• 한국환경농학회지
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• 제15권4호
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• pp.448-454
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• 1996

본 연구는 자외선-B 조사(照射)가 피나무 유묘의 초기 생장에 미치는 영향을 알고자 수행되었다. 자외선-B는 유묘의 하배축 신장, 수고생장, 잎의 생장 및 엽록소 함량증가를 억제하였다. 이러한 억제 효과는 자외선-B 조사(照射)량이 증가할수록 더욱 높았다. 잎생장 감소 뿐만 아니라 형태적 변화도 나타났으며 엽장의 생장보다 엽폭의 생장이 빠르게 일어난 것이 관찰되었다. 자외선-B 처리를 받은 유묘의 1차엽 또는 2차엽에 변색, 반점, 반짝거림, 위축 또는 오그러듬의 피해증상이 관찰되었다.

• 한국작물학회지
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• 제44권4호
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• pp.368-372
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• 1999

The practicality of utilizing chitosan as a natural antimicrobial compound to reduce soybean sprout rot was tested. Domestic and imported soybean seeds were soaked for 6 hours in solutions containing different levels of chitosan and acetic acid (glacial), and cultured at $25^{\circ}C$ for 6 days. In case of domestic seeds, soaking with 1,000ppm chitosan increased germination percentage, hypocotyl thickness, total length, and fresh weight of sprouts by 4%, 5%, 2%, and 1%, respectively. The total sprout yield was increased by chitosan in a concentration-dependent manner in that 1,000ppm chitosan resulted in 8% increment of total yield (7.47kg sprouts/kg seed). Chitosan significantly reduced sprout rot percentage to 7.0% compared to control (13.8%), and consequently enhanced marketable sprout yield by 39%. Compared to domestic seeds, the imported soybean seeds exhibited very low germination percentage regardless of chitosan treatments. Chitosan, nevertheless, consistently induced yield increment and rot decrement in imported soybean sprouts. Although 100ppm acetic acid was effective in reducing sprout rot percentage down to 11.8%, its yield-increasing effects were not as prominent as chitosan. In conclusion, soaking soybean seeds with chitosan seems to be a practical method to enhance the efficiency of soybean sprout production.

• The Plant Pathology Journal
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• 제15권1호
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• pp.72-75
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• 1999

A scab disease occurred on watermelon seedlings by the infection of Cladosporium cucumberinum. This is the first report demonstrating the scab disease on watermelon in Korea. The casual agent attacked all plant parts of the seedlings on the ground. Infection sites were initiated with sunken and dark green spots, and then suddenly developed to large lesions softened with gummy substances. When hypocotyl and leaf stalk of seedlings were infected and softened, upper parts of seedlings were brokin down, dried and eventually died. Conidiophores of the fungus were characterized by pale olivaceous brown color, and variable length of about 3-5 mm in width. Conidia were formed I long branched chains, and conidium was ellipsoidal, fusiform or subspherical single cell mostly without septum. Morphological characteristics of the fungus were almost identical to Cladosporium cucumerinum Ellis & Authur. The fungus was also pathogenic to cucumber, squash and oriental melon, suggesting that it is a common pathogen to cucurbits. However, the fungus was not pathogenic to bottle gourd.

• 생명과학회지
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• 제10권6호
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• pp.598-604
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• 2000

This study was conducted to investigate the effect of simulated acid rain (SAR) on germination, growth, acid buffering capacity and nutrient leaching in Impatiens balsamina L. and Tagetes patula L.. In both species, germination was not inhibited at pH 4.0, but the germination rate decreased at the lower pH of 3.0, showing higher rate in Inpatiens balsamina L. than Tagetes patula L.. As the pH decreases, the growth of radicle was markedly decreased than that of hypocotyl in both species. The plant height, root length, leaf area, total dry weight, relative growth rate and net assimilation rate were inhibited by SAR. The acid buffering capacity in the leaves were increased at pH 4.0, on the other hand, it was shown a tendency to decrease at pH 2.0 in both species. As the pH levels decreased from 5.6 to 2.0, the nutrient leaching from leaves was significantly increased in both species. Based on the results, there are a great difference in the responses to SAR between the two species. In general, Tagetes patula L. represented a higher tolerance to SAR than Impatiens balsamina L.. These results suggested that interspecific variation in the acid buffering capacity and nutrient leaching from leaves may be responsible for the interspecific susceptibility to SAR.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2003년도 학술대회지
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• pp.97-103
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• 2003

