cm, respectively. The spatial distribution of K. septemlobus showed a random pattern (aggregation index is 0.935) in the 1.12 ha study plot. The age of 90 trees among 99 sample trees of K. septemlobus ranged from 90 to 110 years and represented a single cohort, thus suggesting that K. septemlobus in advance regeneration has regenerated as a result of disturbances such as canopy opening.

• Plant Resources
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• 제8권3호
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• pp.275-280
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• 2005

Tissue culture systems to optimize regeneration plant species of Ocimum spp were evaluated as a method to micropropagate individual plants and to better study their biology in vitro. Ocimum species were also evaluated for the production of natural plant products during and following the regeneration process. The primary goal of this project was to enhance the regeneration efficiency of basil. Several factors were examined using different Ocimum species and commercial varieties. The effect of cytokinin combination, activated charcoal, gelling agents, and different carbon sources were investigated. Anthocyanin callus spots were produced only in four varieties among six tested. 'Sweet Dani' showed the best results on anthocyanin accumulation, while 'African beauty', 'Tree basil' and 'Methylcinnamate' produced only a few spots. Shoot regeneration was only achieved from 'Sweet Dani' explants. As the activated charcoal concentration increased, callus formation rate decreased respectively compare to the controls for all varieties. There was a decrease in callus growth with increasing concentration of agar and phytagel.

• 미생물학회지
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• 제30권6호
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• pp.514-518
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• 1992

The present study has been perromed to investigate the optimal conditions for protoplast formation and regeneration of oleandomycin-producing Streptomyces antibioticus (S. antibioticus) KCTC 1081. Mycelia were grown in YME medium containing 0.2% (w/v) glycine and converted into the protoplast by incubating at 35.deg.C for 60 minutes in protoplast buffer (P buffer) containing 4 mg/ml lysozyme. The reversion of protoplasts to the normal filamentous state was examined by the growth on various synthetic agar media. A high reversion rate was obtained by incubating the protoplasts on a hypertonic agar medium containing 20 mM $Mg^{++}$, 5 mM $Ca^{++}$ and 0.3 M sucrose at 28.deg.C for 5 days. From these experiments, we established the improved regeneration medium and a protocol which supports higher and more consistent levels of regeneration of S. antibioticus protoplasts. The regenerant showed an increased antimicrobial activity compared with that of the initial strain.n.n.

• 한국미생물·생명공학회지
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• 제22권2호
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• pp.143-151
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• 1994

In the course of the study on strain inprovement by protoplast fusion, Lactobacillus acidophilus 88 protoplasts production and regeneration conditions were investigated. This strain produced a bacteriocin that revealed strong inhibitory activity against various indicator strains, especially L. helveticus CNRZ 1096. Protoplasts of L. acidophilus 88 strains were very efficiently obtained by treatment with 125 $\mu $g/ml lysozyme in a protoplast forming buffer containing 20 mM N-2 hydroxy-ethtl-piperazine-N'-2-ethane-sulfonic acid(HEPES, pH 7.0) and 1M sucrose at 37$\circ $C for 30 min. Hovever, treatment with mutanolysin was not effective for the production of L. acidophilus 88 protoplasts under the same conditions. High protoplast yield was obtained form the cells at the middle to late logarithmic growth phase in the de Man, Rogosa and Sharpe(MRS) medium. Regeneration was efficiently accomplished with the MRS medium containing 10% sucrose.

• 한국농공학회지
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• 제44권2호
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• pp.161-173
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• 2002

Recently, absorbent biofilters, which are inexpensive and easy to manacle, have been supplied to the rural areas, but have limitations in removing the nutrients effectively. Accordingly, as an alternative plan. natural zeolites were arranged in front or at the rear of the absorbent biofilters, and their removal efficiency for nitrogen and, ultimately, their applicability to the on-site wastewater treatment system were studied. Furthermore, the same experiments were carried out on artificial zeolites, made from coal ashes at National Honam Agricultural Experiment Station, to compare natural zeolites with artificial ones. Treated wastewater through the Absorbent Biofilter showed 22.6% nitrogen removal efficiency, while 64.6% was attained when natural Zeolites were placed in front of the absorbent biofilters (Zeolite-Aerobic process). As an addition, phosphorus was also efficiently removed. On the other hand, Aerobic-Zeolite process, which arranged natural zeolites at the rear of the biofilters, did not have significantly higher nitrogen removal as compared to the treatment using only the absorbent biofilters. Furthermore, upon regeneration of the natural zeolite, the ion exchange rate was fecund to increase over 10% as compared to before regeneration. Our results show that natural zeolites, applied to the on-site wastewater treatment system through the Zeolite-Aerobic process, not only increase the removal efficiency of nutrients, but, by choosing the appropriate regeneration time, can also be cast-effective. Artificial zeolites, on the other hand, though more efficient in removing nutrients, cannot be regenerated and, therefore, are not cost-effective.

• 한국재난관리표준학회지
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• 제1권1호
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• pp.45-51
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• 2008

본 연구에서는 예산지원이 원활치 못한 자연재해위험지구에 대한 정비사업을 효율적으로 추진하고, 재해예방사업을 조속히 이행하며 재정지원을 안정적으로 확보할 수 있는 몇 가지 방안을 제안하고자 한다. 이를 위해서 자연재해위험지구 지정절차 및 법적등 제도적 장치 에 대한 분석을 수행하고, 경기도에서 수행된 정비사업을 지역, 피해이력, 연간투자계획, 재정기금 등의 측면에서 조사 분석 하였다. 추가적으로 재난관리기금을 보존하거나 사용하는 여부를 결정하는 기준을 조사하였으며, 기금출처 및 지출, 기금사용의 법적 문제점을 분석하고 그 해결책을 제시하였다. 결과적으로 본 연구에서는 재난관리기금이 재난위험을 초기에 감소시키기 위해서 자연재해위험지구 정비사업에 투자될 수 있도록 법적제도를 완화하여야 하며, 적립금 상한제를 두어 초과분은 재해예방사업에 안정적으로 투자 할 수 있는 재원으로 활용해야함을 제안하고자 한다.