This study was conducted to investigate effect of feeding beet pulp on reproductive performance, colostrum composition and microbiological characteristics in sows. A total of 12 sows(Landrace×Yorkshire) were randomly allotted three dietary treatments at gestating 90 days. The diets were prepared by adding 0, 5 and 10% of the beet pulp in basal diets. The pigs fed 5% beet pulp showed higher litter size than the 0 and 10% beet pulp treatments, although there was not significant among the treatments. Similarly, birth and 21days weight in piglet were not different among the treatments. In colostrum fat, protein, lactose, citric acid, solid, ffa, true protein were ranged to reference values, but not difference among the treatments. E.coli of feces was lower(P<0.01) in the 5% beet pulp than the 0 and 10% beet pulp treatments. But no effect was observed on Lactobacilli of feces among dietary treatments. These our results indicate the beet pulp has no significant effect of reproductive performance and colostrum composition in sows. But, 5% level beet pulp is effective for reduction of intestinal pathogenic microorganisms.

Insect-killing fungi have high potential in pest management. A deeper insight into the fungal genes at the whole genome level is necessary to understand the inter-species or intra-species genetic diversity of fungal genes, and to select excellent isolates. In this work, we conducted a whole genome sequencing of Beauveria bassiana (Bb) JEF-007 and characterized pathogenesis-related features and compared with other isolates including Bb ARSEF2860. A large number of Bb JEF-007 genes showed high identity with Bb ARSEF2860, but some genes showed moderate or low identity. The two Bb isolates showed a significant difference in vegetative growth, antibiotic-susceptibility, and virulence against Tenebrio molitor larvae. When highly identical genes between the two Bb isolates were subjected to real-time PCR, their transcription levels were different, particularly in heat shock protein 30 (hsp30) gene which is related to conidial thermotolerance. In several B. bassiana isolates, chitinases and trypsin-like protease genes involved in pathogenesis were highly conserved, but other genes showed noticeable sequence variation within the same species. Given the transcriptional and genetic diversity in B. bassiana, a selection of virulent isolates with industrial advantages is a pre-requisite, and this genetic approach could support the development of excellent biopesticides with intellectual property protection.

The Asian corn borer, O. furnacalis (Crambidae) and the old world bollworm, H. armigera (Noctuidae) simultaneously cause ear damage in corn in Suwon area. It has been assumed that the second generation of larvae of both insects is responsible for the damage. We, therefore, studied proper spray timing of insecticide in order to reduce the damage. A waxy corn hybrid cultivar, Ilmichal, was sown directly on four plots of a field at April 10, April 20, May 4, and May 18, 2018, respectively. A sodium channel blocker, indoxacarb, was sprayed eight times at 3- or 4-day intervals around the silking stage of corn in each sowing plot. At ear harvest time of each plot, we investigated damaged ratio and length of ear, and the numbers of both insect species. The significantly effective spray timings on reduction of ear damage were the sprays at June 29 and July 2 in the plot sown at April 10, the sprays from July 2 to 13 in the April 20-sown plot, the sprays from July 2 to 19 in the May 4-sown plot, and the sprays at July 19 in the May 18-sown plot, respectively. The damage level was positively related to the insect number. The result indicated that the spray at the silking stage of corn was effective on reduction of ear damage. It was assumed that occurrence time of neonate larvae of the insects at silking stage cause the damage, based on the experimental results using screened pots inoculated with the two species.

The continuous emergence of chemical-mediated residual toxicity and insect resistance have enforced the regulation of synthetic pesticides. Synthetic pesticides with novel mode of actions could be developed to overcome these issues, but as an alternative biopesticides with more efficacious control activity could be developed by the advanced technology. In pest management, entomopathogenic fungi have high potential in reducing pest population to an economic threshold, and some of isolates have been commercialized. However still a novel application strategy needs to be considered for successful industrialization. An insight on fungal genes in whole genome and transcriptome levels is necessary to understand the role of genes in pathogenesis and genetic diversity of fungal genes. Herein, we have identified the genetic differences of entomopathogenic fungi using whole genome sequencing of Beauveria bassiana (Bb) and tried to understand the interaction between fungus and insect using RNA-seq. We have obtained the whole genome sequence of Bb JEF-007 using PacBio sequencing technology and compared the transcriptomes of Bb JEF-007 and bean bug, Riptortus pedestris before and after the fungal infection using Hiseq 2000 system.

Entomopathogenic fungi have been known as promising candidates for biological control of insect pests. Recently, researchers consider the fungal thermotolerance in formulations and field applications. In this study, we investigated the production of thermotolerant Isaria javanica and I.fumosorosea conidia through grain-based solid cultures and exposure to light stress. As results, of the ten grain substrates, Italian millet, rice, perilla seed and sesame, rice, sorghum produced highly thermotolerant conidia in the strains. The two strains were exposed to a light stress and showed enhanced thermal stability compared to control, when exposed to 45°C for 2 hours. This work suggests that heatresistant entomopathogenic fungal conidia can be produced by grainbased solid cultures and exposure to light stress.

