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.

We evaluated the morphological characteristics of 156 maize inbred lines, which were developed to breeding normal maize variety at Maize Experiment Station, Gangwon Agricultural Research and Extension Services, by examining 11 quantitative and three qualitative characteristics. On the evaluation of three qualitative traits for 156 maize inbred lines, most inbred lines showed yellow (85 and 84 inbred lines) at tassel color (QL1) and silk color (QL2), and showed semi erect (105 inbred lines) at plant type (QL3). While, the evaluation of 11 quantitative traits for 156 maize inbred lines, they showed the morphological variation in days of tasseling (QN1, 56.5 to 76.0 days), days of silking (QN2, 59.0 to 85.5 days), stem thickness (QN3, 12.7 to 42.9 mm), plant height (QN4, 111.8 to 239.8 cm), ear height (QN5, 48.2 to 126.5 cm), 100 kernel weight (QN6, 14.9 to 36.4 g), ear length (QN7, 10.0 to 79.0 cm), setted kernel length (QN8, 8.0 to 70.5 cm), ear thickness (QN9, 4.0 to 22.0 cm), total kernel weight (QN10, 22.0 to 490.0 kg) and water content (QN11, 9.3 to 11.9%), respectively. As a result, 11 inbred lines (00hf3, 00hf19, 00hf30, 00hf36, 02S8069, 02S8072, 02S8090, 02S8099, 05S10011, 06S8085-6, 07S8011) in the 156 normal maize inbred lines have showed comparatively high values. While, the results of PCA (principal component analysis) indicated that the ear length (QN7), setted kernel length (QN8), ear thickness (QN9) and total kernel weight (QN10) greatly contributed in positive direction on the first principal components. And also, days of tasseling (QN1), days of silking (QN2), plant height (QN4) and ear height (QN5) contributed in negative direction on the second principal component. Thus these morphological characters, which were greatly contributed in the first and second principal components, might be considered to be useful for discrimination among 156 normal inbred lines. Specifically, this study's assessment of morphological characteristics of 156 normal inbred lines will be helpful useful for normal maize breeding programs such activities as planning crosses for hybrid and line development at Maize Experiment Station, Gangwon Agricultural Research and Extension Services.

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.

밀×옥수수 원연교잡은 타 방법에 비하여 반수체 밀 육성에 매우 효과적이어서 외국에서는 밀 품종의 육종연한 단축 등을 위하여 많이 활용하고 있다. 본 연구에서는 국내 밀 품종(계통)과 옥수수 품종을 이용한 반수체 밀 생산체계를 구축하기 위하여 원연교잡에 사용하는 품종에 따른 반수체 생산 효율을 조사하였다. 자방친으로는 금강밀 등 총 5종의 품종과 5종의 F1계통을 사용하였고, 화분친으로는 강다옥 등 총 7종의 옥수수 품종을 사용하였다. 자방친으로 사용한 국산 밀 품종의 평균 종자 형성률, 배 형성률 및 반수체 식물체 재분화율은 각각 약 75%, 19% 및 8.4%이었다. 반수체 식물체 재분화율은 3.7∼9.8%의 분포를 보였는데, 조경이 가장 높았다. 밀F1 계통 자방친의 평균적인 종자 형성률, 배 형성률 및 반수체 식물체 재분화율은 각각 약 66%, 16% 및 6.6%이었다. 밀계통의 반수체 재분화율은 3∼10%의 분포를 보였으며 08WG074 계통이 가장 높았다. 한편, 7종의 옥수수 품종의 자방친(금강밀)에 대한 평균 종자 결실률, 배 형성률 및 반수체 식물체 재분화율은 각각 약 78%, 18%, 9.6%이었다. 반수체 재분화율은 7.6∼12.9%의 분포를 보였으며, 광평옥이 가장 높았다. 밀×옥수수 원연교잡에서 종자 결실률과 배 형성률은 자방친과 화분친의 품종에 따라 고도로 유의한 차이를 보였으며, 이들 형질의 품종간 차이는 자방친 품종보다는 화분친인 옥수수 품종 사이에서 더 컸다. 본 연구에서 조사한 품종 중에서는 광평옥, 강다옥 및 강일옥 품종이 밀×옥수수 원연교잡의 화분친으로서 우수한 결과를 나타내었다.

