• Journal of Aquaculture
• /
• v.2 no.2
• /
• pp.91-106
• /
• 1989

Chlorella has been used as a very useful food for rearing rotifer which is an important live food for early stages of fish and crustancean larvae. But Chlorella does not grow well in higher or lower temperature such as during summer or winter season in this country. Therefore, cooling or heating facilities are needed for Chlorella culture during summer or winter, but it costs too much for the commercial scale fish farmers. To solve this problem, the growth rates of 34 different species of phytoplanktons were examined at the various levels of temperatures, salinites and light intensities to select suitable species as the food for rotifers for summer and that for winter. After the suitable species were selected, growth comparisons of rotifer groups which were fed the selected species of phytoplanktons against rotifer group fed Chlorella as a control were done. Fatty acid compositions of the selected phytoplanktons and rotifer groups which were fed these selected phytoplanktons were examined. It was revealed that Nannnochioris oculata was optimum for rotifers in summer season and Phaeodactylum tricornutum was suitable for that in winter season. The optimum temperature, salinity and light intensity for former phytoplankton were $28^{\circ}C$, $33\%_{\circ}$ and 5,000 lux and those for later were $10^{\circ}C$, $30\%_{\circ}$ and 8,000 lux, respectively. In the higher temperature condition, the growth of N. oculata fed rotifer group was better than Chlorella ellipsoidea fed group. In the lower temperature condition, however, the growth of Chlorella fed rotifer group was slightly better than P. tricornutum fed group. Between two selected phytoplanktons, N. oculata has the highest content of linolenic acid (18 : 3 $\omega$ - 3, $\omega$ - 6) which is essential fatty acid for marine fish larvae. A rotifer group which was fed this plankton also showed the highest linolenic acid content among the other rotifer groups.

• Horticultural Science & Technology
• /
• v.32 no.6
• /
• pp.753-761
• /
• 2014

Growth and flowering of Cymbidium 'Red Fire' and 'Yokihi' plants were examined in a greenhouse with cooling systems in summer, and with night interruption (NI) lighting in winter as a forcing culture system. The greenhouse was divided into two sections with separate cooling controls during the summer season. One section was cooled by a mist system (mist), while the other section was cooled by a shade screen (shade). During the winter, the greenhouse was redivided into three sections within each cooling system. Plants were grown with NI either at a low light intensity of $3-7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(LNI) or a high l ight intensity of $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(HNI) u sing h igh-pressure sodium l amps during the 22:00-02:00 HR. The control plants were grown under 9 h short-day condition. NI for 16 weeks and cooling for 9 weeks were employed twice during the 2 years of the experimental period. The air temperature was approximately $2^{\circ}C$ lower in the mist than in the shade and the relative humidity was 80 ${\pm}5%$ in the mist compared to $55{\pm}5%$ in the shade. The daily light integral in the mist section was 48% higher than in the shade section. The time from initial planting to flowering pseudobulb emergence decreased with both LNI and HNI for both cultivars, regardless of the cooling treatments. Under NI conditions, however, between 60% and 1 00% of plants of both cultivars flowered in the mist, whereas no or 20% of 'Red Fire' or 'Yokihi' plants, respectively, flowered in the shade treatment over 2 years. Plants grown under the mist had bigger pseudobulbs than those grown in the shade under both NI treatments. These results show that commercial use of NI in winter and a mist cooling system in summer would decrease crop production time to 2 years and increase profits in Cymbidium forcing culture.

• Korean Journal of Animal Reproduction
• /
• v.14 no.1
• /
• pp.73-83
• /
• 1990

These studies were carried out to find the proper conditions for in vitro maturation and fertilization of bovine follicular oocytes and culture methods capable of further developing early embryos. For these objectives, the cleavage rate of oocytes matured and fertilized in vitro was investigated under medium supplemented with hormones and estrous cow serum and season of oocytes collection as well as different cumulus cell stage before insemination. Finally, 2~8 cell embryos were cultured in in vitro and in vitro culture system to investigate developmental capacity into morula. 1. Cleavage rate of oocytes matured in vitro was 27%(20/73) for A(LH＋FSH＋estradil-17$\beta$＋10% FBS), 38%(27/71) for B(LH＋10% ECS) and 27%(15/56) for C(10% ECS), respectively. Supplement B showed more higher rate and 4~8 cell embryos were also obtained much more in this group(67%, 18/27). In vitro maturation rate of follicular oocytes cultured in TCM 199 supplemented withLH and 10% ECS was 88%(75/85). 2. Cleavage rate(15%, 10/65) of oocytes collected in summer was significantly lower than in fall(47%, 42/89). 3. Cleavage rate(15%, 10/65) of oocytes collected in summer was significantly lower than in fall(47%, 42/89). 3. Cleavage rate(15%, 10/65) of oocytes with partially removed cumulus cell before insemination was more higher than that(44%, 27/62) of oocytes with intact cumulus cell. 4. The frequency of development from early cleaved embryos into morula was 6%(4/65), 12%(4/33) for co-culture of cumulus cell monolayer and bovine oviduct epithelial cell monolayer, respectively and 25%(6/25) in ligated rabbit oviduct.

