• 한국작물학회지
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• 제48권2호
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• pp.120-126
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• 2003

Four different rice varieties, Sindongjinbyeo, Dongjin #1, Saegyehwabyeo, and Iksan 467, were transplanted under three different nitrogen levels and two different seedling numbers per hill to obtain basic information on panicle traits under different cultural conditions and to propose the ideal panicle structure in Japonica rice. Sindongjinbyeo and Iksan 467 were characterized by more primary rachis branches (PRBs) per panicle and more grains on PRB than other cultivars. The two varieties also had fewer secondary rachis branches (SRBs) per PRB and fewer grains on SRB per PRB. These characteristics, consequently, resulted in higher ripened grain rate, contrary to that of Dongjin #1 and Saegyehwabyeo. In the correlation coefficient analysis, PRB number per panicle and grain number on PRB per panicle were positively correlated with ripened grain rate, while SRB number per panicle, number of grains on SRB per panicle, SRB number per PRB, number of grains on SRB per PRB and grain number per panicle were negatively correlated with ripened grain rate. Therefore, the number of grains on PRB per panicle, SRB number per PRB and the number of grains on SRB per PRB were the appropriate criteria for determining and achieving higher ripened grain rate in rice. High ripened grain rate over 90% was obtainable with over 12.5 PRBs per panicle and 63 grains on PRB per panicle, and with under 1.7 SRBs per PRB, 5 grains on SRB per PRB, 130 grains per panicle, and 14 panicles per hill. The study recommended that for over 90% high ripened grain rate, the critical limiting factors should be under 2 SRBs per PRB, 6 grains per PRB, and 130 grains per panicle, irrespective of the PRB number per panicle and the number of grains on PRB.

• Journal of Crop Science and Biotechnology
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• 제11권3호
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• pp.163-170
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• 2008

The detection, characterization and use of quantitative traits loci, QTL, have significant potential to improve the efficiency of selective breeding of species. Therefore, a population with 59 advanced backcross lines($BC_2F_5$), derived from a cross between IR64 and Tarome molaei, were studied in Tonekabon Rice Research Station of Iran in order to map QTLs for panicle length, number of grain per panicle, and panicle grain sterility in rice. The parental screening wtih 235 SSR markers in agarose and polyacrylamide gels revealed 114 markers with clear polymorphic bands. To search for QTLs associated with panicle length, number of grain per panicle, and panicle grain sterility, we constructed a genetic linkage map using 114 microsatellite markers. Positive and negative transgressive segregations were observed in $BC_2F_5$ lines for all traits. Using multiple interval mapping(MIM), a total of 20 putative QTLs were detected, of which eight were for panicle length, three for number of grains, and nine for panicle grain sterility. The maximum number of QTLs were mapped on chromosomes 1 and 2 with eight QTLs. These QTL markers could possible be utilized for marker-assisted selection.

• 한국작물학회지
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• 제44권2호
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• pp.106-111
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• 1999

To investigate the effects of planting density and nitrogen level on growth and yield potential of newly bred heavy panicle japonica rice with large grain (Iksan 435 and Iksan 438) or many spikelets per panicle(HR14022-21-8-4 and HR14022-21-8-6), four heavy panicle type rices and two many panicle type rices(Dongjinbyeo and Donganbyeo) as the checks were planted under standard planting density (30$\times$15 cm) and dense planting density (15$\times$15 cm) with two nitrogen levels of standard nitrogen level(110 kg h $a^{-1}$) and heavy nitrogen level(165 kg h $a^{-1}$). Effective tiller rate decreased in dense planting or heavy nitrogen, when compared to standard nitrogen and planting, while leaf area index and to dry weight increased in dense planting or heavy nitrogen. Tiller numbers and panicle numbers were more increased by dense planting than heavy nitrogen, whereas spikelet numbers were more increased by heavy nitrogen than dense planting. Ripened grain ratio was slightly lower only in dense planting. 1,000 grain weight in brown rice was not significantly different in dense planting or heavy nitrogen. Milled rice yield was highest in heavy nitrogen with standard planting for heavy panicle type rice, while yield for many panicle type rice was highest in heavy nitrogen with dense planting, suggesting that many panicle type rice possesses higher adapt-ability for dense planting than heavy panicle type rice. Path coefficient analysis revealed that top dry weight, spikelet number and grain weight were the greatest positive contributors to yield, whereas tiller number was negative to yield.d.

