선행연구를 통해 침수에 대해 저항성과 감수성을 나타내는 야생콩계통을 선발하고 난 뒤 이들 자원들간 지상부 및 지하부 특성을 분석하였고, 유전자의 발현량도 비교 분석하였다. 1. 연구결과, 침수에 대해 저항성을 나타낸 ‘CW11598’과 감수성을 나타낸 ‘CW11948’는 알코올 발효를 촉매하는 PDC와 ADH효소의 활성을 조절하는 mRNA 발현량에서 차이를 보였다. 감수성계통에서 PDC와 ADH 활성을 조절하는 유전자 모두 침수처리에서 무처리보다 유전자 발현량이 감소하였고, 저항성계통해서는 침수처리에서 오히려 무처리보다 이들 유전자의 발현량이 증가하였다. 이런 침수스트레스 대체 경로의 차이는 감수성계통에서 침수처리 무처리보다 줄어든 LSA, TRL 및 RSA로 나타났다. 2. 식생지수 NDVI와 PRI 모두 감수성계통이 침수처리에서 무처리 대비 크게 감소하였다. 하지만 저항성계통에는 LSA는 침수처리와 무처리간 차이가 없었고, 식생지수 NDVI와 PRI도 침수처리와 무처리간 차이를 보이지 않았다. 하지만 TRL와 RSA는 침수처리에서 무처리보다 감소한 것으로 조사되었다.

This study examines the effects of surrounding outdoor environmental characteristics in multi-use public facilities that are used by the susceptible population, on the concentration and distribution of indoor airborne bacteria. For this study, areas were divided into ‘factory area,’ ‘city area,’ and ‘forest area.’ The research was conducted from October 2017 to April 2018, and the selected target facilities were daycare centers, hospitals, postpartum care centers, and nursing homes for the elderly. In order to measure airborne bacteria, indoor air samples were collected using a six-stage viable particulate cascade impactor, and airborne bacteria samples were collected using MCE (Mixed cellulose esters) filters. Moreover, the outdoor airborne bacteria concentration was also measured to determine the concentration ratio (I/O ratio) of the total indoor airborne bacteria and total outdoor airborne bacteria concentrations. The results showed that the total outdoor airborne bacteria concentration was highest in the city area, with 74.2 ± 60.0 CFU/m3, and the lowest in the factory area, with 45.9 ± 35.8 CFU/m3. Furthermore, the distribution of the total outdoor airborne bacteria concentrations significantly differed across each surrounding environment (p < 0.05). On the other hand, no statistically significant difference in total indoor airborne bacteria concentrations, according to surrounding environments, was observed (p > 0.05). These findings suggest that the concentration of outdoor airborne bacteria differs across surrounding environments, unlike that of the indoor airborne bacteria.

To control an external parasitic mite, a honey bee line possessing high hygienic behavior (HHB) against an external parasitic mite, Varroa destructor, has been bred in South Korea and an assessment method has been necessitated to diagnose HHB line from the low hygienic behavior (LHB) line. Thus, in this study, we developed single nucleotide polymorphism (SNP) markers from whole genome sequencing of each 20 worker bees from HHB and LHB lines of A. mellifera ligustica (Hymenoptera: Apidae). An average of 319,445,977 sequence reads was mapped to the known A. mellifera reference genome (an average of 87.46%). In 2,316,128 and 3,266,756 SNPs from each HHB and LHB line, an average of 93.6% and was located in the intergenic spacers and introns, whereas, the remaining 6.4% was located in the genic region, respectively. Among them 20 SNPs that were fixed at each line possessing within-individual homozygosity were selected and each four SNPs were used to diagnose the two honey bee lines either by typical PCR-restriction fragment length polymorphism method or allele-specific PCR. The remaining six SNPs had the size difference, enabling relatively easy differentiation between the two honey bee lines on typical agarose gel and another remaining six SNPs only has sequence difference including SNP sites. Thus, these SNP markers can be used to diagnose the honey bee line with HHB from LHB line against V. destructor.

The respiration rate of PH3 susceptible strain was significantly higher than the resistant strain. The results showed no significant effect of oxygen level on the respiration rate of both strains. Phosphine reduced the respiration rate of both strains when it was applied in average concentrations. However, the rate of respiration of the resistant beetles increased significantly under a high level of phosphine. The increase of respiration rate was associated with the higher emission of VOCs which prove the acceleration of metabolic processes to face the phosphine action for survival. Flat grain beetle Cryptolestes pusillus and rusty grain beetle C. ferrugineus are similar insect species, but only C. ferrugineus is capable to develop a high phosphine resistance. A direct immersion solid phase microextraction gas chromatography-mass spectrometry (DI-SPME-GCMS) technology has identified the different fatty acids from PH3 resistant and susceptible strain of Tribolium castaneum.