• Journal of the Korean Society of Food Culture
• /
• v.35 no.1
• /
• pp.14-27
• /
• 2020

This study examined the document Shaemirok, which recorded the daily lives of people from Jangsoo (長水), Junrado to Pyeongang (平康), Gangwondo, from 1591 to 1601. This book represents the mid Josun dynasty Noble Lineage's diary together with Muk-Jae (默齋日記). This study analyzed the Shaemirok of Noble lineage's seasonal food and traditional Korean food through the lens of the Shaemirok. The Shaemirok recorded that Josun people practiced the Julsa (節祀) and Julshik (節食) during the spring, as follows: Sakil (中和節) five times on February 1, Dapchungil (Samjiknal) six times on March 3, Hanshikil five times on March 8, and Deungsuk (Chopile) three times on April 8. Samjiknal on March 3, which is mentioned six times, is the spring Julsa and Julshik that show up most frequently within the Shaemirok's records. The Shaemirok recorded that Josun people, practiced the Julsa and Julshik during the summer, as follows: Danyang (Danoh) eight times on May 5 Youdoojul six times on June 15, Chilsuk five times on July 7, and Bakjoong five times on July 15. Dangohjul on May 5, which is mentioned eight times, is the summer Julsa and Julshik that show up most frequently within the Shaemirok's records. The Shaemirok's author recorded Julsa and Julshik practiced in the autumn eight times annually. Joongangjul, which is mentioned six times, is the autumn Julsa and Julshik that show up most frequently within the Shaemirok's records. Shaemirok recorded that Josun people practiced the Julsa and Julshik during the winter, as follows: Dongji during November, Sul on January 1, and Daebohrum on January 15 Dongji and Sul, Daebohrum are mentioned eight and seven times, respectively, in the Shaemirok. The people of the Four Main Families of the mid-period Josun practiced more Julsa and Julshik in the winter than in any other season. The Josun people stored the most food during winter, thus had the highest abundance of food. This seasonal factor explains Dongji and Sul, Daebohrum's unusual frequency with which they were celebrated.

• ALGAE
• /
• v.25 no.2
• /
• pp.99-104
• /
• 2010

A psychrotolerant cyanobacterium, Nodularia spumigena KNUA005, was isolated from a cyanobacterial bloom sample collected near Dasan Station in Ny-${\AA}lesund$, Svalbard Islands during the Arctic summer season. To generate an axenic culture, the isolate was subjected to three purification steps: centrifugation, antibiotic treatment and streaking. The broad antibacterial spectrum of imipenem killed a wide range of heterotrophic bacteria, while the cyanobacterium was capable of enduring both antibiotics, the remaining contaminants that survived after treatment with imipenem were eliminated by the application of an aminoglycoside antibiotic, kanamycin. Physical separation by centrifugation and streaking techniques also aided axenic culture production. According to the cold-tolerance test, this mat-forming cyanobacterium was able to proliferate at low temperatures ranging between 15 and $20^{\circ}C$ which indicates the presence of cold-tolerance related genes in N. spumigena KNUA005. This suggests the possibility of incorporating cold-resistance genes into indigenous cyanobacterial strains for the consistent production of algae-based biofuel during the low-temperature seasons. Therefore, it is needed to determine the cold-tolerance mechanisms in the Arctic cyanobacterium in the next research stage.

• Korean Journal of Breeding Science
• /
• v.40 no.3
• /
• pp.336-339
• /
• 2008

A new spray chrysanthemum cultivar, 'Moon Festival' was released by National Horticultural Research Institute (NHRI), Rural Development Administration (RDA), Korea in 2007. A cross was made in 2002 between '01B1-559', a breeding line of NHRI and 'Baeksokuk', a spray cultivar with white petals. Trials were conducted from 2005 to 2007 for evaluation and selection of this cultivar, including shading culture in summer and retarding culture in autumn. The natural flowering time of "Moon Festival" is late October, but year-round flowering is possible by shading and lighting treatment. The cultivar is semi- double type flowers with light-ivory white petals and green flower center. Flower neck and stem are very hardy. The diameter of flower is 67.5 mm. The number of flowers per stem and petals per flower is 11.5 and 100.5, respectively. The days to flowering under the short day is about 54 in autumn season.

