• Asian-Australasian Journal of Animal Sciences
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• 제17권9호
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• pp.1192-1196
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• 2004

In order to detect the molecular mechanism of heterosis in pigs, the mRNA differential display technique was performed to investigate the differences in gene expression of pig's Longissimus dorsi between the high-parent heterosis cross combination Landrace${\times}$Large White and the mid-parent heterosis cross combination Large White${\times}$Meishan. Three pig purebreds, Large White, Meishan, and Landrace and four types of reciprocal $F_1$ hybrids were analyzed using nine 3'-end anchored primers in combination with ten 5'-end arbitrary primers and nearly 7,000 reproducible bands were examined. The patterns of gene expression of each cross combination were analyzed and eight common patterns (fifteen kinds) were found. When the results from the two cross combinations were put together and compared, eight different typical expression patterns were observed, these indicated that the patterns of gene expression of these two cross combinations had obvious differences. Gene expression correlation and cluster analyses of the two cross combinations indicated that the gene expression of the mid-parent heterosis cross combination was correlated with maternal effect, but in the high-parent heterosis cross combination, paternal effect acted in the gene expression of the hybrids or the gene expression of the hybrids was biased towards one parent.

• 한국농공학회지
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• 제25권4호
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• pp.38-49
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• 1983

This study was intended to develop a curriculum for the agricultural engineering technology, and that on confidence with junior college characteristics. In order to per- formance with this study, job cluster was analyzed on 28 parts in respect to the agricultural engineering field and questionnaire was investigated to the field including in alumni 181, students 537, professional workers 174 and professors 54. The results from the above analysis and investigation can be summarized as follows. 1. According to the investigation on degree of important subjects from the questionnaire, it is presented at mathematics 43%, physics 36% in students and 32%, 12% in professional workers. Considering from this results, it is desirable that primary subjects should be forced. 2. In comparing with fundamental major subjects and applied it, it is presented at that 41%, this 34%, in the total investigations. It can be found that in the degree of requirement, this is lower than that among the major subjects. 3. In investigation to the degree of requirement in the experiment and practice, it is presented at surveying 63%. Soil mechanics 14%, materials 13%, hydraulics 9% in order, in total inspection. 4. From investigation to the degree of requirement on the subjects of established newly, it is presented at majoring and living English 64%, E.D.P.S 30%, in the total questionnaire. Judging from the results, it seems that the foreign language is necessary to technician more and more, for advance to abroad. Also, it is no wonder that make good use of the E.D.P.S. 5 The table 5 is represented the model curriculum from the above results in anaized data on the questionnaire and the job cluster of table 2.

• 농촌지도와개발
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• 제19권2호
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• pp.211-240
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• 2012

The purpose of this study was to identify korean agricultural extension workers' Perception of role ambiguity according to restructuring of Agricultural Administrative Systems. The target population of this study was selected from 21 centers out of 156 centers. The subjects for study were 728 agricultural extension officers by the cluster sampling drawn from the sampled 21 agricultural extension centers in four clusters. A survey questionnaire was utilized to measure variables of this study. It consisted of role ambiguity scale and demographic items. In this study, role ambiguity scale was translated from the existing scale. Through a pilot test and final survey, reliability and validity of these scales were examined. The data were collected by mail. A total 420 questionnaires out of 728 from 21 agricultural extension centers were returned. After data cleaning, 410 responses were used for analysis. Both descriptive and inferential statistics were applied for data analysis. Major findings of the study were as follows. There were significant differences of the degree of role ambiguity among the local extension workers divided by four clusters. Especially, the degree of role ambiguity of restructured local administrative system were more higher than other clusters, comparatively. Thus, the factors causing the role ambiguity to agricultural extension officers need to be measured it in-depth.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.138.1-138
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• 2003

Potato mop-top virus(PMTV) was identified from Solanum tuberosum cv. Gawon showing bright chlorotic mottle symptom in Namwon, Korea. Samples were collected green-house in February, 2003. Electron microscopic examination of negatively stained preparation revealed that PMTV were rigid-rod shaped particles about 100-150, 250-300 nm x 18-20 nm in length. In ultrathin sections of leaf tissue from diseased potato plants, cluster of viruses particles were observed in the cytoplasm. TAS-ELISA determined that the virus was serologically related to PMTV. PMTV produced double ring necrotic local lesion in inoculated leaf of Chenopodium amaranticolor in incubated at 15$^{\circ}C$. The PMTV could be detected with RT-PCR using PMTV detectable primer set designed to amplify about 540 bp of the partial CP gene of PMTV

