본 연구는 옥수수 재배 시 환경에 영향을 미치는 노균병 저항성과 관련된 유전자 후보군을 탐색해서 노균병으로 인한 토양오염과 옥수수 생산량 감소를 해결하기 위하여 노균병 저항성 품종을 효율적으로 발굴하기 위한 연구이다. 옥수수의 6번 염색체의 152,892,333과 154,335,437 사이에 있는 노균병 저항성 유전자를 탐색하였으며 이 부분에 존재할 것으로 예상되는 전사체에서 38개의 프라이머 세트를 디자인하여 이 중 16개의 예측 전사체를 가려 내었다. 또한 RT-PCR을 수행하여 감염된 Ki11의 발현이 높은 7개의 전사체로 5개의 품종에 대하여 건강한 샘플과 감염된 샘플을 검정하였고 최종 5개의 후보 유전자군[알려지지 않은 미확인 유전자 2개, OFP transcription factor, bZIP transcription factor, pentatricopeptide repeat (Ppr)]이 발견 되었다. 본 연구의 결과로 추가적인 실험 설계를 통해 5개의 후보 유전자군에 대한 재검정을 통하여 확실한 노균병 저항성 유전자를 발굴하고 이를 노균병 저항성 품종 개발 및 방재에 이용할 수 있을 것으로 사료된다.

Drought is one of important environmental stress for plant. Drought has deleterious effect to plant growth including maize (Zea mays L.) such as vegetative and/or reproductive growth, root extension, photosynthesis efficiency, flowering, anthesis-silking interval (ASI), fertilization, and grain filling. In this study, we screened drought tolerant maize in 21 cultivars from different sources, sixteen NAM parent lines (B73, CML103, CML228, CML247, CML277, CML322, CML333, CML69, Ki11, Ki3, Ky21, M37W, Mo18w, NC350, Oh43 and Tx303), four Korean hybrids (Cheongdaok, Gangdaok, Kwangpyeongok and Pyeonganok) and one Southeast Asian genotype (DK9955). Drought stress (DS) index was evaluated with leaf rolling score at seedling stage and ASI at silking date. The leaf rolling scoring of CML228, DK9955 and Ki11 were determined 1.28, 1.85, 1.86, respectively. However, M37W, Kwangpyeongok, B73 and NC350 were determined over the 3. ASI analysis revealed that CML228, CML103, Cheongdaok, NC350, B73, CML322, Kwangpyeongok and Ki11 are represented less than 5 days under DS and less than 3 days of difference between DS and well-watered (WW), but CML69, Ki3, Pyeonganok, M37W, Mo18w and Gangdaok were represented more than 10 days under DS and more than 8 days of difference between DS and WW. Multi-Dimensional Scaling (MDS) analysis determined CML228, Ki11, and CML322 were regarded as drought tolerance cultivars. Eventually, Ki11 showed genetic similarity with Korean cultivars by QTL analysis and MDS analysis. Ki11 has a potential for development of drought tolerance maize with Korean cultivars.

동남아시아 주요 옥수수 생산국인 인도네시아의 옥수수 생 산과 생산성 제한 요인에 대하여 조사·분석한 결과는 다음과 같다. 1. 인도네시아는 북위 5°에서 남위 10°사이에 위치하여 연 중 열대성 기후를 보이며 건기와 우기의 구별이 뚜렷하다. 2. 옥수수 재배면적은 약 4,000천ha 정도이며 생산량은 2009년 이후로 17,000천톤 이상을 유지하고 있다. 그 가운데 수확면적과 생산량의 약 50%를 Jawa섬이 차지하고 있다. 2014년 단위 면적당 생산성은 4.95ton/ha로 1980년대에 비하 여 약 3배 증가하였으나 지역적으로는 2.5 ~ 7.32ton/ha의 변이 를 보여 지역 간 차이가 심하다. 3. 생물적 생산성 제한요인은 downy mildew (Peronosclerospora), maydis leaf blights (Helminthosporium spp.), leaf spots (Curvularia spp.), rusts (Puccinia polysora), stalk and ear rots (Fusarium spp., Diplodia spp.), banded leaf and sheath blight (BLSB, Rhizoctonia solani) 등의 병과 바 구미(Sitophilus spp.), shoot flies (Atherigona spp.), Asian corn borers (Ostrinia furnacalis), 멸강충(Mythimna spp.), corn ear worm (Helicoverpa spp.) 등의 충이나, 가장 큰 영 향을 주는 요인은 downy mildew이다. 4. 비생물적 생산성 제한요인은 토양의 산성화에 따른 척박 토양과 관개가 자유롭지 못한 전작 지대의 한발피해 등이며, 경제·사회적 제한요인으로는 비료, 농약 등 농자재 투입 비용 과 hybrid종자 가격 등이다. 5. 인도네시아에 적응하는 품종 개발 시 생산성 제한 요인을 극복하기 위한 주요 타겟 형질은 환경 스트레스 내성으로서, 특 히 downy mildew 저항성과 내산성, 내건성이 요구된다.

