장기 저장과 저장 온도에 따른 소나무 종자 품질과 생리적 특성

구다은,구자정,한심희 한국산림과학회 2022 한국산림과학회지 Vol.111 No.3

Our aim was to evaluate the quality of pine seeds after long-term storage and to analyze the correlation between germination and physiological characteristics. Therefore, we investigated the germination and physiological characteristics of seeds stored for different periods and storage temperatures. Pine seeds lost little viability and vigor after 12 years of storage at 4°C; it is even possible to prolong the storage period at -18℃. The deterioration process operating through long-term storage was characterized by a loss of seed vigor before a loss in seed viability. Electrical conductivity of the seed leachate was significantly higher in seeds that completely lost their viability, and was also found to be significantly correlated with the germination percentage, T50, mean germination time, and germination speed. Among the minerals leaked to the leachate, K had the highest concentration, followed by Na, Ca, Cu, Mg, and Fe, while Mn and Zn were not detected. Concentrations of K, Ca, Cu, Mg, and Fe in the leachate differed significantly by treatment, and in the cases of K, Ca, Cu, Na, and Mg, we observed large differences in the leachate between the seeds that were collected in 2003 and those collected in other years.. Germination percentage was significantly negatively correlated to the concentrations of Ca, Cu, K, Mg, and Na. The coefficient of uniformity of germination was significantly negatively correlated to Cu concentration. The other germination characteristics were not significantly correlated with the mineral concentration. Therefore, the mineral concentrations of pine seed leachate were not reliable indicators of seed deterioration when the differences in quality between seed lots were small. However, electrical conductivity could be an indicator of seed viability and vigor of pine seeds under long-term storage. 연구는 장기 저장된 소나무 종자의 품질을 평가하고 발아 특성과 생리적 특성 간의 상관 관계를 검증하였으며, 이 를 위해 저장 기간과 온도에 따른 종자 발아와 생리적 특성을 조사하였다. 그 결과, 소나무 종자는 4°C에 12년 간 저장되 었을 때, 발아율 99%, T50 6.5일로 종자 활력 및 종자세 저하가 거의 일어나지 않았으며, -18℃에 저장할 경우, 저장기간 이 더 길어졌다. 또한, 장기 저장에 따른 퇴화 과정 중 활력보다 종자세의 감소가 먼저 일어나는 것으로 나타났다. 종자 침 출수의 전기전도도는 4°C에 19년 간 저장되어 활력을 완전히 소실한 종자에서 유의하게 높았으며, 발아율, T50, 평균발아 일수, 발아속도와의 상관관계가 있었다. 침출수에 누출된 무기질 중에서는 K의 농도가 가장 높았으며, 그 다음으로는 Na, Ca, Cu, Mg, Fe 순으로 평균 농도가 높았고, Mn과 Zn은 검출되지 않았다. K, Ca, Cu, Mg, Fe 농도는 처리별로 통계적인 차이가 있었으며, K, Ca, Cu, Na, Mg의 경우, 활력을 완전히 소실한 종자와 그렇지 않은 종자에서 차이를 보였고, Cu의 경우, 2003년에 채집한 종자와 나머지 종자와의 차이가 컸다. 발아율은 Ca, Cu, K, Mg, Na 농도와 부의 상관을 보였으며, 발아균일도는 Cu 농도와 부의 상관을 보였고, 다른 발아 특성은 무기질 농도와 상관이 없었다. 따라서 종자 침출수의 무기 질 농도는 개체간의 품질 차이가 적은 경우, 경향이 뚜렷하지 않았으나, 전기전도도는 장기 저장 종자의 활력 뿐 아니라 종자세의 차이를 나타내는 지표가 될 수 있을 것으로 보인다.

프로티언 커리어 관점으로 본 현직 비서의 이직 경험

구다은,이지연,백지연 한국비서학회 2023 비서·사무경영연구 Vol.32 No.3

This study examines the changes and administrative assistants' experiences of job transitions from a protean career perspective. The aim is to improve the understanding of factors influencing career development and how they align with personal values and goals. The data collected were qualitative to gain insights into the importance of the protean career development process. A total of eight interviews were gathered as a sample of current administrative assistants who have experienced job transitions. The results indicate that interviewees take pride in their current profession as administrative assistants and consider salary and advancement opportunities as the most crucial factors when choosing a career. This confirms a strong association between psychological success and personal growth in a protean career path. Further, the findings provide evidence that self-confidence at work was the primary motivation for transitioning into administrative assistant roles. This emphasizes the importance of personal suitability in a protean career development. Lastly, the data suggest that all participants expressed high satisfaction with their job transitions. It has practical implication in career development of executive assistants such as training in redefining work, professional networking, and other areas of professional development.

