• The Korean Journal of Ecology
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• 제20권6호
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• pp.413-421
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• 1997

Ecological characteristics of Rumex acetosella have been studied both in the laboratory and in the field. R. acetosella grows well straight up after germination, elongating and thickening their rhizomes with sprouts erupting along their bodies of the rhizome. The number and development of leaves and ramets reach their peak by April. The size of leaves and the cover degree of the plant increase from April to May. R. acetosella is an ephemeral, a short life mode plant, finishing its life cycle in July or August. The germination and seedling growth of selected species exposed to aqueous extracts of R. acetosella were in inverse proportion to concentration. The growth of Rumex japonicus and Digitaria sanguinalis cultivated in soil with R. acetosella was more inhibited than that of the control. Twelve chemical compounds were identified from R. acetosella by GC and HPLC and verified by bioassay with the same chemical reagents. It would be assdumed that these chemical substances are responsible for the allelopathic effect of R. acetosella. In short, R. acetosella plants grow vigorously from April and maintain their superior competitive ability to other plants in forming their communities by emitting chemical substances into their environment.

• 한국패류학회지
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• 제21권1호
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• pp.65-70
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• 2005

The purpose of this study is to determine the appropriate substrate for larval settlement and spat growth in the purple clam, Saxidomus purpuratus in laboratory culture. Larvae were reared with 3 different types of sediments (mud, sand, and mixed) for 46 days in settlement experiment, and settled spats were further grown in 3 types of sediments for 36 weeks in growth experiment. The density of settled spats in muddy sediments was more than 2 times higher than those in mixed or sandy sediments. But, the average size of settled spats in muddy sediments was smaller than those in mixed or sandy sediments. After 36 weeks of growth period, growth rate decreased as shell length increased. When shell length was less than 2 mm, growth rate in mixed sediments was significantly higher than that in sandy sediments. When shell length was more than 2 mm, there was no significant difference in growth rate among different substrates. Sediment type affected growth rate only when the spats were relatively small (less than 2 mm). Muddy sediments seems better for larval settlement, while mixed sediments is best for spat growth. We suggest the laboratory procedure for enhancing seedling production of S. purpuratus.

• Journal of Forest and Environmental Science
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• 제36권1호
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• pp.55-61
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• 2020

In this study, basic data with respect to the introduction of Hipphophae rhamnoides L. and its cultivation in Korea could be obtained. According to the size of the plug cell tray, Chinese origin's rate of seed germination was relatively high in 128 plug cell tray, and growth was vibrant in 50 plug cell tray. The germination and growth of Russian origin seeds showed that they were relatively effective in 50 plug cell tray and with respect to soil environment, TKS-2 soil with untreated shading relatively promoted both germination and growth for Chinese origin, the rate of germination was high in bed soil for horticulture and growth result was good in TKS-2 in the case of Russian origin. It was confirmed that the germination rate of Chinese origin H. rahmnoides L. was highest in untreated shading and the shoot growth was vibrant in 70% shading while the growth in roots was vibrant in the untreated shading. In the Russian origin, H. rhamnoides L. the germination rate in 30% and 70% shading was about 50% which was higher than that in the untreated shading and general growth was vibrant in 30% shading.

• 한국패류학회지
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• 제15권2호
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• pp.115-119
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• 1999

We investigated the processes of egg and larval developments for aquaculture technique development of seedling production fo the flat oyster, Ostrea denselamellosa. Teo flat oyster of larviparous type was different from the pacific oyser (ovivarous type) because their larvae (trochophore and prodissoconch larvae) in the gill released into the seawater. The process of egg development was observed by artificial fertilization at $25^{\circ}C$, using a dissecting method. The sizes of Unfertilized eggs ranged from 80 to 90 $\mu\textrm{m}$ and fertilized eggs with globule-shape was 90-100 $\mu\textrm{m}$. The Polar body appeared after fertilization and egg cleavage began within 1 hour, reaching the blastula stage after 10 hours. The trochophore in the gill appeared 2-3 days after fertilization and grew to the prodissoconch larvae (130 140 $\mu\textrm{m}$) having a complete shell after 1-2 days. The shell of prodissoconch larvae grew to 205 220 $\mu\textrm{m}$ after 10 hours, and then they became umbo stage larvae showing oval in shape. The velum of umbo stage larvae was degenerated about 17-20 days after fertilization and grew into a pediveliger with a developed foot, at this time, the shell length size was 320 360 $\mu\textrm{m}$.

• Journal of Ginseng Research
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• 제16권1호
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• pp.37-43
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• 1992

Structural changes of the endosperm of Panax ginseng C.A. Meyer from fertilization to germination were investigated by light microscope. The endosperm of the ginseng seed is cellular type. Since endosperm cells adjacent embryo continuously breakdown and disappear with the elongation of embryo, the real of endosperm is gradually decreased. As the anatropous ovules of immature seed with green seed coat developes more and more, ovary cells adjacent ovary cavity become abundant by the periclinal division, their size is decreased, hypotrophy of cell wall discern, and they are gradually differentiated in seed coat. Though embryo responds strongly to basic dye at the stage of completion of endosperm formation, tissue of endosperm responds to acidic dye positively Cell wall of embryo and endosperm are composed of primary cell wall not lignified. Endosperm cells adjacent embryo begin to breakdown in the endosperm tissue of indehiscent seed before the beginning of the after-ripening. Dehiscent seed of which seed coat is opened through after-ripening represent the form as a seedling in the result of embryo developments with the formation of organs; radicle, cotyledon, plumule. Umbilifom layer represents strong positive response to the toluidine blue and the basic function. Umbiliform layer that endosperm cells breakdown and disappear is observed clearly at the periphery of the embryo cotylemon, while slightly at the periphery of the radicle.

