Milky white spots appeared on red bean leaves in a red bean cultivation area located in Jangyeon-myeon, Goesan-gun, Chungbuk Province. After culturing the pathogen in PDA medium, their morphology was observed, and their genes were BLAST-searched in the National Center for Biotechnology Information (NCBI). The pathogen was identified as a fungus called Rhizopus arrhizus. As a result of reinoculating the isolated pathogen on red beans, the same symptoms as those in the isolated leaves occurred. Characteristic colonies of R. arrhizuson PDA medium initially showed a bright color and then changed to dark gray over time, with mostly spherical sporangia. The sporangiospores were spherical or elliptical, mostly irregular, and small in size. Therefore, based on these results, this disease has not yet been reported in red beans and was called red bean brown leaf blight caused by Rhizopus arrhizus A. Fisch (syn. R. oryzae).
Recently, phosphine resistance of Sitophilus oryzae has been reported from China, India, Brazil and Australia. In this study, susceptibility of three fumigants were assesses on phosphine resistant and susceptible S. oryzae to investigate domestic phosphine resistance level and to use base data for resistance control. On susceptible insects, LCT50 of phosphine was 0.440mg h/L for egg, 0.602mg h/L for early larvae, 3.901mg h/L for late larvae, 6.171mg h/L for pupae and 0.295mg h/L for adult stage, respectively. LCT50 of methyl bromide was 9.997mg h/ L for egg, 12.113mg h/L for early larvae, 18.952mg h/L for late larvae, 21.104mg h/L for pupae and 17.824mg h/L for adult stage, respectively. LCT50 of ethyl formate was 75.795mg h/L for egg, 60.110mg h/L for early larvae, 160.491mg h/L for late larvae, 255.797mg h/L for pupae and 77.711mg h/L for adult stage, respectively. On resistant insects, LCT50 of phosphine was 6.959mg h/L for egg, 28.456mg h/L for early larvae, 48.170mg h/L for late larvae, 29.106mg h/L for pupae and 16.550mg h/L for adult stage, respectively. LCT50 product of methyl bromide was 17.842mg h/L for egg, 14.900mg h/L for early larvae, 25.840mg h/L for late larvae, 43.520mg h/L for pupae and 16.397mg h/ L for adult stage, respectively. LCT50 of ethyl formate was 60.034mg h/L for egg, 64.450mg h/L for early larvae, 149.028mg h/L for late larvae, 140.408mg h/L for pupae and 66.043mg h/L for adult stage, respectively. Domestic resistant S. oryzae showed 4 to 56 times higher resistance rate than susceptible insects.
Phosphine (PH3) resistance in the stored-products insect pests has been reported throughout the world in various insect species, including Rhyzopertha dominica, Tribolium castaneum, and Cryptolestes ferrugineus, leading farmers and fumigators to identify new fumigation tools to control PH3-resistant insect pests in storage facilities. Understanding PH3-resistance mechanisms in insects might contribute to providing clues for the development of new chemicals, including fumigants, to control various PH3-resistant insects. A proteomic study has shown 15 decreased proteins in the PH3-resistant R. dominica (CRD343 strain) in comparison to the PH3-susceptible R. dominica, and among those 15 proteins, dihydrolipoamide dehydrogenase (DLD), a protein involved in the Krebs cycle, was identified (Park et al., 2008). The DLD polymorphisms responsible for genetic resistance have disulfide active sites for PH3 binding and are highly sensitive to arsenic exposure after mutagenesis in insects (R. dominica and T. castaneum) and Caenorhabditis elegans (Schlipalius et al., 2012). Here, two PH3- resistant S. oryzae strains were used to understand the development of PH3 resistance in these insects. Acute toxicity test by PH3 on the two PH3-resistant strains was undertaken followed by ethyl formate inhibition study on cytochrome c oxidase activity. The Lineweaver-Burk plots after inhibition studies showed there were significantly difference in inhibition mode between the resistant strains and the control. The RT-qPCR analysis and the next-generation sequencing of the mitochondrial DNA revealed significant changes in metabolism and energy production. Taken together, the PH3 resistance in S. oryzae was definitely acquired by the overall transformation of biochemical reactions to overcome PH3 toxicity.