We screened the drought tolerant maize using seventeen maize genotypes from different sources, nine inbred genotypes from United States Department of Agriculture (USDA) (B73, CML103, CML228, CML277, CML322, CML69, Ki3, Ki11, and NC350), three Southeast Asian genotypes (DK9955, LVN-4, and 333), and five Korean hybrids (Cheongdaok, Gangdaok, Ilmichal, Kwangpyeongok, and Pyeonganok). We evaluated anthesis-silking interval (ASI), leaf senescence (LS), ears per plant (EPP), tassel length (TL), and fresh weight (FW) at silking date. According to ASI and LS examination, CML103 and Kill were drought tolerant genotypes, wheareas Ki3 and 333 were drought susceptible. EPP, TL, and FW differed according to drought resistance. Grain yield was correlated strongly with ASI, but moderately with LS. Difference in ASI between drought-stressed (DS) and well-watered (WW) conditions was less than three days in CML228, CML103, Cheongdaok, NC350, B73, Ki11, CML322, and Kwangpyeongok, whereas that of Ki3, Pyeonganok, and Gangdaok was more than 6.5 days. We concluded that CML228, CML103, Cheongdaok, NC350, B73, Ki11, CML322, and Kwangpyeongok are drought tolerant genotypes, whereas Ki3, Pyeonganok, and Gangdaok are drought susceptible.

Anther culture is useful and significant tool for producing haploid or doubled haploid (DH) plants in crop breeding system. Androgenesis is the way of inducing haploid and DH plants from anther (immature pollen) or microspore culture. In vitro androgenesis is efficient technique for introducing complete homozygous lines in one generation, thus less time and expense could be necessary than conventional plant breeding. In maize, anther culture is important system for shortening the breeding cycle and enhancing selection efficiency. Anther culture technique is also applicable to various researches such as molecular genetics, genetic engineering, genomics, and plant biotechnology. We review the past and present studies on anther culture and provide useful information for future researches on androgenesis in maize. The combination of androgenesis with other techniques such as molecular breeding and biotechnology is producing a variety of variety of maize species. In addition, we suggest strategy to develop androgenesis technique adapted to Korean research environment.

This study was conducted to evaluate maize downy mildew resistance using spreader row technique in Cambodia. A total of forty maize lines were used in this experiment. Seven Korean varieties and seven breeding lines showed high infection rates (80~100%) and highly susceptible (HS) to downy mildew disease in both spring and fall. Also most of nested association mapping (NAM) parent lines were highly susceptible (HS). Meanwhile three inbred lines, Ki3, Ki11, and CML228, showed highly resistant (HR) or resistant (R) in spring and moderately resistant (MR) in fall. These three lines were already known as resistant inbred lines against downy mildew disease. It appears that spreader row technique was suitable for selection of maize downy mildew resistance in Cambodia. The incidence of downy mildew was influenced by weather conditions, especially relative humidity and temperature. Among several inoculation methods to screen for downy mildew resistance, this spreader row technique is effectively and easily used in the field of Southeast Asia.