The resistance of maize weevil(Sitophilus zeamais), an important agricultural pest of stored grain, on aluminium phosphide fumigant(PH3) has been reported recently in Korea. Many researchers reported that ethyl formate(EF), a potential methyl bromide alternative fumigant, showed good efficacy on several grain pests. In this trial, based on CTP (concentration × time products), we evaluated efficacy of EF on phosphine resistant and susceptible maize weevil. Each of insect strains were collected in grain storehouses and examined the PH3 resistance according to FAO method (Busvine, 1980). L(Ct)90 of PH3 resistant and susceptible strain was 48.3 and 0.3 g h m-3, respectively. When treated with EF, L(Ct)90 of PH3 resistant and susceptible strain was 90.0 and 110.9 g h m-3, respectively. In the case of EF, there was no difference between resistant and sucsecptible strain compare with PH3. These results indicates that EF is a potential alternative for aluminium phosphide resistance management in grain storehouses.

The two spotted mite, Tetranychus urticae Koch, is a global pest, and has developed severe resistance to several types of acaricides. This study compared the development in susceptible (S) and acequinocyl, bifenazate, pyridaben, abamectin and etoxazole-resistant (AcR, BR, PR, AbR and ER) strains of T. urticae by X-ray irradiation. When eggs were irradiated with 100 Gy, the egg hatching was completely inhibited in all strains. When nymphs were irradiated with 200 Gy, their hatching was completely inhibited in all strains. When adults were irradiated, the fecundity and egg hatching was decreased at 150 Gy and above, and hatchability of F1 generation was completely inhibited at 300 Gy in all strains. Adult longevity was slightly increase at 150 Gy and above. In addition, we performed quantitative real-time PCR on several genes. To examine the difference of all strains on radiation stress-induced gene expression, we performed quantitative RT-PCR (qPCR) of several known stress-induced genes.

Three formula types (gel, cookie, and liquid), six commercial roach bait products containing one of active ingredients among Fipronil, Avermectin, Dinotefuran, and Chlorpyrifos were examined against susceptible strain of German cockroach, Blattella germanica (L.). For the results of killing speed (LT50 values), universal killing speed effects depended on bait formula types. The killing speed of liquid bait formula type was the fastest among three formula types. Followed by gel bait type and cookie bait type. However the control speed (LT90 values) effects depended on the active ingredients that contained in roach baits. The baits contained Fipronil were shown the strongest control performance against German cockroaches. Chlorpyrifos was similar with Fipronil. Followed by Avermectin and Dinotefuran.

The melon and cotton aphid Aphis gossypii Glover (Hemiptera; Aphididae) is one of the most serious pests worldwide. We surveyed insecticide susceptibility in A. gossypii field populations to 12 insecticides to examine resistance ratios. The levels of insecticide resistance were extremely high, especially to neonicotinoids. One point mutation was found in the beta1 subunit loop D region of the nicotinic acetylcholine receptor (nAChR) of the imidacloprid-resistant strain. Feeding behavior analysis using an electrical penetration graph showed that sublethal doses of imidacloprid had significant effects on the duration of phloem ingestion. In addition, higher doses of imidacloprid induced contact toxicity rather than inhibition of feeding behavior. Temperature and insecticide are two important factors that affect survival, reproduction and other physiological processes of insects. To determine interactions of temperature and insecticide treatment on susceptible and imidacloprid-resistant strains of A. gossypii, adults were exposed to three temperatures (17, 22, and 28℃) or combinations of three temperatures and imidacloprid (LC20), and the expression of several genes (heat shock protein 70, cuticle protein, cytochrome P450, and elongation factor) were analyzed. Additionally, the effect of electron beam irradiation on development, reproduction, and several gene expression of imidacloprid-resistant and -susceptible A. gossypii were compared.

