• Journal of Ecology and Environment
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• 제32권1호
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• pp.33-39
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• 2009

Brood caring behavior was observed in Amaurobius ferox (Araneae, Amaurobiidae), a semelparous subsocial spider, from cocoon construction until the emergence of spiderlings from the cocoon. Unlike most spiders, which emerge from cocoon by their own means, A. ferox mothers intervene in the process of the emergence of their young. I manipulated broods by removing the mother prior to emergence to determine the effects of maternal behavior on the emergence of spiderlings. My results showed that maternal intervention making the cocoon expansion and its exit, is not absolutely necessary for the emergence of A. ferox spiderlings from the cocoon. Nine clutches out of ten were able to get out of the cocoon by their own means without their mother's help. There was no difference between control groups ('with mother') and experimental groups ('without mother') in the number of spiderlings that emerged ($96.9{\pm}25.3$ vs. $90.4{\pm}14.2$, respectfully) and in the time from the beginning to the end of emergence ($36{\pm}12$ vs. $41{\pm}17$ hours). Time from eclosion until the emergence of the first individual in a clutch, however, was greater in the mother-absent group (3.5 days) than in the control group (2.0 days). The construction of the cocoon by the mother required always occurred in the same area within the retreat, and took approximately 6 hours, and the mother guarded the eggs during the incubation period. The emergence of the spiderlings followed a sigmoidal pattern. After emergence, the spiderlings formed a very compact group on the cocoon, which may be important in securing maternal care. The absence of cribellum and calamistrum, structures likely involved in their survival, observed in individuals of the first instar suggests that in the first stage of life, the spiderlings are dependent on their mother.

• 한국잠사곤충학회지
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• 제13권2호
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• pp.151-154
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• 1971

In the silkworm egg production, cutting of the cocoon's edge formed by silkworms forced to aid the emergence, and emergence is related to the amount of alkaloid liquid in the sucking stomach in certain varieties. In this study, there was no difference between cutting of portion and sex, and no significant between cutting of both sides and one side cocoons when comparing their emergence ratio. Expenditures and emergence ratio between both sides and one side cutting off must be studied in coming future.

• The Korean Journal of Ecology
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• 제23권6호
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• pp.423-429
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• 2000

To understand the effects of elevated $CO_2$ concentration and temperature on seedling emergence of seven herbaceous species, the seedling emergence was monitored between November 1997 and May 1998 using a temperature gradient chamber and a $CO_2$-temperature gradient chamber. Experiment was conducted under current ambient condition (Control plot), 2$^{\circ}C$-warmed condition with ambient $CO_2$ (T2 Plot), 4$^{\circ}C$-warmed condition with ambient $CO_2$ (T4 plot). and 4$^{\circ}C$-warmed condition with 1.8 fold of ambient $CO_2$ (CT4 plot). Species tested in this study were Digitaria adscendens, Echinochloa crus-galli, Panicum bisulcatum, Setaria viridis. Oenothera biennis, Andropogon virginicus, and Imperata cylindrica. Each species often dominates in the herbaceous stage of secondary succession in Japan. The mean seedling emergence times for all species were significantly increased to 23.6 and 32.2 d in the T2 and T4 plot compared to the Control plot, respectively. The most sensitive and insensitive species in seedling emergence time in T2 plot were O. biennis and D. adscendens, respectivel.y, and those in the T4 and CT4 plot were I. cylindrica and D. adscendens, E. crus-galli and A. virginicus, respectively. All experimental species showed no significant difference in the seedling emergence rate between treatments except for O. biennis and I. cylindrica. O. biennis showed a great decrease in the seedling emergence rate from 83.3% in the Control plot to 38.0%, 14.7%, and 29.3% in the T2, T4, and CT4 plot, respectively. Elevated $CO_2$ had very little effect on the seedling emergence. From these observations, it is expected that increased temperature would greatly advance the vegetative recovery time after disturbance through the advancement of seedling emergence time.

• 한국환경과학회지
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• 제30권2호
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• pp.185-189
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• 2021

This study was conducted to determine and to standardize the time of emergence of Protaetia brevitarsis adults, through four breeding experiments, including one which selected the dominant individuals of Protaetia brevitarsis. The breeding experiments were divided into two groups with hibernating and non-hibernating Protaetia brevitarsis by placing 100, 150, 200, 250 and 300 Protaetia brevitarsis in each breeding box (50 cm × 35 cm × 15 cm) filled with 12 L of fermented sawdust. Breeding tests were with four replicates each for 3 months. The test period was classified into four stages: Exp. 1 (Sep 1, 2019 to Nov 30, 2019), Exp. 2 (Dec 1, 2019 to Feb 29, 2020), Exp. 3 (Mar 1, 2019 to May 31, 2020) and Exp. 4 (Jun 1, 2020 to Aug 31, 2020). The survey items included average dead number, average emergence number, average mortality, and average emergence rate. In Exp. 1 and 2, the changes in Protaetia brevitarsis adults were similar. In Tables 1 and 2, the allegorical changes of adult white-spotted flowers were similar. In addition, the average dead number, average emergence number, average mortality, and average emergence rate showed better results in the hibernation state than in both Exp. 1 and 2. Exp. 3 and 4 showed a pattern of change different from the results of Exp. 1 and 2 and these characteristics were superior in the hibernation states compared to the non-hibernation states. In conclusion, this result was found to be most appropriate as a standardization of the emergence time of 200 Protaetia brevitarsis treatments through four breeding experiments in the hibernating state.

