1. 열대아시아지역에 적응하는 수출용 일대잡종 벼 품종을 육성할 목적으로 2013년에 미얀마에서 수집한 도열병과 흰잎 마름병에 저항성인 ‘MY1B’를 국제미작연구소(IRRI)에서 육성 된 일대잡종 벼 웅성불임친인 ’IR68897A’에 4회 여교배하여 2016년에 불임친인 ‘KR1A’와 유지친인 ‘KR1B’를 육성하였으며 육성된 불임친 ‘KR1A’를 회복친유전자를 가진 우량계통들과 검정교배한 결과 베트남 지역 적응성이 높고 도정특성이 우수한 OM052와 교배한 조합이 우수하여 교배번호 KR0695H을 부여한 후 생산력 검정에 필요한 F1종자를 생산하였고 선발된 일대잡종 벼 계통에 대해 2년간의 지역적응시 험을 통해 우수성이 인정되어 2019년 농촌진흥청 직무육성 신 품종선정위원회에서 신품종으로 선정되면서 ‘KGHR1’으로 명명되었음 2. ‘KGHR1’의 F1 종자생산을 위해 육성된 불임친과 유지친, 회복친의 농업형질을 조사한 결과 불임친인 ‘KR1A’의 임실율이 0%인 완전불임을 보였고 불임친인 ‘KR1A’과 유지친인 ‘KR1B’을 1% potassium iodide-iodine(I-KI)에 염색해 본 결과 ‘KR1A’는 염색이 되지 않은 완전불임을 나타내어 일대잡종벼의 특성에 부합되었음 3. ‘KGHR1’는 중부평야지 보통기 재배에서 평균 출수기가 8월 13일로 대비품종 ‘다산’보다 5일 늦은 중생종이었고 간장은 103 cm로 다산의 82 cm보다 21 cm 큰 장간이고, 이삭길이는 28 cm로 ‘다산’ 보다 길고 이삭당 벼알수는 202개로 ‘다산’ 보다 69개 많았고 등숙비율은 76.3%로 대비품종 ‘다산’ 83.7% 보다 낮게 조사되었음 4. ‘KGHR1’는 도열병과 줄무늬잎마름병에 저항성이었고 흰 잎마름병은 K1, K2, K3 균계에 저항성을 보였지만, 오갈병 및 멸구류에 대한 저항성은 없었으며 도복에는 강하며, 수발 아와 내냉성은 ‘다산’과 비슷한 수준을 보였음 5. ‘KGHR1’의 입형은 현미장폭비가 3.37로 장원립이고 백미외관은 심복백이 0/1로 맑고 투명하였으며 단백질함량은 6.3%로 ‘다산’ 보다 낮은 반면 아밀로스함량은 22.7%로 ‘다산’ 보다 높았음 6. ‘KGHR1’의 제현율과 현백률은 대비품종 ‘다산’과 차이가 없었고 완전미도정수율은 40.5%로 ‘다산’ 보다 낮았으나 베트남 현지 일대잡종 벼 품종인 IIA838 보다 높았음 7. ‘KGHR1’의 쌀수량은 ‘수원’ 등 3개 지역에서 실시한 지역적응시험 보통기 보비재배 평균 6.60 MT/ha로 ‘다산’의 6.59 MT/ha와 차이가 없는 수량성을 보였고 수원에서 3년간 실시한 생산력 검정에서는 ‘다산’ 보다 23% 증수하였으며 특히 2019년에 7.59 MT/ha로 베트남 대조품종인 IIA838 보다 도 11% 증수하였으나 베트남 하이하우에서 2018년에서 2019 년까지 2년간 2작기씩 현지 관행재배로 4회 실시한 생산력검 정시험에서는 8.25 MT/ha로 대조품종인 IIA838 보다 12% 떨어지는 수량을 나타내었음 8. ‘KGHR1’는 국내 종자산업 육성과 수출경쟁력을 높이기 위해 2014년부터 수행한 골든시드프로젝트(Golden Seed Project, GSP)의 결과로 개발된 첫 번째 일대잡종 벼 품종으로 우리나라 벼 종자수출산업의 발전을 위한 밑거름이 될 것임