Novel Ionic Additives and Their Impact on Lithium Battery Characteristics

구다은,문홍철 한국고분자학회 2023 한국고분자학회 학술대회 연구논문 초록집 Vol.48 No.2

현지외 보존을 위한 죽절초 종자의 건조 내성과 저장성 평가

구다은,한심희,임은영,김진,구자정 한국산림과학회 2023 한국산림과학회지 Vol.112 No.4

This study sought to determine the desiccation tolerance and storage behavior of Sarcandra glabra seeds to assist in the establishment of an ex-situ conservation strategy for the species. The basic germination characteristics of S. glabra seeds were investigated. Subsequently, the seeds were dried to various desiccation levels to allow for analysis of their germination characteristics and seed integrity. In addition, the seeds were subjected to germination tests after being stored for different durations. The initial seed moisture content following the removal of the fleshy fruit was 32.8%, and the fresh seeds maintained their seed viability even after a decrease in the seed moisture content to 4.8%, while the germination percentage was 81.0%. The germination percentage of the seeds decreased to 55.0% and 30.0% when they were desiccated to moisture contents of 2.3% and 2.2%, respectively. By contrast, when the stored seeds were desiccated, they maintained their seed viability and vigor at a moisture content of 18.6%; however, when the moisture content decreased below 5.0%, both the seed viability and vigor significantly declined and the germination percentage fell below 20.0%. Furthermore, analysis of the seed leachate revealed that the decrease in the seed viability and vigor was associated with both increased electrical conductivity and increased concentrations of inorganic compounds such as potassium and calcium. In conclusion, the findings of this study show S. glabra seeds to possess desiccation tolerance that falls somewhere between the recalcitrant and intermediate seed types, with the observed variations depending on the degree of deterioration.

희귀 식물 박달목서 유묘의 생장 및 생리적 특성에 대한 차광 효과

구다은,한심희,임은영,김진,구자정 한국산림과학회 2024 한국산림과학회지 Vol.113 No.1

This study was conducted to determine the optimal light conditions for the in situ and ex situ conservation and restoration of Osmanthus insularis, a rare plant species in South Korea. Evaluations included the growth performance, leaf morphological features, photosynthetic characteristics, and photosynthetic pigment contents of seedlings grown from April to November under different light conditions (100%, 55%, 20%, and 10% relative light intensity). The shoot lengths and root collar diameters did not differ significantly with relative light intensity. The dry weights of leaves, stems, and roots and the leaf number were highest at 55% relative light intensity. The leaf shape showed morphological acclimation to light intensity, with leaf area decreasing and thickness increasing as the relative light intensity increased. Several leaf parameters, including photosynthetic rate and stomatal conductance at light saturation point, net apparent quantum yield, and dark respiration, as well as chlorophyll a, chlorophyll b, and carotenoid contents, were all highest at 55% relative light intensity. Under full light conditions, the leaves were the smallest and thickest, but the chlorophyll content was lower than at 55% relative light intensity, resulting in lower photosynthetic ability. Plants grown at 10% and 20% relative light intensity showed lower chlorophyll a, chlorophyll b, and carotenoid contents, as well as decreased photosynthetic and dark respiration rates. In conclusion, O. insularis seedlings exhibited morphological adaptations in response to light intensity; however, no physiological responses indicating enhanced photosynthetic efficiency in shade were evident. The most favorable light condition for vigorous photosynthesis and maximum biomass production in O. insularis seedlings appeared to be 55% relative light intensity. Therefore, shading to approximately 55% of full light is suggested for the growth of O. insularis seedlings. 본 연구는 우리나라의 희귀식물인 박달목서의 현지내ㆍ외 보존 및 복원을 위한 생육 환경 조성 시 적정 광 조건을구명하기 위해 수행되었다. 이를 위해 차광 처리구를 설치하여 전광 기준 100%, 55%, 20%, 10% 상대 광량 조건에서 4월부터11월까지 생육 관리한 박달목서 유묘의 생장 특성, 잎 형태, 광합성 특성 및 광합성 색소 함량을 조사하였다. 그 결과, 수고와근원경의 상대 생장률은 광량에 따른 차이가 없었으나, 잎, 줄기 및 뿌리의 건중량 및 잎 수는 55% 상대 광량 조건에서가장 높았다. 잎의 형태는 광량이 높아질수록 엽면적이 작아지고 두께가 두꺼워지는 경향을 보였다. 광포화점에서의 광합성속도와 기공전도도를 비롯하여 순양자수율, 암호흡, 잎의 엽록소 a, b와 카로테노이드 함량 역시 55% 상대 광량에서 가장높았다. 전광 조건에서 박달목서 유묘의 잎은 작고 두꺼워지는 형태적 적응이 나타났으나, 엽록소 함량은 가장 낮아 광합성속도가 55% 상대 광량보다 떨어졌다. 10%, 20% 상대 광량에서는 광량이 적을수록 엽록소 a, b, 카로테노이드 함량이 감소하였고, 광합성 속도와 암호흡 속도가 낮아졌다. 결론적으로, 박달목서 유묘는 광량에 따라 형태적인 적응 반응을 보였으나, 그늘에서 광합성 효율을 높이는 생리적인 반응은 뚜렷하지 않았다. 또한 생육에 가장 적절한 광조건은 전광의 55% 수준으로, 이조건에서 광합성이 가장 활발하고 최종 산물인 건중량 생산이 최대로 나타났다. 따라서 박달목서는 현지외 보존을 위한 생육환경 조성 시 광량이 전광의 55% 정도가 될 수 있도록 조절 관리하는 것이 필요할 것으로 판단된다.