Temperature and insecticide are two important factors that affect survival, reproduction and other physiological processes of insects. To determine interactions of temperature and insecticide treatment on susceptible (S) and imidacloprid-resistant strains (IMI-R) of Aphis gossypii, adults were exposed to three temperatures (17, 22, and 28℃) or combinations of three temperatures (17, 22 and 28℃) and imidacloprid (LC20), and the expression of several genes (heat shock protein 70, cuticle protein, cytochrome P450, and elongation factor) were analyzed. The expression level at 17℃ of heat shock protein 70, cuticle protein, and elongation factor in S strain were up-regulated with increased time and higher than those of IMI-R strain. However, expression of cytochrome P450 was not affected by elevated temperature both S and IMI-R strain. Combined treatment of elevated temperature and imidacloprid were significantly up-regulated only cuticle protein in S strain and higher than those of IMI-R strain.

This study compared the development, reproduction, and DNA damage in insecticide (acequinocyl, bifenazate, and etoxazole)-resistant (AR, BR, and ER) and -susceptible (S) strains of Tetranychus urticae by electron beam irradiation. When eggs were irradiated with 150 Gy, the egg hatching was completely inhibited in all strains. When nymphs were irradiated, their emergence rate was decreased with increasing doses of electron beam irradiation. When adults were irradiated, the longevity and the number of eggs was not affected at all target dose in all strains. However, hatchability of F1 generation was perfectly inhibited at 400 Gy in all strains. The DNA damage caused by electron beam irradiation was evaluated by an alkaline comet assay. These results suggest that electron beam irradiation induced abnormal development and reproduction in S, AR, BR, and ER strains of T. urticae.

The Riptortus (stinkbug) has a specialized symbiotic organ, M4 midgut, to harboring symbiont Burkholderia. M4 midgut is located in abdomen and surrounded with insect hemolymph. Recently our group demonstrated that symbiotic Burkholderia showed different physiology after adapting in M4 gut compare with in vitro cultured Burkholderia. And population of symbiotic Burkholderia in the M4 midgut is regulated by special organ. However, the molecular mechanism to prevent spreading and migrating symbiont bacteria to other host tissues from symbiotic organ is not clear. Therefore, we assumed that symbiont Burkholderia are susceptible to host humoral immunity after established infection in M4 midgut to prevent spreading and migrating into the other host tissues through Riptortus hemolymph. To prove this assuming, we tested the susceptibility and survival rate of symbiont Burkholderia in hemolymph of Riptortus in vitro and in vivo. We also examined the susceptibility of symbiont Burkholderia using purified antimicrobial peptides (AMP), pyrrhocoricin-like, thanatin-like and defensin-like AMPs. Finally, we tested inducing ability for AMPs by systemic infection of symbiotic Burkholderia. Gene expression of purified AMPs was not different after systemic infection of both symbiont and in vitro cultured Burkholderia. Surprisingly, in vitro cultured Burkholderia resisted on bacteria injected hemolymph and purified AMPs but symbiont Burkholderia were highly susceptible in bacteria injected hemolymph and purified AMP. These results suggest that symbiont Burkholderia can't survive in the hemolymph after escaping symbiotic organ. Moreover, humoral immunity of host Riptortus is important to prevent spreading and migrating symbiont Burkholderia into the other host tissue or organ from symbiotic organ.

The effect of electron beam irradiation on development and reproduction of susceptible strain (S) and imidacloprid-resistance strain (IMI-R) of Aphis gossypii were compared. Nymphs and adults of S and IMI-R strain were irradiated at target doses of 50, 100, 150, and 200 Gy. When nymphs were irradiated, emergence rate was not affected at all target dose, but number of F1 nymphs was perfectly inhibited at 150 Gy in both strains when irradiated to the adults, longevity slightly decrease at 150 Gy and above. Fecundity was strongly decreased at 100 Gy, but was not completely inhibited even at 200 Gy. Emergence rate of F1 nymph was decreased at 100 Gy and completely inhibited at 200 Gy. However, there was no significant differences on development and reproduction of S and IMI-R strain. We also conducted the comet assay immediately after irradiation and over the following 7 day periods. In addition, we performed quantitative real-time PCR on several genes.

The effect of electron beam irradiation on development and reproduction of imidacloprid-resistant (R strain) and -susceptible (S strain) Aphis gossypii were compared. Nymphs and adults of R and S strain were irradiated at target doses of 50, 100, 150, and 200 Gy. When nymphs were irradiated, emergence was not affected at all target dose, but number of F1 nymph was perfectly inhibited at 150 Gy in both strains. When irradiated to the adults, longevity slightly decrease at 150 Gy and above. Fecundity was strongly decreased at 100 Gy, but was not completely inhibited even at 200 Gy. Emergence of F1 nymph was decreased at 100 Gy and completely inhibited at 200 Gy. However, there were no significant differences on development and reproduction of R and S strain. We also conducted the comet assay immediately after irradiation and over the following 10 day period. Severe DNA fragmentation in A. gossypii cells was observed just after irradiation and the damage was repaired during the post-irradiation period in a time-dependent manner. These results suggest that electron beam irradiation induced abnormal development, reproduction, and DNA damage in A. gossypii, but there were no significant differences between R and S strain.

