This study was designed to investigate the effects of antagonistic microorganism, Bacillus subtilis, on the growth of forage seedlings in repeated cultivation soils and unrepeated cultivation soils. The field experiment was wnducted in pots in a vinyl hou

The corn is one of the most important forage crop in Korea. The harvest time for silage affects dry matter (DM) yield and silage quality. This study was carried out to determine the effect of harvest time on the DM yield and nutritive value of corn forage

Tall fesuce 9 개 품종을 공시하여 가을철 예취시기를 달리했을 때 l 번초의 수량구성요소와 개체중에 미치는 영향을 조사하여 가을철 최종예취시기를 추정하고 이 지역의 환경조건에 적응성이 높은 품종 을 선발하려고 하였다. l. 가을철 예취시기에 따라서 l 번초의 개체중에 관여하는 수량구성요소의 차이가 인정되었는데 의 l 번초 개체중은 출수관련형질들과 유의한 정상관이 인정되었으나 의 1 번초 개체중에서는 유의한 상관이 인정되지 않았다. 2. 에서는

Although corn is regarded as the most feasible forage corp, its relatively low content of protein is the critical we a kness for animal feeding. Many researches have been carried out to improve protein level in corn forage, however, there are no indicatab

This experiment was carried out to compare chemical composition, TDN yield of corn-soybean intercropping and corn monocropping forage plants at different harvesting time and obtained the following results. 1. In both cropping systems, the content of chemi

The growth characteristics and yield per unit area of two cropping systems, corn monoculture and 'wrnsoybean intercropping, were compared and the obtained results were as follows; 1.The two cultivation systems were not significantly different in leaf leng

This experiment was carried out to compare chemical composition of corn-cowpea intercropping and corn monocropping plants at different harvesting time and obtained the following results. 1. In both cropping systems, the contents of crude fat and nitrogen

This experiment was carried out to compare chemical composition of corn-cowpea inter cropping and corn monocropping plants at different harvestion time and obtained the following results. 1. In both cropping systems, the contents of crude fat and nitrogen

The growth characteristics and yield per unit area of two cultivation systems of forage, corn (Zea mays L.) monoculture and corn-cowpea (Vigna sinesis King) inter-cropping were compared and obtained follow results. 1. The two cultivation systems were not

This study was conducted to compare changes of total carotenoid contents and antioxidant activities in yellow waxy corns (Zea mays L.) depending on harvest time. The total carotenoid contents of yellow waxy inbred lines and hybrids increased from 19 days and then the highest content of total carotenoid contents was observed at 25 to 27 days after pollination. Thereafter, there was little change in total carotenoid contents. According to analysis total content of carotenoids on 23 days after pollination, which was the period of harvesting waxy corn, KY2 was the highest as 15.4 ㎍/g in inbred lines and KY2/KY39 was the hightest as 11.2 ㎍/g in hybrids, respectively. The total carotenoid contents of each hybrid were higher than mean that of their parent lines except for some hybrids. The total carotenoid contents of KY27/KY37 were significantly higher than those of their parental lines. Antioxidant activity of yellow waxy corn showed a tendency to increase after decrease depending on delaying harvesting time. Antioxidant activities of hybrids were higher than that of inbred lines. As a result of correlation analysis between total carotenoid contents and antioxidant activity, correlation coefficient of inbred lines and hybrids was as low as -0.12 and -0.13, respectively. When the harvest time was delayed, the lightness of yellow waxy corn decreased but the redness and yellowness increased. As a result of correlation analysis between Hunter’s Lab value and total carotenoid contents, correlation coefficient of lightness, redness and yellowness were -0.22, 0.67, 0.53, respectively.

The objective of this study was to find a rapid determination of the hot air stress in maize (Zea mays L.) leaves using a portable chlorophyll fluorescence imaging instrument. To assess the photosynthetic activity of maize leaves, an imaging analysis of the photochemical responses of maize was performed with chlorophyll fluorescence camera. The observed chlorophyll imaging photos were numerically transformed to the photochemical parameters on the basis of chlorophyll a fluorescence. Chlorophyll a fluorescence imaging (CFI) method showed that a rapid decrease in maximum fluorescence intensity (Fm) of leaf occurred under hot air stress. Although no change was observed in the maximum quantum yield (Fv/Fm) of the hot air stressed maize leaves, the other photochemical parameters such as maximum fluorescence intensity (Fm) and Maximum fluorescence value (Fp) were relatively lowered after hot air stress. In hot air stressed maize leaves, an increase was observed in the nonphotoquenching (NPQ) and decrease in the effective quantum yield of photochemical energy conversion in photosystem II (Φ PSII). Thus, NPQ and ΦPSII were available to be determined non-destructively in maize leaves under hot air stress. Our results clearly indicated that the hot air could be a source of stress in maize leaves. Thus, the CFI analysis along with its related parameters can be used as a rapid indicating technique for the determining hot air stress in plants.

