The toxicity of neem extracts that induce abnormality and lethality is strongly enhanced by the ingestion rather than surface contact. Oral toxicity of neem extracts was analyzed using a plant sapping pest Bemisia tabaci. When adults were allowed to ingest various doses (0, 5, 10, and 50 ppm) of azadirachtin diluted in 20% sugar solution in a double-layered parafilm chamber for 72 h, mortality was 12.5, 77.5, 97.5, 100%, respectively. When a cucumber leaf which has many nymphs were submerged into the solution of neem extract, adult eclosion was decreased to 87.0, 16.6, 16.1, and 6.6%, respectively. Further, when neem extracts were irrigated into the tomato cultivar the average number of nymphs per leaf was decreased to 60.3% in comparison with the untreated control. These result suggest that systemic treatment of neem extracts was effective for the control of whiteflies as well as other sucking insect pests.

The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex, including at least 24 biotypes which express different ecological and physiological characteristics. B. tabaci is one of the most serious pests in the horticultural crops in worldwide level. B. tabaci infests over 600 plant species and also indirectly damages plants by the honeydew excretion. Moreover, whiteflies transmit more than 100 plant viruses, especially begomoviruses. Tomato yellow leaf curl virus (TYLCV) which infested severely in tomato cultivars is transmitted by the vector insect, B. tabaci. Here, we demonstrated whether gene expression of B. tabaci is regulated by the oral ingestion of dsRNA. Double strand RNA (dsRNA) of heat shock protein 70 gene (hsp70) was produced from cDNA by using the specific primer. Whitefly adults were allowed to ingest sugar solution containing dsRNA for 3 hr in the two-layered parafilm feeding tube. Quantitative realtime PCR showed that whiteflies which ingest hsp70 dsRNA completely knockdown its transcript expression. Whiteflies ingestded dsRNA increased mortality by heat shock but not by cold shock. Further research will focus the role of hsp70 in various environmental stresses against insects.

Chrysanthemum stunt viroid (CSVd) is a serious pathogen affecting chrysanthemum that has caused significant economic losses to Chrysanthemum flower production worldwide. Control of CSVd disease is difficult due to its contagious nature and long latent period in the field. As chrysanthemum is most often produced by implanting seedlings, it is necessary to diagnose CSVd infection before cultivation. In this study, we screened CSVd infection in seedlings from 30 varieties including 5 domestic, 6 Japanese, and 19 European varieties. Molecular diagnosis of the combination of RT-PCR and nested PCR showed that CSVd was not detected by the first RT-PCR but detected by the second nested PCR analysis in 10 varieties, including 1 domestic, 2 Japanese, and 7 European varieties. Further comparison of 10 identified CSVd nucleotide sequences showed that those are highly conserved (99-100%) and the most similar to an isolate (AB006737) identified in Hokkaido, Japan. Our study suggests that the combination of RT-PCR and nested PCR analysis is successful for the CSVd diagnosis of seedlings and the molecular diagnosis is necessary to prevent the introduction and propagation of viroid disease into the fields.

Paratlanticus ussuriensis enter prolonged diapause at an egg stage. Environmental conditions, such as temperature, can modify the diapause duration at initial diapause. Eggs enter initial diapause at 20℃, but continued early embryonic development at 30℃. Final diapause at a fully developed embryonic stage is obligatory regardless of temperature conditions. To determine temperature effects on diapause mechanism of P. ussuriensis eggs, we compared weights, DNA and RNA amounts of eggs incubated at either 20℃ or 30℃ for 50 days after oviposition. Both egg weight and total amount of DNA were constant at 20℃ but gradually increased at 30℃. However, total RNA level was rapidly increased at 15 days-old eggs at 30℃ and maintained high levels during further period whereas its level was constant at 20℃. In addition, we identified three heat shock protein 70 (hsp70a, hap70b, hsp70c) genes of P. ussuriensis and determined those expression levels at different temperature conditions. The levels of hsp70a and hsp70b was not detectable until 20 days after oviposition at both temperature conditions, but highly increased at 50 and 60 days when incubated at 30℃. In contrast, hsp70c level was rapidly peaked at 20 days after oviposition, which is the time of initial diapause entrance. Our results suggest that high temperature breakdown initial diapause and a certain hsp gene, such as hsp70c, may involve in the initial diapause mechanism of P. ussuriensis eggs.

