• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.105.1-105
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• 2003

The Plant growth Promoting rhizobacteria (PGPR), Pseudomonas sp. (A3) and Bacillus sp. (AT33) were isolated from the rhizosphere of Amaranthus blitum collected from soil contaminated with chromium. Both bacterial strains quantitatively reduced hexavalent chromium to trivalent chromium. Pseudomonas sp. broughter greater conversion of Cr6+ in the medium (100％) as compared to Bacillus sp.(62％). Phaseolus mungo seeds inoculated with Pseudomonas sp. or Bacillus sp. were grown under different concentration of chromium. The monitored parameters included elongation of shoot and root, fresh weight, dry weight and concentration of chromium in the shoot and root systems. As compared to non inoculated seedlings those inoculated with A3 and AT33 exhibited better growth.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 제10차 국제학술회의 및 추계정기 학술발표회
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• pp.57-57
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• 2003

The plant growth promoting rhizobacteria (PGPR), Pseudomonas sp. (A3) and Bacillus sp. (AT33) were isolated from the rhizosphere of Amaranthus blitum collected from soil contaminated with chromium. Bothbacterial strains quantitatively reduced hexavalent chromium to trivalent chromium. Pseudomonas sp. broughter greater conversion of Cr6+ in the medium (100%) as compared to Bacillus sp.(62%). Phaseolus mungo seeds inoculated with Pseudomonas sp. or Bacillus sp. were grown under different concentration of chromium. The monitoredparameters included elongation of shoot and root, fresh weight, dry weight and concentration of chromium in the shoot and root systems. As compared to non inoculated seedlings those inoculated with A3 and AT33 exhibited better growth.

• Journal of Ginseng Research
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• 제44권3호
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• pp.506-518
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• 2020

Background: Red-skin root of Asian ginseng (Panax ginseng) significantly reduces the quality and limits the production of ginseng in China. The disease has long been thought to be a noninfectious physiological disease, except one report that proved it was an infectious disease. However, the causal agents have not been successfully determined. In the present study, we were to reveal the pathogens that cause red-skin disease. Methods: Ginseng roots with red-skin root symptoms were collected from commercial fields in Northeast China. Fungi were isolated from the lesion and identified based on morphological characters along with multilocus sequence analyses on internal transcription spacer, β-tubulin (tub2), histone H3 (his3), and translation elongation factor 1α (tef-1α). Pathogens were confirmed by inoculating the isolates in ginseng roots. Results: A total of 230 isolates were obtained from 209 disease samples. These isolates were classified into 12 species, including Dactylonectria sp., D. hordeicola, Fusarium acuminatum, F. avenaceum, F. solani, F. torulosum, Ilyonectria mors-panacis, I. robusta, Rhexocercosporidium panacis, and three novel species I. changbaiensis, I. communis, and I. qitaiheensis. Among them, I. communis, I. robusta, and F. solani had the highest isolation frequencies, being 36.1%, 20.9%, and 23.9%, respectively. All these species isolated were pathogenic to ginseng roots and caused red-skin root disease under appropriate condition. Conclusion: Fungal complex is the causal agent of red-skin root in P. ginseng.

• 한국균학회지
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• 제47권4호
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• pp.407-416
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• 2019

A common post-harvest disease of sweetpotato tuber is root rot caused by Fusarium solani in Korea as well as the other countries. Storage root rot disease was monitored earlier on sweetpotato (Ipomoea batatas) in storehouses of different locations in Korea. In the present study, an isolate SPL16124 was choosen and collected from Sweetpotato Research Lab., Bioenergy Crop Research Institute, NICS, Muan, Korea, and confirmed the identification as Fusarium solani by conidial and molecular phylogenetic analysis (internal transcribed spacer ITS and translation elongation factor EF 1-α gene sequences). The isolate was cultured on potato dextrose agar, and conidiation was induced. The fungus was screened for Fusarium root rot on tuber of 14 different varieties. Among the tested variety, Yenjami, Singeonmi, Daeyumi, and Sinjami showed resistant to root rot disease. Additionally, the pathogen was tested for pathogenicity on stalks of these varieties. No symptom was observed on the stalk, and it was confirmed that the disease is tissue specific.