• 한국잡초학회지
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• 제30권1호
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• pp.50-57
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• 2010

본 연구는 환삼덩굴의 생태적 자연출아를 서울과수원의 자연포장 조건에서 평가하여 환삼덩굴의 지역별 출아시기를 예측하고자 실시하였다. 환삼덩굴의 일별 및 유효적산온도별 누적 출아율을 Gompertz 모델을 이용하여 회귀분석하였다. Gompertz 모델은 환삼덩굴의 출아를 지역에 상관없이 양호하게 설명하였으며 환삼덩굴의 최초 출아 유효적산온도는 $56.7^{\circ}C$이며, 최대출아율 50%에 도달하는데 필요한 유효적산온도는 $76.3^{\circ}C$로 계산되었다. 2000년부터 2009년까지 지난 10년간의 지역별 일평균기온을 바탕으로 최초 출아에 필요한 유효적산온도 $56.7^{\circ}C$에 도달하는 시기를 예측한 결과 대구가 3월 21일로 가장 빨랐고 광주(3월 26일), 전주(3월 29일), 대전(3월 30일), 서울(4월 1일), 수원(4월 4일), 춘천(4월 6일), 철원(4월 12일) 순이었다. 같은 방식으로 최대출아율의 50%에 도달하는 출아시기를 예측한 결과 대구가 3월 25일로 가장 빠르며 광주(3월 30일), 전주(4월 2일), 대전(4월 3일), 서울(4월 5일), 수원(4월 8일), 춘천(4월 9일), 철원(4월 15일) 순이었다.

• 한국연초학회지
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• 제24권2호
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• pp.82-87
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• 2002

The purposes of this study are to investigate water content and treatment period in Solid Matrix Priming(SMP; method for enhanced rapid and uniform seedling emergence in tobacco seeds). The higher water content made the faster imbibition speed of tobacco seed. But the radicle emergence shorten the period of water equilibrium. The range of water content in SMP treatment within the limits of no radicle emergence of tobacco seed was 28∼32% to dry weight of tobacco seed. The rate of radicle emergence and seedling emergence was higher in water content 30% and 40% treatment plot than that in 50% and 60% treatment plot. But it was not different between SMP treatment and non-SMP treatment. In water content 40% during 9 days treatment, germinative energy was highest, and T50 and mean germination time(MGT) were the shortest. The germination speed was higher in SMP treatment than that in non-SMP treatment. It was not different on the germination rate between non-SMP treatment and SMP treatment.

• 한국작물학회지
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• 제49권1호
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• pp.46-51
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• 2004

The film coated snap bean (Phaseolus vulgaris) seeds with five different coating materials treated with 3% increase in seed weight were planted at sandy loam soil controlled moisture content of 18, 19, 20 and 21 %. The oxygen diffusion rate (ODR) was calculated from the different moisture content soil. The number of normal seedlings, seedling vigor, and seedling capability in field (seed vigor x dry matter weight) were observed at 9 days after planting and compared to the changes of ODR. The germination rate and ODR were sharply decreased simultaneously in the seeds planted at 21 % soil moisture content. Seedling emergence did not occur at all as the soil moisture content increased above 22 %. Hence this value should be considered as the threshold of soil moisture content for seedling emergence. An ODR value under 20% did not influence the percent emergence significantly. The certain difference observing in the emergence at the same ODR was not related clearly to the condition of soil. So it can be assumed that the limit of soil moisture content for the emergence of snap bean was approximately 20%. The value of 18% soil moisture content may be considered as the optimum for snap bean emergence. There was close relationship between the mean value of ODR in different soil moisture contents and the emergence. The germination rates of the seeds coated with the different materials were quite different when the seeds were planted at 21 % soil moisture. Dry weight of the seedlings from film coated seeds was decreased slightly, but the germination rates were not much different from the non-treated control under relatively higher soil moisture content (21 %). Major factor lowering emergence rate was oxygen stress while film coating act as a minor constraint for snap bean sown in excess soil moisture condition.

