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        검색결과 4

        2.
        2014.10 구독 인증기관·개인회원 무료
        The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the most important citrus pest, because it serves as a vector of “Candidatus Liberibacter” species that cause huanglongbing disease. Thus, when exporting Rutaceae (citrus), exporting countries put them into quarantine. However, as the size of an imago is so small that only skilled experts can identify it using morphology-based species identification. A PCR-based assay was developed for monitoring psyllids using a rapid, using the DNA extraction from psyllid bodies and PCR amplification. Thus, this study aims to develop a DNA marker system with high species specificity and discrimination power that helps identifying psyllid. We analyzed the base sequence of mitocondria DNA. Based on this sequence, restriction sites were determined and a species particularity primer was made. Several polymorphic regions of mitochondrial DNA of both species were sequenced and used for developing specific restriction sites and polymerase chain reaction (PCR) primers. Also, species-specific PCR primers were devised to develop diagnostic PCR method for identifying the internal feeders. Base sequence results from PCR, which used psyllid species-specific primers, was analyzed by the Mealign program of the CLC Main Workbench analysis software, and used to develop a phylogenic tree. After analyzing this, Hemiptera proved to be allied species.
        3.
        2010.05 구독 인증기관·개인회원 무료
        The silkworm (Bombyx mori), as an industrial insect, possesses a high economic value. Casual discrimination and accumulated genetic information of silkworm varieties are essential ground for the practical utilization and long-term conservation. In this study, nine available microsatellite loci were successfully genotyped from ~50 silkworm strains preserved in Korea. According to genotyping analysis, we obtained 3 ~ 16 alleles per locus, with an average of 7.4, the observed heterozygosity ranging from 0.04 to 0.98, and the polymorphic information content (PIC) ranging from 0.06 to 0.88, revealing that some loci are highly variable. Among 54 strains 13 strains were casually identified by the presence of 17 strain-specific apomorphic alleles. Furthermore, 30 among remaining strains contained strain-specific allele combinations that are also apomorphic to each strain, allowing us to discriminate each of these from other strains by genotyping of multiple loci. These results collectively suggest that the silkworm microsatellite DNA is actually and potentially important molecular marker for the discrimination of the silkworm strains that are preserved as hundreds in Korea, as more loci are genotyped.
        4.
        2016.10 서비스 종료(열람 제한)
        Background : Angelica dahurica is the dried root of Angelica dahurica Bentham et Hooker f., a perennial plant belonging to the Umbelliferae family. Since its peak at 63 hectares in 2000, the cultivated area of Angelica dahurica dropped to its lowest level at 14 hectares in 2014 although there had been a short bounce back to 59 hectares in 2007. The decrease in the cultivated area has created a vicious cycle where even a small change in production amounts causes Angelica dahurica prices to fluctuate, leading farmers to become reluctant to cultivate the species. Therefore, this study aims to provide growers with new information on Angelica dahurica cultivation technology development, based on surveys and analyses of the difficulties and needs the farmers have. Methods and Results : Setting the nationwide Angelica dahurica farming households as the population, this study looked into 11 households of growers from main producing areas including Yeongju, Yeongcheon, and Bonghwa. Researchers carried out the survey by visiting the farmers and conducting face-to-face interviews using a prepared questionnaire. The survey was conducted for 2 months (from July to August 2016) to identify difficulties and specific characteristics of farming Angelica dahurica. SAS 9.2 was used for the statistical analysis. Conclusion : The surveyed types of difficulties identified were varieties, seeding, fertilization, pests, water management, weeding, soil, and drying. The results indicate that seeding (2.2) is the most serious difficulty, and water management (2.5), weeding (3.1), fertilization (3.7), pests (3.9) and others followed. Regarding specific technical problems, browning roots in the process of drying (61.5%) was the biggest concern along with germination after seeding (23.1%) and water management in the fields (15.4%). In response to the question about their willingness to expand farming in the future, no households showed intentions of expansion, while 36.4% reported intentions to reduce and 63.6% to maintain their current Angelica dahurica cultivation. The causes of weakening supply include low prices (54.5%), unreasonable pricing (36.4%), and difficulties in selling due to lack of retailers. Therefore, it seems necessary for the government to support sustainable Angelica dahurica farming by taking measures such as contract farming with herbal medicine circles, a minimum production cost guarantee system, or joint purchasing by the Agricultural Cooperative Association.