과일이나 농작물의 부패 및 발효 환경에서는 Methanol, Ethanol, Acetic acid을 비롯한 다양한 화학물질들이 생산된다. Drosophila melanogaster는 이러한 발효·부패 환경에 서식하면서 일정 농도 이상의 다양한 화학물질에 지속적으로 노출되어 생존하도록 적응되어온 것으로 생각된다. 다양한 화학물질이 포함한 환경에 안정적으로 서식하기 위해서는 D. melanogaster는 화학물질에 능동적으로 반응하여 해독 유전자나 대사 관련 유전자의 발현량을 변화 시킴으로써 발효·부패 환경에서 생성되는 화학물질에 대한 높은 내성을 가지고 있을 것으로 판단된다. 현재까지 유전자의 발현량 측정을 위해 real-time PCR를 이용하여 reference gene의 발현량을 기준으로 정량화하는 방법이 가장 널리 사용되고 있다. 그러나 조직별, 환경별, 발달단계를 비롯한 다양한 조건에서 안정적으로 발현되는 reference 유전자 선정이 필수적으로 선행되어야 하므로 본 연구에서는 발효·부패 환경에서 생산되는 두 화학물질인 Methanol과 Ethyl Acetate에 노출된 D. melanogaster에서 안정적으로 발현되는 reference gene을 찾는 연구를 실시하였다. 본 연구에서는 다양한 농도의 Methanol과 Ethyl Acetate을 D. melanogaster에 노출시킨 후 RNA 추출과 cDNA 합성을 실시였고, 5가지 후보 reference gene (hsp22, nd, rpL18, tbp and ef-1b)의 안정적 발현 여부를 qRT-PCR을 통해 조사하였으며, 유전자 발현의 안정성을 측정하는 3가지 프로그램(geNorm, NormFinder, BestKeeper)을 이용해 비교·분석하였다. 본 학회에서는 연구의 과정과 그 결과를 발표하고자 한다.

Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is considered as a serious pest in pine trees. To develop an eco-friendly strategy to manage this forest insect, we collected entomopathogenic fungi from Korean soil and assessed their virulence against the adults of the insect in laboratory conditions. As a result, two isolates with conidial suspension (1.0×107conidia/ml), showed 87% and 90% mortality 12 days after fungal treatment, respectively. We assessed the potential of the fungi-derived destruxin and protease as additives to the fungal isolates, and they showed insecticidal activity via feeding and spraying treatments. Finally, we produced fungal conidia in massive solid cultures and formulated wettable powders, and now studying optimal conditions of oil-based formulation with two isolates. Based on these results, we are evaluating the control efficacy of the fungal agents against M. alternatus in field conditions.

본 연구에서는 국내 유통 중인 농산물 9품목(n = 578)에 대한 납과 카드뮴 함량을 조사하고 이들의 섭취로 인한 위해성을 평가하고자 하였다. 납과 카드뮴의 함량은 마이크로웨이브 분해 후 ICP-MS로 분석하였다. 조사대상 농산물의 납 평균 함량은 각각 보리 0.014 mg/kg, 완두콩 0.010 mg/kg, 강낭콩 0.008 mg/kg, 녹두 0.006 mg/kg, 파인애플 0.008 mg/kg, 살구 0.016 mg/kg, 매실 0.015 mg/kg, 자두 0.021 mg/kg, 대추 0.019 mg/kg이었고, 카드뮴 평균함량은 보리 0.017 mg/kg, 완두콩 0.004 mg/kg, 강낭콩 0.007 mg/kg, 녹두 0.005 mg/kg, 파인애플 0.001 mg/kg, 살구 0.002 mg/kg, 매실 0.002 mg/kg, 자두 0.002 mg/kg, 대추 0.003 mg/kg이었다. 모든 시료의 납, 카드뮴 함량은 EU, CODEX 및 국내 기준보다 낮은 수준이었다. 조사 대상 농산물에 대한 납, 카드뮴의 인체노출량을 산출한 결과, 납은 잠정주간섭취허용량(PTWI, 25 μg/kg b.w./week)의 0.067%, 카드뮴은 월간잠정섭취허용량(PTMI, 25 μg/kg b.w./month)의 0.28%이었다. 이상의 결과는 조사 대상 농산물의 납, 카드뮴 오염도와 이들의 섭취에 의한 위해성이 모두 낮은 수준이라는 것을 보여준다.

벼메뚜기의 인공사료 개발을 위하여 일본의 Konno식 먹이를 대조구로 하고, 28개의 배합비율별 인공사료를 제작하여 급이시험을 하였다. 시험결과, Konno식 보다 6주 후 1마리당 체중은 22개 처리에서 높았고 우화성공율은 23개 처리에서 높았다. 폐사율은 부화입식 후 45일까지 Konno식 대비 24개 처리에서 높았다. 1마리당 체중, 우화성공율, 폐사율을 종합해 볼 때 탄수화물원으로는 옥수수 건조잎 분말 또는 통밀가루와 단백질원으로는 2~5%의 탈지대두분 또는 어분의 배합비율이 벼메뚜기의 인공사료로서 가능성이 높았다.