Phytochrome controls diverse aspects of plant development in response to the ambient light conditions. HFRl, a basic helix-loop-helix protein, is required for a subset of phytochrome A (phy A)-mediated photo-responses in Arabidopsis. Here, we show that overexpression of HFR1-N105, but not the one of the full-length HFR1, confers exaggerated photo-responses. The transgenic plants overexpressing HFR1- N105 exhibited light-independence in a subset of photo-responses, including germination, de-etiolation, gravitropic hypocotyl growth, and blocking of greening. Overexpression of HFR1-N105 also caused constitutive light-responses in the expression of some light-regulated genes. In addition, the HFR1-N105 overexpressor showed hypersensitive responses under R and FR light, dependently on phyB and phyA, respectively. End-of-day far-red light response and petiole elongation were suppressed in the HFR1-N105 overexpressor plants. Together these results imply that overexpression of HFR1-N105 activated a branch of light signaling, supporting the hypothesis that transcriptional regulation in the nucleus would be the primary mechanism of light signaling in Arabidopsis. We discuss the biotechnological potential of the mutant bHLH protein, HFR1-N105 in regard to suppressed shade avoidance syndrome.

• 한국작물학회지
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• 제46권4호
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• pp.309-316
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• 2001

Helianthus tuberosus has been known to inhibit the growth of weeds and other plants sharing its habitat. This study was conducted to identify the allelochemicals of Helianthus tuberosus which were extracted with water and solvents. Aqueous extracts of leaf, stem, root, tuber and tuber peel of Helianthus tuberosus except tuber did not show significant differences in phytotoxicity to alfalfa seedlings. It was considered that Helianthus tuberosus contained fewer or less potential water-soluble substances that were toxic to alfalfa. Methanol extract of leaves of Helianthus tuberosus was sequentially partitioned in increasing polarity with n-hexane, ethylacetate and n-butanol. Each extract had a yield of 148, 12, 15.7 and 9.5g, respectively. Inhibitory effects on germination of alfalfa seeds treated with four fractions were not significantly different. But the significant reductions on hypocotyl length were observed for all the solvent extracts. Among the four fractions, the ethylacetate fraction showed the most significant inhibition effect on bioassay with alfalfa. Further separation of the active ethylacetate fraction by open column chromatography led to the 25 subfractions. In bioassay of each sub-fraction with alfalfa seeds, sub-fraction No. 13 showed the most inhibitory effect on seedling growth. $^1$H NMR and gas chromatography-mass spectrometry analysis revealed that sub-fraction No. 13 was the mixture of straight-chain saturated fatty acids.

• 한국작물학회지
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• 제38권2호
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• pp.166-173
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• 1993

하대두는 추대두에 비하여 생육특성상 고온다습의 조건에서 성숙하는 관계로 미이라병의 종자감염이 높아 적정입모를 확보하기 위해서는 종자소독의 필요성이 요구된다. 따라서 본 시험은 입중을 달리한 하대두 계통에서 종자소독에 의한 입모율 향상이 후기생육 및 수양에 미치는 영향과 미이라병의 감염정도에 따른 종자소독제의 처리효과를 구명코자 하였다. 1. 입중을 달리한 하대두 계통에 종자소독제를 분의 처리하여 파종하면 무처리에 비하여 발아율이 향상되었고 배축장이 길었으며 약제처리의 약효는 대립종에서 높고 소립종에에서 낮은 경향이였다. 2. 종자소독제를 처리했을때 후기생육, 주당엽수, 백립중 및 수양은 무처리와 비교하여 큰 차이가 없었다. 3. 동일품종내에서 미이라병의 가시적 감염증세가 경미하면 종자소독제의 처리효과는 적었고 심할수록 약제처리에 의하여 발아율과 발아세가 현저히 향상되었는데 그 정도는 대립종에서 높았다.

