• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.703-709
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• 2015

A breeding pair of the Black-faced Spoonbill Platalea minor was firstly recorded on Chilsando Islands, Younggwang, Jeollanamdo Province in 1991. Since the mid 2000s, breeding population on the breeding sites has gradually increased. This study was conducted to identify breeding status and nest site characteristics of the species from May to August, 2013 on Chilsando Islands. We recorded number of nests, length and width of the nest base, slope around the nests, nest materials, distances from the nearest nest, presence of nest cover and nesting area. In 2013 breeding season, 25 of 49 nests produced at least one successful fledging. A total of 55 youngs were successfully fledged and number of fledging per nest was 2.20 individuals. Nesting area was $77.8m^2$ and $93.4m^2$ for Sansando and Yuksando Islet, respectively. Soil and soil mixed with tree root were preferred for substrate of nest base over rock and Brassica napus was dominantly selected as nest materials by Black-faced Spoonbills. Nest characteristics of 22 nests in Sasando and Yuksando Islet varied $49.59{\pm}6.53cm$(mean${\pm}$SD) for length of nest base, $41.00{\pm}5.82cm$ for width of nest base, $20.85{\pm}9.96^{\circ}$ for slope above the nest, $34.09{\pm}17.75^{\circ}$ for slope below the nest and $130.82{\pm}84.17cm$ for distances from the nearest nest. Fifteen pairs (68.2%) occupied where nest cover existed. Nest cover were located in front of the nest for 5 pairs, back of the nest for 9 pairs and both front and back of the nest for 1 pair.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.694-704
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• 2016

Various infectious and parasitic diseases are known to be the main factors that cause decline in the global amphibian population. In Korea, commercial frog farms have been running since 2005. However, until now, studies on diseases including studies on parasitic diseases that occur in farm frogs have not been conducted. In this study, we studied and compared the acanthocephalan infection rates and the number of parasites in the body cavity, stomach, and small and large intestines of the Dybowskii's brown frogs collected from inside and outside the frog farms in Inje, Goesan, Gongju and Boryeong. In addition, we classified the acanthocephalan parasites into genera by analyzing their nuclear 18S rRNA genes. On an average, 51.7% of the investigated frogs were infected by acanthocephalans, which belong to the Centrorhynchus genus. The infection rate of the frogs collected in the Inje farm was 15%, significantly lower than those from the Goesan, Gongju and Boryeong farms. The rate in Goesan was 55%, which is lower than Gongju (80%) and Boryeong (90%) although it is not statistically significant. No difference was found in the infection rate and in the number of parasites in male and female frogs and between the groups collected from inside and outside of the farms. The number of infected parasites negatively correlated with the body condition of the frogs. The most parasites were found in the stomach followed by the small and large intestines and the body cavity. This study is the first report on the Centrorhynchus acanthocephalan infection of amphibians in Korea and it suggests the necessity for acanthocephalan parasite management and for conducting further disease-related studies in commercial frog farms.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.269-274
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• 2006

Temperature-dependent development studies of two aphid species, A. egomae and A. gossypii occurring in green perilla greenhouse were conducted at $15{\sim}35^{\circ}C$, and 16:8 (L:D h) of light period in the laboratory. The mortality of two aphid species was high in young stages (1st and 2nd). In A. egomae, the mortalitiy increased with increasing and decreasing temperature: the mortalitie at $15^{\circ}C$ and $35^{\circ}C$ were 22.3% and 15.6%, respectively. While the mortalities of A. gossypii increased with increasing temperature: the mortality at $35^{\circ}C$ was 50.0%. The developmental periods of A. egomae and A. gossypii ranged from 20.8days to 5.4days and from 22.6days to 9.1days at $15^{\circ}C$ to $30^{\circ}C$ of temperature resion, respectively, and were 7.2days and 10.7days at $35^{\circ}C$ for each species. The lower developmental threshold temperatures for total nymphs of A. egoame and A. gossypii were $9.9^{\circ}C$ and $4.9^{\circ}C$, respectively and an effective degree-days (DD) for the developmental completion of total nymph were 108.0 DD for.A. egomae and 221.2DD for A. gossypii. In green perilla greenhouse, the occurrence period of A. gossypii was earlier about 15 days than that of A. egomae. When the occurrence period of two aphid species was estimated by degree-days based on lower threshold temperatures, A. gossypii occurred earlier than A. egomae in the field. A. gossypii occurred from early April and showed dominant position to late May compared with A. egomae Whereas, A egomae started to occur from mid April and then were abundant after late May followed by abrupt population crash around late July.