Transposon elements are widely distributed in the plant genomes. Maize genome consists of various transposable elements that constitute as much as 80% of the genome. Transposon display (TD) is a modified from AFLP, and can be used to generate and display hundreds of genomic fragments affixed to transposons, consequently tagging transposons. We developed maize specific transposon insertion- sequence characterized amplified regions (Ti-SCAR) using Isaac and CACTA transposons. Currently, we have developed 58 dominant Ti-SCAR markers. Validation of the Ti-SCARs is being carried out using a various maize germplasm. Since AFLP is tedious and unsuitable for large scale application in MAS, the Ti-SCAR markers displayed simple binary presence or absence pattern. Thus, the Ti-SCARs can provide a fast, cheap and reliable PCR based assay. A pipeline in developing the Ti-SCAR will be presented in the poster.

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.

Wheat is one of the most important food crops in the world and provides 20% of nutritional requirement to the consumers in developing countries. The consumption per capita of wheat is persistent but the self-sufficiency has decreased owing to the less competitive world market and double cropping system with rice in Korea. This study was conducted to obtain baseline data on the selection lines with early maturity and good agronomic traits. Geumgangmil, a leading Korean variety, was crossed with CIMMYT’s line, and a DH (double haploid) line was released using pollens of Maize in Mexico. The 71 inbred lines were grown in fields at NICS, Miryang. The culm length of inbred lines were normally distributed from 37cm to 106cm, though that of the P1 (Geumgangmil) was 71 and P2 (CIMMYT’s Line) was 77cm. Especially, some lines were very short and measured below 50cm. The spike lengths of most of the lines were longer than that of P1 (7.5cm), but were normally distributed. The number of spikelet was less than that in P2 (19ea.), but was more than P1(10ea.). The heading day of most of the lines was between P1 (11th April) and P2 (25th April) and the maturity day of the lines was similar to P1 (1st June) but 5 lines showed 2~6 days shorter maturity period than that of P1. However, 20 lines were found to have 2~10 days longer maturity period than that of P2.

With the economy development, people have an increasing demand for meat and eggs. Hence the market demand for cereal crop keeps increasing. maize is the major crop to meet the conditions of market demand. As a part of the Golden Seed Project, we are planning to develop maize varieties for adaptation in Southern Asia, especially in India. This project was started at 2013 and has been collaborated with Nongwoo Bio Co. Our project is based on overseas maize breeding in Bangalore, India. At first year, we tested 40 maize hybrids to investigate adaptability, yield capacity, and growing characteristics. Planting materials for this test were developed and selected in Cambodia by researchers of Maize Research Institute. Growing performance is usually quite different by the growing area and seasons, but some of our materials have shown good adaptability and yield at dry season in Southern India. 13IN07 was selected by yield and grain color, 13IN39 was selected by yield and plant type. These two selected hybrids were applied to regional test controled by Indian Council of Agricultural Research in India. We will see how our hybrids adapt in various regions in India, assess how other tested hybrids perform in those regions, and compare each other. We may also expect one of the selected hybrids can be a candidate variety for some regions in India and we will continuously select good hybrids and develop new varieties in India.

청다옥은 다수성 사료용 옥수수 품종 개발을 목표로 2010년에 농촌진흥청 국립식량과학원에서 자식계통 KS159과 KS155의 교잡으로 육성된 다수성인 단교잡종이다. 청다옥의 종피색은 황색이며 입질은 마치종이다. 2006～2007년까지 생산력검정시험을 거쳐, 2008～2010년까지 3년간 4지역에서 지역적응시험을 실시하였다. 청다옥의 출사일수는 광평옥보다 1일 빠르고 간장은 광평옥보다 다소 짧고 착수고율은 광평옥보다 낮다. 도복은 광평옥과 비슷한 정도로 강하다. 후기녹체성은 광평옥과 비슷하며 이삭비율은 광평옥과 같다. 깨씨무늬병 저항성은 중정도이고, 그을음무늬병에는 강한 편이다. 검은줄오갈병, 이삭썩음병 및 조명나방 저항성은 중정도를 보인다. 청다옥의 건물수량(20.24 톤/ha)은 광평옥과 비슷하였으며, TDN수량(13.80 톤/ha)도 광평옥과 비슷하였다. 청다옥의 종실수량(8.51 톤/ha)은 장다옥보다 많았다. 4∶1(모본:부본) 재식비율로 동시 파종하여 채종시험한 결과 모본의 출사기와 부본의 화분비산기간이 일치하였으며 채종수량은 1.8 톤/ha이었다. 청다옥은 전국적으로 재배가 가능하다.