Drought stress has detrimental effects on the seedling development, vegetative/ reproductive growth, photosynthesis, root proliferation, anthesis, anthesis-silking interval (ASI), pollination and grain yield in maize. Typically, two weeks before silking through pollination are an important time in maize life. Here we reviewed the effects of drought stress on growth, physiological/ molecular researches for drought tolerance, and breeding to genomics in maize. Drought stress during kernel development increases leaf dying and lodging, decreases grain filling period and grain yield. Physiological factors of drought stress/ effects are water content, water deficits, and water potential. Nowdays molecular marker assisted breeding method is becoming increasingly useful in the improvement of new germplasm with drought stress tolerance.

The maize production in South-eastern Asian countries showed a continuous increase with increasing poultrylivestock from the beginning of the 1990s to early 2010. Also the need for a new variety development of each contries was increased rapidly in the same period. Single-Cross hybrid varieties have been developed and supplied from 2001 instead of multi-cross maize varieties since 1992 in Indonesia. In Cambodia, CP group is mainly manufacturing feeds with most of the forage maize from farmers who are growing its seeds from the company. Cambodian main cultivars are varieties of multinational corporations such as DK8868 from Monsanto, NK6326, NK7328 from Syngenta and CP333 from CP group including local business company. Vietnam is the main maze importing country in South-Eastern Asia which had imported 13 times scale of amount compared to exports in average from 1990 to 2011. Vietnamese government has developed a range of varieties for improving their efficiency in production, such as the LVN-10 with political investments. Their production has been reached to 80% of the total. According to the 2012 MIFAFF (Ministry for Food, Agriculture, Forestry and Fisheries) data in Korea, domestic edible maize cultivation area was approximately 15,000ha. It showed 74,399 tons of production, 3.8% of food self-sufficiency in maize and around 0.9% of grain self-sufficiency rate. The consumption of grain is mostly rely on imports in Korea. To overcome the limit of the domestic seed market and increase maize self-sufficiency, the need to develop maze varieties for world-class is increasing at present through analyzing the market trend and prospect of the seed industry in South-eastern Asia

The maize genome is complex with exceeding the levels of intra-specific variation, repetitive DNA content, and allelic content observed between many species. Because of tremendous diversity and variants, maize is considered as a forefront crop development and estimation of molecular markers for agricultural trait in genetics and breeding. Using quantitative trait loci (QTL) and marker assisted breeding (MAS), molecular breeders are able to development of drought tolerance and grain yield in maize genotype. To study QTL congruency, a meta QTL analysis including results from eight-teen QTL publications for grain yield and drought tolerance were considered. Among them, we assembled 420 QTLs for abscisic acid (ABA) concentration, anthesis silking interval (ASI), days to flower, days to silk, ear number, kernel number, grain number and grain yields, involved in drought tolerance and grain yield. The meta QTL analysis revealed significant evidence for linkage of these traits to 39 different segments as candidates regions on maize genome. A total of 571 marker was selected as QTL or integrated QTL markers for narrowing down the QTL region into specific functionally relevant candidates. The results of meta QTL analysis helped to refine the genomic regions of agricultural traits, interest described and provided the closest flanking markers.

Next generation sequencing technologies provide opportunities to reveal the genetic variants and differentially expressedgenes. The genetic variants are closely relevance to understanding of genes and phenotypic differences related to agronomic characteristics among cultivars. In this study, we conducted RNA-seq using two Korean soybean accessions, including Daewon and Hwangkeum, by using next generation sequencing against Williams 82 genome as reference. A number of variants such assingle nucleotide variants (SNV), multiple nucleotide variants (MNV), insertion/deletion (InDel) and replacement, was 34,411 and 55,544 in Daewon and Hwangkeum, respectively. Among these variants, 9,611 nonsynonymous variants were detected within 4,290 genes in Daewon and 13,225 non-synonymous variants were located on 5,672 genes in Hwangkeum. The distribution of nonsynonymous variants and expression values of genes can serve as invaluable resource for genotyping and study of traits within genes for soybean improvements.