• 한국작물학회지
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• 제27권2호
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• pp.163-168
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• 1982

향끽미종 연초는 4월 상순에 개량멀칭으로 이식했을 때를 정점으로 하여 이식 시기가 늦어질수록 수량과 품질의 저하가 심한 경향이나, 이식작업의 성력화와 자재비의 절감을 위해서는 5월 상순경의 나지작 이식이 바람직하다. 나지작 이식을 위한 관행 묘와 관행묘보다 20일 조기 파종한 묘에 농도(0, 500, 1,000ppm)와 시기(4-5, 7-8매기)를 달리하여 ethrel을 처리한 후 동일시기에 이식하여 나지작 재배의 실용성을 검토한 결과, 1. 500ppm의 에스렐 1회 처리로 묘상에서의 생장이 10일 이상 정지되었으며, 처리 농도가 증가할수록 초장, 엽의 장, 폭 및 뿌리의 생장이 억제되었다. 2. 에스렐 처리묘에서 엽수는 같거나 약간 증가하였으며, 개화일수는 무처리구와 같거나 다소 지연되는 경향이었다. 3. 나지작 관행묘에 비해 4-5매기에 500ppm으로 처리하여 이식한 묘는 엽수가 1-2매 증가하고 엽면적이 크게 증대되어 40%의 증수를 가져왔으며, 4. 개화일수에서 4-5매기 에스렐 처리구는 무처리구와 같았으나 관행 나지작 묘보다는 3일 빨랐으며, 품질은 대등했다.

• 한국작물학회지
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• 제44권1호
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• pp.74-77
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• 1999

The object of this study is to determine the effect of priming on the germination ability and seedling emergence of aged soybean seeds in lab and field conditions. Artificial or natural procedure for seed aging was applied in this study. One seed lot was artificially aged for 3 to 5 days at 42$^{\circ}C$ with high relative humidity (nearly RH 100%), and the other one was stored at room temperature for 17 months. Aged seeds were osmoconditioned in -1.1 MPa polyethylene glycol 8000 (PEG) solution for 3 days at $25^{\circ}C$ and air-dried. When Danyeobkong was aged for 4 days average germination was 61.5%, however, this improved to 98.5% after the priming treatment. Improvement of seed germination by priming the aged seed was consistent with large seed sized Jangyeobkong cultivar, indicating that the priming was effective in enhancing seed germinability regardless of seed size. Priming aged seeds also resulted in good stand establishment in the field trials. Germination of aged seeds of Danyeobkong without priming was 17.0%, whereas that of primed ones was 66.4%.

• 미생물학회지
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• 제54권2호
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• pp.158-160
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• 2018

Streptomyces sp. P3 균주는 대한민국 강원도 평창의 더뎅이병 이병괴경으로부터 2017년 분리되었다. 이 논문에서는 9,851,971 bp (71.2% G + C 함량)로 구성된 P3 균주의 전체염기서열을 보고한다. 지놈은 8,548개의 코딩서열, 18개의 rRNA 그리고 66개의 tRNA 유전자를 포함하고 있다. 특히 P3 균주는 감자표면과 무종자를 이용한 병원성 검정에서 병원성을 나타내지는 않았지만, 감자 더뎅이병 유발 Streptomyces들이 보유한 병원성 유전자 중 tomA 유전자만이 존재하였다. 따라서 본 논문에 제공되는 전체염기서열은 감자 더뎅이병원세균들의 병원성 획득을 위한 진화단계에서의 이해를 높이기 위한 중요한 단서가 될 것이다.

• 현장농수산연구지
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• 제5권1호
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• pp.20-27
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• 2003

유색칼라 조직배양묘의 순화재배 용토선발실험에서 초기생육 출엽율은 큰 차이가 없었으나 생육 6개월 후의 괴경비대는 모래(50%)+Peatmoss(50%) 처리에서 가장 좋았다. 순화재배 시기별 순화율은 8월 20일 정식에서 64%~70.4%로 가장 저조하였고, 3월 20과 4월 20일은 90%이상의 순화율을 나타냈다. 괴경비대은 3월 20일 정식에서 구중이 가장 무거웠다. 순화 재배시 배양묘의 재식거리 10×10cm에서 괴경중이 가장 양호했다.

• 한국수산과학회지
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• 제30권1호
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• pp.132-138
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• 1997

동해안 한해성 조개인 북방대합의 자원 증대를 위한 기초 자료를 얻기 위하여 1994년 3월부터 1995년 5월까지 주로 조직학적 방법에 의해 생식소의 발달과정과 생식주기를 조사하였다. 북방대합은 자웅이체로서, 생식소는 해부학적으로 소화맹낭과 족부 근육 사이에 위치하였다. 비만도는 1994년 6월에 0.19로 가장 높았으며 11월에 최소값을 보였다. 생물학적 최소형은 각장 50.0mm였으며, 80.0mm 이상의 대형개체에서도 $10\%$ 미만의 성적으로 미분화한 개체가 관찰되었다. 성숙한 난모세포의 크기는 $50\~60{\mu}m$였으며, 성숙기의 정소에서 정소란이 관찰되었다. 북방대합의 생식주기는 분열증식기 ($10\~1$월), 성장기 ($2\~4$월), 성숙기 ($4\~6$월), 산란기 ($6\~7$월) 및 휴지기 ($8\~9$월)의 연속적인 5단계로 구분되었다.