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.

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.

Insecticidal crystal toxins from the bacterium Bacillus thuringiensis (Bt) kill insects via a complex mode of action resulting in the creation of cytolytic pores in the membrane of midgut epithelial cells. These toxins are expressed in transgenic cotton and maize which have been adopted worldwide to control lepidopteran pests while reducing dependence on chemical insecticides. However, insect resistance to Bt toxins is increasing in certain key pest species. Beginning with Heliothis virescens, genetic studies in Bt-resistant Lepidoptera and Coleoptera have found mutations in ABC transporters. Cry1A, Cry1C, Cry2A, and Cry3B toxins each appear to target a different member of the ABC superfamily. These studies confirm the essential role of ABC proteins in Bt toxin mode of action. It is proposed that ABC proteins assist in the insertion of the toxin into the midgut epithelial membrane, a crucial step for which the mechanism has not been known in detail. Properties of ABC transporters suggest strategies to increase efficacy of Bt toxins and to delay the evolution of Bt toxin resistance in target insect pests.

Resistance development in insect pests against pesticides is one of the most important issues for pest management. Biological control is an attractive strategy for suppressing insects that have become resistant to chemical pesticides. The smaller tea tortrix Adoxophyes honmai (Lepidoptera: Tortricidae) is a serious pest of tea and has acquired resistance to various chemical pesticides, and baculovirus agents have been developed to control this pest in Japan. However, there was great concern about whether A. honmai might also acquire resistance against baculoviruses. To address this question, we developed a model resistant population and studied the mechanism of resistance in A. honmai against baculoviruses. A population of A. honmai that is resistant to nucleopolyhedrovirus (NPV) was selected by exposing a field-collected A. honmai population to the 70% lethal concentration (LC70) of NPV over multiple generations in the laboratory. After 155 generations, the selected strain (Resistant strain; R-strain) showed over 400,000-fold higher resistance to AdhoNPV than the non-selected strain (Susceptible strain; S-strain). In this presentation, mode of resistance of R-strain against baculoviruses were discussed.

폴리드나바이러스(polydnavirus: PDV)는 일부 내부기생봉에 공생하는 이중나선형 DNA 바이러스 분류군이다. Cotesia plutellae bracovirus (CpBV)는 프루텔고치벌(C. plutellae)에 공생하는 일종의 PDV이다. 프루텔고치벌은 어린 배추좀나방(Plutella xylostella) 유충에 기 생한다. 기생 초기에 발현하는 CpBV-ELP1 유전자는 혈구세포에 세포독성을 발휘하면서 기주의 세포성 면역을 억제하여 기생에 중요한 역할을 담당하고 있다. 본 연구는 이 유전자를 담배 식물에서 발현하여 해충에 대한 경구독성을 분석하는 데 목적을 두었다. 재조합 CpBV-ELP1 단백질 이 배큘로바이러스 발현시스템을 통해 합성되어 세포배양액에 분비되었다. 수거된 세포배양액은 일련의 단백질 분리과정(ammonium sulfate 단백질 분획, size exclusion 크로마토그래피, 이온교환 크로마토그래피)을 통해 CpBV-ELP1 단백질을 분리하는 데 이용되었다. 분리된 rCpBV-ELP1 단백질은 파밤나방(Spodoptera exigua) 혈구에 대한 뚜렷한 세포독성을 보였다. CpBV-ELP1은 파밤나방 5령충에 대해서 혈강 주입하여 살충력을 나타냈고, 엽침지법을 이용하여 경구독성을 갖고 있는 것을 확인하였다. CpBV-ELP1 유전자를 CaMV 35S 유전자 프로모터 와 opaline synthase 유전자 전사종결신호를 갖는 pBI121 벡터에 클로닝하여 Agrobacterium tumefaciens LBA4404 세균에 형질전환을 유도하였 다. 형질전환된 세균은 담배(Nicotiana tabacum Xanthi)잎에 감염하여 캘러스를 유도하게 하였고 이후 차세대(T1)를 확보하였다. T1 세대 담배 는 파밤나방에 대한 해충저항성을 갖고 있음을 확인하였다. 이러한 결과는 CpBV-ELP1 유전자가 형질전환작물을 통해 해충방제에 응용될 수 있 다는 것을 제시하고 있다.

Polydnaviruses (PDVs) are a group of insect viruses and symbiotic to some endoparasitoid wasps. Genome analyses of different PDVs provide a number of genes putatively associated with alteration of host insect physiological processes. Especially, PDV gene products assist host wasp development by suppressing immune responses and delaying larval development of parasitized lepidopteran hosts. Thus, PDV genes can be applied to control insect pests by incorporating them into crop genomes. This talk illustrates two examples of PDV genes: CpBV-CST1 and CpBV-ELP1. CpBV-CST1 has been known to inhibit insect cysteine proteases to suppress immune and development, while CpBV-ELP1 exhibits a high cytotoxicity to insect cells. Transgenic tobaccos expressing CpBV-CST1 or CpBV-ELP1 were constructed by using Agrobacterium-mediated transgenic system and exhibited antixenosis against chewing and sucking insect pests on tobacco.