Since pine wilt disease was first reported in Busan in 1988, this disease has become a serious threat to pine forests in Korea. A general survey for Bursaphelenchus xylophilus group (B. xylophilus, B. mucronatus) nematodes were carried out to determine their geographic range, host tree species and insect vectors, Monochamus species. Based on the survey results, B. xylophilus were found over 57 cities or district and a similar nematode, B. mucronatus also has been isolated over 30 cities or district including Jeju and Pocheon. The Asian type of B. mucronatus was founded from Pinus thunbergii and P. densiflora, generally associated with M. alternatus as its insect vector. The European type of B. mucronatus which was limited distribution to the central areas, such as Yeongwol, Bonghwa, Yeongdeok, was also found on P. koraiensis and P. desiflora associated with M. saltuarius. Both Monochamus species transmitted both Bursaphelenchus species and co-existed in Muju and Yeongdeok predicted as their range margin. Their range margins shifted northwards compared to 2006, seemingly as a result of climate change. Recently, the European type of B. mucronatus has been identified in other several areas since it was first reported in Pocheon in 2008. Several reports indicate the potential pathogenicity of European type of B. mucronatus and other species, B. sexdentati and B. lenoni in Europe. Therefore, sustainable survey and the study for the newly invading Bursaphelenchus species as well as the member of B. xylophilus group should be performed to protect Korean forests.

‘Nokwoo’, a mid-late maturing, high dry matter yielding rice (Oryza sativa L.) cultivar with a good early growth and low-temperature germinability, was developed for whole crop silage (WCS) use. It was derived from a cross between a leafy tropical japonica ‘LK1A-2-12-1-1’ with high biomass and good germinability in low temperature and new plant type (NPT), ‘IR72225-29-1-1’ which had low tillering trait, large panicle, dark green leaf, thick and sturdy stem and vigorous root system. This cultivar had about 123 days growth period from seeding to heading, 122㎝ culm length, 29㎝ panicle length, 9 panicles per hill, 144 spikelets per panicle and 1,000-grain weight of 24.4 g as brown rice in central plain region, Suwon. This wide and long leafy WCS rice variety was weak to cold stresses similar to ‘Nokyang’ but was a little resistant to lodging in the field, strong to viviparous germination and good to low temperature germination. In addition, ‘Nokwoo’ was resistant to leaf and neck blast but susceptible to bacterial blight, rice stripe virus and brown planthopper. Its average dry matter yield for three years reached 16.5 MT/ha, 14% higher than that of ‘Nokyang’. This cultivar had 5.3% crude protein and 68.8% total digestible nutrients a little low compared to ‘Nokyang’. In Korea peninsular, ‘Nokwoo’ grows well in central and southern plain and is good to harvest between 15 to 30 days after heading to improve its feeding value and digestion rate of livestock (Grant No. 6072).

Knowledge of the chromosomal constitution of the ancestors of modern soybean will complement plant breeding efforts to improve agronomic and economic characteristics of soybean. Variation block (VB)-based comparison using genome-wide insertion/deletion (InDel) markers was used on a diverse panel of 147 soybean cultivars to assess the impact of chromosomal changes during modern breeding. There were identical variation patterns of the examined InDels consistently appearing in the genome parts arising from parental varieties, indicating that soybean chromosomes in descendants should be all determined by genetic reshuffling of VBs inherited from parental chromosomes. Structure analysis of the accessions through the 202 InDels separated the accessions into four subgroups. Gene introgression revealed by the structure analysis agreed with the fact that a limited number of landraces and elite varieties were introduced and used as donors for breeding soybean cultivars in pedigree analysis. Especially, VBs became more reshuffled over time as a result of the breeding process, which resulted in using breeding parents with new VB-types for improving the end-use value of soybean. Therefore, their clustering using the 202 VB-specific InDels is strongly influenced by the difference in breeding ancestors among the subgroups. This indicates that the 202 InDel markers are very useful for genetic study by analyzing the reshuffling patterns of the parental genomes in the descendant.