• 한국작물학회지
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• 제13권
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• pp.77-81
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• 1973

대두의 근계에 관한 연구의 제1보로 3개품종을 상토와 모래의 2개토양에서 각시기별로 재료를 채취하여 몇 개형질에 대한 조사측정을 하고 통계처리를 한 바 그 결과를 요약하면 다음과 같다. 1. 경직경의 비대는 발육초기 1개월까지는 완만하며 8월하순이후부터 급격하여지고 모래보다 상토에서 그 비대정도가 높았다. 2. Top의 길이의 신장도 발육 1개월이후부터 급격하여지고 모래보다 상토에서 더욱 신장이 잘된다. 3. Top길이보다 Root길이가 발육초기 1개월까지는 길고 Root의 길이는 반대로 상토보다 모래에서 신장이 잘된다. 4. Top무게도 발육초기 1개월까지는 완만히 증가하고 모래보다 상토에서 무겁게 나타나나 Top길이보다 Top무게의 경우에 그 증가의 정도가 완만하다. 5. Top무게보다 Root무게는 발육초기 1개월까지는 무거우며 상토에서 모래보다 무겁게 나타난다. 6. 5개형질 상호간에는 모래, 상토, 전체에 있어서 어느것이나 높은 상관관계를 보이고 Root길이와의 관계를 보면 Top무게, Top길이, Root무게, 경직경의 순서로 높은 상관계수를 나타내었다. 7. Root무게와의 관계를 보면 경직경, Top무게, Top길이, Root길이의 순서로 상관계수가 높았다.

• 한국해양공학회지
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• 제12권1호
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• pp.23-31
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• 1998

Kind 1 propeller shaft in ships is the shaft which is provided with effective measures against corrosion by sea water, or the shaft which is made of approved corrosion resistance materials. The propeller shaft other than specified above is Kind 2. Thus, this study is mainly concerned with the resistance to fatigue damage in sea water against stress concentrations due to the notches. The results obtained can be summarized as follows; (1) The stress increases with curing time, however, when the curing time reaches at 96 hours the stress becomes a constant value. The elongation decreases with curing time, however, when the curing time reaches at 48 hours the elongation becomes a constant value. Thus, in case of FRP coating on propeller shaft, it is necessary to cure for 48 hours at least. (2) The relation of $\sigma$$_n$-K$_t$ is to be classified into two parts, which is a part where fracture nominal stress, $\sigma$$_n$, decreases with increasing $K_t$, and a part where $\sigma$$_n$ is nearly constant independent of $K_t$. (3) According to a linear notch mechanics, the measure of severity controlling the fracture in notched FRP body is the notch root radius, $\rho$. The notched static strength of an arbitrary specimen will be estimated from $\sigma$$_{max}$ -1/$\rho$ curve. (4) Through the observation of cross section after fatigue test, the part of interface was kept good condition irrespective of loading conditions.

• Journal of Plant Biotechnology
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• 제46권4호
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• pp.291-296
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• 2019

본 연구는 티크의 기내 생장 및 발근에 미치는 light-emitting diode (LED) 효과를 구명하기 위해 수행되었다. 티크의 정아 절편체의 줄기 신장은 LED 혼합광(BR, 50% 청색광 + 50% 적색광) 하에서 DKW 배지 배양 시 3.2 cm로 가장 좋았고, 줄기유도는 광원 및 배지(MS 및 DKW) 효과가 그리 크지 않은 것으로 나타났다. BA 농도 처리 시 최대 줄기 유도는 BR 광원 및 1.0 mg/L 처리구에서 2.4개, 최대 줄기 신장은 BR 및 0.5 mg/L 처리구에서 4.94 cm로 가장 효과적이었다. 발근에 영향하는 IBA 농도 효과는 정아 절편체를 BR 및 0.5 mg/L 처리구에서 배양 시 최대 발근율(93.8%)과 최대 뿌리 길이 신장(1.3 cm)을 보였고, 뿌리 수는 0.2 mg/L (3.1개/절편) 처리구에서 가장 좋은 것으로 나타났다. 발근 식물체는 상토로 이식 후 순화 과정을 거쳐 정상적은 생장을 보였다.