쌀바구미류(Sitophilus spp.)에 대한 분류학적 정립의 모호함과 쌀바구미(S. oryzae; rice weevil)와 어리쌀바구미(S. zeamais; maize weevil)를 외부형태적 특징으로 구별하기 어려워 2000년 이전까지 국내 저장 쌀에 발생하는 바구미와 관련하여 보고된 거의 대부분의 문헌들은 쌀바구미(S. oryzae)로 다루어졌다. 그 후, 분류학적 재정립과 쌀바구미와 어리쌀바구미의 생식기 구조상 차이로 확실하게 구별이 가능하여 국내 여러 기관들이 소장하고 있던 쌀바구미류 표본들을 검경한 결과, 모두 어리쌀바구미(S. zeamais)로 동정되었고, 쌀바구미(S. oryzae) 표본은 확인되지 않았다(홍 등, 2001). 그러나 2015~2016년 전국의 미곡처리장(RPC) 및 저장창고에 발생하고 있는 저곡해충을 조사하는 과정에서 충북 청주와 보은, 전북 군산, 전남 장성 소재의 창고에 저장된 쌀에서 쌀바구미(S. oryzae)의 발생을 확인함으로써, 앞으로 쌀바구미류를 정확하게 구별할 수 있도록 성충의 생식기 및 유충의 아랫입술수염 형질을 비교하는 한편, 종 특이프라이 머를 이용한 구별방법을 제공한다.
본 연구에서는 벼 부산물인 미강을 이용한 글루텐-프리 조미소재를 개발하기 위하여 Aspergillus oryzae를 이용한 미 강의 발효조건을 평가하였다. Aspergillus oryzae의 종류에 따라 미강을 발효하여 발효액의 일반성분을 분석한 결과 조 단백, 총질소(TN), 아미노태질소(AN) 항목에서 MC-01 균주가 높은 함량을 나타내었다. 균주별 발효액의 SDS-PAGE 와 유리 아미노산 분석 결과에서도 저분자성 물질로의 분해율이 MC-01 균주에서 가장 우수한 것으로 평가되었다. MC-01 균주를 이용하여 미강을 13일까지 발효를 진행하면서 3, 5, 7, 10, 13일 경과 후 각각의 미강 발효액의 품질을 평가하였다. 발효 10일 시료에서 조단백, 총질소(TN), 아미노태질소(AN)의 함량이 가장 높게 나타났고, 총 유리아미노 산 함량은 발효 10일까지 증가하다 이후부터는 유사한 수준을 나타내었다. 관능평가 결과 색, 향, 감칠맛, 종합 기호도 에서 발효 10일 시료의 기호도가 가장 높게 나타났다. 따라서 조미소재 개발을 위한 미강의 발효는 MC-01 균주를 이 용하여 10일 동안 발효시키는 것이 적합할 것으로 사료된다.
In this study, we compared the organoleptic and other qualities of fermented milk containing 10 or 15% purple carrot extract that had either been previously fermented with Aspergillus oryzae or not fermented. Fermentation characteristics, pH, chromaticity, viscosity, viable cell counts, and sensory evaluations were measured. The pH and acid values did not differ between purple carrot extract fermented with Aspergillus oryzae and non-fermented extract. Viable cell counts were significantly higher in 15% purple carrot extract fermented with Aspergillus oryzae compared to the control after fermentation. Regarding characteristic changes, purple carrot extract fermented with Aspergillus oryzae group showed a lower red value but higher yellow value compared with non-fermented purple carrot extract due to heat-sterilization. Both fermented and non-fermented extract groups showed significantly increased viscosity compared to control. In the sensory evaluation, 15% purple carrot extract fermented with Aspergillus oryzae showed the highest score. In conclusion, addition of 15% purple carrot extract fermented with Aspergillus oryzae resulted in a superior fermented milk product.
종자 등 유전자원의 국가간 교류는 새로운 병원균을 유입시켜 새로운 병을 일으키고 경제적인 손실을 극대화 시킬수 있는 원인을 제공하기 때문에 국가별로 검역이 더욱 강화되고 있는 실정이다. 그러한 연유로 국가별로는 자국에 존재하지 않은 유사한 병원균을 발견할 경우 종자도입을 막고 있어 불필요한 경제적 손실원인이 되기도 한다. 따라서 이러한 손실을 막기위해 각국에 검역소에서는 병원균의 형태적인 감별보다 더 정확한 검정기술이 시급한 실정이다. 본 연구에서는 다중PCR을 통하여 한번의 PCR 증폭으로 벼종자에 존재하는 벼흰잎마름병을 일으키는 Xanthomonas oryzae pv. oryzae (Xoo)과 세균성 줄무늬병을 일으키는 Xanthomonas oryzae pv.oryzicola (Xoc) 를 검출하고 이 두병원균을 판별할수 있는, 국제미작연구소가 최적화한 다중PCR 검정방법의 실질적 적용성 여부를 검증하기 위한 연구였다. 그 결과 51개의 비병원성이나 Xoo 또는 Xoc 와 유사하며 벼종자에서 분리된 균들은 다중PCR검정에서 어떤 밴드도 증폭하지 않은 반면, 대조구(positive control)에서는 알맞은 band size의 amplicon들을 증폭해냈다. 따라서 본 연구에 사용된 국제미작연구소에서 최적화된 다중 PCR방법 (IRRI-optimized multiplex PCR)은 벼종자에서 발견할수 있는 Xoo와 Xoc 의 존재 여부 뿐만 아니라
이들과 형태적으로 유사하나 비병원성균으로부터 구분해 내는데 탁월한 방법이었음을 확인할 수 있었다.