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.

본 연구는 하천변 농경지에서 질소시비수준에 따른 옥수수의 생육특성과 수량성을 살펴보고 광합성 측정과 성분 분석을 통해 질소가 미치는 영향을 구명하여 하천변 농경지재배에서 질소 시비의 필요성과 적정 질소 시비를 통한 수량 증대의 가능성을 검토하기 위하여 수행하였다. 질소 처리에 따른 옥수수 생육특성은 초장과 착수고의 경우 질소시비량에 의한 큰 차이가 없었다. 광합성은 질소 시비량이 증가할수록 증가하여 36 kg 처리구에서 가장 높았다. 옥수수의 NDF와 ADF 함량은 처리구간 차이 없었으며 NDF는 출웅 후 8일 이후 감소하였으며, ADF는 출웅 후 15일 이후 감소하였다. 옥수수 잎의 질소 흡수량은 출웅기에 36 kg 처리구에서 가장 높았다. 수량 및 수량구성요소는 이삭길이와 100립중의 경우 처리구간 유의차가 없었으나 이삭직경과 립수의 경우 무처리구와 9 kg 처리구에 비하여 18 kg 처리구와 36 kg 처리구에서 증가하였고, 과피는 18 kg 처리구와 36 kg 처리구에 비하여 무처리구와 9 kg 처리구에서 두꺼웠고, 수량은 무처리구에 비하여 18 kg 처리구, 36 kg 처리구, 9 kg 처리구가 많았다. 옥수수 종실의 전분함량은 처리구간 유의차가 없었으며, 총당은 18 kg 처리구가 가장 높았고 아밀로펙틴은 18 kg 처리구에서 가장 높았으나 아밀로오스는 18 kg 처리구에서 가장 낮아 18 kg 처리구에서 찰성이 가장 강하였다. 이상의 결과로 하천변 농경지에서 옥수수 재배시 질소시비가 필요하며 가장 이상적인 질소 시비량은 10a당 18kg 정도로 판단된다.

Our study is performed to confirm the level of genetic diversity and population structure with 80 maize inbred lines (40 waxy inbred lines and 40 flint inbred lines) and to explain the genetic basis of agronomic traits using an association mapping. The 200 SSR loci are confirmed a total of 1,610 alleles in total 80 maize inbred lines. The average number of alleles per locus was 8.05. The average GD was 0.72. The average PIC value was 0.68. The average MAF was 0.40. Population structure was revealed for K=2. Total 80 maize inbred lines were divided by groups I, II and admixed group. The 14 waxy inbred lines were assigned to group I. The 45 inbred lines include 5 waxy inbred lines and 40 flint inbred lines were contained to group II. The 21 waxy inbred lines were contained in the admixed group with lower than membership threshold 0.8. Association mapping between 200 SSR markers and 10 phenotypic traits of waxy/flint maize inbred lines were performed by Q GLM and Q+K MLM. In significant level at 0.01, 72 SSR markers were associated with 10 phenotypic traits using Q GLM. The 4 marker-trait association were detected in Q+K MLM. The results derived from this study will be used for designing efficient new maize breeding programs.

