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        검색결과 9,927

        3661.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been known as promising candidates in biological control. However, a large number of conidia with higher stability should be produced for industrialization. In this work investigated the possibility of several grains for the production of thermotolerant Isaria javanica and I. fumosoroseus conidia. The fungal conidia were produced on ten grains for 14 days in Petri dish conditions. Of the ten granular substrates, millet, perilla seed and barley showed the high conidial production, 15.7 ± 8.4, 17.3 ± 5.2 and 13.5 ± 1.9 × 109 conida/g in I. javanica and 15.9 ± 0.6, 15.0 ± 0.5 and 15.0 ± 0.7 ×109 conida/g in I. fumosoroseus, respectively. However, the two strains showed relatively low thermal stability regardless of substrates, when exposed to 45℃ for 1, 2 and 3 hours. This work suggests a possible substrate for conidial production of entomopathogenic fungi with low cost.
        3662.
        2017.04 구독 인증기관·개인회원 무료
        Oriental fruit fly, Bactrocera dorsalis, is one of the serious pests of fruit throughout the world. Two regional populations (Bangladeshi and Malaysia) were collected using methyl eugenol lure and one laboratory population was obtained from Thailand. Three populations were compared in cytochrome b (CYB) cytochrome oxidase I (COI) sequences. COI sequences were highly homologous. However, CYB sequences were polymorphic and used to discriminate these regional populations by a phylogenetic analysis. In CYB phylogeny analysis, Malaysia and Thailand populations were clustered and Bangladeshi population was separated
        3663.
        2017.04 구독 인증기관·개인회원 무료
        The objectives of this study are to examine the genetic variation in oriental fruit flies (Diptera: Tephritidae) and to use it as a barcode for the origin elucidation, in preparation for the their incursions into Korea. About 1,600 specimens of B. dorsalis sp. complex and B. correcta were collected from 10 countries, the Indochina peninsula, the Philippines, Taiwan and South China. A total of 182 cytochrome c oxidase (COI) sequences were obtained and aligned from these regional specimens. Three sequences from the Genebank reference were also included. Six hundreds base pair fragments were aligned and trimmed and used for a barcode. The phylogenetic tree was generated using the neighbor-joining method with 1,000 bootstrap replicates. There were two distinct groups in the phylogenetic tree, Bactrocera dorsalis sp. complex and B. correcta. Three specimen, intercepted in the hand-carried mango at the airport inspection and collected in the confiscated mango, smuggled from Vietnam were included for a test. The DNA from the airport were 100% identical to that of one of various Vietnam specimens, and that from the confiscated mango was mostly similar to those of Vietnam, suggesting the usefulness of the barcode for the origin elucidation tool of oriental fruit fly.
        3664.
        2017.04 구독 인증기관·개인회원 무료
        The oriental fruit fly, Bactrocera dorsalis (Hendel), has potential of serious damage to various vegetables or fruits, especially genus of Citrus, such as mandarin orange and tangerine in Korea, where its larvae do damages. Animal and Plant Quarantin Agency of Korea and Animsl Systematics Laboratory of Kunans National University have collected the samples of oriental fruit fly in East Asian countries, Vietnam, Philippines, Myanmar, China, Cambodia, India and Nepal. To confirm genetic differences and structure of B. dorsalis population samples collected from those countries, we analyzed 192 individuals from 28 locations over 7 countries using 15 microsatellite loci. In total samples, number of different alleles, number of effective alleles and Shannon's Information Index were 6.421±0.364 (standard error, SE), 3.664±0.137 (SE) and 0.902±0.030 (SE), respectively. Grand means (±SE) of observed and expected heterozygosity over all loci and populations were 0.534 (±0.018) and 0.597 (±0.017), respectively. Among all populations, Fst values ranged from 0.016 to 0.705 with averaging 0.194 (±0.026).
        3665.