• 한국잡초학회지
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• 제15권1호
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• pp.19-29
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• 1995

파종심도별(播種深度別) mesocotyl신장(伸長) 차이(差異)에 의한 벼와 피의 생장(生長) 및 제초제(除草劑) 반응차이(反應差異)을 구명(究明)하여 직파재배시(直播栽培時) 잡초방제체계구축(雜草防除體系構築)을 위한 기초자료(基礎資料)를 삼고자 온실내(溫室內) pot 시험(試驗)으로 수행(遂行)되었다. 식물재료(植物材料)로서 자포니카형(型) 품종(品種) 동진벼와 피중강피가 공시(供試)되어 파종심도별(播種深度別), 담수심별(湛水深別) 생장반응(生長反應)이 검토되었다. 또한 건답조건(乾畓條件)에서 파종심도(播種深度) 0cm, 1cm, 2cm 및 3cm 깊이로 파종(播種)하여 파종(播種) 후(後) 5일째 butachlor를 1800g, thiobencarb를 2100g 및 4200g ai/ha로 각각 처리(處理)하여 처리후(處理後) 10일째 벼와 피의 생장(生長) 및 제초제(除草劑) 반응(反應)을 측정(測定)하여 LSD검정(檢定)에 의해 비교(比較) 해석(解析)하였다. 무처리(無處理)된 파종심도별(播種深度別) 벼의 초장(草長)은 파종심도(播種深度)가 깊을수록, 근장(根長)은 1cm 깊이에서, 지상부생체중(地上部生體重)은 3cm 깊이에서 가장 컸으며, mesocotyl신장(伸長)은 거의 이루어지지 않았다. 한편 피의 초장(草長)은 파종심도(播種深度) 및 담수심(湛水深)과 무관한 생장(生長)을 보였고, 근장(根長), 지상부(地上部) 및 지하부생체중(地下部生體重)은 건답조건(乾畓條件)에서 1cm 깊이에서 가장 컸고 근장(根長)은 담수심(湛水深)이 클수록 감소(減少)하였고 mesocotyl신장(伸長)은 건답조건(乾畓條件)에서만 파종심도(播種深度)가 클수록 컸으나 담수심(湛水深)과는 무관하거나 큰 차이(差異)가 없었다. 건답직파재배조건(乾畓直播栽培條件)에서 두 약제(藥劑)에 대한 벼의 지상부(地上部)경우 0cm 파종심도(播種深度)에서 약해발생(藥害發生)이 불가피하나 1cm 이상 파종심도(播種深度)에서와 지하부생장(地下部生長)은 무처리(無處理)보다 큰 생장(生長)을 보였으며 파종심도(播種深度)가 클수록 큰 생장(生長)을 보였고, 배량(倍量)에서도 큰 차이(差異)가 없었다. 한편 피의 mesocotyl 신장(伸長)은 약량(藥量) 및 파종심도(播種深度)가 클수록 감소경향(減少傾向)이 뚜렷하게 인정되었으나 제초제(除草劑)에 대한 지상부(地上部), 지하부생육(地下部生育) 및 엽신장(葉伸長) 반응(反應)은 파종심도(播種深度)와 파종심도(播種深度) 차이(差異)에 다른 mesocotyl 신장(伸長) 차이(差異)와는 무관하게 무처리(無處理)에 비해 급격히 감소(減少)하였으며 지하부(地下部)보다는 지상부생장(地上部生長)의 감소(減少)가 더 크게 나타났다.