• Korean journal of applied entomology
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• v.51 no.2
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• pp.99-109
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• 2012

Seasonal fluctuations of Riptortus pedestris were investigated in four regions including two sites each at Mt. Yangseong (Munui-myeon, Cheongwon-gun), O-chang (Cheongwon-gun), and Jujung-dong (Cheongju) using aggression pheromone traps from April to November in 2010 and 2011. Aggression pheromone and aggression pheromone + soybean traps were set at all investigated sites, and the Mt. Yangseong A and B sites were investigated at a farmland (80 m, asl) and forest (200 and 300 m). The population density of R. pedestris was high in mid June, mid August, and late October in 2010 and in early May, mid June, mid September, and early October in 2011 with trivoltine. O-chang and Jujung-dong populations, which were distinguished in farmlands and forests, were highest from June to August in the farmland and in September in the forest. Similar numbers of R. pedestris were capture in the farmlands and the forest in June-August, September-November, respectively. From the results of the four regions, more R. pedestris adults were captured in the aggression pheromone + soybean trap than that in the pheromone trap. To investigate the migration route by altitude, 500 R. pedestris adults marked with fluorescent paint were released and re-caught insects were counted in traps after 10 and 20 days. The pattern of the re-caught R. pedestris indicated migration from the forest to farmlands during April-June. These results suggest that the insects did not migrate in August because food was plentiful in the forest at 200 m, but they moved to the forest during October due to the scarcity of food and for overwintering. The R. pedestris seasonal fluctuations in 2011 were affected heavily by the environment, particularly rain precipitation.

• Korean Journal of Plant Taxonomy
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• v.39 no.1
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• pp.12-23
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• 2009

To verify hybridity of Asplenium castaneo-viride, external morphology, spore morphology, anatomy and chromosomes of the species and of the two presumed parental species, A. incisum and A. ruprechtii, were examined. A. castaneo-viride usually had 1-pinnately divided frond. However, some individuals had almost simple fronds with pinnatisect basal parts similar to A. ruprechtii, while others had fronds similar to A. incisum in having oblanceolate blades and basal pinnae with triangular, 2-3 lobed apices. On the surface of the spores, sculpturing consisted of folds that were usually prominent; forming long wings, and irregular or incomplete reticulation. However, reticulation patterns varied among species. A. castaneo-viride showed a wide range of variation from sparse to dense patterns, whereas A. incisum showed only from sparse to intermediate patterns. A. ruprechtii showed from intermediate to dense patterns. The spore size of A. castaneo-viride was $54.63{\mu}m$, larger than other two species ($47.81{\mu}m$ in A. incisum and $44.22{\mu}m$ in A. ruprechtii). The level of undulation of epidermal cell wall was also different. A. incisum had the most shallowly undulated wall, and A. castaneo-viride had a pattern intermediate between the two presumed parental species. This same patterns was recognized in the density of stomata. The density of $45.91/mm^2$ in A. castaneo-viride was intermediate between the two presumed parental species ($67.00/mm^2$ in A. incisum, and $37.86/mm^2$ in A. ruprechtii). Chromosome number was constant (2x =2n = 72) as in A. incisum and A. ruprechtii. However, A. castaneo-viride showed a different ploidy level. The populations of Mt. Mai (Jeonbuk province) and Mt. Duryun (Jeonnam province) were diploid (2n = 72) which is a new record for this taxon, whereas the population of Mt. Buram (Seoul) was tetraploid (2n = 144). Conclusively, A. castaneo-viride was revealed to be a hybrid of A. ruprechtii and A. incisum based on evidence involving leaves, spores, epidermal cells, stomata and chromosome number.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.91-91
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• 2017