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pest species devastating many horticultural and ornamental crops and fruit trees. In the present study, a field strain was collected in January 2001 and has been selected for sixteen years with acequinocyl. The resistance ratio calculated from the LC50 of eggs and adults was 191- and 4,237-fold, respectively. The laboratory-selected acequinocyl resistance (LSAR16) strain was screened with 11 acaricides for cross-resistance. The detoxifying enzyme activities and quantitative real-time PCR analysis were performed in the LSAR16 strain. Crossing experiments revealed that LSAR16 strain was inherited maternally, incompletely dominant and monogenic. Most importantly, we identified two new point-mutations at mitochondrial cytb from acequinocyl resistant T. urticae.

Beauveria bassiana (Bb) is a potential biopesticide against western flower thrips. To understand molecular characteristics of two Bb isolates (ERL836 and JEF-007), whole genome sequencing and RNA-seq were performed. The whole genome of Bb ERL836 was sequenced (3,934,801,443 bp) using Pacbio sequencing and 15 contigs were analyzed. To understand the molecular mechanisms of pathogenicity in two Bb genome (before infection and after infection), next generation sequencing (NGS) was analyzed to compare transcriptomes. A result of differentially expressed gene (DEG) showed that 2,689 contigs were up-regulated and 2,619 contigs were down-regulated. Randomly selected five genes were validated to be highly up-regulated. This work can provide an understanding of the interaction between Bb and westetn flower thrips.

Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae) in forest is considered as a serious forest pest in pine trees. In this study, we collected entomopathogenic fungi from soil and assessed their virulence against the adults of the inset using a spray method in laboratory condition. Two entomopathogeinc fungi isolates showed high virulence against the adults. In the concentration of 1.0 × 107conidia/ml, the mortality rate of the adults were 53% and 60%. In semi-field condition, one isolate showed a virulence of 60% against the adult. Consequently, we confirmed the possibility of the fungal isolates in controlling the beetles. In near the future, we will investigate several factors which is possibly related to the control of the forest insect pest using entomopathogenic fungi in field conditions, given the importance of fungal formulation and practical application methods.

The hard tick, Haemaphysalis longicornis (Ixodida: Ixodidae) is one of the vectors of severe fever with thrombocytopenia syndrome virus (SFTSV) causing in humans, however little consideration was given to the biological control of the pest. Therefore, this study provides a screening method to select entomopathogenic fungi, having high virulence against H. longicornis. The virulence test was conducted by dipping method with a conidial suspension (1×107 conidia/ml). As a result, cadavers of H. longicornis infected with entomopathogenic fungi were obtained by this method. Based on this results, we selected several isolates having high virulence to H. longicornis. We suggest that, selected isolates in this study can be used for the control of H. longicornis.

Entomopathogenic fungi have been known as promising candidates for biological control of insect pests. Recently, researchers consider the fungal thermotolerance in formulations and field applications. In this study, we investigated the production of thermotolerant Isaria javanica and I.fumosorosea conidia through grain-based solid cultures and exposure to light stress. As results, of the ten grain substrates, Italian millet, rice, perilla seed and sesame, rice, sorghum produced highly thermotolerant conidia in the strains. The two strains were exposed to a light stress and a heat stress. And they showed enhanced thermal stability compared to control, when exposed to 45°C for 2 hours. This work suggests that heat-resistant entomopathogenic fungal conidia can be produced by grain-based solid cultures and exposure to light stress.

Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae) is a serious insect pest of various crops in the world. The management of this pest mainly have relied on chemical agents. However, the overuse of chemical agents for long times causes insect resistance, and negative effects on environment. Therefore, alternative control methods, such as biological control, that are less harmful to the environment and have different mode of action are needed to control this pest. In this study, we isolated entomopathogenic fungi from Korean soil, and characterized them via morphological and molecular identifications and pathogenicity check against Tenebrio molitor larvae. The isolated fungi were subjected to virulence assay against T. Palmi with a conidial suspension of 1×107 conidia/ml in laboratory conditions. This entomopathogenic fungi library would be a good resource to select effective strains for the control of T. palmi in fields.

Entomopathogenic fungi play an important natural role in regulating their insect host populations, and their ecology was also associated with plant and soil. These microorganisms have been living by reacting to insect, plant and environmental factor. The advanced bioinformatics technology such as next-generation sequencing and RNA sequencing has revolutionized in understanding of entomopathogenic fungi. Recently studies provided a lot of information on evolutionary relationships and virulence-related characteristics. We are starting to know where these microorganisms from is, and how they live in nature. The bioinformatics technology will give us further our understanding of the natural roles of these fungi in nature.