• Journal of Ecology and Environment
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• 제42권4호
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• pp.308-316
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• 2018

Background: Genus Sasa, dwarf bamboos, are considered to be species that lower biodiversity in the temperate forests of East Asia. Although they have a long interval, they, the monocarpic species, have a unique characteristic of large-scale synchronized flowering. Therefore, once they have flowered and then declined, it may be an opportunity for suppressed surrounding species. A previous study reported that Sasa borealis showed specialized flowering nationwide with a peak in 2015. However, this was based on data from a social network service and field survey at Mt. Jeombong. Therefore, we investigated S. borealis in the forests of five national parks in order to determine whether this rare synchronized flowering occurred nationwide, as well as its spatial distribution. Results: We found a total of 436 patches under the closed canopy of Quercus mongolica-dominated deciduous forests in the surveyed transects from the five national parks. Of these patches, 75% occupied a whole slope area, resulting in an enormous area. The patch area tended to be larger in the southern parks. Half (219 patches) of the patches flowered massively. Among them, 76% bloomed in 2015, which was consistent with the results of the previous report. The flowering rate varied from park to park with that of Mt. Seorak being the highest. The culms of the flowering patches were significantly taller (F = 93.640, p < 0.000) and thicker (F = 61.172, p < 0.000). Following the event, the culms of the flowering patches declined, providing a good opportunity for the suppressed plant species. The concurrent massive flowering of the mature patches was believed to be triggered by some stress such as a spring drought. Conclusion: We confirmed that the rare synchronized flowering of S. borealis occurred with a peak in 2015 nationwide. In addition, we explored that S. borealis not only monopolized an enormous area, but also dominated the floors of the late-successional Q. mongolica-dominated deciduous forests. This presents a major problem for Korean forests. As it declined simultaneously after flowering, there are both possibilities of forest regeneration or resettlement of S. borealis by massively produced seeds.

• 한국환경생태학회지
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• 제31권6호
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• pp.564-577
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• 2017

본 연구는 전남 광양시 백운산의 조릿대 개화지에서 외적 환경인자가 개화원인으로 작용하는가를 조사했다. 이를 토대로 조릿대의 개화원인, 개화양식 및 생활사 전략을 고찰했다. 조릿대 개화지와 비개화지 사이의 토양 물리적 조건 광량 차이는 없었다. 2014~17년 사이에 조릿대가 개화했던 한국과 일본 개화지의 강수량 기온은 평년치(과거 30년)와 다른 특이점을 찾을 수 없었다. 또한 대면적으로 조릿대가 꽃을 피운 후에 대부분 죽었으나 일부 조릿대 간이 다시 발생하기도 하고 일부는 죽지 않았다. 즉, 조릿대는 외적 환경인자와 상관없이 일제히 개화했으며, 대부분의 조릿대 간은 죽지만 일부는 살아남았다. 이는 조릿대 개화원인은 외적 환경인자 영향보다 생물시계에 따라 주기적으로 발현하는 특정 유전자(일명, 유전자 시계)로 촉발된다고 본다. 한편, 멀리 떨어져 있는 조릿대 개체와 동조해 꽃을 대규모로 피우며, 소규모 단독으로 여러 번 개화하기도 한다. 이것은 평생 한 번 개화하는 조릿대의 유성번식 실패 리스크를 분산하기 위한 일종의 보험시스템이라고 판단된다. 열대성 대나무 조릿대류가 온대로 분포를 넓히면서 환경의 불확실성 증가에 따른 유성번식의 최적화를 위해 장주기 단개화성이 강화된 것으로 추정된다.

• 한국작물학회지
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• 제25권3호
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• pp.31-34
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• 1980

대두 일장반응둔감 계통의 mass screening 방법을 확립하기 위하여 국내수집재래종 278계통과 그외 6계통을 재료로 5월 4일부터 7월 13일까지 7일 간격으로 파종기를 달리하여 재배하여 얻어진 결과를 다음에 요약한다. 1. 5월 4일부터 7월 13일까지 파종했을 때 파종기가 늦을수록 개화에 이르는 소요 기간이 짧아졌다. 2. 파종기를 달리했을 때 개화기(파종후 개화까지의 소요기간)의 계통간 차이는 만기파종보다 초기파종에서 그 차이가 컸다. 3. 5월 4 일 파종과 7월 13일 파종에서 두 파종의 개화기간의 관계를 조사한 결과 높은 정의 상관이 있었다. 4. 일장반응둔감 계통의 screening 방법으로서는 극조기파종과 극만기파종을 통해 개화일을 조사하는것이 효율적이었다. 5. 공시계통중에서 일장에 민감한 계통과 둔감한 계통을 구분할 수가 있었으며 그중 둔감하다고 생각되는 몇 계통을 선발하였다.