‘Jungmo1024’ is a blast resistant early maturing rice cultivar with high temperature tolerance during grain filling stage. ‘Jungmo1024’ was derived from a sodium azide treatment on ‘Suweon472’, a high yielding japonica elite line which was latterly registered as ‘Namil’. Comparison with the agronomical traits of ‘Namil’, ‘Jungmo1024’ was uniquely characterized as the induced gained function due to the reduced culm length, increased tiller number, strong blast resistance and especially high temperature tolerance during grain filling stage. The high temperature tolerance of ‘Jungmo1024’ was supported by two years experiments by comparing the head rice ratio produced in ordinary paddy field and green house condition. The heading date of ‘Jungmo1024’ was July 29 in central plain area, which was 9 days earlier than that of ‘Hwaseong’. The milled rice yield performance of ‘Jungmo1024’ was about 4.98 MT/ha in local adaptability test for three years. ‘Jungmo1024’ had 69 cm in culm length, which was 15 cm shorter than that of ‘Hwaseong’, 20 cm in panicle length, 16 in tiller number, and 22.3g in 1,000 grain-weight of brown rice. ‘Jungmo1024’ exhibited strong rice blast resistance, but do not have any clear resistance gene sources against bacterial blight, viral diseases and insect fests. ‘Jungmo1024’, nevertheless, would be a useful rice cultivar could be used as a donor line for the breeding programs for developing southern plane adaptable early maturing rice cultivars with enhanced rice blast resistance, lodging tolerance, and especially high temperature tolerance during grain filling stage.

감자 수요를 확대하기 위해서는 소득 증가와 함께 소비자 의 관심이 증대하고 있는 신선편이식품으로 시장을 보다 더 넓혀 나가야 한다. 이를 위해서는 감자에 존재하는 유독 물질 인 glycoalkaloids에 대한 주의가 필요하다. 본 연구에서는 도 입품종인 대서, 수미와 최근 국내에서 개발된 하령, 고운, 홍 영, 자영 품종을 포함하여 국내 주요 24품종을 대상으로 부위 별 PGA 함량을 분석하였으며 그 연구 결과를 요약하면 다음 과 같다. 1. 총 PGA 함량(mg/100g·FW)은 하령(10.1), 수미(9.3), 홍영(7.3), 자영(6.9), 대서(4.8), 고운(3.4), 자심(3.1) 순으로 나타났다. 2. 공시품종의 껍질부위 PGA 함량은 전체 함량의 41 ~ 85% 분포를 보였으며, 국내주요 재배 품종에서 대서는 PGA 함량이 껍질(85%)에서 높고 육질 부위(0.7)에서 낮아 PGA 독성으로부터 가장 안전한 품종이었다. 3. 특히 고운, 자심 품종은 PGA 함량이 제일 낮아 껍질째 감자를 이용하기에 적절하며 중간모본으로 활용가치가 크다 고 판단된다.

The Arabidopsis gene AVP1 encodes a vacuolar H+-translocating inorganic pyrophosphatase (EC3.6.1.1) that functions as an electronic proton pump in the vacuolar membrane and affects growth development and stress responses in plants. This study was conducted to evaluate the molecular properties of the A. thaliana vacuolar H+-pyrophosphatase (AVP1) gene in rice. Incorporation and expression of the transgene was confirmed by PCR and quantitative real-time PCR, respectively. Expression of the AVP1 gene in transgenic rice plants (TRP1 and TRP2) resulted in significantly enhanced tolerance to 100 mM NaCl under greenhouse conditions when compared to control wild-type (WT) rice plants. Augmented AVP1 expression in the transgenic rice plants also affected total biomass and improved ion homeostasis through increased accumulation of Na+ ions in whole tissues when compared to control WT rice plants under high salinity conditions. The Fv/Fm values of transgenic rice plants were higher than those of WT rice plants, even though the values decreased over time in both WT and transgenic (TRP1 to TRP8) rice plants. Furthermore, rice grain yield and biomass of the transgenic rice plants were at least 15% higher based on the culm and root weights and panicle and spikelet numbers when compared to those of the WT rice plants during the farming season in Korea. Thus, these results suggest that ectopic AVP1 expression conferred tolerance and stress resistance to genetically modified transgenic crop plants by improving cellular ion homeostasis against salt conditions, which enhanced the rice yield and biomass under natural conditions in paddy fields.