• 한국작물학회지
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• 제44권1호
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• pp.32-37
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• 1999

The experiment was conducted to investigate emergence response of lowland weeds at different soil moisture contents, burying depths and upon changes in soil moisture. Rice germination was over 50% at all burying depths under aerobic condition, but the emergence rate of the soil surface placed seeds in saturated and flooded conditions decreased by 19% and 29%, respectively, as compared with that of aerobic condition. Rice seeds at burying depth of over 3 cm did not emerge at all. The emergence rate of Echinochloa crus­galli (L.) Beauv. in aerobic condition was lower than 30%, but the emergence pattern of E. crus galli (L.) Beauv. at different soil moisture contents and seeding depths was similar to that of rice. Emergence behavior of lschaemum rugosum Salisb., Ludwigia octovalvis (Jacq.) Raven and Sphenoclea zeylanica Gaertn. which are dominant lowland weed species in the Philippines also differed depending on soil moisture conditions and burying depths. lschaemum rugosum Salisb. emerged at all burying depths under aerobic condition, whereasLudwigia octovalvis (Jacq.) Raven emerged only at 0 cm deep under saturated and aerobic condition and Sphenoclea zeylanica Gaertn. at 0 cm deep under flooding condition. Weed seeds planted at 1, 3, and 5 cm deep in continuous flooded and saturated condition did not emerge at all, but upon a change of soil moisture condition from saturated to drainage (S$\rightarrow$D) and flooded to drainage (F$\rightarrow$D), grass weeds began to germinate again and the average emergence rate in S$\rightarrow$D and F$\rightarrow$D were 26% and 5% forE. crus­galIi (L.) Beauv., 9% and 8% forI. rugosum SaIisb., respectively. Weed seeds buried in soil in the pot showed great emergence at S$\rightarrow$D but did not emerge under continuous flooded condition. The diversity index accounting for dominance degree and occurrence aspect of weed, was the lowest at F$\rightarrow$D.

• 한국작물학회지
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• 제37권6호
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• pp.506-513
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• 1992

대두 성력재배에 있어서 저조한 출아ㆍ입묘율을 제고시키기 위한 기초연구의 일환으로 종자조건과 토양조건이 한국 주요 대두 장려품종들의 출아에 미치는 영향을 조사하였던 바 그 결과를 요약하면 다음과 같다. 1. 포장출아율은 저하축신장이 양호한 품종이 불량한 품종에 비해 뚜렷하게 높았다. 2. 파종심도가 깊을수록 종자표면적이 작은 소립종자가 큰 중, 대립종자에 비하여 출아저항력이 작아 파종심도 5cm이하에서는 대립종자가 7.5cm에서 소립종자가 출아율이 높았다. 3. 토양별 출아율은 진흙에서 65%, 진흙 : 모래(1 : 1) 모래 : vermiculite(1 : 1)에서 각각 80, 84%였고 vermiculite, 모래 및 진흙 : vermiculite(1 : 1)에서 각각 80, 90, 91%로 높은 출아율을 나타냈다. 4. 토양수분 potential이 -0.1bar에서 -0.5bar까지 점차 낮아짐에 따라 출아율은 순차적으로 높아져 -0.5bar에서 87.2%로 최고 출아율을 보였으나 이후 낮은 potential에서는 수분부족으로 인하여 -0.7bar 출아율이 25.2%로 최저치를 보였다.

• 한국작물학회지
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• 제53권4호
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• pp.434-439
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• 2008

The amount of salt to make seed sorting solution of the specific gravity of 1.13 was reconsidered and determined as 3.8 kg salt in 18 L water, which is lower amount than currently used. Five rice cultivars were examined. Percent germination and seedling emergence were not similar. Seedling emergence rate of Japonica varieties, Nampyungbyeo and Daerypbyeo-1 were 87% and 95% under specific gravity of 1.13, respectively. Seedling emergence rate of Tongil type variety, Dasanbyeo was as high as 67% in specific gravity of 1.06. Seedling emergence rate of waxy rice, Hwasunchalbyeo and Aranghangchalbyeo were examined. Seedling emergence rate was 94% in both cultivars in specific gravity of 1.04. Seedling emergence rate was same in specific gravity of 1.08 which is generally used for selecting seed currently. Early growth (plant height, leaf number, and dry weight) were not significantly different by specific gravity within species. In all cultivars except waxy rice, highest seedling emergence rate was observed in specific gravity of 1.13 which is currently used for selection and decreased as specific gravity is lowed. However, considering total amount of seeds in each group of specific gravity, amount of seed in lower specific gravity group is relatively small and total seedling emergence rate within variety dose not show big difference. However, if seeds with low speicific gravity are produced due to the bad grain filling condition and consequently total seed content of low specific gravity increases, results will be differnt. Reduction in total growth and yield could occur. It will be important to comply with the seed sorting criterion of 1.13 for Japonica, 1.06 for Tongil, and 1.04 for waxy rice variety to ensure the maximum rice growth and yield.