The toxicity of red pine needle hydrodistillate, its constituents, and 12 structurally related compounds to third instar larvae of insecticide-susceptible Aedes aegypti and wild Aedes albopictus was examined using a direct-contact bioassay. Results were compared with those of the currently used larvicides fenthion and temephos. The red pine needle hydrodistillate constituents were identified by GC-MS and co-elution of authenticated samples following co-injection. Based on 24 h LC50 values, 3-carene (8.60–9.33 mg/L), limonene (10.34–10.77 mg/L), and thymol (10.65–11.45 mg/L) were the most toxic constituents. The moderate toxicity was produced by (1S)-(–)-α-pinene, p-cymene, geranyl acetate, myrcene, and β -caryophyllene (LC50, 27.62–38.01 and 28.61–39.52 mg/L). Overall, these compounds were less effective than either fenthion (LC50, 0.012–0.022 mg/L) or temephos (LC50, 0.010–0.015 mg/L). In the light of global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment, red pine needle hydrodistillate and the compounds described merit further study as potential larvicides for the control of mosquito populations.

The toxicity of materials derived from the seed of Pongamia pinnata to third instars of insecticide-susceptible Culex pipiens pallens and Aedes aegypti and wild Aedes albopictus was examined using a direct contact bioassay. Results were compared with those of the currently used insecticides fenthion and temephos. The active principles of Pongamia pinnata were identified as the karanjin (1), karanjachromene (2), pongamol (3), pongarotene (4), oleic acid (5), and palmitic acid (6) by spectroscopic analysis. Based on 24 h LC50 values, karanjin (14.61 and 16.13 mg/L) was the most toxic compound, followed by oleic acid (18.07 and 18.45 mg/L) and karanjachromene (18.74 and 20.57 mg/L). These constituents were less toxic than either fenthion (LC50, 0.0031 and 0.0048 mg/L) or temephos (0.021 and 0.050 mg/L) against Ae. aegypti and Cx. p. pallens. Low toxicity was produced by pongamol (LC50, 23.95 and 25.76 mg/L), pongarotene (25.52 and 37.61 mg/L), and palmitic acid (34.50 and 42.96 mg/L). Against A. alpopictus instars, oleic acid (LC50, 18.79 mg/L) was most toxic. Low toxicity was observed with the other five constituents (LC50, 35.26- 85.61 mg/L). P. pinnata seed-derived active principles, particularly karanjin, karanjachromene, and oleic acid, merits further study as potential mosquito larvicides for the control of mosquito populations in light of global efforts to reduce the level of highly toxic synthetic larvicides in the aquatic environment.