        2017.04 구독 인증기관·개인회원 무료
        The adult activity of M. alternatus caught in a pheromone trap showed a bimodal form consisted of the first peak in mid to late June and the second peak in mid to late September in Jeju area, Korea. The two peaks were separated apparently between mid and late August, showing a valley. The pine trees without oleoresin flow were abundant during early July to early August, and declined thereafter, which did not match with the valley of adult activity curve. Thus, the hypothesis that dying pine trees attract much strongly M. alternatus adults than that of pheromone lures may not fully explain the bimodal pattern, because the first adult activity peak occurred during the peak period of dying pine trees and it declined with decreasing dying pine trees. The accumulated degree-days showed that the emergence of the 2nd generation adults could occur before the second peak when the diapause ecology of M. alternatus was not considered. The voltinism of M. alternatus can affect basically the control strategy of this pest. Consequently, further studies are required to find out clearly the voltinism of M. alternatus in Korea.
        3666.
        2017.04 구독 인증기관·개인회원 무료
        Despite of a substantial effort, the phylogeny of Lepidoptera still has unstable taxa and unresolved relationships particularly form Apoditrysia to Ditrysia (e.g. phylogenetic position and familial relationships of Gelechioidea, the monophylies of Tineoidea and Zygaenoidea and so on). We performed phylogenetic analysis using ~13,000-bp length of mitogenome sequences form 50 species (with seven species in two superfamilies form this study) representing 13 superfamilies to improve the lepidopteran phylogeny from Apoditrysia to Ditrysia. A close relationship of Gelechioidea to Obtectomera than to apoditrysian taxa was noteworthy, although the nodal support is very weak (ML, 23%; BI, BPP = 0.94). Monophyly of Zygaenoidea without Epipyropidae (Epipomponia nawai) was also noteworthy in spite of weak nodal support (ML, 64%; BI, 1.0). Scrutinized analysis is currently underway.
        3667.
        2017.04 구독 인증기관·개인회원 무료
        Dendrolimus superans (Lepidoptera: Lasiocampidae) has long been acknowledged to present in South Korea under the circumstance of a substantial change in species names of Dendrolimus. In the present study, we found that specimens of D. superans collected from South Korea were D. sibiricus, rather than D. superans. Comparison of Korean specimens to the D. superans from Japan and the D. sibiricus from Russia in terms of wing morphology, female and male genitalia, a partial COI gene sequence, and a partial internal spacer sequence 2 (ITS2) consistently supported the presence of D. sibiricus in South Korea. Phylogenetic analyses using concatenated sequences of COI and ITS2 from available individuals of D. sibiricus and D. superans both by Bayesian inference and maximum likelihood methods the Korea samples to be D. sibiricus.
        3668.
        2017.04 구독 인증기관·개인회원 무료
        We sequenced the complete mitochondrial genome (mitogenome) of Vespa velutina nigrithorax and V. ducalis (Hymenoptera: Vespidae). The genomes were 16,475-bp and 15,779-bp long and contained typical sets of genes. The V. velutina and V. ducalis A+T-rich region was 132-bp long and 166-bp long and was the shortest of all sequenced Vespoidea genomes. Start and stop codons in several Vespa species—including V. velutina and V. ducalis—were diversified, despite these species belonging to the same genus. In comparison with the ancestral mitogenomes, Vespa mitogenomes showed substantial gene rearrangement; however, we detected no gene rearrangement among Vespa species. We conducted phylogenetic reconstruction based on concatenated sequences of 13 PCGs and two rRNAs in available species of Vespoidea—22 species in six subfamilies in two families (Vespidae and Formicidae). The Bayesian inference and maximum likelihood (ML) methods revealed that each family formed strong monophyletic groups.
        3669.
        2017.04 구독 인증기관·개인회원 무료
        One species of the genus Coleopius (Hymenoptera: Braconidae: opiinae) are reported in this study. The genus Coleopius is a small braconid group distributed in the Palaearctic and Oriental regions, which has three species in the korea in current. In this study, Coleopioides postpectalis Li and van Achterberg is recognized for the first time in South Korea, which had been recently recorded from China. Descriptions, diagnosis distribution and illustration are provided
        3670.
        2017.04 구독 인증기관·개인회원 무료
        Aphidiinae in Braconidae includes more than 400 species within approximately 60 genera worldwide. Species of Aphidiinae are mostly known as solitary koinobiont endoparasitoids specifically associated with aphid hosts, and some of them are used for biological control. In the present study, two aphiniine species are newly recognized from South Korea based on morphological and molecular study: Aphidius rhopalosiphi de Stefani-Perez 1902 and A. uzbekistanicus Luzhetzki 1960. Although It was very difficult to discriminate two species morphologically, we cleary identified them by using COI (cytochrome c oxidase subunit I) DNA Barcode sequences. Here we present their morphological descriptions, illustrations and barcoding results.