The diapause duration P. ussuriensis eggs is known to either one year or prolonged to additional years. This complex life cycle is mainly caused by the interruption at two embryonic stages: early stage (initial diapause) and fully developed late stage (final diapause). The environmental cues, such as temperature, is critical to determine the diapause duration but the precise diapause mechanism of P. ussuriensis eggs is unclear. We demonstrated temperature effects on the entrance of initial diapause. Newly oviposited eggs were incubated at two temperature conditions (20℃and 30℃) for 60 days. When eggs were incubated at 20℃, egg weights were not significantly changed, but at 30℃ those were gradually increased to 1.5 times for 50 days. Genomic DNA contents of eggs were similarly increased at 30℃. Total RNA contents at 30℃ were highly increased from the 15-days-old but not at 20℃. In addition, we further analysed expression levels of two heat shock protein 70 (hsp70a, hap70b) genes during embryonic development. Our results suggest that initial diapause occurred between 10 and 15 days after oviposition and its entrance was blocked by high temperature incubation.

Spider mites are one of major pests in cultivations of various ornamental plants and also important in plant quarantine service. Due to the very small body size and high similarity within the Genus the identification of species is difficult even at the microscopic observation. To identify 5 major species (Tetranychus cinnabarinus, T. urticae, T. phaselus, T. kanzawai and T. truncatus) in the Genus Tetranychus at the molecular level, we designed 4 species-specific primer sets using nucleotide sequences of the internal transcribed spacer (ITS2) region in the nuclear ribosomal repeat unit. At the PCR diagnosis of extracted genomic DNAs of 5 species using each primer set, specific primers of both T. phaselus and T. truncates were species-specific to their own species samples. However, specific primer set of T. urticae detected T. cinnabarinus as well as T. urticae. Specific primer set of T. kanzawai detected T. truncates as well as T. kanzawai, even though detection intensities were lower in non-target species.

During the last several years, the population of the ussur brown katydid, Paratlanticus ussuriensis has been highly increased at mountain-side orchards in Youngdong province in Korea. Nymphs and adults emerged one time per year from early May to August and cause a serious demage on the crop production. Adults oviposit eggs from July to September under the ground and eggs overwinter at diapause stage. However, the diapause duration P. ussuriensis is known to either one year or prolonged to additional years. The environmental cues, such as temperature, could be a critical to determine the diapause duration but the precise diapause mechanism of P. ussuriensis eggs is unclear. We demonstrated to determine the stage of diapause initiation during embryogenesis. Newly oviposited eggs were incubated for 60 days at two temperature conditions (20℃and 30℃). When the eggs were incubated at 20℃ those weights were not changed, but when they incubated at 30℃ those were increased from 15-days-old. Total RNA contents of eggs incubated at 30℃ were highly increased from the 15-days-old when they compared with those of eggs incubated at 20℃. In addition, total DNA contents of eggs were greatly higher when they incubated at 30℃. Our results suggest that early embryonic development was sensitive to high temperature and it was stimulated at 15-days-old. To determine the temperature response of embryonic development at molecular level we identified heat shock protein 70 (hsp70) gene of P. ussuriensis. Further analysis would conduct the gene expression rate of diapausing eggs on different temperature conditions by using real time RT-PCR technique and determine the molecular characteristics of P. ussuriensis egg diapause.

