Toxicities of 10 insecticides were examined against late third instars of Culex tritaeniorhynchus using the direct-contact mortality bioassay. Six geospatially distant field mosquitoes were collected from Chuncheon-si (designated CC-CT), Hwaseong (HS-CT), Seosan (SS-CT) Jeonju (JJ-CT), Daegu (DG-CT), and Busan (BS-CT) in the Republic of Korea (ROK). Marked regional variations of insecticide susceptibility were observed. Field populations of SS-CT, JJ-CT and DG-CT from agricultural areas showed higher to extremely higher insecticide susceptibility to pyrethroids than those of CC-CT, HS-CT and BS-CT strains from none agricultural areas. Extremely high to low levels of susceptibility were measured: bifenthrin, susceptible ratio (SR) = 2.7–896.3; β-cyfluthrin, SR = 1.8–633.3; α-cypermethrin, SR = 1.2–1,051.9; deltamethrin, SR = 1.3–711.1; permethrin, SR = 1.5–1,053.4 etofenprox, SR = 2.2–29.3; chlorfenapyr, SR = 5.1–103.6; chlorpyrifos, SR = 2.3–337.0; fenitrothion, SR = 2.0–142.3 and fenthion, SR = 1.4–186.2. Culex tritaeniorhynchus populations from rice paddies had been under heavy selection pressure due to the agricultural insecticides and that’s why the mosquito species demonstrated high resistance to pyrethroids which were used for a long time to control agricultural pests in the localities. These results indicate that careful selection and rotational use of these insecticides mayresult in continued satisfactory control against field populations of Japanese encephalitis vector mosquitoes.
An assessment was made of the toxicity of 12 insecticides, three essential oils and Bacillus thuringiensis var. israelensis (Bti) alone or in combination with the oil major constituents, (E)-anethole (AN), (E)-cinnamaldehyde (CA) and eugenol (EU), to third instars from bamboo forest collected Aedes albopictus and rice paddy field collected Anopheles sinensis resistant to various groups of insecticides. The toxicity of the test insecticides, essential oils and binary mixtures of Bti and the oil constituents (1:1 ratio) was evaluated using a direct-contact mortality bioassay. Binary mixtures of B.t.i. and CA, AN or EU were significantly more toxic against Ae. albopictus larvae (LC50, 0.0084, 0.0134 and 0.0237 mg/l) and An. sinensis larvae (0.0159, 0.0388 and 0.0541 mg/l) than either B.t.i. (1.7884 and 2.1681 mg/l) or CA (11.46 and 19.43 mg/l), AN (16.66 and 25.11 mg/l) or EU (24.60 and 32.14 mg/l) alone. Based on the co-toxicity coefficient (CC) and synergistic factor (SF), the three binary mixtures operated in a synergy pattern (CC, 140.7–368.3 and SF, 76–213 for Ae. albopictus CC, 75.1–245.3 and SF, 40–136 for An. sinensis).The binary mixtures of Bti and essential oil constituents described, particularly (E)-cinnamaldehyde, merit further study as potential mosquito larvicides for the control of malaria vector mosquito populations in light of global efforts to reduce the level of highly toxic synthetic insecticides in the aquatic environment.
황사는 태양광, 대기 가스, 에어로졸, 해양생태계와 상호작용하여 지구 기후에 영향을 미치며, 광물특성은 이와 같은 황사와 환경의 상호작용 이해에 필수적이다. 이 연구에서는 2015년 2월 22일 인천광역시 덕적도에서 포집된 황사시료의 광물특성을 분석하였다. X선회절분석(XRD) 결과, 층상규 산염광물이 총 62 wt%이었는데, 일라이트류 점토광물(일라이트 및 일라이트-스멕타이트 혼합층)이 55%로 함량이 가장 높았으며, 그 외 녹니석이 5%, 캐올리나이트가 2% 정도 함유되어 있었다. 비층상 규산염 광물로서 석영 18%, 사장석 10%, K-장석 4%, 방해석 5%, 석고 1% 등이 함유되어 있었다. 주 사전자현미경(SEM)과 에너지분산분광분석(EDS)에 의한 황사 개별 입자의 광물학적 분석에서도 유사 한 조성이 얻어졌다. 황사의 주성분인 극미립 층상규산염광물입자에 대하여 투과전자현미경(TEM) 및 EDS 분석을 실시한 결과, 다양한 성분비율과 혼합양상을 보이는 일라이트류 점토광물이 주요 광물로 확인되었다. SEM 형태 관찰에 의하면 황사입자들은 점토광물이 주성분인 덩어리, 혹은 점토광물로 피복된 석영, 장석, 운모 입자들로 구성되어 있었다. 석고가 점토와 함께 황사입자표면에서 자주 관찰 된 반면, 이전에 황사입자에 흔히 수반되는 것으로 보고된 섬유상 방해석은 드물어서, 황사 이동 중에 방해석이 산성대기오염물과의 반응에 의하여 석고로 변한 것으로 추정된다. 2015년 분석 결과는 황사 와 환경의 상호작용 모델링을 위한 광물의 대표 특성 수립에 기여할 것이다.
Methyl jasmonate(MeJA) treatment promotes the plant secondary, especially triterpene saponin which is main compounds in Platycodon grandiflorum. We were performed 5,760 expressed sequence tags from MeJA treated hairy root. Total number of ESTs are 2,536 (811 contigs and 1,725 singletons) among them 2,299 are pass the annotation. The most abundant transcript were encoding fatty acid desaturase (FAD) and lots of secondary metabolite transcript were observed. Four MVA pathway genes (HMGS, HMGR, MK, MDD) and one MEP pathway gene (IDI) are identified. The unigene were classified into three major functional categories by standard GO (Gene Ontology) - cellular component, molecular function and biological process. In this study we were cloned four genes from ESTs : HMGS (1401bp ORF), MK (1167bp ORF), MDD (1254bp ORF), IDI (909bp ORF)