Drought is the most serious abiotic stress limiting rice production. However, little progress has been made in the genetic analysis of drought tolerance, because it is a complex trait controlled by a number of genes and affected by various environmental factors. In here, we screened 218 rice genetic resources for drought tolerance at vegetative stage and selected 32 highly drought tolerant varieties in greenhouse. Under rain-fed conditions, Grain yield of Nagdong was decreased by 53.3% from 517 kg/10a to 241 kg/10a when compare to irrigation condition. By comparison, grain yield of Samgang was decreased by 23.6% from 550 kg/10a to 420 kg/10a. The variety Samgang exhibited strong drought tolerance and stable yield in rain-fed conditions and was selected for further study. To identify QTLs for drought tolerance, we examined visual drought tolerance (VDT) and relative water content (RWC) using a doubled haploid (DH) population consisted of 101 lines derived from a cross between Samgang (a drought tolerance variety) and Nagdong (a drought sensitive variety). Three QTLs for VDT were located on chromosomes 2, 6, and 11, respectively, and explained 41.8% of the total phenotypic variance. qVDT2, flanked by markers RM324 and S2016, explained 8.8% of the phenotypic variance with LOD score of 3.3 and an additive effect of -0.6. qVDT6 was flanked by S6022 and S6023 and explained 12.7% of the phenotypic variance with LOD score of 5.0 and an additive effect of -0.7. qVDT11, flanked by markers RM26765 and RM287, explained 19.9% of the phenotypic variance with LOD score of 7.1 and an additive effect of -1.0. qRWC11 was the only QTL for RWC to be identified; it was in the same locus as qVDT11. qRWC11 explained 19.6% of the phenotypic variance, with a LOD score of 4.0 and an additive effect of 9.7. To determine QTL effects on drought tolerance in rain-fed paddy conditions, seven DH lines were selected according to the number of QTLs they contained. Of the drought tolerance associated QTLs, qVDT2 and qVDT6 did not affect tiller formation, but qVDT11increased tiller number. Tiller formation was most stable when qVDT2 and qVDT11 were combined. DH lines with both of these drought tolerance associated QTLs exhibited the most stable tiller formation. These results suggest that qVDT11 is important for drought tolerance and stable tiller formation under drought stress condition in field.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.246-250
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• 2003

In order to preserve the soundness of agro-ecosystem and products safety in agriculture, this study was evaluated environmental impact in relation to the INM (Integrated Nutrient Management) and IPM (Integrated Pest Management) at paddy fields at Ok-Chun and Yang-Pyung region. By introduction of INM with the application of BB(bulk-blanded) fertilizer based on soil analysis and IPM, the application rate of fertilizer was reduced to about $28.6{\sim}39.4%$ and the yield of brown rice was increased to about $3{\sim}10%$ compared to conventional practices. The concentrations of COD, $NH_4-N$, and $NO_3-N$ in irrigation water flowed to the environmental-friendly agriculture practices were 15.0, 0.67, and 1.39 mg/L, respectively. The concentrations of COD, $NH_4-N$, and $NO_3-N$ from paddy fields in drainage water were 12.4, 0.29, and 2.42 mg/L, respectively. The total number of the freshwater invertebrates was higher in field treated with fertilization by prescription with soil testing. Also, the population density of aquatic insects was higher than the other fields at both demonstration villages. In conclusion, it was possible to reduce the amount of fertilizer and agricultural chemicals application, and increase the yield of rice by application of the environmental-friendly agriculture practices.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.159-169
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• 2008