In U.S.A. maize breeding, exotic germplasm is considered as high-risk and usually introduced by backcrossing specific traits into elite lines. The U.S.A. maize germplasm base is narrow. Only a few open-pollinated varieties are well represented in current programs. Currently, the barrier in using of exotic germplasm in the U.S.A is less formidable than in the 1980s. The major reason is that U.S.A materials are now used in tropical breeding to accelerate earlier maturity and lodging resistance. These exotic materials, developed with U.S.A germplasm, are being introduced back into the U.S.A.Since1994, the ARS-led Germplasm Enhancement of Maize (GEM) project has sought to help broaden the genetic base of America’s corn crop by promising exotic germplasm and crossing it with domestic lines. New hybrids derived from such crosses have provided corn researchers and the producers. These may include improved or alternative native source of resistance to insect pests such as corn rootworms and diseases like northern leaf blight. GEM’s aim is to provide source of useful genetic maize diversity to help the producers to reduce risks from new or evolving insect and disease threats or changes in the environment or respond to new marketing opportunities and demand. During the 2009 growing season, the Ames (Iowa) and Raleigh (North Carolina) locations managed or coordinated evaluations on 17,200 nursery plots as well as 14,000 yield trial plots in Ames and 12,000 in Raleigh. A new “allelicdiversity” study is devoted to exploring and capturing the genetic variation represented by over 300 exotic corn races. Since 2001, GEM has released 221 new corn lines to cooperators for further development into elite commercial new hybrids. GEM has already identified about 50%-tropical, 50%-temperate families tracing primarily to tropical hybrids that are competitive with commercial checks. In North Carolina State University program, they have examined the potential of tropical inbredand hybrids for U.S.A. breeding by crossing temperate-adapted, 100%-tropical lines to U.S.A hybrids. There should be favorably unique alleles or genomic regions in temperate germplasm that can be helpful in tropical maize improvement as well as utilization of tropical lines in temperate areas.

국내 적응 Quality Protein Maize (QPM) 옥수수 교잡종을 육성하려면 효율적인 선발 체계를 확립하는 것이 필요하다. 본 연구는 최근 국립식량과학원에서 육성중인 QPM1 등 4 교잡계 종실의 일반성분, 지방산 조성 및 아미노산 함량을 대비품종인 일반 옥수수 장다옥과 비교 검토하여 QPM 옥수수 신품종 육성을 위한 기초 연구 자료로 활용하고자 실시하였다. QPM 교잡계들의 단백질함량은 10.0〜11.40%로 장다옥의 8.1%보다 모두 많았다. QPM 교잡계들의 지방함량은 3.8〜4.0%이었으며 QPM1을 제외한 QPM 교잡계들은 장다옥과 차이가 없었다. QPM2 교잡계를 제외한 QPM 교잡계들의 회분함량은 장다옥보다 많았다. QPM 교잡계들과 장다옥 모두 linoleic acid의 조성비가 가장 높고 oleic acid, palmitic acid, stearic acid, linolenic acid의 순으로 지방산 조성비가 높은 것으로 나타났다. QPM 교잡계들의 포화지방산 함량은 17.2〜18.4%로 장다옥과 비슷하였다. QPM 교잡계들의 불포화지방산 함량은 81.6〜82.8%로 장다옥과 비슷하였다. QPM 교잡계들과 장다옥간 필수아미노산 중 isoleucine, valine, threonine, 황을 함유한 methionine, cystine 등의 함량 차이는 없었으나, lysine함량은 QPM 교잡계들이 장다옥(3.84g/100g)보다 4.05〜4.69g/100g로 많았으며 그중 QPM1 교잡계가 4.69g/100g으로 가장 많았다. QPM 교잡계들과 장다옥간 산성아미노산인 MMA(monoamino monocarboxylic acid), DMA(diamino monocarboxylic acid), 방향족 아미노산인 AAA(aromatic amino acid) 등의 함량 차이는 없었다. 본 연구에서 육성된 국내 적응 QPM1 교잡계는 옥수수의 경우 필수아미노산 중 가장 문제시 되고 있는 lysine 함량이 보통 옥수수보다 개선되어 식용 및 사료용 옥수수로 활용 가치가 높을 것으로 기대된다.

Exserohilum turcicum is considered serious destructive disease of maize (Zea mays L.) in North Korea. This study aimed to understand genetic inheritance and combining ability of newly bred lines of maize tolerant to E. turcicum by diallel crosses. Three diallel sets for two different ecological regions and one agronomic trait; eastern (E), northern (N) and stay green (SG) involving 29 inbred lines were tested in eight locations of 2000 and 2001. E. turcicum infections were under natural conditions, respectively. Lines used were selected for high yield potential in test crosses with good agronomic traits and tolerance to biotic and abiotic stresses. Selection for race specific high resistance to biotic stresses was avoided to select quantitatively inherited genes. Host plant responses to E. turcicum were rated on a scale of 1 (highly tolerant) to 9 (highly susceptible). Highly significant variations were recorded in all trials. General combining ability (GCA) mean square was roughly twice that of specific combining ability (SCA). The genotype (G) by environment (E) interaction was highly significant. The overall results of genetic studies in three diallel sets show that genetic control for inbred tolerance to E. turcicum is polygenic and quantitatively inherited. New inbreds; E-3, N-1 and SG-4 confer better tolerance to E. turcicum than the widely used inbreds; Mo17, and B73. Proper use of genetic information from this study shall increase of corn production under high E. turcicum infection in the Far Eastern Regions of Korea and China.