Much effort has been expended to find agronomically important QTLs for improving soybean yield. However, the complexity of genome, such as genome duplication, limits the utility of genome-wide association studies and linkage analyses to identify genes controlling yield traits. We propose the variation block method, a three-step process for recombination block detection and comparison. The first step is to detect variations by comparing short-read DNA sequences of the cultivar to a reference genome of the target crop. Next, sequence blocks with variation patterns are examined and defined. The boundaries between the variation-containing sequence blocks are regarded as recombination sites. All the assumed recombination sites in the cultivar set are used to split the genomes, and the resulting sequence regions are named as variation blocks. The practicality of this approach was demonstrated by the identification of a putative locus determining soybean hilum color and known genes such as flower color gene. We suggest that the variation block method is an efficient genomics method for recombination block-level comparison of crop genomes. We expect that this method holds the prospect of developing crop genomics by bringing genomics technology to the field of crop breeding.

Potato glycoalkaloids(PGAs) are potentially toxic to humans at high levels and current safety regulations have recommended that PGAs content in tubers of potato cultivars should not exceed 20 mg/100g·FW. Accordingly, it is important to determine the PGAs composition and levels on potato cultivars for food safty and the breeding for new cultivars with low levels of PGAs. The main aim of this study was to evaluate α-chaconine, α-solanine and total PGAs content in the peel and cortex portions in 24 cultivars including ‘Haryoung’, ‘Goun’, ‘Hongyoung’ and ‘Jayoung’, recently released by Highland Agricultural Research Institute. The total PGAs ranged from 3.1 to 10.1 mg/100g·FW. 75-94% of total PGAs was existed in the peel part of all cultivars. We selected two cultivars, which can be eaten wth the skin on tubers, and so used for soy sauce braised potatoes and baby potatoes for the rest area. These results will provide consumers and breeders with fundamental information about the content of PGAs in Korea major cultivars.

PGA 함량 정보가 없는 유전자원을 활용한 다양한 용도의 감자 품종 개발은 괴경 내 PGA 함량을 높이는 비의도적 결과를 초래할 가능성이 있다. 이러한 배경에서 신품종에 대한 정밀한 PGA 함량 분석은 감자의 식품안전성 제고와 PGA 저 함유 품종 개발을 위한 교배 모부본 확보차원에서 중요하다. 본 연구에서는 도입품종인 대서, 수미와 최근 개발된 하령, 고운, 홍영, 자영 4품종을 대상으로 괴경 부위, 저장기간별 PGA 함량변화를 분석하였다. 그 연구 결과를 요약하면 다음과 같다.

The perturbation of the steady state of reactive oxygen species due to biotic and abiotic stresses in a plant could lead to protein denaturation through the modification of amino acid residues, including the oxidation of methionine residues. Methionine sulfoxide reductases (MSRs) catalyze the reduction of methionine sulfoxide back to the methionine residue. To assess the role of this enzyme, we generated transgenic rice using a pepper CaMSRB2 gene under the control of the rice Rab21 promoter with/without a selection marker, the bar gene. A drought resistance test on transgenic plants showed that CaMSRB2 confers drought tolerance to rice, as evidenced by less oxidative stress symptoms and a strengthened PSII quantum yield under stress conditions, and increased survival rate and chlorophyll index after the re-watering. The results from immunoblotting using a methionine sulfoxide antibody and nano-LC-MS/MS spectrometry suggest that porphobilinogen deaminase (PBGD), which is involved in chlorophyll synthesis, is a putative target of CaMSRB2. The oxidized methionine content of PBGD expressed in E. coli increased in the presence of H2O2, and the Met-95 and Met-227 residues of PBGD were reduced by CaMSRB2 in the presence of dithiothreitol. An expression profiling analysis of the overexpression lines also suggested that photosystems are less severely affected by drought stress. Our results indicate that CaMSRB2 might play an important functional role in chloroplasts for conferring drought stress tolerance in rice