A glucose-regulated protein 78 (grp78) gene, which is belongs to a heat shock cognate 70 (hsc70) subfamily, was cloned from Indian meal moth, Plodia interpunctella. Its full length cDNA was 2679 bp and contains a 1980 bp open reading frame. The translated amino acid sequence consists of 660 residues with a calculated molecular mass of 72,975 Da and an isoelectronic point (pI) of 5.27. It contains several highly conserved functional motifs of the Hsp70 family and, particularly, C-terminal motif of KDEL that is characteristic for endoplasmic reticulum (ER) hsc70. Its deduced amino acid sequence shows a high identity (83-94%) with Hsc70s of other insects and grouped with Hsc70-3 among 5 Hsc70 members of Drosophila melanogaster. During development the grp78 transcript level was high in egg, feeding larval and adult stages but low in molting and wandering larval and pupal stages. Particularly its level was higher in the gut than integument and fat body of fifth instars. Furthermore its level was greatly decreased when fifth instar larvae were starved for 48 hrs but recovered at 3-6 hrs after re-fed diet. Our data suggests that grp78 is a member of hsc70 gene that belongs to ER and may have a role for energy metabolism at cellular level.

본 연구에서는 효율적인 와류형 미필터 비점오염저감장치를 개발하고 검증하였다. 저감장치의 검증을 위해 오염물질을 이용하여 총 12개 형태(3개 강우강도×2개 상태×2개 단계)의 실험을 진행하였다. 실험은 (1) 모의유입량 산정(강우강도 2.5 mm/hr: 0.00152 m3/s, 강우강도 3.395mm/hr: 0.00206 m3/s, 강우강도 6.870 mm/hr: 0.00326 m3/s); (2) 오염물질 채취 및 투입(4개 입경 사이즈의 25%씩 혼합); (3) 오염물질 제거효율 측정으로 구성하였고, 장치 초기상태와 운영상태로 구분하여 수행되었다. 강우강도별로 분석한 결과, 모든 강우강도에서 초기상태 및 운영상태 모두 오염물질 농도가 감소하였으며, 유입수 대비 유출수 오염물질 제거효율에서도 오염물질을 환경부 기준 80% 이상 제거하는 결과를 보였다. 특히 제거효율이 시간이 지남에 따라 서서히 증가하여 약 90%를 상회하였으며, 초기상태보다 운영상태에서 오염물질 제거효율이 더 높은 것으로 나타났다. 따라서 본 연구에서 개발한 와류형 미필터 비점오염저감장치로 효율적인 비점오염원을 제거할 수 있음을 증명하였다.

기존 기후변화 영향평가에서 발생하는 불확실성에 대한 연구들은 전체과정에서 총 불확실성과 그 전파에 대한 것보다 각 단계별 불확실성에 초점을 맞추어 연구가 진행되었다. 따라서 본 연구에서는 first-order Taylor series expansion에 기반하여 전망의 분산을 이용하는 Uncertainty Delta Method (UDM)를 제안하였으며, 이 방법은 각 단계별 불확실성 정량화와 증감정도, 단계별 불확실성 비율, 총 불확실성의 전파 과정 제시가 가능 하다. 본 연구에서는 기후변화 영향평가 과정의 단계별 불확실성 정량화와 전파과정 분석을 위해 미래 2030년부터 2059년까지를 대상으로 2개 배출 시나리오, 3개 GCM, 2개 상세화기법, 2개 수문모형을 사용하였다. 결과를 분석하면, UDM을 이용한 총 불확실성은 5.45(배출시나리오: 4.45, 상세화기법: 0.45, 상세화기법: 0.27, 수문모형: 0.28)이며, 배출 시나리오의 불확실성(4.45)이 가장 크게 나타났다. 불확실성은 각 단계를 거칠수록 증가하는 것으로 나타났다. 이러한 결과는 어떠한 배출시나리오를 선정하느냐에 따라 미래 수자원전망이 매우 달라질 수 있음을 의미한다. 다음으로 Hawkins and Sutton (2009)가 제안한 Fractional Uncertainty Method (FUM)을 이용한 기후변화 영향평가 불확실성 분석에서 가장 불확 실성이 큰 요인은 배출 시나리오(FUM 불확실성: 0.52)이며, 이 결과는 UDM 결과와 동일하게 나타났다. 따라서 이 연구에서 제안한 UDM은 기후 변화 영향평가에서의 불확실성 이해와 적합한 분석 및 미래 기후변화 대비 보다 나은 수자원 전망이 가능하도록 기여할 것으로 판단된다.