밭전환 1년차 논의 토양물리성 악화를 개선하고 사료용 옥수수 생육을 증진시키기 위한 심토파쇄의 효과를 살펴본 결과 다음과 같은 결과를 얻었다. 1. 심토파쇄에 의해 토심 25~35 cm 층위의 토양의 경도가 크게 감소하였고 토층 15~30 cm에서 가밀도, 공극율 및 고상비율 등 하층토의 토양물리성이 개선되는 것으로 나타났다. 2. 심토파쇄 추가 시 옥수수의 간엽 및 이삭의 생육이 크게 증가하였으며, 특히 이삭당 립수의 증가가 이삭중을 크게 증가시키는 것으로 나타났다. 3. 심토파쇄 추가 시 옥수수는 이삭 및 간엽의 수량증가에 의해 TDN 수량이 19~39% 증가하였으며, 특히 습해에 의해 생육이 불량한 2011년도의 옥수수의 생육촉진 효과가 컸다.

식용 풋찰옥수수 고품질 육종에 관련된 주요 형질들의 특성을 파악하고자 수행한 본 연구는 모계 02S6140(찰옥수수, SSww)와 부계 KSS22(단옥수수, ssWW)의 교잡(F1)에서 분리된 F2 집단에서 수량 및 식미관련 형질들의 유전적 특성을 조사하였다. 그 결과 출사일수는 모본(02S6140) 계통이 85일, 부본(KSS22) 계통이 66일로 현저한 차이가 있었지만, F1은 71일로 교배친의 평균값 75.5일보다 작아지는 방향으로 나타났다. 간장(PH)은 F1에서 159 cm, 모부의 평균값 95 cm와 비교하여 크게 나타났다. 착수고율은 F2 집단의 평균이 교배친의 평균값 44와 동일하였고 찰질이 일반질 옥수수보다 높은 것으로 나타났다. 과피두께는 F1, F2 계통들에서 71 μm과 74 μm로 나타나 모부의 83.5 μm 평균보다 얇아지는 방향으로 나타났다. 아밀로스함량은 입질별로 매우 유의하게 차이가 있어 일반질이 평균 14.0%로 가장 높았으며 당질은 7.4%, 찰질은 5.0%의 값을 보였으며, 아밀로스함량에 대한 F1의 잡종강세는 비교적 높은 116.1의 값을 보였다. 유전자형 suwx는 이중열성돌연변이로 표현형은 sugary로 나타났다.

본 연구는 총 50개의 SSR primer를 이용하여 색소옥수수(색소종실 옥수수 12계통, 색소찰 옥수수 12계통) 및 비색소옥수수(종실옥수수 2계통, 찰옥수수 5계통) 계통들에 대하여 유전적 다양성, 계통유연관계 및 집단구조를 분석하였다.1. 그 결과 50 개의 SSR primer들은 색소 및 비색소옥수수 31계통들에서 총 282개의 대립단편을 증폭시켰으며, SSR primer들에서 증폭된 대립단편의 수는 최소 2개에서부터 최대 11개까지의 범위로 나타나 평균 5.64개가 증폭되었다. MAF(major allele frequency)는 0.23(bnlg279)에서 0.90(umc2338)의 범위로 나타나, SSR primer 당 평균 0.45개로 나타났고, 유전적 다양성(GD)값은 0.17(umc2338)에서 0.86(bnlg279)의 범위로 나타나, SSR primer 당 평균 0.67의 값을 나타내었다. 2. 31개의 색소 및 비색소옥수수 계통들의 집단구조를 분석한 결과, 이들 옥수수 계통들은 Groups I, II, III, IV, V, admixed로 구분되었다. Group I은 찰옥수수 1계통, 색소종실옥수수 1계통, 색소찰옥수수 5계통이 포함되었고, Group II는 찰옥수수 1계통, 색소찰옥수수 3계통이, Group III는 색소종실옥수수 3계통, Group IV는 색소종실옥수수 2계통이, Group V는 종실옥수수 2계통, 찰옥수수 2계통, 색소종실옥수수 5계통이 포함되어 있었다. 그리고 admixed group에는 찰옥수수 1계통, 색소종실옥수수 1계통, 색소찰옥수수 4계통 이 포함되어 있었다.3. UPGMA법에 의한 계통유연관계 분석 결과, 31개의 색소 및 비색소옥수수 계통들은 유전적 유사성 27.4%의 수준에서 크게 3개의 그룹으로 나누어졌다. Group I은 10개의 옥수수 계통(종실옥수수 2계통, 찰옥수수 2계통, 색소종실옥수수 6계통)을 포함하고 있었고, Group II는 20개의 옥수수 계통(찰옥수수 3계통, 색소종실옥수수 5계통, 색소찰옥수수 12계통)을, 그리고 Group III은 색소종실옥수수 1계통을 포함하고 있었다. 따라서 본 연구의 결과는 앞으로 강원도 농업기술원 옥수수시험장에서 색소옥수수 자식계통들에 대한 선발과 품종 육성 연구에 유용한 정보를 제공할 것으로 생각된다.

