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.

Use of public tropical lines for U.S. commercial maize (Zea mays L.) breeding is either undocumented or non-existent. A possible exception is the old Cuban line A6, which was still being used in tropical hybrids over 40 years after its development. A major reason for the under-utilization of this valuable germplasm source is the sparse amount of yield-trial data available for most tropical lines. Effective evaluation of tropical, unadapted maize is costly and time-consuming in the U.S. corn-belt, where most temperate maize breeding is done. Thus, temperate maize breeding programs have shown minimal interest in such lines. The narrowness of the temperate maize (Zea mays L.) germplasm base has long been recognized, and there are many available, elite tropical lines that might be used to profitably broaden it. However, there are few comparative yield-trial data by which to choose which line(s) might be most useful. As the investment required for using a tropical line in a temperate breeding program is large, line-choice is critical. Tropical maize (Zea mays L.) represents a valuable genetic resource containing unique alleles not present in elite temperate maize. The strong delay in flowering in response to long daylength photoperiods exhibited by most tropical maize hinders its incorporation into temperate maize breeding programs. The objective of this study was to integrate candidate gene analyses with photoperiod QTL mapping across multiple maize populations. We tested the hypothesis that diverse tropical inbreds carry alleles with similar effects at four key photoperiod response quantitative trait loci (QTL) previously identified in maize. Four tropical maize inbreds were each crossed and backcrossed twice to the temperate recurrent parent B73 to establish four sets of introgression lines. Evaluation of these lines under long day lengths demonstrated that all four QTL have significant effects on flowering time or height in these lines, but the functional allelic effects varied substantially across the tropical donor lines. At the most important photoperiod response QTL on chromosome 10, one tropical line allele even promoted earlier flowering relative to the B73 allele. Significant allelic effect differences among tropical founders were also demonstrated directly in an F2 population derived from the cross of Ki14 and CML254. The chromosome 10 photoperiod response QTL position was validated in a set of heterogeneous inbred families evaluated in field tests and in controlled environments.

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.

Northern corn leaf blight caused by Exserohilum turcicum Pass is considered the most important disease infecting corn (Zea mays L.) in the Peoples' Republic of Korea (North Korea). It contributes to the food shortage in North Korea. The objectives of the current research were to study resistance expression and responses of corn crosses made between ten hybrids from North Korea and inbreeding lines (S3-4 stage) from the Republic of Korea (South Korea). The experiments were conducted in six trials with a total of 184 crosses including two commercial hybrids in each trial. The trials were conducted at two locations in North Korea (Mirim and Eunsan) and one location in South Korea (Gunwi) under natural infestation of E. turcicum. Host plant responses were rated on a scale of 1 (highly tolerant) to 9 (highly susceptible). A total of 111 crosses (62.4%) showed significant tolerant or susceptible response variations among three locations; 42 crosses (22.8%) at two locations and 69 crosses (39.0%) at one location, respectively. At least 8 crosses of high level of tolerance and 12 crosses of high level of susceptibility showed significantly different biotic responses (P = 0.05). The results of the current study and historical reviews of E. turcicum epidemics in both North and South Korea suggest that breeding of tolerance with quantitatively inherited genes should be carried out for a sustainable corn production in North Korea.

