• 한국작물학회지
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• 제44권3호
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• pp.214-220
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• 1999

Rice production in Korea has markedly increased during the last two decades due to newly developed high yielding varieties and improved production technology. This experiment was conducted to determine the potential of tropical japonica germplasm in enhancing the yield of temperate japonica. The yield performance of two tropical japonicas (IR 65597-29-3-2 and IR66154-52-1-2) and one temperate japonica (Dongjinbyeo) was compared at different plant densities and nitrogen levels under Korean environmental conditions. Although tropical japonicas showed low tillering habit and large panicles, they had similar leaf area index and dry weight at heading stage to Dongjinbyeo of the high tillering type indicating that there was not much difference between tropical and temperate japonica in terms of biomass production. The highest milled rice yield of 6.15 t/ha was obtained from Dongjinbyeo at a high nitrogen level with less planting density (220 kg N/ha and 30 $\times$ 15 cm). However, those of the two tropical japonicas were 5.36 t/ha at the condition of 165 kg N/ha and 30 x 10 cm planting density and 5.06 t/ha at the condition of 165kgN/ha and 15 x 15 cm planting density, respectively. Ripened grain of tropical japonicas ranged from 65 to 87%, while that Dongjinbyeo ranged from 82 to 97% under Korean conditions.

• 한국작물학회지
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• 제43권3호
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• pp.135-140
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• 1998

Diallel analysis was conducted with FI's derived from crossing in all combinations without reciprocals among six rice varieties; three tropical japonica and three temperate japonica varieties, with different traits associated with panicle and flag leaf. Epistasis was observed in the number of primary branches (PB) per panicle and of spikelets per panicle, while flag leaf length, flag leaf color, PB length and neck node thickness were explained with the additive-dominance model. The estimated genetic mode of flag leaf length and PB length was a positive complete dominance model with high heritability, and that of flag leaf color and neck node thickness was an incomplete dominance model. In particular, tropical japonica varieties with low-tillering and heavy-panicle appear to have higher number of dominant genes for flag leaf length and PB length than temperate japonica varieties.

• Parasites, Hosts and Diseases
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• 제58권5호
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• pp.537-542
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• 2020

Cockroaches inhabit various habitats, which will influence their microbiome. Although the microbiome can be influenced by the diet and environmental factors, it can also differ between species. Therefore, we conducted 16S rDNA-targeted high-throughput sequencing to evaluate the overall bacterial composition of the microbiomes of 3 cockroach species, Periplaneta americana, P. japonica, and P. fuliginosa, raised in laboratory for several generations under the same conditions. The experiments were conducted using male adult cockroaches. The number of operational taxonomic units (OTUs) was not significantly different among the 3 species. With regard to the Shannon and Pielou indexes, higher microbiome values were noted in P. americana than in P. japonica and P. fuliginosa. Microbiome composition was also evaluated, with endosymbionts accounting for over half of all OTUs in P. japonica and P. fuliginosa. Beta diversity analysis further showed that P. japonica and P. fuliginosa had similar microbiome composition, which differed from that of P. americana. However, we also identified that P. japonica and P. fuliginosa host distinct OTUs. Thus, although microbiome compositions may vary based on multiple conditions, it is possible to identify distinct microbiome compositions among different Periplaneta cockroach species, even when the individuals are reared under the same conditions.

• Parasites, Hosts and Diseases
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• 제33권2호
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• pp.75-84
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• 1995

Gorgoderidae에 속하는 흡충류는 어류, 양서류 및 파충류 등의 방광에 기생하며 우리 나라의 양서류에서는 Gonodera japonica 1종만이 기록되어 있다가 유와 이(1983)에 의해 Corgoderina bombinae 1종이 신종으로 보고된 바 있다. 본 연구에서는 1989년부터 1994년에 걸쳐 전국 각지에서 채집한 양서류를 대상으로 그들의 방광에 기생하는 윤충류를 조사한 결과 Gorgoder japonica 및 Conoderinc bombinae 2종을 동정하였으며. 분류된 2종에 대한 형태학적인 특징을 기술하고 이들의 분류학적 위치에 대해 상세히 논하였다 G. japonica가 G. cygnoides와 명확히 구별되는 점은 난황선이 깊은 열개에 의해 뚜렷한 여러 개의 엽을 형성하는 점이었다. G. bombinoe는 기존의 종들과 비교한 결과 뚜렷한 종으로서 확인되었으며, 이 종에 대한 국명을 "무당개구리방광흡충"으로 제안한다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.292-292
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• 2022