• Korean Journal of Breeding Science
• /
• v.40 no.4
• /
• pp.495-498
• /
• 2008

A new spray chrysanthemum cultivar, 'Golden Festival' was released by National Horticultural Research Institute (NHRI), Rural Development Administration (RDA), Korea in 2007. It was selected from the progenies of open-pollination of 'Torbay' in 2002. Trials were conducted from 2005 to 2007 for evaluation and selection of this cultivar, including shading culture in summer and retarding culture in autumn. The natural flowering time of 'Golden Festival' is late October, but year-round flowering is possible by shading and lighting treatment. The cultivar is semi-double type flowers with bright yellow petals and green flower center. Flower neck and stem are very hardy. The diameter of flower is 56.5 mm. The number of flowers per stem and petals per flower are 12.0 and 93.5, respectively. The days to flowering under the short day treatment is about 50 in spring season.

• 한국해양학회지
• /
• v.12 no.2
• /
• pp.75-81
• /
• 1977

Distribution of drifting larvae of Anadara broughtnoii SCHRENCK was studied based on the planktonic sampling which has been collected in fifteen sampling areas of southern coast of Korea and Ulsan Bay during summer season from 1973 to 1977. Vertical and horizontal occurrence was analyzed related to the environmental factors such as surface water temperature, current velocity and depth of water column. High density of the larvae was observed in the Chinhae Bay which included the sampling areas Rampo, Sockcheon, Majeon, Changpo, Dangdong, Bedun, Changchoa, and Wonmun. Maximum occurrence of the farvae was accompanied with the highest water temperature of the summer season, and it was usually August when the water temperature was over 27$^{\circ}C$. In August, 1975, the highest density of the farvae was observed, when the mean surface water temperature was the highest compared to those of other years. The first appearence of the drifting larvae was also related to the surface water temperature. Each year the larae begin to appear from the late July and the ready-to-fall larvae appear in abundance from the mid-August. Vertical distribution patterns of the larvae are closely related to the depth of the water column as well as to the current velocity. In shallow water the larvae tend to aggregate in the bottom layer, while they are diffused to some extent in deep water. In shallow water column ( 8m) more or less 75% of the total larvae individuals was observed in the lower 4m layer and in deep water column ( 16m) only 45% of those was found in the lower 4m layer. In the water of lower velocity a large fraction of the larvae population is distributed in the lower depth layer.

• Korean journal of applied entomology
• /
• v.48 no.4
• /
• pp.503-508
• /
• 2009

Biological-control-based-integrated-pest-management of major pests occurring on sweet pepper in greenhouse during summer season was tried. As many as 2.1 Orius laevigatus per $m^2$ were released in two times on June 6 and 19, and the population of thrips was kept under control and accordingly the damage was negligible throughout the season. To control aphids, a total of 0.8 Aphidius colemani per $m^2$ were released in four times, 0.2 of them at a time, flonicamid on May 14 and July 18 and pymetrozine on June 14 and September 4 were sprayed on the spots of high aphid occurrence to reduce the release of the wasp, and the density of aphids was kept under control. Whitefly was controlled successfully by releasing a total of 343.4 Amblyseius swirski per $m^2$ in nine times, 38.1 of them at a time, from May 9 until November 12 and dinotefuran was sprayed on November 12 when the density of whitefly increased up to 200 per trap. Tetranichus kanzawai was controlled by both Phytoseiulus persimilis which was released a total of 44.4 per $m^2$ in five times 8.9 of them at a time from May 23 to September 10, and the A. swirski which was released for the control of whitefly.

• Journal of Aquaculture
• /
• v.9 no.1
• /
• pp.65-71
• /
• 1996

To estimate the variation of food organisms on the corrugated PVC sheets, we analysed the chlorophyll a and. pheopigments of the benthic microalgae on the sheets from the oyster culture ponds. We estimated the standing crops as the amounts of chlorophyll a, and the physiological state of cells as the pheopigments level in the benthic microalgae. The amount of chlorophyll a was increased by immersion time in winter but the peak was observed every two weeks in summer, while the ratio of pheopigments was highest in summer but the low level was observed in spring and autumn. These seasonal variation were well coincided with the natural spawning season and the good microalgae nutritional valance.