Effects of Polymeric Additives on Li-Battery Performance

구다은,문홍철 한국고분자학회 2023 한국고분자학회 학술대회 연구논문 초록집 Vol.48 No.1

자작나무 종자 저장기간 및 온도처리에 따른 발아 특성

구다은,이하나,하주완,최규성,송기선,성환인,홍성권,김종진 경상국립대학교 농업생명과학연구원 2019 농업생명과학연구 Vol.53 No.1

본 연구는 우리나라의 주요 조림수종인 자작나무(Betulaplatyphylla var. japonica Hara.) 종자의 저장기간 및 온도처리에 따른 발아 특성을 구명하고자 수행되었다. 공시수종 종자는 각각 1996년, 2003년, 2012년, 2013년, 2014년, 2015년, 2016년 채집된 자작나무 종자이며, 발아실험은 5℃, 10℃, 15℃,20℃, 25℃, 30℃, 35℃의 온도 조건에서 실시하였다. 저장기간에 따른 발아율(GR)의 조사 결과 2012년 이전에 채집된 종자에서는 발아가 전혀 되지 않았다. 저장기간별 발아율은 2015년에 채집된 종자가모든 온도에서 가장 높았고, 저장기간이 길어질수록 낮은 것으로 조사되었다. 온도별 발아율의 경우 15℃ 이하의 온도 조건에서는 모든 종자에서 발아가 전혀 되지 않고, 30℃에서 가장 높은 발아율을 보였다. 그 외의 발아특성은 저장기간이 짧은 종자이고 발아율이 높은 온도일수록 발아기(T50)와 평균발아일수(MGT)가 낮고 발아속도(GS)가 높은 경향을 보였다. 발아균일도(GU)는 상대적으로 고온인 35℃에서높은 것으로 나타났다. This study was carried out in order to survey the effect of storage period and temperaturetreatment on germination characteristics and the optimum, minimum, and maximum temperaturefor seed germination of Betulaplatyphylla var. japonica Hara., which are major productive treespecies in Korea. B. platyphylla var. japonica seeds used in this experiment were produced inthe year 1996, 2003, 2012, 2013, 2014, 2015, and 2016. Germination test was carried out at5℃, 10℃, 15℃, 20℃, 25℃, 30℃, and 35℃ for all seeds. The seeds produced in 1996, 2003,and 2012 were not germinated at all. The seeds produced in 2015 showed the highestgermination rate, followed by the seeds produced in 2016, 2014, and 2013. The seeds were notgerminated at all at 5℃, 10℃, and 15℃. And the seeds showed the highest germination rate at30℃. T50 and mean germination time got lower and germination speed got higher at shorterseed storage period and temperature for higher germination rate. As for germination unity, itwas surveyed to get much higher at 35℃ than the other temperatures.