Rhizopus fruit rot was observed on strawberry fruit (Fragaria x ananassa Duchesne) grown in a glass greenhouse at the Gyeongsangnam-do Agricultural Research and Extension Services, Jinju, South Korea, from 2011 to 2013. Symptoms included water-soaking, rapid softening, and rotting. When these symptoms were left untreated, vigorous fungal growth was observed on the surface of infected fruits. Colonies on potato dextrose agar (PDA) at 30°C were white-cottony to brownish-black. Sporangia were globose, black, and 40–210 ㎛ in diameter. Sporangiophores were light-brown and 6–22 ㎛ in diameter. Sporangiospores were globose to oval, brownish, streaked, and 4–12 ㎛ in length. Columellae were light brownish gray, hemispherical, and 80– 120 ㎛ in diameter. To confirm the identity of the causal fungal pathogen, the complete internal transcribed spacer (ITS) ribosomal RNA gene region was amplified and sequenced. Based on these symptoms, mycological characteristics, pathogenicity tests on host plants, and molecular identification, the fungus was identified as Rhizopus oryzae Went & Prinsen Geerligs. This is the first report of Rhizopus fruit rot on strawberry caused by R. oryzae in Korea.
Real Time PCR을 이용한 벼 흰잎마름병균의 밀도를 측정할 수 있는 새로운 방법을 개발하였다. Real Time PCR을 이용하여 벼 흰잎마름병을 예찰하기 위하여 TaqMan MGB probe를 이용한 프라이머인 Xan_PahgeF & Xan_PahgeR primer와 Xan_Pahge FAM MGB probe를 제작하였으며, 높은 특이성이 인정되었다. 병원균 배양액, 벼 흰잎마름병원균의 DNA, 병원세균에 오염된 물에서도 효과적으로 검출이 되었다. 농수로물이나 관개수에서 벼 흰잎마름병균의 밀도를 측정할 때 정량 PCR의 저해인자 제거 후 신속하게 벼 흰잎마름병균의 밀도를 측정할 수 있다.
벼 흰잎마름병균의 정확한 진단을 위하여 PCR용 진단 kit를 개발하였다. 본 PCR kit를 개발하기 위하여 벼 흰잎마름 병균 유전체 정보 중 phage-related integrase and transposase gene의 염기서열을 이용하여 프라이머를 각각 제작하였다. 프라이머 염기서열은 XOP-F (5-CGG TCT GCT CAA TGA GGA AGA-3)와 XOP-R2 (5-TGC AAT TGG TGT TCTCCA GG-3), XOT-F (5-GTC ATA GGT GAG GCT TCCC-3)와 XOT-R2 (5-AGT GCG ATC TTT CAG CAG G-3)로 벼 흰잎마름병균의 DNA를 401bp와 492bp를 증폭하게 제작하였다. PCR 증폭은 벼 흰잎마름병균만 증폭하였으며 다른 세균인 Escherichia coli, Agrobacterim, Pectobacterium caratovora subsp. cartovorum, P. atrosepticum, Pseudomonasputida, P. syringae, P. savastanoi pv. phaeolicola, P. savastanoipv. savastanoi and P. marginalis pv. Marginalis 등은증폭되지 않아 특이성이 인정 되었다. 본 프라이머로 병이 의심되는 벼잎과 논물에서 병원균을 3시간 이내에 검출할 수 있었다.
We evaluated insecticidal activity of 11 Apiaceae plant essential oils and their constituents against rice weevil, Sitophilus oryzae.. Of 11 Apiaceae plant essential oils tested, dill (Anethum graveolens), carvi (Carum carvi), caraway seed (Carum carvi) and cumin (Cuminum cyminum) essential oils demonstrated strong fumigant toxicity against adults of rice weevil. Components of 4 active compounds were analyzed by GC and GC-MS, and fumigant toxicity of individual compound was also tested. Among test compounds, carvone, dihydrocarvone, carveol, linalool oxide, neral, cuminaldehyde, and anethole demonstrated the strong insecticidal activity. The toxicity of blends of constituents identified in 4 active oils indicated that carvone, and cuminaldehyde were major contributors to the fumigant toxicity of the artificial blend.