Three rice planthoppers, the brown planthopper (Nilaparvata lugens), the white back planthopper (Sogatella furcifera), and the small brown planthopper (Laodelphax striatellus) and the green rice leafhopper (Nephotettix cincticeps) are major homopteran sap-sucking rice pests in Korea. These insect pests commonly have highly modified mouthparts, the stylet bundle, for piercing and sucking. Two pairs of mandibular and maxillary stylets consist of the stylet bundle by interlocking each stylet, which forms the two canals, larger one for food canal and smaller one for salivary canal. Destructive damages result from direct feeding effects (hopperburing) with heavy infestation and/or transmitting virus diseases (Rice stripe virus and Rice black-streaked dwarf virus by L. striatellus and Rice dwarf virus by N. cincticeps). Damage level is closely related to the feeding behavior of sap-sucking insects, so generally honeydew excretion amount on the resistant rice variety is smaller than that on the susceptible. Therefore, the method to measure the honeydew excretion amount has been primarily used as an indirect way to compare the feeding amount between the susceptible and the resistant. On the other hand, the electrical penetration graph (EPG) technique was firstly developed by McLean and Kinsey (1964) to measure voltage changes during piercing and sucking of insect on the plant. Since specific voltage waveforms were identified and it was known that each waveform is commonly related to salivary and feeding behavior of insect stylets in the plant tissue, EPG technique has been used to real-timely and quantitatively measure feeding behavior of piercing and sucking insects on susceptible and resistant rice variety. However, identifying each different waveform distinctly and understanding biological function of each waveform are certainly necessary to analyze feeding behavior in the plant tissue such as phloem sap ingestion. In this study, the stylet penetration behavior of N. lugens, S. furcifera, L. striatellus, and N. cincticeps on rice plants (Oryza sativa) was evaluated through the use of a direct current based electrical penetration graph (DC-EPG). To accomplish this, we classified the EPG waveforms of planthopper group into seven different patterns, np, N1, N2, N3, N4-a, N4-b, and N5, according to their shapes, voltage amplitudes, voltage levels, and frequencies. The N4-b pattern was always preceded by N3 and N4-a, in that order. Continuous honeydew excretion only occurred during the N4-b period, and the honeydew deposited on a filter paper containing ninhydrin reagent during the N4-b period were stained into violet. Based on the location of the stylets in the cross-section of rice tissue and honeydew excretion, the EPG waveforms for the stylet penetration behaviors of the three rice planthoppers were assigned to the following groups; np: non-penetration of stylets, N1: penetration initiation, N2: salivation and stylet movement, N3: an extracellular activity near the phloem region, N4-a: an intracellular activity in phloem region, N4-b: phloem sap ingestion, and N5: activity in the xylem region. Futhermore, we classified the EPG waveforms of the green rice leafhopper, N. cincticeps into seven different patterns, Nc1, Nc2, Nc3, Nc4, Nc5, Nc6, and Nc7 according to their shapes, voltage amplitudes, voltage levels, and frequencies. The Nc6 pattern was always preceded by Nc5 pattern. The Nc6 pattern of the leafhopper was carefully considered as a phloem sap feeding behavior based on regular honeydew excretion. On the other hand, the planthopper group and the leafhopper hardly showed the phloem sap feeding pattern on resistant rice varieties during an EPG-recording. In addition, the duration of the phloem sap feeding patterns was highly decreased on resistant rice varieties relative to susceptible ones. From these results, it is suggested that the phloem sap feeding related patterns are an important parameter to determine resistance of rice plant.

The toxicity of imperatorin (1) and osthol (2) identified in Cnidium monnieri seed and four structurally related compounds to third instar larvae of insecticidesusceptible (KS-CP strain) and field-collected (DJ-CP colony) of Culex pipiens pallens was examined. Results were compared with those of to conventional mosquito larvicide, fenitrothion and temephos. Based on 24-h LC50 values, imperatorin was 1.9, 3.7, 4.2, 12.4, and 15.1 times more toxic than isopimpinellin, isoimperatorin, osthole, xanthotoxin, and bergapten against KS-CP larvae, respectively. Overall, these compounds were less toxic than either fenitrothion or temephos. However, these compounds did not differ in toxicity against larvae from the two Culex strains, even though the DJ-CP larvae exhibited high levels of resistance α-cypermethrin, deltamethrin, chlorpyrifos, fenthion, and chlorfenapyr (resistance ratio, 94-1179). This finding indicates that the isolated compounds and the pyrethroid, organophosphorus, and pyrrole insecticides do not share a common mode of action or elicit cross-resistance.

Vapormate™, a new gas formulation of ethyl formate (EF) with carbon dioxide, is an alternative fumigant to methyl bromide (MB). The efficacy of the vapormate fumigation was evaluated on an acaricide susceptible and resistant Tetranychus urticae strains. A resistant strain showed resistance ratio (RR) of 21.9 and 379.6 to acrinathrin and chlorfenapyr, respectively. Fumigation was done in desiccators (6.8 L) which were empty or filled 30% in space with paprika for 6 h at 15℃ in the laboratory. The concentration adopted were 9.6, 17.2, 24.5, 36.4 mg/L in empty desiccator and 10.2, 17.9, 24.9, 35.2 mg/L in paprika-filled desiccator. In empty desiccator, susceptible and resistance T. urticae showed 100% mortality at higher concentration than 17.2 and 24.5 mg/L, respectively. In paprika-filled desiccator, susceptible and resistance T. urticae showed 100% mortality at higher concentration than 24.9 and 35.2 mg/L, respectively. Hatchability was greatly reduced by the fumigation. Hatchability was 3.7% in the empty desiccator at 9.6 mg/L and 37.2% in the paprika-filled desiccator at 10.2 mg/L.