In contrast with wild species, cultivated crop genomes consist of reshuffled recombination blocks, which occurred by crossing and selection processes. Accordingly, recombination block-based genomics analysis can be an effective approach for screening target loci with agricultural traits and for developing designed cultivars. We propose the molecular breeding platform based on the variation block (VB) method, which is a three-step process for recombination block detection and comparison. The first step is to detect variations by comparing the short-read DNA sequences of the cultivar to the reference genome of the target crop. Next, sequence blocks with variation patterns are examined and defined. The boundaries between the variation-containing sequence blocks are regarded as recombination sites. All the assumed recombination sites in the cultivar set are used to split the genomes, and the resulting sequence regions are termed variation blocks. Finally, the genomes are compared using the variation blocks. The variation block method identified recurring recombination blocks accurately and successfully represented block-level diversities in the publicly available genomes of 31 soybeans and 23 rice accessions. The practicality of this approach was demonstrated by the identification of a putative locus determining soybean hilum color. In addition, we identified recombination hot spots of soybean genome in 614 recombinant inbred lines (RILs) using VB-specific indel markers. We expect that this platform facilitate the development of designed cultivars by introducing precise target loci into plant genomes.

선향흑미는 밥쌀용 쌀에 현미 기능성 성분인 종피에 유색색소 C3G의 함량을 높이고 쌀에 구수한 향을 추가하여 식미 증진을 목적으로 종피가 흑자색인 수원477호(흑광)를 모본으로하고 C3G 성분이 많고 쌀에서 구수한 향이 있는 CG2- 2-75-4-1-22-3을 부본으로하여 2002년 교배하여 계통육종법으로 육성하여 2007~2008년 2년간 생산력검정시험 2009~2011년 3년간 지역적응시험 실시한 결과 그 우수성이 인정되어 2011년 12월 농촌진흥청 농작물 직무육성 신품종선정위원회에서 품종으로 선정되었다. 이 품종의 주요특성을 요약하면 다음과 같다. 1.출수기는 8월 11일로 중부평야에서 흑진주벼 7월 24일보다 늦는 중생종 품종이다.2.간장은 89 cm로 흑진주보다 8 cm 정도 크고, 주당수수는 흑진주벼와 비슷한 14개이며 수당립수는 122개로 흑진주 100개보다 많다. 현미천립중은 17.0 g 이다.3.도열병에는 강하지는 않으나 흰잎마름병에 강하고 줄무늬잎마름병은 중정도로 강하다.4.불시출수는 없고 성숙기 하엽노화는 흑진주벼와 같이 늦으며, 수발아는 6.6%로 적은 편이다. 내냉성과 도복은 약한 편이다.5.전국 7개 장소의 평균 현미수량은 4.75 Mt/ha 이다.6.아밀로스 함량은 19.7%로 메벼이며 향이 흑진주벼에 비하여 강하다. 7.현미색은 진한 검정색으로 안토시안 함량은 136 mg/100g, 항산화 성분인 폴리페놀 함량은 529 mg/100g 이다.8.재배적응 지역은 중부평야 및 호남평야이다.