• 한국환경과학회지
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• 제12권11호
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• pp.1189-1196
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• 2003

The effect of boron and aluminum on the development of adventitious roots was studied in sunflower cuttings. Three-day-old seedlings were de-rooted and grown in nutrient solutions with or without boron and supplemented with different concentrations (from 50 to 700 ${\mu}$M) of aluminum. The number and length of the adventitious roots and proline content in adventitious roots in response to insufficient boron and aluminum stress were determined periodically. The micronutrient boron caused the development of numerous roots in the lower parts of the hypocotyl. A dose-response of boron-induced rooting yielded an optimum concentration of 0.1 mM boron. In the absence of boron, in the majority of the adventitious roots, a significant inhibition was observed with or without aluminum, indicating that the most apparent symptom of boron deficiency is the cessation of root growth. Increasing concentrations of aluminum caused progressive inhibition of growth and rooting of the hypocotyls, and a parallel increase in proline levels of adventitious roots. Supplemental boron ameliorated the inhibitory effect of aluminum, suggesting that aluminum could inhibit root growth by inducing boron deficiency. Ascorbate added to medium in the absence of boron improved root growth and induced a significant decrease in proline levels. These findings suggest that adventitious root growth inhibition resulting from either boron deficiency or aluminum toxicity may be a result of impaired ascorbate metabolism.

• 한국작물학회지
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• 제32권3호
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• pp.268-276
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• 1987

대두종자의 퇴화과정에서 일어나는 생리ㆍ화학적인 변화를 탐색하여 종자세의 차이를 비교하고 종자세 예측에 적합한 방법을 구명하기 위하여 대두 5품종의 종자를 인위노화처리시켰다. 대두종자세의 지표로서 발아율$\times$배축의 길이로 나타낸 값을 매개변수로 하여 각종 종자세 검정성적과 비교검토하였다. 종자세검정의 가장 적합한 방법으로는 발아시험에 의한 방법임을 알 수 있었다. ATP와 GADA 검정법을 제외하고는 모든 검정법이 종자세 지표와 고도의 유의성이 있었다. 대두종자세 검정을 위하여는 배축의 길이. 전기전도도에 의한 검정 및 저온발아 검정법이 적합한 방법임을 알 수 있었다.

• 생명과학회지
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• 제12권4호
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• pp.416-422
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• 2002

B. ehimensis YJ-37은 생육촉진미생물이면서 모잘록병의 생물학적 방제균으로서 관찰되었다 길항균 B. ehimensis YJ-37의 무와 수박의 근권정착밀도는 인공용토에 존재하는 길항균의 평균밀도 $10^4$(cfu/g) 보다 주근과 측근에서 약 1.2~2배 이상의 증가하였다. 길항균 배양액으로 만든 토양미생물제제에 의한 무의 생육촉진은 토양미생물제제 무처리구에 비해 처리구에서 잎면적은 85% 자엽의 길이는 33% 뿌리의 길이는 23% 건조중량은 89% 촉진되었고, 수박의 경우도 무처리구에 비해 처리구에서 잎면적은 63% 자엽의 길이는 27% 뿌리의 길이는 25% 건조중량은 69% 촉진되었다. 토양미생물제제는 채소류 모잘록병균 R. solani AG-4와 P. ultimum 등의 생육을 억제하여 모잘록병을 유발시키지 못하게 하였으며, 생육촉진현상도 동시에 가져왔다.