Dow AgroSciences has a long history of proactive insecticide resistance management efforts. In our experience, the key to managing resistance is to reduce selection pressure on any one mode-of-action by convincing farmers to rotate among effective insecticide products with different modes of action and to use only the number of insecticide applications required for effective Integrated Pest Management (IPM). To accomplish this, farmers may need to use non-chemical control methods and to rotate to insecticide products that are effective but may not provide the highest levels of control. Integrating rotation of effective insecticides with other IPM techniques can provide high quality and quantity of the harvested crop. We will share our experience managing spinosyn resistance with a series of best management practices for western flower thrips (Frankliniella occidentalis Pergande) and our resistance management recommendations for ISOCLASTTM (sulfoxaflor), our new insecticide for control of sap-feeding insect pests. Dow AgroSciences is an active member of the IRAC (Insecticide Resistance Action Committee) and strongly supports the placement of IRAC mode-of-action group numbers on insecticide product labels. This simple approach greatly facilitates effective product rotation. Resistance management is critical to maintaining the effectiveness of the current arsenal of conventional insecticides and transgenic insect-resistant crops for as long as possible. Responsibility for resistance management is shared between manufacturers, formulator-distributors, retailers, influencers (universities, government), and farmers. It is up to all of us to make sure all stakeholders, and especially farmers, fully understand the benefits associated with insecticide resistance management (IRM) programs and the consequences associated with the resistance development in insect pest populations. ™ Trademark of The Dow Chemical Company ('DOW') or an affiliated company of Dow.

Highland agriculture is a kind of specified agricultural term based on altitude and meteorological characteristics and their main crops are seed potato and vegetables. These crops are only cultivated in summer season when insect pests are most dynamically attacking such as diamondback moth (DBM, Plutella xylostella) and aphids son on. Aphids, insect virus vector, are really annoying factor, particularly in seed potato. Furthermore, these insect pests formed small sub-population or colony based on small field area. For instance, green peach aphid (GPA, Myzus persicae) populations’ genetic backgrounds and insecticide susceptibilities were different even in the same Pyeongchang area. Therefore, we suggested that highland agriculture should adopted IRM strategy for the control of insecticide-resistant aphids. First. Monitoring of annual fluctuation of insect population using traps for more effective monitoring. Second. Performing the insecticide resistant monitoring patch by patch or field using high throughput molecular diagnosis for more accurate monitoring. Third. Establishing the insect pest management program based on these results. We will deeply discussed practical monitoring results and IRM strategy in highland agriculture.

The rapid increase in cases of insect resistance to insecticides indicates that the contribution of present chemical control practices inevitably leads to exhaustion of available insecticide resources against key insect species. Now the problem of insecticide resistance exists worldwide among insects and mites affecting field crops and animals including human beings, ranging from minimal or absent in some developing countries, where use of insecticides has been low, to extremely severe in many developed countries. Since the occurrence of insect resistance to insecticides was firstly recognized in 1908, the increase in recent decades has been almost linear and now the number of species of insects and acarines in which resistant strains have evolved have been increased to a total of 432. Of these, are agricultural importance and of medical/veterinary importance. The phenomenon of insecticide resistance is asserting itself as the greatest challenge to effective chemical control of many important insect pests. Resistance of insects to insecticides has a history of nearly 80 years, but its greatest increase and its strongest impact have occurred during the last 40 years following the discovery and extensive use of synthetic organic insecticides and acaricides. The impact of resistance should be considered not only in terms of greater cost of pest control due to increased dosages and number of applications but also in terms of the ecological disruption of pest-beneficial species density relationships, the loss of investment in the development of the insecticides concerned, and socio-economic disruption in agricultural communities. Despite its grave economic consequences, the phenomenon of insecticide resistance has received surprisingly little attention in Korea. Since the study of insecticides started firstly in 1963, many entomologists have been concerned with this study. According to their results, some of the rice pests and some of the mites on orchard trees, for example, have developed worrisome level of resistance in several areas of this peninsula. With many arthropods, considerable advances in the developed countries have been made in the study of the biochemical and physiological mechanisms of resistance. Progress involves the biochemical characteristics of specific defense mechanisms, their genetics, interactions, and their quantitative and qualitative contribution to resistance. But their studies arc still inadequately known and relatively little have been contributed in terms of unique schemes of population management in achieving satisfactory pest control. It is apparent that there is no easy solution to resistance as a general phenomenon. For future challenging to effective control of insect pests which are resistant to the insecticides concerned, new insecticide groups with distinctly novel mode of action are urgently needed. It is clear, however, that a great understanding of the factors which govern the intensity of selection of field population for resistance could lead to far more permanently successive use of chemicals within the framework of integrated pest management than heretofore practiced.