‘목양’은 국립식량과학원 벼 육종연구진이 총체 사료용 벼 품종을 육성할 목적으로 2001년 하계에 SR24592-HB2319 를 모본으로 하고 신초형 IR73165-B-6-1-1을 부본으로 교배 하여 계통육종법으로 육성한 품종으로 2010년 12월 농작물 직무육성신품종선정위원회에서 국가목록등재품종으로 선정 됨과 동시에 ‘목양’으로 명명하였다. ‘목양’의 출수기는 보통 기 재배에서 8월 23일로 ‘녹양’보다 8일 정도 늦은 만생종이 다. ‘목양’은 도열병, 줄무늬잎마름병, 오갈병에는 ‘녹양’보다 강하지만, 흰잎마름병, 벼멸구에는 약한 편이다. ‘목양’은 ‘녹 양’보다 탈립에 강하고, 후기녹체성이 우수하였다. ‘목양’은 가소화양분총량(TDN) 함량이 높고 중성세제불용섬유소(NDF) 와 산성세제불용섬유소(ADF)가 낮았다. ‘목양’의 총체수량은 지역적응시험에서 2008년부터 2010년까지 평균 17.7 MT/ha 로 ‘녹양’보다 25% 증수하는 경향을 보였다. ‘목양’은 가소화 양분총량(TDN)은 59.5%였으며 ADF와 NDF가 낮아 상대적 사료가치가 ‘녹양’에 비해 높은 품종이다. ‘목양’의 정조 수량은 보통기 재배에서 5.59 MT/ha로 ‘녹 양’보다 16% 증수되었다. 재배적지는 중부 및 남부평야지 1 모작 지대이다.

The Brown planthopper (Bph) is one of the most serious pests of rice affecting rice yield and quality throughout the country. Combining the Bph resistance in the existing quality japonica cultivars is an important breeding target in Korea. Wide crosses using several strains of AA-genome wild rices, O.rufipogon have been used to produce the primary germplasm which is highly resistant to Bph. By repeated backcrossing, the resistance gene was introgressed in the background of two japonica cultivars, Ilpum and Hwaseong. Among the advanced backcross progenies, the ten BC2F3 lines were identified as the highest resistance in the comparative Bph bioassay with other resistant sources. The 24 polymorphic markers spanning the twelve chromosomes were tested for association with marker genotypes and resistance/susceptibility reaction in the 80 BC2F3 lines, RM3748 on the chromosome 7 showed the highest association.

국내 대학과 국립식량과학원 간의 협력 연구를 통해 확보된 32개 벼 형질전환 계통들에 대하여 주요 작물학적 특성및 수량성을 평가하였다. 이들 계통들은 수량성, 내병성, 스트레스저항성, 미질변이 등에 관여하는 17종의 유전자가 니폰바레, 낙동벼, 동진벼 등에 형질전환 되어 육성된 계통들이다. 주요 결과는 아래와 같다.1. 형질전환 계통들은 출수기, 간장, 수장, 수수 등의 주요작물학적 특성뿐만 아니라 수량성에서도 모품종과 상당한 차이를 보였다.2. 조사된 벼 형질 전환계통들에서 조사된 농업형질에 대한다변량분석 결과, 모품종에 비해 각 형질전환 계통군 내에서 관찰된 작물학적 상이성은 일정한 방향성이 없는무작위적이었으며, 그 변화폭도 3개의 모품종들의 작물학적 차이보다 훨씬 크게 관찰되었다.3. 따라서 우량 벼 형질전환 계통 육성의 효율성을 제고하기 위해서는 모품종에 형질전환 되어 발현될 유전자의우수성뿐만 아니라, 계통육성과정에서 다양한 유전학적요인에 의해 야기되는 ‘표현형 왜곡현상’을 적절히 제어할 수 있는 육종전략도 함께 고려되어야 할 것으로 사료되었다.

가뭄저항성벼의 복수세대에 대한 후대안정성을 서던 블롯과 PCR로 분석한 결과, 가뭄저항성벼의 CaMsrB2-8 T4 ~ T6 세대에서는 도입된 모든 유전자들이 안정적으로 도입되어 있으며, T-DNA 구성요소 이외의 backbone DNA는 가뭄저항성벼에 삽입되지 않았음을 확인하였다. 목적 유전자인 CaMsrB2와 제초제 저항성 선발 마커인 bar가 가뭄저항성벼의 CaMsrB2-8 T4 ~ T6 세대에서 안정적으로 발현됨을 검증하였다. 제초제 저항성 선발 마커로 도입된 PAT 단백질의 발현 분석 결과에서도 CaMsrB2-8 T4 ~ T6의 3세대에서 생육시기별, 부위별로 안정적으로 발현됨을 입증하였다. 도입유전자의 삽입 위치를 확인한 결과, 가뭄저항성벼 CaMsrB2-8의 도입유전자가 벼 1번 염색체 내에서 intergenic한 상태로 안정적으로 유지되고있음을 확인하였다. 이상의 분석 기법을 통해 복수세대에서 가뭄저항성벼의 도입 유전자들이 안정적으로 유지되고 목적 단백질들이 안정적으로 발현되고 있음을 확인하였다.