In monsoon climates, persistent shade is a troublesome weather condition with an impact on the growth and yield of corn (Zea mays L.). We imposed 7, 14, 21, and 28 days of consecutive shade (CS) on Gwangpyeongok and P3394 corn hybrids at the beginning of the kernel filling stages. Shade had little impact on leaf area and dry matter accumulation in the stem and leaves. However, dry matter accumulation in the ear was severely reduced by approximately 28% and 53% after 14 and 28 days of CS, respectively. For the components of grain yield, 7 and 14 days of shade did irreparable damage to the number of filled kernels, the kernel number per ear row, and the percent of filled kernels, but did little damage or reversible damage after removal of the shade to the 100-grain weight and the row number per ear. Shade significantly reduced the relative growth rate (RGR) due to a decrease in the net assimilation rate (NAR). These results suggest that source activity limitation by shade during the kernel filling stages leads to the inhibition of sink activity and size. The yield of biomass, ear, and grain logistically declined as the length of CS increased. Probit analysis revealed that the number of days of CS needed to cause 25% and 50% reductions in grain yield were 3.7 and 23.1, respectively. These results suggest that the plant yield loss induced by shade at the beginning of the kernel filling stages is mainly achieved within the first 7 days of consecutive shade.

We investigated the antioxidative and protective effects of corn silk (Zea mays L.) ethanol extracts on human HaCaT cells and erythrocytes. The NICS-2 fraction, extracted from corn silk, exhibited favorable 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activities with IC50valuesof13.3± 0.3 μg/mL and 14.2 ± 0.1 μg/mL when compared with those of α-tocopherol, a positive control, with IC50=10.4± 02.2 and 22.2 ± 3.6 μg/mL, respectively. In addition, we investigated skin protection effects of NICS extracts of corn silk in HaCaT keratinocytes. To investigate the pharmacological potential of NICS-1 and NICS-2 extracts of corn silk on UV-B-induced damage in HaCaT cells, we measured the activity of interleukin (IL) 1a. Our results showed that all the corn silk extracts inhibited the UV-B-induced activity of IL-1a. In particular, NICS-1 extracts of corn silk significantly suppressed IL-1a activity in a dose-dependent manner without inducing cytotoxicity. These results indicate that the ethanol extracts of corn silk (Zea mays L.) could function as natural cytoprotective agents and antioxidants in biological systems, particularly the skin exposed to UV radiation, by protecting cellular membrane against reactive oxygen species (ROS).

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.

Fresh edible sweet corns demand relatively short period to harvest fresh ears, which can allow farmers to make a choice sweet corns for various cropping systems. For this reason, we were to find the optimum planting date of late-planted sweet corns to sell fresh ears in the autumn linked to cropping system with winter crops, investigating yield and properties of marketable fresh ears and growth traits of sweet corns (cv. 'Godangok' and cv. 'Guseulok') depending on planting dates such as 10 July, 20 July, and 30 July in Suwon 2012 and 2013, respectively. The 20 July-planted sweet corns showed the most fresh ear yield. However, the 10 July-planted and the 30 July-planted had 32% less yield caused by consecutive rainfall from 10 July through 20 July, and 15% less yield due to low air temperature during ripening than the 20 July-planted, respectively. The 10 and 20 July-planted sweet corns had average 140g of a fresh ear weight and 15% heavier ear than the 30 July-planted. For the July-planted sweet corns, silking days after planting (r=-0.80**), and harvesting days after silking (r=-0.97**) and planting (r=-0.91**) were highly negatively correlated with daily mean air temperature during the period, resulting in it takes 1,100 growing degree days (GDD) to harvest fresh ears from the July-planted sweet corns. The fresh ears of the 20 July-planted sweet corns are able to be harvested by early October. Therefore it will be a good choice for the cropping system based on winter vegetable cash crops such as temperate garlic and onion with medium or late maturity. Among three planting dates 20 July-planted sweet corns had the best field performance in every year considering fresh ear yield, ear size, and stability to grow.

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.

본 연구는 검정찰옥수수 교잡계와 그의 자식계통들에 대해 수분 후 일수가 늘어남에 따라 옥수수 알맹이의 총안토시아닌 함량과 항산화 활성의 변화 양상을 구명하고 육종에 활용할 수 있는 기초자료를 제공하고자 수행하였으며 그 결과는 다음과 같다.2009년 31개의 검정찰옥수수 자식계통의 총안토시아닌 함량은 평균 52.3 mg/100 g 이었고 KBW39가 173.3 mg/100 g으로 가장 높았으며 KBW1 등 4개 계통의 총안토시아닌 함량은 150 mg/100 g 이상이었다.2010년 33개의 검정찰옥수수 교잡계의 총안토시아닌 함량은 수확시기가 늦어질수록 증가하였고 항산화 활성 역시 안토시아닌 축적과 유사한 경향을 나타내었으며 상관분석 결과 0.64의 정의 상관을 보였다.2011년 자식계통과 그의 교잡계의 총안토시아닌 함량과 항산화 활성의 변화는 2009년과 2010년에서 본 결과 총안토시아닌 함량, 수분 후 일수에 따른 변화 양상, 항산화 활성 등에 차이가 있었으며 이는 기상환경에 따른 안토시아닌 축적의 변화와 안토시아닌 이외의 항산화물질들 함량변화와 관련 있을 것으로 사료되었다. 총안토시아닌 함량은 KBW2/KBW39의 교배조합이 120 mg/100 g으로 가장 높았고 모본과 부본 역시 각각 118.1 mg/100 g, 195.0 mg/100 g으로 함량이 높았다.총안토시아닌 함량과 Hunter’s Lab 값은 유의한 차이가 있었으며 명도는 총안토시아닌 함량이 증가할수록 감소하였고 상관분석결과 상관계수가 2010년에는 -0.8456, 2011년에는 -0.9050으로 고도로 높은 부의 상관을 나타내었다.

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.

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.