옥수수 우량 교잡종 육성을 위한 자료로 활용하고자 국내 육성 옥수수 자식계통, F1 종실 및 F2 종실의 이화학적 특성과 지방산 및 아미노산 조성을 각각 분석 검토하였다. 1. F2 종실의 단백질 함량이 9.0%로 자식계통 11.4%와 F1 종실 10.9%에 비하여 유의하게 낮은 것으로 나타났다. 지방 함량은 F2 종실이 자식계통과 F1 종실보다 높았다. 회분은 자식계통, F1 종실, F2 종실간 조성변이에 차이가 없었다. 2. 자식계통, F1 종실, F2 종실 모두 linoleic acid의 조성비가 가장 높고 oleic acid, palmitic acid, stearic acid, linolenic acid의 순으로 지방산 조성비가 높은 것으로 나타났다. F2 종실의 포화지방산의 함량은 17.6%로 F1 종실과는 비슷하였으나, 자식계통보다는 낮았다. F2 종실의 불포화지방산의 함량은 82.4%로 F1 종실과는 비슷하였으나, 자식계통보다는 높았다. 3. F2 종실의 leucine의 함량이 자식계통 및 F1 종실보다 낮았다. 반면 F2 종실의 valine, serine, threonine, cysteine, aspartic acid, lysine, arginine, histidine 등의 함량이 자식계통 및 F1 종실보다 높았다. Alanine 등 나머지 아미노산은 자식계통, F1 종실, F2 종실간 조성변이가 비슷한 경향이었다. 4. 산성아미노산인 MMA(monoamino monocarboxylic acid)가 자식계통, F1 종실, F2 종실에서 그 조성 비율이 가장 높았으며 산성 아미노산인 DMA(diamino monocarboxylic acid), 방향족 아미노산인 AAA(aromatic amino acid) 순으로 조성비가 높았다.

얼룩찰1호'는 자식계통 KBW23을 종자친으로 하고 KW33을 화분친으로 하여 교잡된 단교잡종이며 알맹이가 흰색과 검정색의 두 가지 색을 가진 얼룩찰 옥수수이다. '얼룩찰1호'는 2003년 생산력검정시험을 거쳐, 2005년부터 2007년까지 3년 동안 전국 5개 지역에서 지역적응시험을 실시한 결과 그 우수성이 인정되어 2007년 농작물 직무육성 신품종으로 결정되었다. 이 품종의 주요특성을 요약하면 다음과 같다. 1. '얼룩찰1호'의 출사일수는 76일로

본 연구는 총 50개의 SSR 마커를 이용하여, 찰옥수수 및 종실용 옥수수 핵심집단(찰옥수수 40계통, 종실용 옥수수 40계통)의 자식계통들의 유전적 다양성, 집단구조 및 계통유연관계를 분석하였다. 1. 그 결과 65bp에서 225bp 크기의 범위로 총 242개의 대립단편들을 증폭시켰다. SSR primer들에서 증폭된 대립단편의 수는 최소 2개에서부터 최대 9개까지의 범위로 나타났고, 평균 4.84개가 증폭되었다. 그리고 GD값은 0.420에서 0.8

옥수수에서 자식계통들에 대한 유전적 다양성 및 계통유연관계 정보는 1대잡종 품종개발을 위한 교배조합 선발에 유용한 전략을 제공한다. 본 연구는 86개의 튀김 옥수수 자식계통들에 대한 유전적 다양성 및 계통유연관계를 밝히기 위하여 옥수수 전체 게놈을 대표할 수 있도록 50개의 SSR primer를 선발하여 분석에 이용하였다. 그 결과 50개의 SSR primer들은 86개의 튀김 옥수수 자식계통들에서 총 256개의 대립단편을 나타내었으며, SSR loci

The effect of nitric oxide (NO) on antioxidant system and protective mechanism against oxidative stress under UV-B radiation was investigated in leaves of maize (Zea mays L.) seedlings during 3 days growth period. UV-B irradiation caused a decrease of leaf biomass including leaf length, width and weight during growth. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated UV-B stress induced growth suppression. NO donor permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem Ⅱ than in non-treated controls under UV-B stress, suggesting that NO has protective effect on chloroplast membrane in maize leaves. Flavonoids and anthocyanin, UV-B absorbing compounds, were significantly accumulated in the maize leaves upon UV-B exposure. Moreover, the increase of these compounds was intensified in the NO treated seedlings. UV-B treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide (H2O2) in maize leaves, while NO donor prevented UV-B induced increase in the contents of malondialdehyde (MDA) and H2O2. These results demonstrate that NO serves as antioxidant agent able to scavenge H2O2 to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, catalase (CAT) and ascorbate peroxidase (APX) in maize leaves in the presence of NO donor under UV-B stress were higher than those under UV-B stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3- oxide (PTIO), a specific NO scavenger, to the maize leaves arrested NO donor mediated protective effect on leaf growth, photosynthetic pigment and free radical scavenging activity. However, PTIO had little effect on maize leaves under UV-B stress compared with that of UV-B stress alone. Nω -nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), significantly increased H2O2 and MDA accumulation and decreased antioxidant enzyme activities in maize leaves under UV-B stress. This demonstrates that NOS inhibitor LNNA has opposite effects on oxidative resistance. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative stress induced by UV-B radiation and thus confer UV-B tolerance.