• 한국환경복원기술학회지
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• 제26권6호
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• pp.155-164
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• 2023

Sedirea japonica is one of the critically endangered species in South Korea mostly due to artificial harms such as illegal collection and habitat destruction. Therefore, artificial propagation through improving germination rate, increasing growth, and controlling flowering is meaningful for the conservation and reintroduction of S. japonica. It is suggested that cytokinins are one of the multi-factors that contribute to plant growth and floral responses. Especially, exogenous cytokinins have been known to induce or promote shoot growth or earlier flowering in orchids. Therefore, it was investigated how the application of 6-benzylaminopurine (BA) influenced the growth and inflorescence of S. japonica. A foliar spray containing BA at 100, 200, 300, and 400 ppm was applied from 1st July to 30th December 2021. Leaf length, leaf length growth rate, leaf width, and width and length ratio were measured as growth-related factors. Visible inflorescence rate, inflorescence length, the number of flowers per inflorescence, and the distance between the stalks were measured as flowering-related factors. Growth-related factors except for leaf growth rate were not affected by BA treatments, while leaf growth rate was significantly increased by 200 ppm of BA treatment. The visible inflorescence rate increased by 200 ppm of BA treatment, and there seems an optimal concentration and threshold of BA treatment. An iterative experiment with more seedlings and measurement factors would be helpful to figure out the effects of exogenous BA treatment on S. japonica, and it can be applied for mass propagation.

• Journal of Plant Biology
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• 제39권4호
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• pp.257-263
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• 1996

Flower-inducing activity in the phloem exudata of Pharbitis cotyledons was investigated using the bioassay of Pharbitis and Lemna. By SDS-PAGE and 2-D gel electrophoresis of the phloem exudate, two polypeptides of 11 kDa and of approximately 32 kDa (pI 6.9) showing qualitative changes during the flower induction were detected. A polypeptide of approximately 20 kDa (pI 4.8) specifically labeled in vivo with [35S]methionine was found during the inductive dark period in Pharbitis cotyledon tissues. The polypeptide of the equivalent molecular mass and with the identicl pI value was also detected by in vitro translation assay. Thus, it is assumed that the 20 kDa polypeptide plays a role in the process of flower induction in Pharbitis cotyledons.

• The Plant Pathology Journal
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• 제38권2호
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• pp.115-130
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• 2022

Though information exists regarding the pathogenesis of the shot-hole disease (SH) in flowering cherry (FC), there has been a lack of research focusing on SH management. Therefore, here, we investigated the inhibitory activities of antagonistic bacteria against SH pathogens both in vitro and in vivo as well as their biochemical characteristics and bioactive compounds. Two biosurfactant-producing bacterial antagonists, identified as Bacillus velezensis strains JCK-1618 and JCK-1696, exhibited the best effects against the growth of both bacterial and fungal SH pathogens in vitro through their cell-free culture filtrates (CFCFs). These two strains also strongly inhibited the growth of the pathogens via the action of their antimicrobial diffusible compounds and antimicrobial volatile organic compounds (VOCs). Crude enzymes, solvent extracts, and biosurfactants of the two strains exhibited antimicrobial activities. Liquid chromatography/electrospray ionization time-of-flight mass spectrometric analysis of the partially purified active fractions revealed that the two antagonists produced three cyclic lipopeptides, including iturin A, fengycin A, and surfactin, and a polyketide, oxydifficidin. In a detached leaf assay, pre-treatment and co-treatment of FC leaves with the CFCFs led to a large reduction in the severity of the leaf spots caused by Epicoccum tobaicum and Bukholderia contaminans, respectively. In addition, the two antagonists produced indole-3-acetic acid, siderophore, and a series of hydrolytic enzymes, along with the formation of a substantial biofilm. To our knowledge, this is the first report of the antimicrobial activities of the diffusible compounds and VOCs of B. velezensis against the SH pathogens and their efficiency in the biocontrol of SH.

• 한국산림과학회지
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• 제102권1호
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• pp.129-135
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• 2013

낙엽송(Larix kaempferi) 채종원의 종자생산을 증진하기 위하여 접목 32년생의 채종목에 환상박피 처리를 하였다. 환상박피처리에 의하여 무처리보다 4배에 이르는 착과량 증가 효과가 있어 환상박피 처리의 효과가 뚜렷하게 나타났다. 환상박피 처리에 의한 낙엽송 주간 수피조직내의 대사물질의 변화를 IR-MS, GC-MS 및 HPLC로 분석하여 무처리와 비교한 결과 전질소 함량, sucrose 함량 및 전체 유리 아미노산의 함량이 무처리에 비해 유의적(p<0.05)으로 증가되었다. 또한 유리아미노산의 경우 화아원기가 형성되는 8월의 aspartic acid, glutamic acd, glycine, serine, cysteine, threonine 및 alanine이 환상박피 처리에서 무처리에 비해 유의적으로 높게 함유된 것으로 나타났다. 대사물질과 착과량간에 상관관계를 분석한 결과 착과량과 수피조직내의 전질소 함량(r=0.765, p<0.01)과 전체 유리 아미노산 함량(r=0.802, p<0.01)간에 고도의 정의 상관관계가 있었다. 특히, 화아원기 형성기인 7월 및 8월의 수피조직내의 aspartic acid, glutamic acd, glycine, serine 및 cysteine이 착과량과 정의 상관관계(p<0.05)가 있어, 아미노산의 질소화합물 인자가 낙엽송 화아원기 유도에 직, 간접적으로 관련이 있을 것으로 추정되었다.