• 한국약용작물학회지
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• 제10권5호
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• pp.333-339
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• 2002

둥굴레속 식물의 활용도를 높이기 위한 기초 자료를 얻고자 변종 포함 10종(種) 20영양계(營養系)를 재배한 후 특성을 조사하고 주성분 분석과 군집 분석을 통하여 분류하였다. 주성분 분석 결과 제 1주성분은 전체 분산의 54.10%, 제 2주성분은 18,95% 그리고 제 3주성분은 11.62%를 차지하였으며, 상위 제 3주성분까지의 누적 기여율이 84.68%였다. 제 1주성분은 식물체의 형태와 크기, 동화기관, 저장기관 및 생식기관과 관련된 주성분이었고, 제 2주성분은 식물체의 생육 및 저장기관과 관련된 주성분이었으며, 제 3주성분은 식물체의 생육과 관련된 주성분이었다. 군집 분석 결과 군집간 평균거리가 약 0.7일 때 20개 영양계가 4개 군으로 분류되었으며, 제 I군에는 층층갈고리둥굴레, 제 II군에는 둥굴레, 무늬둥굴레, 산둥굴레 및 큰둥굴레, 제 III군에는 용둥굴레, 안면용둥굴레 및 각시둥굴레 그리고 제 IV군에는 죽대 및 통둥굴레가 속하였다.

• 한국자원식물학회지
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• 제31권1호
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• pp.71-76
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• 2018

본 연구는 수세가 강한 '캠벨얼리'를 시험재료로 착립률 증진을 위한 개화기 신초 비틀기의 효과를 규명하기 위하여 수행되었다. 수세가 강한 '캠벨얼리'의 신초 비틀기 처리에 따른 발아기 및 개화기는 처리별 차이가 없었으나 수확기는 3일 정도 지연되었다. 신초 비틀기 처리구에서 수확기가 지연된 것은 '캠벨얼리'의 과방중과 착립률이 개화전 7일과 개화시 모두 3절 비틀기 처리구에서 높게 나타났기 때문이었다. 신초 비틀기에 의한 '캠벨얼리'의 가용성 고형물 및 산도는 처리간 차이를 보이지 않았으나, 수량은 '개화 전 7일 3절 비틀기' 처리에서 12.1 kg/주으로 무처리에 비하여 1.6배 증가하였다. 안토시아닌 함량은 무처리에 비하여 수량이 많은 처리구에서 낮았으나 착색도인 Hunter 값은 처리간 유의적 차이를 보이지 않았다.

• 한국토양비료학회지
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• 제37권4호
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• pp.235-244
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• 2004

국내 3지역으로부터 수집한 19종의 벼 잎에 서식하는 methylo-trophlc bacteria의 군집성을 비교하였다. Methanol에 따른 특징적인 생장을 나타내는 분홍색 색소를 띤 19개의 균체를 분리하였다. 분리된 이들 균체들은 Bergey의 방법에 따라 각각 생리, 생화학적 특성들을 조사 하였으며, 표현형들은 37가지의 특성들을 계통분석법을 통해 명찰히 구분하여, 최종 별개의 4군(cluster)으로 분리하였다. 대조균주인 M, extor벼둔 AM1과 M. fujisawaense KACC10744는 각각 IV군과 III군에 속해있다. I군에 속해있는 균체들은 nitrate의 환원을 근거로 하여 구분하였으며, 4개의 분리균주는 NaCl 0.5M 농도까지 염에 대한 내성을 보였다. I군과 III군의 균체들은 탄소원으로 methane을 이용하는 특성을 가졌으며, 4군의 대부분의 균체들은 탄소원으로 단당류, 이당류, 다당류를 이용하였다. L-tryptophan의 존재 하에 모든 균체들의 indole-3-acetlc aclu (IAA) 생성 실험에서는 선별균체 중 8균체만이 IAA를 생성하였다. 게다가 배지의 질소원은 IAA의 생성에 영향을 미치는 것으로 관찰되었으며, 질소원으로 $(NH_4)_2SO_4$를 이용하였을 때 IAA 생성은 최대 20-30배까지 증가하였으나 $KNO_3$, $NH_4NO_3$ 그리고 $NH_4$ CI을 질소원으로 사용하였을 때에는 IAA 생성에 큰 영향을 미치지 않았다. 선별된 methylo trophic bacteria를 뿌리에 접종한 결과 균체가 생성한 IAA 영향으로 식물체의 뿌리와 줄기의 길이 그리고 곁뿌리의 수가 상당히 증가하였으며, 균주를 접종한 벼 종자의 초기 뿌리 생장은 균을 접종하지 않은 종자보다 평균 27-56% 증가하였다. 높은 농도의 IAA ($400{\mu}g\;mL^{-1}$)를 처리했을 때는 오히려 뿌리의 생장을 억제 시켰으나, $10-200{\mu}g\;mL^{-1}$ 농도의 IAA를 처리했을 때는 뿌리 생장을 촉진시켰다. 이러한 결과는 박테리아가 생산하는 IAA가 식물 뿌리생장에 중요한 역할을 한다는 것을 의미한다.