The objective of this study was to evaluate the drought tolerance in maize seedling using leaf rolling. Nineteen maize resources, seven Nested Association Mapping parents lines, six Korean commercial cultivars, and six Southeast Asia commercial cultivars, were used to examine drought tolerance. The leaf rolling scores were measured on each leaf in three stress conditions with moderate drought (10%), severe drought (7%), and extreme drought (5%). Generally leaf rolling score of seedlings increased at the lower soil water potentials (5~7%). As a result, drought-tolerant cultivars showed lower leaf rolling score (below 2.5) than the drought sensitive cultivars (above 3.5). Nine varieties, NK4043, CML322, DK9955, NK4300, Ki11, DK8868, CML228, LVN99, and LVN10, have been selected for tolerance to drought stress. These results suggest that the leaf rolling score in maize seedling has been made available to indirect index for drought tolerance.

The photochemical characteristics were analyzed in the context of sowing time and different levels of fertilized nitrogen during the maize (Zea mays L.) growth. When maize was early sawn, the fluorescence parameters related with electrontransport, in photosystem II (PSII) and PSI, were effectively enhanced with the higher level of fertilized nitrogen. Highest values were observed in maize leaves grown in double Nfertilized plot. The photochemical parameters were declined in the progress of growth stage. In early growth stage, the fluorescence parameters were highest, and then reduced to about half of the parameters related with electron transport on PSII and PSI at middle and late growth stages. In 1/2 N plot, the photochemical energy dissipation was measured to 13% in term of active reaction center per absorbed photon resulting in decrease in performance index and driving force of electron. This decrease induced to lower the photochemical effectiveness. In 2 N plots, the electron transport flux from QA to QB per cross section and the number of active PSII RCs per cross section were considerably enhanced. It was clearly indicated that the connectivity between photosynthetic PSII and PSI, i.e. electron transport, was far effective.

Transcription factors are essential for the regulation of gene expression in plant. They are binding to either enhancer or promoter region of DNA adjacent to the gene and are related to basal transcription regulation, differential enhancement of transcription, development, response to intercellular signals or environment, and cell cycle control. The mechanism in controlling gene expression of transcription can be understood through the assessment of the complete sequence for the maize genome. It is possible that the maize genome encodes 4,000 or more transcription factors because it has undergone whole duplication in the past. Previously, several transcription factors of maize have been characterized. In this review article, the transcription factors were selected using Pfam database, including many family members in comparison with other family and listed as follows: ABI3 / VP1, AP2/EREBP, ARF, ARID, AS2, Aux/IAA, BES1, bHLH, bZIP, C2C2-CO-like, C2C2-Dof, C2C2-GATA, C2C2- YABBY, C2H2, E2F/DP, FHA, GARP-ARR-B, GeBP, GRAS, HMG, HSF, MADS, MYB, MYB-related, NAC, PHD, and WRKY family. For analyzing motifs, each amino acid sequence has been aligned with ClustalW and the conserved sequence was shown by sequence logo. This review article will contribute to further study of molecular biological analysis and breeding using the transcription factor of maize as a strategy for selecting target gene.

Maize is one of the most important food and feed crops in the world including Southeast Asia. In spite of numberous efforts with conventional breeding, the maize productions remain low and the loss of yields by drought and downy mildew are still severe in Asia. Genetic improvement of maize has been performed with molecular marker and genetic engineering. Because maize is one of the most widely studied crop for its own genome and has tremendous diversity and variant, maize is considered as a forefront crop in development and estimation of molecular markers for agricultural useful trait in genetics and breeding. Using QTL (Quantitative Trait Loci) and MAS (Marker Assisted Breeding), molecular breeders are able to accelerate the development of drought tolerance or downy mildew resistance maize genotype. The present paper overviews QTL/MAS approaches towards improvement of maize production against drought and downy mildew. We also discuss here the trends and importance of molecular marker and mapping population in maize breeding.