수문 ․ 기상레이더는 강우량을 바로 추정하지 못하고 여러 단계의 정량적 강우량 추정과정을 거치게 되므로 많은 불확실성 발생요소가 존재한다. 불확실성 관련한 기존 연구들은 정량적 레이더기반 강우량 추정과정에서 보정방법을 이용하여 각 단계별 불확실성을 줄이는 연구들을 수행하였다. 하지만 기존 연구들은 전체 과정에 대한 포괄적인 불확실성을 나타내지 못하고 각 단계별 불확실성의 상대적인 비율도 제시하지 못하는 단점이 있다. 본 연구에서는 정량적 레이더강우량 추정과정의 각 단계별 불확실성을 정량화하고 불확실성 전파를 나타낼 수 있는 적합한 방법을 제시하였다. 첫 번째로 초기와 최종 불확실성, 각 단계별 불확실성의 변동과 상대적인 비율을 나타낼 수 있는 새로운 개념을 제안하였다. 두 번째로 레이더기반 추정과정의 불확실성 정량화와 전파과정을 분석하기 위해 Maximum Entropy Method (MEM)와 Uncertainty Delta Method (UMD)를 적용하였다. 세 번째로 레이더기반 강우량 추정과정의 불확실성 정량화를 위해 2개 품질관리 알고리즘, 2개 강우량 추정방법, 2개 후처리 강우량 보정방법을 2012년 여름철 18개 사례에 대하여 사용하였다. 적용결과, MEM에서 최종 불확실성(후처리 강우량 보정 불확실성: ME = 3.81)이 초기 불확실성(품질관리 불확실성: ME = 4.28)보다 작게 나타났으며, UMD에서도 최종 불확실성(UMD = 4.75)이 초기 불확실성(UMD = 5.33)보다 작게 나타나 불확실성이 감소하는 것으로 나타났다. 하지만 레이더강우량 추정단계의 불확실성은 증가하는 것으로 나타났다. 또한 레이더강우량 추정과정에서 각 단계별로 적합한 방법을 선정하는 것이 각 단계별로 불확실성이 감소시킬 수 있음을 확인하였다. 따라서 본 연구는 새로운 방법이 명확히 불확실성을 정량화할 수 있으며 정확한 정량적 레이더 강우추정에 기여할 것으로 판단한다.

본 연구는 기후변화에 따른 수자원 영향평가를 위해 적합한 수문모형을 선택하고 지역기후모형인 SNURCM에서 생성한 모의기상자료로 유출량을 생성하여 모의정확성을 평가하였다. 4개의 월 물수지모형과 두개의 일 유출모형을 이용하여 대청댐 상류유역의 유입량 모의능력을 비교한 결과 abcd모형이 월 물수지모형 중에서는 가장 뛰어났고, 국내에서 널리 사용되고 있는 일 유출모형인 SSARR와 비슷한 모의정확성을 보였다. 다음으로 abcd모형을 금강유역의 12개 소유

일단위 강우-유출모형인 SSARR모형을 이용하여 한강, 낙동강, 섬진강유역에 월 앙상블 유량예측 시스템을 구축하였다. 우선 SSARR모형의 월 평균 유출량에 대한 모의정확성을 평가한 결과 한강과 낙동강유역에서는 과소추정하는 경향이 뚜렷하였으며, 섬진강유역에서는 모의오차의 분산이 커 정확성 개선이 필요하였다. 최적선형 보정기법을 적용하여 SSARR모형의 모의유량을 보정한 결과, 섬진강을 제외한 한강과 낙동강유역의 검증지점에서는 모의 정확성이 크게 개선되었