Since 1992, the Rural Development Administration (RDA), Republic of Korea in collaboration with International Rice Research Institute (IRRI) has developed 6 japonica rice varieties(MS11, Japonica 1, 2, 6, 7 and Cordillera 4) that are adaptable to tropical regions. However, these varieties show moderate resistance or susceptibility to certain biotic and abiotic stress. The development of varieties with more stable forms of resistance is highly desirable, and this could be possibly achieved through rapid introgression of known biotic and abiotic resistant genes. In this study, we analyzed the allele types of major biotic stress resistant genes including Xa5, Xa13, Xa21 and Xa25 for bacterial leaf blight, Pi5, Pi40, Pish and Pita2 for blast, tsv1 for rice tungro spherical virus, and Bph6, Bph9, Bph17, Bph18 and Bph32 for brown planthopper by using gene-specific molecular markers. In addition, seed quality related genes Sdr4 for preharvest sprouting and qLG-9 for seed longevity were also analyzed. The results revealed that2h5 and Xa25 resistance alleles showed in all varieties while Pi5 resistance allele showed only in MS11. The Pish resistance allele were present in five varieties except for Japonica 1. Meanwhile, for the rest of the genes, no presence of resistance alleles found in six varieties. In conclusions, most of tropical japonica varieties are lack of the major biotic stress resistant genes and seed quality genes (Sdr4 and qLG-9). Moreover, the results indicated that rapid deployment of a few major genes in the current tropical japonica rice varieties is urgent to increase durability and spectrum of biotic stress resistance and also seed dormancy/longevity which are essential traits for tropical environments.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.214-214
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• 2022

Soluble starch synthases (SSs) elongate α-glucans from ADP-Glc to the glucan nonreducing ends and play a critical role in synthesizing resistant starch in the rice. A total of 10 SSs isoforms were reported in rice, including granules-bound starch synthase I (GBSSI), GBSSII, starch synthase I (SSI), SSIIa (SSII-3), SSIIb (SSII-2), SSIIc (SSII-1), SSIIIa (SSIII-2), SSIIIb (SSIII-1), SSIVa (SSIV-1), and SSIVb (SSIV-2). SSIII proteins are involved in forming the B chain and elongating cluster filling chains in amylopectin metabolism. The functions of SSIIIb (SSIII-1) are less clear as compared to SSs. Here, we sought to shed light on the genetic diversity profiling of the SSIII-1 gene in 374 rice accessions composed of 54 wild-type accessions and 320 bred cultivars (temperate japonica, indica, tropical japonica, aus, aromatic, and admixture). In total, 17 haplotypes were identified in the SSIII-1 coding region of 320 bred cultivars, while 44 haplotypes were detected from 54 wild-type accessions. The genetic diversity indices revealed the most negative Tajima's D value in the temperate-japonica, followed by the wild type, while Tajima's D values in other ecotypes were positive, indicating balancing selection. Nucleotide diversity in the SSIII-1 region was highest in the wild group (0.0047) while lowest in temperate-japonica. Lower nucleotide diversity in the temperate-japonica is evidenced by the negative Tajima's D and suggested purifying selection. The fixation index (F_ST) revealed a very high level of gene flow (low F_ST) between the tropical-japonica and admixture groups (F_ST=-0.21) followed by admixture and wild groups (-0.04), indica and admixture groups (0.02), while low gene flow with higher F_ST estimates between the temperate-japonica and aus groups (0.72), tropical-japonica and aromatic groups (0.71), and temperate-japonica and admixture groups (0.52). Taken together, our study offers insights into haplotype diversity and evolutionary fingerprints of SSIII-1. It provides genomic information to increase the resistant starch content of cooked rice.

• 한국작물학회지
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• 제50권3호
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• pp.186-190
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• 2005

서로 다른 벼 3아종의 품종군에 대한 아밀로그램 특성을 상관 및 주성분 분석으로 품종의 다양성을 파악한바 결과를 요약하면 아래와 같다. 1. 최고점도와 강하점도에서 나타난 성적으로 보아 통일형의 temperate indica품종군이 전형적인 인디카 품종군과 신초형의 tropical japonica품종군보다 자포니카 혈연에 가까웠다. 2. temperate indica 품종군이 전형적인 인디카 품종군과 tropical japonica 품종군보다 최종점도, 응집점도 및 취반점도는 낮게 나타났다. 3. 최고점도와 최저점도는 3아종의 품종군에서 다같이 고도의 정상관을 보였고 강하점도와 취반점도는 3아종에서 다같이 고도의 부상관을 보였다. 4. 제1주성분은 호화온도, 최종점도, 응집점도 및 취반점도를 증가시키는 방향으로 그리고 최고점도 및 강하점도는 감소시키는 방향으로 작용했다. 5. 주성분치로서 평면상 도표를 그린 품종군 분류로 품질관련 아밀로그램 특성의 공통된 품종의 특성을 파악할 수 있었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.219-219
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• 2022