콩의 수량은 건물생산성에 비해 고온에 민감하게 반응하는 하는 형질로 알려져 있다. 따라서 본 연구는 등숙기 고온이 종실의 발달, 품질특성 및 수분흡수특성에 미치는 영향을 검토하기 위해 수행하였으며 그 결과를 요약하면 다음과같다.1. 등숙온도가 높을수록 백립중은 감소되었는데, 황금콩은 선유콩에 비해 감소폭이 컸고, 등숙기 지속적인 고온은 종실비대를 억제시켜 소립종의 비율이 증가될 뿐만 아니라 종피율을 감소시키는 것으로 나타났다.2. 등숙온도가 높을수록 지방 함량 및 C/N율이 감소되고,단백질 및 총당 함량이 증가되었으나 당의 조성으로볼 때 단당류와 이당류는 증가되고 올리고당류는 오히려 감소되는 것으로 나타나 고온은 동화물질의 축적을억제시키는 것으로 판단되었다.3. 고온에서 등숙된 콩은 침지초기에 부피 및 무게의 증가가 비교적 빠르게 이루어졌으나 침지시간이 경과됨에 따라 대조구에 비해 부피 및 무게증가율이 모두 낮게 나타났고, 황금콩은 선유콩에 비해 침지에 따른 부피증가율 및 무게증가율이 상대적으로 낮았다.4. 콩의 백립중과 종피율은 침지에 따른 종실의 부피 및무게증가율뿐만 아니라 용출액의 TDS와 EC에 영향을 미치는 주요 형질로 판단되었고, 단백질 함량과C/N율은 TDS 및 EC와 유의한 상관을 보였으나, 당함량은 부피증가율과 무게증가율뿐만 아니라 TDS 및EC와 상관이 인정되지 않았다.5. 따라서 등숙온도가 높을수록 종실에 동화물질의 축적이 불완전하게 이루어져 침지에 따른 가용성 고형물의용출량이 많아지고, 결과적으로 TDS 및 EC가 높아지는 것으로 판단되었다.

Soybean is an important crop with useful traits such as the high seed protein and oil contents. Soybean reproduction is sensitive to temperature over 35℃. To obtain database of gene expression profiles, we used soybean cultivars, sensitive and tolerant. RNA sequencing was performed to find differentially expressed genes in two Korean soybean cultivars under heat stress condition. The transcriptomic changes in each cultivar under heat stress. We found 2727 common transcripts in two soybean cultivars under heat stress, and selected 20 transcripts to heat stress response genes. The 20 selected genes were analysed using BLAST2GO and PLANEX. The genes were major factor in co-expression networks. It appears that these 20 genes were mainly attributable to heat stress.

To determine the expression levels of genes related to the salt stress response in rice, gene expression profiles were investigated through microarray analysis using the rice mutant line Till-II-877. There were no significant changes in physiological response under salt stress of the mutant increased less than that in the WT. The intensity of gene expression was analyzed and compared between the wild type and mutant lines using a microarray. Among the most significantly affected pathways, α-linolenic acid metabolism and linoleic acid metabolism (in lipid metabolism), fructose and mannose metabolism and glycolysis-gluconeogenesis (in carbohydrate metabolism), cysteine and methionine metabolism (in amino acid metabolism), and carbon fixation (in the energy metabolism of photosynthetic organisms) showed changes in gene expression levels under salt stress. These results further our understanding of the effects of salt stress in rice and may aid in the development of salt-tolerant rice cultivars.

Soluble sugar content in soybean seed is an important quality attribute for soyfood and feed. Usually, soluble sugars comprise 6 to 17% of total dry wt. in mature soybean seeds. In this study, 414 soybean mutant lines induced by gamma-ray were screened by colormetric assay, FACE (Fluorophore-assisted carbohydrate electrophoresis), and GC-MS to identify the change of soluble sugar contents. Among 414 soybean mutant lines, 12 mutant lines derived from three different soybean cultivars (Hwanggum, Paldal, and Bangsa) showed higher level of soluble sugar content compared to their original cultivars. However, 5 mutant lines derived from soybean landrace KAS 636-15 showed lower level in the colormetric assay. In FACE, 17 soybean mutant lines selected by colormetric assay also showed different band intensity compared with their original cultivars. However, there were no different soluble sugar patterns between soybean original cultivars and mutant lines. Finally, the variations of soluble sugar content in 17 soybean mutant lines were confirmed by using GC-MS. These mutant lines will be used for genetic study to find mutations of genes related soluble sugar biosynthesis.