본 연구는 유전자 조작 옥수수의 유전자 유출을 막기 위한 관리방법 개발의 목적으로 고려대학교 GMO 격리포장에서 2010년에 수행된 화분 비산실험의 결과를 이용하여 Yamamura(2004)의 Gamma model로 모델링하였다. 1. 모델의 결정계수는 0.44로 예측치가 실측치를 잘 설명하였다. 2 옥수수 화분의 최대 비산 방향은 북서쪽으로 나타났다. 3. 최대 비산 방향으로 타가수분율이 0.001까지 낮아지는 거리인 '유전자유출 한계거리(0.001)'는 525 m 그리고 국내법상 비의도적 GMO 혼입허용치인 0.03 까지 낮아지는 거리인 '최소 동일작물 재배 한계거리(0.03)'는 35 m로 나타났다.

2007년부터 2009년까지 3년간 보리이모작으로 옥수수를 6월 만파 시 사료용 및 종실용으로의 생육 및 수량변화를 2007 및 2009년의 4월 하순 적파 및 2008년 5월 하순 옥수수와 대비하여 살펴보았는데 그 결과는 다음과 같다. 1. 4월 하순 적파에 비해 보리 이모작으로 6월 중 하순 만파 시 옥수수의 생육 많이 감소하여 사료 종실의 수량성이 20~30% 감소하였지만, 이모작으로 동계 재배한 보리의 사료 종실의 수량성을 합할 경우 년간 전체 수량성은 30~40% 증가하였다. 2. 6월 만파 시 옥수수 부위별로는 간엽보다 이삭(종실)의 감소가 적었다. 사료 및 종실용으로 수량감소가 가장 적었던 품종은 광평옥이었으며, 6월 만파에서도 850 kg 10a1의 수량성을 얻을 수 있었다. 따라서 이모작 옥수수는 사료용 보다 종실용으로 만파적응 품종 및 재배법의 개발이 필요한 것으로 나타났다. 3. 6월 만파 옥수수는 4월 적파 옥수수보다 유효적산온도의 증가와 더불어 출사일수는 40일 가량 단축되었고, 만파에 따라 출사기는 1달 정도 늦어 수확적기는 사료용이 9월 하순, 종실용이 10월 중순으로 4월 적파 옥수수에 비해 수확 시 기후조건은 좋은 것으로 나타났다.

Maize (Zea mays.L) is the third important crop after wheat and rice in Afghanistan. The productivity is low 2.14 ton/ha due to lack of diversity and well-adapted varieties. 65% of maize production is used as feed and 17.5% as food. Afghanistan is facing seriously malnutrition and poverty, therefore more maize is required to recover food security. Popcorn is also important snack food in Afghanistan, but it is luck of breeding donors. The main objective of this work is to evaluate and identify the introduced hybrids of Korean germplams. International Corn Foundation (ICF), Kyungpook National University (KNU) and Institute of Asian Culture and Development (IACD) collaboratively planted three different types of maize (Silage1, KNU waxy1, Popcorn) in two locations (Isharak and Sherabad) in Mazar-i-sharif. All hybrids have shown good performances and can easily be adapted in Afghanistan climate. Among them KNU waxy1 was the most attractive which has been planted first time. Farmers showed highly interest on new taste and they were so enthusiasm to replant. Maize breeding laboratory at KNU is developing new popcorn cultivar for commercial use in Korea that has shown outstanding result in Afghanistan climate. This experiment described that introducing of new maize hybrids especially KNU waxy1 and popcorn can have great potential to fill up food demand in Afghanistan.