Granule-bound starch synthase I (GBSSI), encoded by the waxy gene, is responsible for the accumulation of amylose during the development of starch granules in rice endosperm. Despite many findings on waxy alleles, the genetic diversity and evolutionary studies are still not fully explored regarding their functional effects. Comprehensive evolutionary analyses were performed to investigate the genetic variations and relatedness of the GBSSI gene in 374 rice accessions composed of 54 wild accessions and 320 bred cultivars (temperate japonica, tropical japonica, indica, aus, aromatic, and admixture). GBSS1 coding regions were analyzed from a VCF file retrieved from whole-genome resequencing data, and eight haplotypes were identified in the GBSSI coding region of 320 bred cultivars. The genetic diversity indices revealed the most negative Tajima's D value in the tropical-japonica, followed by the aus and temperate-japonica, while Tajima's D values in indica were positive, indicating balancing selection. Diversity reduction was noticed in temperate japonica (0.0003) compared to the highest one (wild, 0.0044), illustrating their higher genetic differentiation by F_ST-value (0.604). The most positive Tajima's D value was observed in indica (0.5224), indicating the GBSSI gene domestication signature under balancing selection. In contrast, the lowest and negative Tajima's D value was found in tropical japonica (-0.5291), which might have experienced a positive selection and purified due to the excess of rare alleles. Overall, our study offers insights into haplotype diversity and evolutionary fingerprints of GBSSI. It ako provides genomic information to increase the starch content of cooked rice.

• 한국국제농업개발학회지
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• 제31권3호
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• pp.249-254
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• 2019

'Japonica 6'(Registration No. BPI-NSIC-2017-Rc 484SR)은 열대지역에 적응하는 고품질 다수성 자포니카 벼를 개발하기 위하여 육성되었으며 육성 과정 및 주요 특성은 다음과 같다. 1. 'Japonica 6'는 열대지역 적응 고품질 자포니카 다수성 품종 육성을 목적으로 2010년 필리핀 소재 국제미작연구소(IRRI)에서 농촌진흥청 파견 연구원 주도로 인공교배와 계통 육종법으로 육성된 품종이다. 2. 인공교배와 계통육성은 국제미작연구소 온실과 육종포장에서 실시하였고 열대기후에서 생육과 임실이 안정적인 IR94746-24-3-2-2-2을 선발하여 2015~2016년 2년간 우기 및 건기 각 2회 지역적응시험을 실시한 결과 그 우수성이 인정되어 2017년에 필리핀 벼 품종심의위원회에서 장려품종으로 선정하였다. 2. 'Japonica 6'은 파종부터 수확까지 생육일수가 121일인 중생종으로, 간장은 70 cm, 이삭길이는 21 cm, 주당 이삭수 16개였으며, 현미 천립중이 26.7 g으로 단원형 중대립이다. 3. 'Japonica 6'의 병해충 반응은 도열병과 잎집무늬마름병에서 중도 저항성을 보였으나, 흰잎마름병, 퉁그루바이러스, 멸구류에는 저항성이 없다. 4. 'Japonica 6'의 도정특성 중 도정률은 73.0%로 대비품종인 'MS11'보다 높았고 완전미도정수율은 64.2%로 'MS11'보다 유의하게 개선되었다. 5. 'Japonica 6'의 쌀수량은 필리핀 5개 지역에서 지역적응시험 결과 평균 3.59 MT/ha으로 대비품종 'MS11'보다 43% 높았다.

• 한국작물학회지
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• 제31권3호
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• pp.277-285
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• 1986

인도네시아의 8개품종과 한국의 8개품종을 선정하여 계 16개품종을 인도네시아 발리(115$^{\circ}$ 14'E, 8$^{\circ}$42'S, 해발 l0m지점)와 한국 수원(126$^{\circ}$19'E, 37$^{\circ}$16'N, 해발 37m)에서 반복시험한 결과 공시품종의 출수기 및 생육형질의 변리는 아래와 같이 요약된다. 1. 16개 공시품종중 Japonica 4개품종 (레이메이, 삼남. 수원 313, 섬진)은 발리지역에서 이앙후 14~15일에 모두 출수하였으며 품종간에 조만성을 구분할 수 없었다. 2. Indica/Japonica품종(태백, 만석, 한강찰, 금강)은 수원에서 보다 발리에서 26~31일 출수가 촉진되었으며 품종간의 조차성은 양지역에서 동일한 경향을 보였다. 3. Indica의 4개품종중 3개품종(IR 36, IR 50, Semeru)은 수원에서 발리보다 출수가 26~29일정도 늦게 출수하였으며 품종간의 조만성도 양지역에서 동일한 경향을 보였으나 만생종인 Cisadane 품종은 수원에서 47일 이나 늦게 출수하여 (수원지방출수일 : 9.27일) 성숙치 못하였다. 4. Bulu 4개품종중 3개품종(Putih Gangsar, Kesambi, Putih, Jamu)은 수원에서는 출수치 않았으며 조생종인 Untup 품종은 Cisadane와 비슷한 시기에 수원에서 출수하였으나 역시 성숙치 못하였다. 5. 발리지성에서 Japonica 품종은 출수이후 수확까지 계속하여 초장이 자라났으며 수원에서 출수하지 못한 Bulu 3개 공시품종의 초장은 수원에서 예취시까지 계속하여 자랐다. Indies 공시품종은 수원과 발리에서 초장의 차리가 없었으나 Indica/Japonica및 Bulu 품종은 수원보다 발리에서 초장이 크게 나타났으며 Japonica는 수원에서 초장이 크게 자랐다. 6. 건물중은 발리지성에서 품종군간에 차리가 두드러지게 나타났으나 수원지방에서는 그 차이가 적었다.