In order to clarify the chromosomal location of quantitative trait loci (QTL) associated with the yield and agronomic traits in waxy corn and sweet corn (Zea maysL.), we were conducted identifying of QTLs associated with yield and agronomic traits by employing genetic linkage map of F2:3 population. A total of 14 QTLs each for days to silking (DTS), plant height (PH), ear height (EH), ear height ratio (ER), ear length (L-Ear) and kernel setting length (L-Sear) were detected in the 158 F2 families. The number of QTL per each trait was ranged from 1 to 6, and also phenotypic variance was ranged from 3.55 to 16.86%. For DTS, one QTLs was found to be controlled by genomic regions at locations chromosomes 1 contributing 9.21% of phenotypic variance. While three QTLs for PH, were found to be controlled by 3 genomic regions at locations chromosomes 1 and 2 contributing 6.68, 6.85 and 8.17% of phenotypic variance, respectively. For EH, six QTLs were found to be controlled by 6 genomic regions at locations chromosomes 1, 7, 8 and 10 range from 3.55 to 11.44% of phenotypic variance. The one QTLs for ER was found at locations chromosomes 1 contributing 7.25% of phenotypic variance. For L-Ear, two QTLs were found to be controlled by 2 genomic regions at location chromosome 7 and 10 contributing 7.40 and 11.63% of phenotypic variance, respetively. The one QTLs for L-Sear was found at locations chromosomes 3 contributing 16.86% of phenotypic variance. Among them, three QTLs, such as qEH8 (11.44%), qLEar10 (11.63%), and qLSear3 (16.86%) may be considered as a major QTLs, while the remaining 11 QTLs might be regarded as minor QTLs. This study may provide valuable information for the further identification and characterization of genes responsible for agronomic traits in waxy corn and sweet corn.

Is backcrossing a good strategy for improving elite lines for quantitative traits in general? Results reported here demonstrate the effectiveness of a backcrossing program for improving quantitatively inherited disease resistance traits, which are strongly influenced by the environment. Through backcross breeding, we were able to improve an important commercial inbred line, FR1064, for ear rot and fumonisin contamination resistance without significantly lowering its yield potential, even with the use of a donor line with poor agronomic potential. Following one generation of selection on advanced backcross-derived lines, gains were observed for the primary trait of interest in advanced inbred generations. Following two generations of selection, we improved potential performance for ear rot resistance and reduced fumonisin accumulation in the 19 selected lines without significantly affecting important agronomic characteristics such as plant height, ear height, or flowering time compared to the recurrent parent, FR1064. The 19 selected lines were also significantly more resistant to ear rot under inoculated conditions than the FR1064 topcross without exhibiting significant reductions in topcross grain yield or other agronomic traits. Several individual lines were identified that were not statistically different from GE440 for ear rot or fumonisin content as inbreds or from the GE440 topcross for ear rot. These lines exhibited topcross yields comparable to the FR1064 topcross, although they were not competitive with commercial check yields. Thus, from a practical standpoint, the backcrossing method was effective at improving quantitative disease resistance in an elite commercial line using an unadapted donor parent. We also genotyped selected lines at DNA markers linked to ear rot and fumonisin resistance quantitative trait loci (QTL) identified in the BC1 generation of this cross to determine which QTL demonstrated allele frequency shifts due to selection.