        3671.
        2017.04 구독 인증기관·개인회원 무료
        We found a new recorded species, Drosophila subpulchrella Takamori & Watabe from Dopyeong-ri, Idong-myeon, Pocheon-si, Gyeonggi-province. The species of the D. suzukii subgroup in the D. melanogaster species group is reported from Japan and southern China up to now. This species is morphologically very similar to D. suzukii: with spots on the tip of fore-wing(male) and serrated ovipositor(female). The goals of this study are to add a new recorded species, D. subpulchrella to Korean fauna and provide the biological references such as morphological and molecular data using for the species identification
        3672.
        2017.04 구독 인증기관·개인회원 무료
        Phospholipase A2 (PLA2) hydrolyzes phospholipids at sn-2 position to release free fatty acids. PLA2 consists of a superfamily mainly categorized as secretory PLA2 (sPLA2), cellular Ca 2+ -dependent PLA2 (cPLA2), and cellular Ca 2+ -independent PLA2 (iPLA2). We are the first to report iPLA2 in insect. Here an objective of our study is to purify a recombinant iPLA2 protein (SeiPLA2) of Spodoptera exigua using bacterial expression system. An open reading frame of SeiPLA2 was cloned into an expression vector and then transformed into Escherichia coli BL21. Over-expression with IPTG yielded recombinant SeiPLA2 (rSeiPLA2), which was then purified by an affinity chromatography using Ni-NTA column. The purified rSeiPLA2 gave significant PLA2 activity using a pyrene substrate. Its activity was inhibited by an iPLA2 specific inhibitor (BEL), but not by sPLA2 inhibitor (BPB) or cPLA2 inhibitor (MAFP
        3673.
        2017.04 구독 인증기관·개인회원 무료
        Nitric oxide (NO) is an immune mediator in several insects. In addition, eicosanoids mediate various immune responses in response to microbial challenges. This study focuses on cross-talk between two immune mediators. Nitric oxide synthase (SeNOS) of Spodoptera exigua was predicted in its cDNA sequence by interrogation to the transcriptomes and validated by RT-PCR against developmental stage and larval tissues. RNA interference (RNAi) of SeNOS suppressed nodule formation of S. exigua larvae against heat-killed Xenorhabdus hominickii. RNAi of SeNOS also suppressed NO levels in fat body and hemocytes along with suppression of PLA2 activity. NOS-specific inhibitor, L-NAME, also inhibited PLA2 activity, but its enantiomer, D-NAME, did not. However, PLA2 of dexamethasone or oxindole did not suppress NO levels in the immune tissues. In addition, X hominickii did not inhibit up-regulation of NO levels. These results suggest that NO signal activates PLA2 to produce eicosanoids to mediate immune responses
        3674.
        2017.04 구독 인증기관·개인회원 무료
        Agrobacterium tumefaciens-mediated transformation (AtMT) has been widely used for generation of fungal transformants and recently applied to Beauveria bassiana. In this study to comprehend how the AtMT promoter influences on the expression of selection marker (hygromycin B resistance gene; hph), two different Ti-Plasmids were constructed: pCeg (gpdA promoter-based) and pCambia-egfp (CaMV 35S promoter-based). Putative transformants were subjected to the PCR, RT-PCR and qRT-PCR to inspect the T-DNA insertion rate and gene expression level. In conclusion, more than 80% of the colonies succeeded in AtMT transformation and the hph expression level of AtMT/pCeg colonies was higher than that of AtMT/pCambia-egfp colonies. This result can provide useful information on the AtMT of B. bassiana, especially antibiotics susceptibility and promoter-dependant expression level.
        3675.