Rice transformation method using A. tumefaciens has already been widely used to generate transgenic plants, the transformation rate is still low in most Korean elite cultivars. We made several modifications of the standard protocol especially in the co-cultivation step to improve the efficiency of the rice transformation. The co-culture medium was modified by the addition of three antioxidant compounds (10.5㎎/ℓ L-cysteine, 1mM sodium thiosulfate, 1mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (5㎎/ℓ silver nitrate). Co-cultivation temperature (23. 5℃ for 1 day, 26.5℃ for 6 days) and duration (7 days) were also changed. The plasmid of pMJC-GB-GUS carrying the GUS reporter gene and the bar gene as the selectable marker was used to evaluate the efficiency of the transformation. After co-cultivation, a high level of GUS gene expression was observed in calli treated with the modified method. It is likely that those newly added compounds helped to minimize the damage due to oxidative bursts during plant cell-Agrobacterium interaction and to prevent necrosis of rice cells. And the transformation rate under the modified method was also remarkably increased approximately 8-fold in Heungnambyeo and 2-fold in Ilmibyeo as compared to the corresponding standard method. Furthermore, we could produce the transgenic plants stably from Ilpumbyeo which is a high-quality rice but its transformation rate is extremely low. Transformation and the copy number of transgenes were confirmed by PCR, bar strip and Southern blot analysis. The improved method would attribute reducing the effort and the time required to produce a large number of transgenic rice plants.

Rice transformation method using A. tumefaciens has already been widely used to generate transgenic plants, the transformation rate is still low in most Korean elite cultivars. We made several modifications of the standard protocol especially in the co-cultivation step to improve the efficiency of the rice transformation. The co-culture medium was modified by the addition of three antioxidant compounds (10.5㎎/ℓ L-cysteine, 1mM sodium thiosulfate, 1mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (5㎎/ℓ silver nitrate). Co-cultivation temperature (23. 5℃ for 1 day, 26.5℃ for 6 days) and duration (7 days) were also changed. The plasmid of pMJC-GB-GUS carrying the GUS reporter gene and the bar gene as the selectable marker was used to evaluate the efficiency of the transformation. After co-cultivation, a high level of GUS gene expression was observed in calli treated with the modified method. It is likely that those newly added compounds helped to minimize the damage due to oxidative bursts during plant cell-Agrobacterium interaction and to prevent necrosis of rice cells. And the transformation rate under the modified method was also remarkably increased approximately 8-fold in Heungnambyeo and 2-fold in Ilmibyeo as compared to the corresponding standard method. Furthermore, we could produce the transgenic plants stably from Ilpumbyeo which is a high-quality rice but its transformation rate is extremely low. Transformation and the copy number of transgenes were confirmed by PCR, bar strip and Southern blot analysis. The improved method would attribute reducing the effort and the time required to produce a large number of transgenic rice plants.

Rice grain number and grain dimensions including grain length-width ratio are critical components in determining the rice yield and quality. Manual or visual inspection for breeding lines and germplasm over these traits are time-consuming jobs. We developed and tested two algorithms for analysing grain number and dimensions (grain length, grain width) through image analysis system, Metamorph offline 7.0 (Molecular devices™). The algorithm for determining number of grain and shape constitutes a series of fragmentation processes including Shading, Color separate, Threshold, Euclidean, Dialate, Watershed Line, Arithmetic. When the six rice cultivars with different grain shapes were tested, there was no difference in the averaged values and distribution for the grain number and grain length between mannual and image analysis methods. However, image analysis resulted in the slightly increased values for grain width and more wider distribution whereas length/width ratio was slightly reduced by about 0.1, indicating that image analysis can be utilized more effectively and accuately in investigating the grain number and dimensions for sizable breeding lines.