This study was aimed to classify the intertidal macrozoobenthic community status after 2 years of Sea Prince oil spill, and oil spill effects along oil spreading track from heavily impacted to unaffected reference site. Field sampling was initiated in late February and continued through November 1998 seasonally, after 2.5 years of oil spill. 7 rocky sampling sites were selected among coastal regions coated and/or affected by the Sea Prince spilled oil. Identified species was 158 species, 65 family, 24 order, 9 class, 5 phylum. Mollusca was the dominant faunal group comprising 100 species (63.3%), and followed by 38 species of Crustacea (24.1%), 12 species of Echinodermata (7.6%), 5 species of Porifera (3.2%), and 3 species of Cnidaria (1.9%). On Dugpo of Sori Island, the fewest species was collected from 28 species to 35 species seasonally among sampling stations. But far away Dugpo toward Gamak Bay, the number of species increased, collecting the maximum on Sohwoenggan Island. At the wreck site of Sori Island, especially the species number of attached animals such as poriferans and anthozoans was very low compared to another site. The density and biomass on the higher tidal zone increased toward the low affected sites, but biomass on middle tidal zone decreased. The invertebrate biomass of study area was dependent on the sessile animals. The major dominant species were small-sized barnacles, Chthmallus challengeri, periwinkles, Littorina brevicula, mussels, Septifer virgatus, and so on. The biomass of C. challengeri and L. brevicula on the higher tidal zone was highest in the wreck site of Sori Island and decreased further and further. However, mussels on the middle tidal zone showed the inverse trends because of the larger individual size of mussel inhabited in Sori Island than those of another sites. As a result of community analysis, the effect of oil spill was not found distinctly. Several ecological indices and cluster analysis did not show the meaningful variation with oil track despite of the conspicuous differences among tidal heights. These indicate that the macrozoobenthic community level of oil spreaded zone recovered in some degree after the Sea Prince oil spill accident, but population or individual levels of dominant sessile animals took more recovery times.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.139-143
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• 2010

Quail is a very useful animal model for studying vertebrate development because of its small body size and unique reproductive traits. This species is also ideal model for producing germline chimeras via transferring exogenous primordial germ cells (PGCs) into the recipient embryo. To increase the contribution efficiency of donor PGCs into recipients' tissues, decreasing the population of endogenous PGCs has been rate-limiting factor. We therefore conducted this study to investigate if gamma ($\gamma$)-irradiation depletes endogenous PGCs in developing quail embryo. Firstly, freshly laid stage X quail embryos were irradiated with various output of $\gamma$-irradiation and its teratogenic effect on the embryo was evaluated. Although a dose-dependent increase in the number of embryo showing malformation was found as the output increased (0, 250, 500, 750, and 1,000 rads), only a maximum of 10.1% of embryos were abnormal in 1,000 rads. Immunocytochemical analysis using the QCR1 antibody, which is specific marker for quail PGCs, was conducted to analyze the effect of sterilization. As results, $\gamma$-rays at a dose-rate of 500 rads/73 sec onto undeveloped stage X embryo significantly reduced the number of germ cells to an average of 75.55 % and 82.03 % in male and female embryos, respectively. We conclude that $\gamma$-ray selectively targets PGCs while affects minimally to the somatic development in quail embryo. Our results will not only provide important data for germline chimera production but can be used for analyzing the effect of ionized rays on the differentiating germ cells in various stages during animal development.

• Korean Journal of Poultry Science
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• v.41 no.2
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• pp.105-113
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• 2014

The current study was performed to investigate the effects of dietary supplementation of dried coffee meal (CM) on growth performance, intestinal and blood biochemical index, intestinal enzymes, and cecal microbial populations. A total of 162, 3-day-old male broiler chicks were randomly allocated into three dietary groups: control group (CON), basal diet added with 0.5% CM (CM I), and basal diet added with 1.0% CM (CM II). Dietary supplementation of CM did not change bird performance and the relative weight of intestinal mucosal tissues. The birds fed the diet supplemented with CM (0.5 and 1.0%) significantly decreased mucosal glucose concentration (P<0.05) without affecting blood glucose level compared with those fed control diet. The level of blood aspartate aminotransferase (AST) significantly increased in CM II group (P<0.05) without affecting ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GTP) compared with that in the CON group. The specific activity of intestinal maltase, leucine aminopeptidase (LAP) and alkaline phosphatase (ALP) were not affected by dietary supplementation of CM, whereas sucrase activity in birds fed the diet supplemented with CM was decreased (P<0.05) compared to that in the control birds. The colony forming units (CFU) of E. coli in the cecum of CM-fed birds was significantly decreased (P<0.05) compared with that of control birds without changing the CFU of Lactobacillus. In conclusion, dietary supplementation of lower level of CM (0.5%) can be used as a beneficial feed resource without liver toxicity in broiler chicks.