        2017.04 구독 인증기관·개인회원 무료
        RNAi (RNA interference) is a tool for silencing of target genes through sequence-specific manner. Spodoptera exigua belongs to Noctuidae family of Lepidoptera and is serious threat to crops of economic importance. One of S. exigua chymotrypsin gene (SeCHY2) was cloned into the L4440 vector to produce sequence specific dsRNAs (double-stranded RNAs). Recombinant L4440 vectors were transformed into Escherichia coli strain HT115 (DE3). Oral delivery of bacterially expressed dsRNA gave significant larval mortality. Quantitative real-time PCR results showed that expression level of target SeCHY2 gene in the larval gut tissue was significantly down-regulated. Pretreatment with an ultra-sonication and heating to disrupt bacterial cell wall/membrane significantly increased the insecticidal activity of the transformed bacteria
        3676.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are expected to play a role as great biological control agents in the global bio-pesticide market in the future. The first step is the collection of fungal isolates and it should be a platform for the development of highly effective biopesticides. In this work, we constructed a fungal library using a mealworm pathogenecity-based fungal collection method and further characterized some isolates with high virulence. A phylogenetic tree was generated, and of the isolates 17 isolates’ biological features were characterized, such as morphology, virulence against several insect, stability of conidia for heat, production of biologically active materials, such as enzymes. This work reports an attractive entomopathogenic fungal library including the information of effective isolates in pest management.
        3677.
        2017.04 구독 인증기관·개인회원 무료
        Many turfgrass pests, Ectinohoplia rufipes, Exomala orientalis and Popillia quadriguttata, cause serious damage to grass fields in Korea. In this study, control of turfgrass pests using entomopathogenic fungi were investigated using Protaetia brevitarsis seulensis as an alternative insect. In a preliminary experiment, some Metathizium sp. showed ca. 60% virulence after 7 days exposure to the entomopathogenic fungi. Compared to the contact-exposure, overall a spray treatment showed lower control efficacy against P. brevitarsis seulensis. Furthermore, mortality of various developmental stages of P. brevitarsis seulensis was investigated under laboratory conditions. This work suggests that when treated with fungi mortality of P. brevitarsis seulensis was closely related with developmental stage. These results provide a basic information for the control of P. brevitarsis seulensis using entomopathogenic fungi
        3678.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are potential pesticides as biological control agents. However, many previous studies have focused on basic researches to control pest using insect-pathogenic fungi. Herein, the molecular characteristics of insect defense mechanisms against fungal pathogens and fungal pathogenicity to insects were investigated. The whole genome of Beauveria bassiana (Bb) JEF-007 was sequenced (36,538,394 bp) using Pacbio sequencing. Based on this data, the transcriptomes of bean bug and fungus were analyzed using RNA-seq. In the transcriptome analyses, six and five genes were validated to be involved in the fungal pathogenicity and insect defense, respectively. This work can provide an understanding of the insect-pathogen interactions
        3679.
        2017.04 구독 인증기관·개인회원 무료
        The diamondback moth (DBM), Plutella xylostella, is a globally distributed and important economic pest. Chemical control is the primary approach to regulate populations of this pest. Chlorantraniliprole is the first commercial insecticide that belongs to the new chemical class of diamide insecticides. In this study, the resistant strain was observed 1578-fold resistance to chlorantraniliprole. Point mutation (G4946E) in ryanodine receptor (RyR) showed a high frequency. Enzyme assays indicated that glutathione S-transferase (GST) activity in the resistant strain was 2.4 times higher compared with the susceptible strain, whereas no difference was seen for P450 and esterase. In addition, the expression of two GSTs genes was up-regulated. These findings pave the way for the complete understanding of the mechanisms of diamide insecticides resistance in insects.
        3680.
        2017.04 구독 인증기관·개인회원 무료
        Dermanyssus gallinae is parasitic to chicken, and they cause many damages such as disturbing sleep reducing for body weight and egg production by blood-sucking. To develop acaricide against D. gallinae, The acaricidal activity of 40 species plant extract were examined. Cnidium officinale extracted by Me-OH showed 82.0% acaricidal activity after treated 48 hrs at 4,000 ppm. The hexane fraction showed 92.4% mortality against D. gallinae at 48 hrs at 2,000 ppm. Purification of the biologically active constituents from the hexane extraction with acaricidal activity was done using silica gel open column chromatography and HPLC. H1122 fraction gave 80.9% mortality to D. gallinae at 400 ppm after treated 48 hrs. H1122 fraction was analyzed by GC-MS and NMR.