쉬나무의 용기묘 대량생산을 위한 적정 시비 수준 구명

최규성,구다은,성환인,김종진,원창오,송기선 경상국립대학교 농업생명과학연구원 2019 농업생명과학연구 Vol.53 No.5

This study was conducted in order to closely examine about optimum fertilization for superior seedling producion a container seedling of Tetradium daniellii, which is being increased the demand for a seedling due to being used for alternative energy, ecological restoration and honey plant. The experiment of investigating the optimum fertilization on T. daniellii was carried out by using plastic container types (350 ㎖/cavity) for the forestry facility cultivation. The fertilization level was made by modulating Multifeed 19 (N:P:K=19:19:19, v/v), which is water soluble compound fertilizer, to 500 ㎎·L-1, 1000 mg·L-1, 1500 mg·L-1, 2000 mg·L-1, together with non-fertilization plot. As a result, height and root collar diameter growth showed higher growth value as fertilization level increased, but decreased when fertilization above 1000 mg·L-1. Root development was the highest in 1000 mg·L-1. Dry matter production, it was investigated to be the highest in 1000 mg·L-1. It was surveyed to be the similar tendency to the outcome of height and root collar diameter growth. QI, which is index of showing the quality of a seedling, stood at 0.97 in 1000 mg·L-1, thereby having been surveyed to be higher than other treatment plots. As a result of surveying the whole experiment, optimum fertilization for superior seedling producion a container seedling of T. daniellii is determined at 1000 mg·L-1. It is expected that this will be used as a basic data for mass production. 본 연구는 대체에너지, 생태복원 및 밀원식물용 등으로 이용되어 묘목 수요가 증가되고 있는 쉬나무의 우량한 용기묘 생산을 위한 적정 시비수준을 구명하고자 실시하였다. 공시용기는 임업시설양묘용 플라스틱 용기(350 ㎖/구)를 사용하였다. 시비처리는 무시비구와 함께 수용성 복합비료인 Multifeed 19 (N:P:K=19:19:19, v/v)를 500 ㎎·L-1, 1000 ㎎·L-1, 1500 ㎎·L-1, 2000 ㎎·L-1로 조절하여 시비하였다. 실험결과, 간장과 근원경 생장은 시비수준이 높아짐에 따라 높은 생장값을 나타내다가 1000 ㎎·L-1 이상의 시비에서는 낮아지는 경향을 보였다. 뿌리발달은 1000 ㎎·L-1에서 가장 왕성하였다. 건물생산량도1000 ㎎·L-1에서 가장 높았고 전체적으로 간장 및 근원경 생장 결과와 유사한 경향으로 나타났다. 묘목의 품질을 나타내는 지수인 QI (Quality Index)도 1000 ㎎·L-1에서 0.97로 다른 처리구 보다 높게 조사되었다. 연구결과를 종합하면, 쉬나무 용기묘의 우량한 묘목생산을 위한 적정 시비수준은 1000 ㎎·L-1로판단되며, 쉬나무 용기묘의 대량생산을 위한 기초자료로 활용될 것으로 기대된다.

낙엽송 클론 채종원에서 구과 채취시기에 따른 구과특성 및 종자품질

김예지,구다은,조계홍,최희윤,우영곤,이채빈,유성열,주혜준,강규석 한국산림과학회 2023 한국산림과학회지 Vol.112 No.3

Harvest time is one of the most important determining factors of seed quality, especially for species that produce seeds over irregular and long-term periods, such as Larix kaempferi. A cone collection plan must be established to increase seed production efficiency and stable mass production. We investigated seed qualitiessuch as seed efficiency, germination rate, and T50 (germination speed), with 7 or 8 cone collection times at a clonal seed orchard of L. kaempferi in Chungju between 2021 and 2022. A multivariate analysiswas then performed for the collected data. In early August, decreasesin the moisture contents and browning of cones were observed. These were followed by a decrease in germination rate, with a peak at the end of September, but no clear trend was observed. The later the cones were harvested, the better the seed vigor (T50). However, the seed yield and efficiency decreased owing to increases in seed scattering and the number of insect-damaged seeds. As a result, the optimal time of seed harvest for the seed orchard was in early August. To produce uniform seedlings, insect damage must be reduced through timely control and harvest cones in early September. This shows that the degree of browning and moisture content of cones can be used as indicators of the timing of cone collection in L. kaempferi seed orchards.

FT NIR 분광법 및 이진분류 머신러닝 방법을 이용한 소나무 종자 발아 예측

김용율,구자정,구다은,한심희,강규석 한국산림과학회 2023 한국산림과학회지 Vol.112 No.2

본 연구에서는 -18℃ 및 4℃에서 18년간 저장된 소나무 종자 963개에 대해 FT NIR 스펙트럼을 조사하여 7개 머신러닝 방법(XGBoost, Boosted Tree, Bootstrap Forest, Neural Networks, Decision Tree, Support Vector Machine, PLS-DA)을 이용한 종자발아 예측모델을 만들고, 그 성능을 비교하였다. XGBoost 및 Boosted Tree 모델의 예측성능이 가장 우수하였으며, 정확도, 오분류율 및 AUC 값은 각각 0.9722, 0.0278, 0.9735과 0.9653, 0.0347, 0.9647이었다. 2개 모델에서 종자발아 유무를 예측하는 데 있어 상대적 중요도가 높았던 54개 파수 변수들에 대한 파장대는 크게 6개(811~1,088 nm, 1,137~1,273 nm, 1,336~1,453 nm, 1,666~1,671 nm, 1,879~2,045 nm, 2,058~2,409 nm) 그룹으로 나눌 수 있었으며, 방향족 아미노산, 셀룰로스, 리그닌, 전분, 지방산 및 수분과 관련된 것으로 추정되었다. 이상의 결과를 종합할 때, 본 연구에서 얻어진 FT NIR 스펙트럼 데이터과 2개의 머신러닝 모델은 소나무 저장종자의 발아 유무를 정확도 96% 이상으로 예측할 수 있기에 장기저장 종자 유전자원의 비파괴적 활력검정에 유용하게 활용될 수 있을 것으로 생각된다.