• 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.

• The Plant Pathology Journal
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• 제21권2호
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• pp.87-92
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• 2005

The structural differences between healthy and diseasedpanicle necks caused by Pyricularia oryzae were observed using electron-microscope. In the diseased panicle neck, the infection hyphae of the rice blast pathogen grew through the sclerenchymatous fiber tissue and reached to the central internal lacuna. Since the pathogen grew through the sclerenchymatous fiber tissues, the vascular bundle composed with xylem and phloem had been destroyed and finally the nutrients from the leaf and stem were not able to be transported into the grains. Infection of panicle base by the blast pathogen until 20 days after heading caused more than 50% of yield loss in both Jinmibyeo and Chucheongbyeo. There was a positive correlation between incidence of the panicle blast and rice yield losses. The regression equations between incidence of the panicle blast and yield losses were y= -3.61+496.7 ($R^2$=0.70) in Jinmibyeoand y=-3.93+520.2 ($R^2$=0.82) in Juanbyeo. The panicleblast caused deterioration of grain quality. Healthy grain rate was reduced by increase of panicle blast infection.

• The Plant Pathology Journal
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• 제39권1호
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• pp.136-140
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• 2023

Rice panicle blast is one of the most serious diseases threatening stable rice production by causing severe damage to rice yields and quality. The disease is easy to occur under low air temperature and frequent heavy rainfall during the heading season of rice. In 2021, a rice panicle blast severely occurred in the Jeonbuk province of Korea. The incidence area of panicle blast accounted for 27.7% of the rice cultivation area of Jeonbuk province in 2021, which was 13.7-times higher than in 2019 and 2.6-times higher than in 2020. This study evaluated the incidence areas of rice panicle blast in each region of Jeonbuk province in 2021. The weather conditions during the heading season of rice, mainly cultivated rice cultivars, and the race diversity of the Jeonbuk isolates were also investigated. It will provide important information for the effective control of the rice panicle blast.

• 한국육종학회지
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• 제42권2호
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• pp.169-180
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• 2010

국내에서 육성된 178개 품종을 이용하여 12개 이삭형질에 대한 검토 결과는 다음과 같다. 통일형이 자포니카형보다 이삭길이는 길었고 이삭목은 두꺼웠다. 또한 수당립수, 총지경수, 2차 지경수, 2차 지경 총립수, 2차 지경 평균립수 및 1차 지경당 2차 지경수 각각에서 많았다. 반면에 자포니카형이 통일형보다 이삭추출은 양호하였고 1차 지경 평균립수도 약간 많았다. 12개 이삭형질 값을 가지고 평균 연결법을 이용하여 178개 품종을 대상으로 군집분석을 한 결과 4개 그룹으로 분류할 수 있었다. Group I은 자포니카형 133품종, Group II는 자포니카형 24품종, 통일형 6품종, Group III은 자포니카 1품종, 통일형 11품종, Group IV에는 농안벼가 포함되었다. 12개 이삭형질간 상관관계를 분석한 결과 이삭목 두께는 이삭길이, 2차 지경 총립수 및 수당립수와 높은 정의 상관관계를 보였다. 수당립수는 총지경수, 2차 지경 총립수, 2차 지경수, 1차 지경당 2차 지경수, 2차 지경 평균립수와 정의 상관을 보였다. 총지경수는 2차 지경수, 수당립수, 2차 지경 총립수, 1차 지경당 2차 지경수와 정의 상관을 보였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.94-94
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• 2017