우리나라 재래종벼 6품종의 벼 흰잎마름병 저항성 유전자를 동정하고자 저항성 유전자 Xa1를 갖는 IR-BB 101과의 교배조합을 양성하고 일본균주 ⅠA(T7174)를 접종한 결과 청군벼의 벼 흰잎마름병 저항성 유전자는 Xa1 이었고, 육성재래, 아국도, 흑피 및 이천7일찰은 Xa1 및 다른 우성유전자 1개를 보유하였으며, 긴까락샤레는 Xa1 및 다른 우성유전자 2개를 갖고 있었고 이 중 2개는 저항성 발현에 보족적으로 작용하는 것으로 추정되었다.
5-Hydroxy-1,4-naphthoquinone and its derivatives were evaluated for insecticidal effect against Sitophilus oryzae and S. zaemais adults. This study was examined using fumigant method. Mortality was determined after 72 h of treatment. 5-Hydroxy-1,4-naphthoquinone showed strong (+++) activity at 5 mg and the 1,4-naphthoquinone showed strong (+++) and moderate (++) activity at 5 mg, against S. oryzae and S. zaemais, respectively. However, 5-hydroxy-2-methyl-1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone, and 2-methoxy-1,4-naphthoquinone had non-activity (-) at 5 mg. Based on the LD50 values, the compound most highly effect to S. oryzae was 1,4-naphthoquinone (0.012 mg/cm2), followed by 5-hydroxy-1,4-naphthoquinone (0.013 mg/cm2). However, against S. zeamais, 5-hydroxy-1,4-naphthoquinone (0.044 mg/cm2) was the most toxic compound, followed by 1,4-naphthoquinone (0.155 mg/cm2). These results suggest that the introduction of various functional group (hydroxy, methyl and methoxy) into the 1,4-naphthoquinone skeleton contributes to insecticidal activity. Accordingly, 5-hydroxy-1,4-naphthoquinone and 1,4-naphthoquinone could be used highly effective rice weevil control agents.
The rice weevil, Sitophilus oryzae, is the most serious storage pests worldwide of grocery shops, flour mills, and warehouses. The phototactic response of the rice weevil, S. oryzae, to light emitting diodes (LEDs) at five different wavelengths and various light intensities was tested within an LED-equipped Y-maze chamber, and compared with its response to a luring lamp, which is used in commercial traps. Various wavelengths in this study were UV (365 nm), blue (450 nm), green (520 nm), red (660 nm), and infrared (IR) (730 nm). Based on attraction rate (%), blue (84.3%) was the most attractive to S. oryzae, followed by green (74.3%), red (64.3%), UV (63.3%), and IR (48.7%). Moreover, blue and green wavelengths were 1.5 and 1.3 times more attractive than luring lamp (56.7%), whereas the UV wavelength was slightly less attractive to the weevils than luring lamp. These results suggested that blue and green wavelengths could be more useful than those currently used for monitoring and mass trapping of S. oryzae.
The rice weevil, Sitophilus oryzae, is one of the most common storage pests worldwide of grocery shops, flour mills and warehouses. This study investigated to assess the contact and fumigant toxicities of Juglnas regia and its active component against the S. oryzae adults. Using the two different bioassays against S. oryzae adults, the methanol extract of J. regia at 20 mg had the moderate (++) activity and weak (+) activity using direct contact and fumigant method, respectively. The methanol extract was partitioned with hexane, chloroform, ethyl acetate, butanol and water fraction. Ethyl acetate fraction obtained from the methanol extract showed strong (+++) and weak (+) activity at 10 mg using direct contact and fumigant method, respectively. Ethyl acetate fraction was purified by silica gel column chromatography and high performance liquid chromatography (prep-HPLC). The structure of active component was analyzed by EI-MS, 1H-NMR and 13C-NMR spectra, and was identified as C-21233. Purified C-21233 from ethyl acetate fraction had strong (+++) and moderate (++) activity using direct contact and fumigant method against S. oryzae adults. These results indicate that active component in J. reiga derived materials could be potential candidates as a contact and fumigant for managing S. oryzae adults. Further studies should be performed to the structure activity relationship of C-21233 and compared with its derivatives.