Yield losses due to diseases and insect pests were mentioned and emphasized the efficiency of resistant cultivars in curving the yield losses and increasing chemical efficiency. Present status of resistance breeding for blast, bacterial leaf blight viruses, brown planthopper and white backed planthopper were introduced and the resistance sources for those are discussed. Breeding strategies for above items were presented. Specially for the blast resistance, discussions were made in some detail. With brief future prospects of resistance breeding in Korea, a suggestion was made for pathologists to make clear about whether the blast spores will be brought from mainland China as we see with Bph and Wbph or not.

본 연구에서는 관행의 교배육종과 DNA 마커를 이용한 MAS의 접목을 통하여 벼멸구 저항성과 관련된 단점을 보완하고, 효율적으로 도열병, 줄무늬잎마름병, 흰잎마름병, 벼멸구, 끝동매미충 저항성이 집적된 복합내병충성 우량계통을 육성하고자 수행하였다. 교배모본으로는 완전미율이 높고, 끝동매미충에 저항성인 '남평'과 단간이면서 흰잎마름병에 저항성인 '주남'을 반복친으로 사용하였고, 벼멸구저항성 유전자 Bph1을 가지고 있지만 간장이 크고 재배안전성이 미흡한

한강찰 1호'는 국립식량과학원 기능성작물부에서 2006년도에 육성한 중생 복합내병충성 통일형 찰벼 품종으로 그 주요 특성은 다음과 같다. 1. 출수기는 중부평야지 및 영 호남평야지 보통기 보비재배에서 8월 13일로 신선찰벼 보다 3일 늦은 중생종이다 2. '한강찰 1호'의 주당수수는 10개, 수당립수는 156개의 수중형이고, 등숙비율은 85%, 현미 천립중은 21.2 g이다. 3. 성숙기의 엽노화는 중간 정도이며 못자리일수 50일묘 이앙 시에 불시출수가

대두 씨스트 선충포에 있어서 대두 품종별 선충저항성정도를 검정하여 내선충성 대두 품종육성시 기초자료로 삼고져 본 시험을 실시하였던 바 그 결과를 요약하면 다음과 같다. 1. 지표품종에 대한 평균 종실중 감소율은 저항성 품종은 38~44%, 감수성 품종은 6972%로 차리가 뚜렷하였으며 전중 및 협수도 같은 경향이었다. 2. 공시된 품종중 저항성정도가 최강 인 품종은 5, 강 에 속하는 것이 8품종으로써 이를은 모두 중ㆍ만생종이었다. 저항성 품종으로 유망시 되는 것으로는 울산, 강림, pickett 71, Forrest, Bedford 등이었다. 3. 선충포에 있어서 종실중, 전중 및 협수의 감소율을 조생종을 62~75%, 중생종은 39~65%, 만생종은 29~36%로써 생육일수가 짧은 품종일수록 저항성이 약하게 나타났다. 이 원인으로서는 선충의 분포범위와 대두 뿌리의 발생심도 및 발생량, 가해시기와 대두의 개화기 및 회복가능기간이 밀접히 관여하고 있는 것으로 고찰되었다. 4. 내선충성 품종선파을 위한 유의 상관 형질은 전중, 협수, 100입중, 주전장이었으며 특히 전종과 협수는 모두 +0.9 이상의 고도의 상관계수를 보였다.

수도에 있어서 원활엽형질의 이용성을 검토하기 위하여 껄끄러운 잎의 품종과 매끄러운 잎의 품종에서 벼멸구저항성이 있는 것, 없는 것을 공시하여 원활엽형질이 벼멸구의 식이선호성과 우해율에 미치는 영향을 비교하고, 매끄러운 잎을 가친 품종과 껄끄러운 잎을 가진 품종의 수량 및 제현비율을 비교하였다. 그 결과를 요약하면 다음과 같다. 1. 벼멸구의 식이선호성, 우해율 및 항충성은 찰과메에 껄끄러운 형질 및 찰과메에 따라 차가 나타나지 않았다. 2. 지엽중의 SiO2/N 비율과 수량은 여리 N시용수준에 있어서 잎의 매끄러운 형질과 절끄러운 형질에 따라 차가 나타나지 않았다. 3. 매끄러운 잎을 가진 계통은 껄끄러운 잎을 가진 계통보다 우해율이 높았는데 메에 있어서만 유의하였다. 4. 매끄러운 잎을 가진 품종의 효용성을 검토하였다.