• 한국유기농업학회지
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• 제11권4호
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• pp.103-115
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• 2003

In order to investigate the possibility for use to control environmental pollution, Kenaf(Hibiscus cannabinus L.) was used to obtain information of their growth and $CO_2$ response under different temperatures and $CO_2$ concentration. The highest percentage of germination and aboveground dry mass of Kenaf were found at 30$^{\circ}C$ and 35$^{\circ}C$ by 89.0% and 3.2g, respectively under different temperatures. The amount of $CO_2$ absorption and aboveground dry mass production of Kenaf were higher than those of maize during the whole growing period and the last sampling of aboveground dry mass of Kenaf and maize were 252.9g and 200.8g, respectively. The highest plant height was found at 400ppm by 131.0cm and the next was in the order of 600ppm by 1293cm, and 800ppm by 108.8cm. Leaf area was higher in the order of 400ppm > 600ppm > 800ppm, whereas leaf dry mass was in the order of 800ppm > 600ppm > 400ppm under different $CO_2$ concentration, showing that leaf became thicker as $CO_2$ concentration was increased. Days from seeding to flowering became shorter by 13 days in 35/25$^{\circ}C$ compared with 25/15$^{\circ}C$ between two temperature regimes and they also became shorter as $CO_2$ concentration was increased. Aboveground dry mass was higher in 35/25$^{\circ}C$ than that of 25/15$^{\circ}C$ between two temperature regimes. while it was increased in the order of 800ppm > 600ppm > 400ppm as CO2 concentration was increased. Temporal changes of leaf dry mass during growth period showed no difference between $CO_2$ concentration in 25/15$^{\circ}C$ , but the highest of it was found at 800ppm in 35/25$^{\circ}C$. The highest temporaI increase of root dry mass was found at 800ppm in 25/15$^{\circ}C$, but 35/25$^{\circ}C$ showed no difference between different $CO_2$ concentration.

• Applied Biological Chemistry
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• 제41권3호
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• pp.247-252
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• 1998

콩 재배시 근류균의 합리적 이용을 위한 기초자료를 얻고자 남부지방의 평야지 밭토양과 논토양, 산간지 밭토양에 분포한 토착 Bradyrhizobium japonicum의 질소고정 잠재능을 상호 비교, 분석하였다. 토착 B. japonicum의 밀도는 산간 밭토양에서 $5.7{\times}10^4\;cells/g.soil$ 로 가장 높았고, 다음으로는 평야지 밭$(5.0{\times}10^4\;cells/g.soil)$, 평야지 논토양$(4.0{\times}10^3\;cells/g.soil)$ 순이었다. 콩 개화기의 지상부 건물생산력과 수확기의 종실수량은 서로간에 고도의 상관관계$(P{\leqq}0.001)$를 보이면서 두 성분 모두 평야지 밭 >산간지 밭 > 평야지 논토양 순으로 높았는데, 평야지 밭토양 중에서는 남해토양과 선산토양이 건물생산면에서, 김해토양은 종실수량면에서 각각 우수하였다. 콩 개화기에 조사된 근류수와 근류무게의 물질생산 기여도는 지상부 건물중의 경우 근류수$(r=0.383^*)$ 보다 근류무게가$(r=0.439^*)$ 더 높은 값을 보였으나 종실수량에서는 근류무게$(r=0.449^{**})$ 보다 근류수가$(r=0.505^{**})$ 더 높은 값을 나타내었다. 근류무게당 지상부 건물중과 종실수량 성적은 평균적으로 단원콩에서 보다 남해콩에서 각각 1.7배와 1.4배 높은 변이계수를 보였다.

• Current Research on Agriculture and Life Sciences
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• 제1권
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• pp.113-140
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• 1983

This is a study on a landscape planning along the street 1~4, which are gateways to Taegu city and an important scenery. Therefore, emphasis was given to provide a bright, clean and beautiful first impression to visitors and citizens. The area is being developed for education and athletic park. Plans to construct a fountain, pergolas and a pond were set up to complement the active and passive facilities to the existing a athletic facilities in the area. Since D part in the area have alkali soil (pH 8.1), soil amendment is necessary for successful growth of trees and ground covers. When the area is filled or added with new soil for soil amendment, it will be important to use fresh soil which can support plant growth. It will be ideal to use ground covers and shrubs on the existing retaining walls along the street for keeping natural vegetation and slope stability instead of further cutting and reconstruction. It is not reasonable in technical and economic sense to remove rocks of the slope for planting trees. In order to harmonize plant color distribute, tall needle and broad leaf trees in the background as a screen, flowering trees were arranged in groups at front, and annuals were mass-planted along the footway. Natural-form-trees will be planted because they not only serve as a greenbelt but also are more economics in maintenance than formative trees.