Oryza sativa and Oryza glaberrima are rice cultivars distributed in Asia and Africa. There are several differences between these cultivars in morphological characteristics such as panicle structure and especially the secondary branch number of O. glaberrima is less than that of O. sativa. Generally, branch number of panicle related to a large vascular bundle number (VBN) among O. sativa and there is a wide variation of the VBN of the peduncle from where the bundles enter into the rachis branches. However, there is less information about VBN in O. glaberrima and also the relationship between VBN and branch numbers, the primary branch number (PBN) and secondary branch number (SBN). Additionally, the genetic factor for VBN and branch number in O. glaberrima is not completely exploited. In this study, phenotypic variation for VBN and panicle structure were investigated using a set of 40 $BC_3$ -derived from IRGC 104038 (O. glaberrima from Senegal) and 35 $BC_4$ -derived from IRGC103777 (O. glaberrima from Mali) introgression lines with a genetic background of japonica rice Taichung 65. Taichung 65 had 11.8 PBN, 16.0 SBN and 11.5 VBN, while IRGC 103777 had 12.0 PBN, 15.0 SBN and 15.3 VBN. The introgression lines derived from IRGC 104038 had range from 9.0 to 14.4 in the PBN, range from 9.6 to 33.5 in the SBN and range from 9.8 to 14.8 in the VBN. Additionally, the introgression lines derived from IRGC 103777 had range from 9.0 to 18.5 in the PBN, range from 10.3 to 39.0 in the SBN and range from 9.0 to 15.3 in the VBN. Among two set of introgression lines, there are significant correlation between VBN and PBN. Multiple introgression lines indicated higher PBN, SBN and VBN than Taichung 65 and these examined characteristics are supposedly controlled by quantitative traits loci. The genetic factor related to VBN and panicle architecture can be revealed using segregating population in future study.

• 한국작물학회지
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• 제48권1호
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• pp.44-49
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• 2003

In vitro culture of panicle has been the method to accumulate starch and protein in immature grains by providing nutrients after florets crossed between remote genotypes artificially. Grain filling means embryo development and sucrose translocation from photosynthetic source, and starch manufacture in endosperm. The concentrations of sucrose used to culture immature rice panicle were 5, 10, 15, 20% and glutamine was 20 mM. When immature rice panicles at 5 days after flowering were cultured in distilled water with different concentrations of sucrose, glutamine 20 mM and MS medium with different concentrations of sucrose, glutamine 20 mM for 30 days the later was effective on grain filling. The optimal concentration of sucrose on grain filling in vitro culture of rice panicle was 10% and the weight of grain cultured was 10.14 mg that was corresponded to 57% of intact plant. In the method of treating plant growth regulators, the culture of immature rice panicle adding in MS medium with Kinetin, IAA, $\textrm{GA}_3$ were effective on grain filling than the culturing of immature rice panicle after submerging in solutions of Kinetin, IAA, $\textrm{GA}_3$ for 1day. When immature rice panicle was cultured in MS medium with sucrose 10% and Kinetin 46.47 $\mu$M it was effective on grain filling, respectively. The weight of grain cultured was 13.1mg that was corresponded to 75% of intact and germination rate was 51 %. When immature rice panicles were cultured in medium with different concentrations combined with Kinetin 4.65, 46.47, 464.7 $\mu\textrm{M}$, IAA 5.71, 57.08, 570.80 $\mu\textrm{M}$ for 30 days and in medium with IAA 5.71, 57.08, 570.80 $\mu\textrm{M}$ for 15 days after culturing in medium with Kinetin 4.65, 46.47, 464.70 $\mu\textrm{M}$ for 15 days the effect on grain filling was similar.

• 한국농림기상학회지
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• 제3권4호
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• pp.177-184
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• 2001

본 연구는 벼 휴립건답직파 절수재배에 알맞은 질소 수비량을 구명하고자 파종량을 6kg/10a과 10kg/10a으로 하고, 질소 수비 시비량을 10a당 4.8kg(표준구), 2.4kg, 7.2kg 및 9.6kg을 시비 처리하여 시험한 결과를 요약하면 다음과 같다. 가. 질소 수비량이 많을수록 엽면적지수와 지상부 건물중은 약간씩 증가하는 경향이었다. 나. 출수기 광합성능은 질소 수비량이 많을수록 높았으며, 파종량간에는 6 kg/10a 파종에서 높았다. 다. 질소의 흡수량은 질소 수비량이 많을수록 많았으며, 질소 이용율은 6kg/10a 파종에서는 질소 표준수비(4.8kg/10a) 보다 50% 증시에서 가장 높았고 10 kg/10a 파종에서는 별 차이가 없었다. 라. 단위 면적당 수수는 질소 수비량이 많을수록 많았고, 등숙비율과 현미 천립중은 비슷하여, 쌀 수량은 표준(6kg/10a 파종시 수비량 4.8kg/10a 시용) 보다 50%증시(7.2kg/ha)구에서 6kg/10a 파종에서는 6%, 10 kg/10a 파종에서는 13% 증수되었다.