• 한국미생물·생명공학회지
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• 제45권1호
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• pp.71-80
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• 2017

차는 세계적으로 인기있는 음료로서, 그 종류는 불발효차(녹차), 반발효차(우롱차), 완전발효차(홍차), 후발효차 등으로 구분된다. 후발효차는 차나무(Camellia sinensis)의 잎을 미생물 발효과정을 거쳐 생산된다. 본 연구에서 한국 후발효차(알가차, 단차)와 중국 후발효차(보이차 2종)에 우점하는 미생물 분석을 위해 16S rRNA 유전자를 이용하였다. 후발효차에 우점하는 미생물은 ${\alpha}$-proteobacteria에 속하는 Rhodobacteraceae와 Sphingomonas, ${\gamma}$-proteobacteria에 속하는 Pantoea가 우점하였다. 미생물 군집 cluster 분석결과, 한국 후발효차와 중국 후발효차는 다르게 분류됨을 확인하였다. 또한, 매우 흥미롭게도 한국 후발효차는 미생물이 우점하였고 중국 후발효차는 곰팡이가 우점하는 것으로 분석되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.66.1-66
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• 2003

The aim of this study was to characterize the interactions of rice and Burkholderia glumae, a causal agent of bacterial grain rot of rice, at molecular levels using whole genomic sequences and to identify genes important for pathogenicity and symptom development. To do these, we sequenced whole genome of the bacterium and constructed cosmid clone profiles. We generated pools of mutants using various transposons and determined mutation sites by sequencing rescued plasmids. We focused on studying toxoflavin biosynthetic genes, quorum sensing regulation, and Hrp type III protein secretion systems. We found that two possible operons consisting of five genes are involved in toxoflavin biosynthesis and their expression is regulated by quorum sensing and LysR-type regulator, ToxR. We have isolated the nn PAI of B. glumae and characterized by mutational analyses. The hrp cluster resembled most the putative Type III secretion systems of B. pseudomallei, which is the causative agent of melioidosis, a serious disease of man and animals. The Hrp PAI core region showed high similarity to that of Ralstonia solanacearum and Xanthomonas campestris, however some aspects were dissimilar.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권1호
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• pp.7-12
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• 2022

Farming practices that balance environmental friendliness with biodiversity are increasingly valuable. Wild plants on farmlands compete for nutrients with crops and create a crucial microhabitat and resources for animals such as natural enemies. Investigating farmlands and their surrounding plants with limited human and material resources has become an essential aspect of evaluating the agricultural ecosystem services. This study investigated plants in six agricultural long-term ecological research sites in Taiwan from 2017 to 2020 to determine the ideal season for investigation. Cluster analysis was performed to group habitats with similar plant composition, and the species-area curves of the clusters in each season were created. The results indicated that the agricultural ecosystem could be divided into farmlands, banks, orchards, and tea gardens. The habitats were divided into farmland, bank, Chia-Yi orchard, Gu-Keng orchard, and tea garden clusters. Ground plant cover can be investigated all year with at least 18 quadrats. However, if human and material resources are limited, 10 quadrats should be the minimum for farmlands in autumn and for the other microhabitats in spring. The minimum number of quadrats is 10 for banks, 17 for orchards, and 9 for tea gardens.