• 생물환경조절학회지
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• 제15권3호
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• pp.277-282
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• 2006

천연 살초성분 해발을 위한 기초적 연구로 발아 및 생장억제물질 동정을 위하여 몇 가지 유기용매에 따른 황련의 분획 추출물에 대한 다른 식물의 종자발아 및 유묘생장에 미치는 영향을 조사하였다. 추출물에 대한 검정식물의 발아율은 들깨, 배추, 피, 참깨 순으로 억제되었으며, 2,000ppm ethyl acetate추출물에서 가장 높은 발아억제를 보였다. 초장 및 뿌리생육은 참깨, 들깨, 배추, 피 순으로 억제되었으며, 특히 뿌리신장은 $H_2O$, butyl alcohol, hexane, ethyl acetate 추출물 순으로 억제정도가 심하였다 추출물에 대한 발아 및 유묘생육의 억제정도는 참해 및 배추에서 종특이적으로 작용하였으며, 특히 물 추출물은 종자발아 및 뿌리 신장에 천연살초활성을 보였다. 이러한 결과들은 금후 천연제초제 개발을 위한 기초자료로 이용될 것으로 기대되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.321-321
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• 2017

Water availability in rainfed lowlands (RFL) is strongly affected by climate change. In RFL, rice plants are exposed to soil moisture fluctuations (SMF) but rarely to simple progressive drought as widely believed. Typical RFL field is characterized by a about 5-cm thick high bulk density hardpan layer underneath the cultivated layer at about 20 cm depth that impedes deep root development. Root system has the ability to develop in response to changes in SMF, known as phenotypic plasticity. We hypothesized that genotypes that can adapt to RFL have root plasticity. The roots can sharply respond to re-wetting after drought period and thus penetrate the hardpan layer when the hardpan is wet and so becomes relatively soft, and thus access water under the hardpan. This study aimed to identify CSSLs derived from a cross between Sasanishiki and Habataki which adapted to such RFL conditions. We used 39 CSSLs together with the parent Sasanishiki, which were grown in hydroponics and pot under transient soil moisture stresses (drought and then rewatering), and compared with continuously well-watered (WW) (control) up to 14 days after sowing (DAS), and 20 DAS, respectively. Based on the results of hydroponics and pot experiments, we selected a few lines, which were grown in the soil-filled rootbox with artificial hardpan layer and without artificial hardpan. For the rootbox without artificial hardpan, plants were grown under WW and transient soil moisture stresses for 49 DAS. While the rootbox with artificial hardpan, the plants were grown under WW (control) and SMF (WW up to 21 DAS, 1st drought (22-36 DAS), rewatering (37-44 DAS), and followed by 2nd drought (45-58 DAS)). Among the 39 CSSLs, only CSSL439 (SL39) consistently showed significantly higher shoot dry weight (SDW) than Sasanishiki under transient soil moisture stress conditions as well as SMF conditions in all the experiments. Furthermore, under WW, SL39 consistently showed no significant differences from Sasanishiki in shoot and root growth in most of traits examined. SL39 showed significantly greater total root length (TRL) than Sasanishiki under transient soil moisture stress, which is considered as phenotypic plasticity in response to rewatering after drought period. Such plastic root development was the key trait that effectively contributed to root elongation and branching during the rewatering period and consequently enhanced the root to penetrate hardpan layer when the soil penetration resistance at hardpan layer reduced. In addition, using the rootbox with artificial hardpan layer ($1.7g\;cm^{-3}$, heavily compacted), SL39 showed greater root system development than Sasanishiki under SMF, which was expressed in its significantly higher TRL, total nodal RL, and total lateral RL at hardpan layer as well as at below the hardpan layer. These results prove that SL39 has plasticity that enables its root systems to penetrate hardpan layer in response to rewatering. Under SMF, such root plasticity contributed to its higher gs and Pn.