• Current Research on Agriculture and Life Sciences
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• 제21권
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• pp.31-37
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• 2003

나리속(屬) 식물의 엽초는 품종에 따라 엽위별 형태와 숫자가 큰 차이를 보여 품종별로 식재깊이에 따른 엽초수를 조사하고, 엽초를 제거한 후 생육 반응을 알아보았다. 품종별 엽초는 0cm로 식재한 경우 'Jolanda'는 6매엽, 'Dream Land'는 5매엽과 'Casablanca'는 11매엽으로, 6cm로 식재한 경우 'Jolanda'는 6매엽, 'Dream Land'는 5매엽과 'Casablanca'는 14매엽으로 밝혀져 'Jolanda'와 'Dream Land'는 식재깊이에 따라 엽초수의 차이가 없었으나 'Casablanca'는 6cm로 식재한 것이 0cm로 식재한 것에 비해 엽초가 3장이 더 많아졌다, 한편 엽초를 제거함으로써 'Le Reve'와 'Casablanca' 두 품종 모두 초장이 작아졌으며 stem root의 생육이 나빠졌다. basal root의 생육과 꽃수는 품종별로 다른 양상을 나타냈으며 줄기 직경, 개화소요일수와 꽃의 크기는 차이가 없었다.

• Journal of Plant Biology
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• 제17권3호
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• pp.118-126
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• 1974

Mulberry plants cultivated in mid-Korea were studied on the growth habitat, canopy type, productive structure and vertical light intensity in relation to the quality of mulberry leaves for sericulture. The growth in length of new branch of summer cut mulberry in spring was vigorous on the uppermost of old shoot. Numbers of leaves on a branch were barely 4 leaves on lower than 20th branch from base, but those were 13 leaves on higher than 24th branch. Area of leaves completely expanded was broad on high branch, but narrow on low one. The form of canopy, the type of productive structure and the vertical light distribution depend upon varieties of cultivated mulberry plants were classified according to characteristic of each variety in two groups, respectively; globular and columnar form in canopy, broad leaves and narrow leaves types in productive structure, and seriously obstructured the light and fairly transmitted the light into lower leaf stratum invertical light distribution. Out of varieties of mulberry investigated, Suwon No. 4 and Rosang were belong to the former characters, but Illchiroe and Kaeryangsubun were to the latters. The values of leaf dry matter index and dry matter production produced by leaves were increased in direct proportion to the height of leaf stratum; the leaf dry matter index of the uppermost leaf was twice as much that of the lowest, and the dry matter production by the highest leaf was 17 times compared with that by the lowest leaf. It is assumed that the meagre leaves occurred in the lower leaf stratum of Suwon No. 4 and Rosang were caused to diminished the dry matter index and dry matter production in the under leaves of plant, which were affected by receiving the weak light.

• 한국식물병리학회지
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• 제11권3호
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• pp.282-284
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• 1995

Grey leaf spot on tomato plants was first observed in Sedo-myeon, Puyo-kun, Chungnam province of Korea in 1994. This disease which had not been reported before in Korea exhibited different symptoms from those of other leaf spot diseases on tomato plants. The symptoms were characterized by small irregular-shaped spots on leaves at the initial stage of the infection, subsequent spread and coalescence of the spots throughout the leaves with ultimate necrosis, and abscission from the plants. When healthy tomato plants were inoculated with a conidial suspension of the fungus isolated from the lesion of a diseased plant in a field, the same characteristic symptoms as those in the field were produced. Furthermore, the same pathogen could be reisolated from the lesions formed buy the inoculation. Conidial characteristics of the pathogen were as follows; oblong shape with constricted 3 transverse septa, round-shaped base, round- or point-shaped apex, size of 45~75$\times$12.5~17.5 ${\mu}{\textrm}{m}$, and 3.5 : 1 ratio of length to width. The pathogen was identified as Stemphylium lycopersici and thus this is the first report on the occurrence of grey leaf spot disease on tomato plants caused by s. lycopersici in Korea.

• Journal of Ecology and Environment
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• 제45권2호
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• pp.78-87
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• 2021

Background: To understand shade and wind effects on seedling traits of common reed (Phragmites australis), we conducted a mesocosm experiment manipulating day length (10 h daytime a day as open canopy conditions or 6 h daytime a day as partially closed canopy conditions) and wind speed (0 m/s as windless conditions or 4 m/s as windy conditions). Results: Most values of functional traits of leaf blades, culms, and biomass production of P. australis were higher under long day length. In particular, we found sole positive effects of long day length in several functional traits such as internode and leaf blade lengths and the values of above-ground dry weight (DW), rhizome DW, and total DW. Wind-induced effects on functional traits were different depending on functional traits. Wind contributed to relatively low values of chlorophyll contents, angles between leaf blades, mean culm height, and maximum culm height. In contrast, wind contributed to relatively high values of culm density and below-ground DW. Conclusions: Although wind appeared to inhibit the vertical growth of P. australis through physiological and morphological changes in leaf blades, it seemed that P. australis might compensate the inhibited vertical growth with increased horizontal growth such as more numerous culms, indicating a highly adaptive characteristic of P. australis in terms of phenotypic plasticity under windy environments.

• 식물조직배양학회지
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• 제27권2호
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• pp.89-94
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• 2000

큰용담의 기내배양에서 EMS를 처리한 경우 돌연변이체를 선발하기에 최적의 농도는 200 uM이며 농도가 높아질수록 생존률이 저하되었으며 줄기는 가늘고 나선형으로 꼬이고 백화현상이 가장 심하였다. Colchicine의 경우 30일 까지는 전 농도에서 84~97%의 높은 생존률을 보였으나 60일 이후에는 농도에 따라 생존률의 차이가 보였다 변이체가 단간이며 왜소하였다. MNU의 경우 10 $\mu$M에서 200$\mu$M까지는 89~97%의 높은 생존률을 보이다가 500$\mu$M이상에서는 18.2%로 급격한 감소를 보였으며 변이체의 잎의 형태가 도피침형에서 주걱형과 도란형으로 변형된 것과 잎의 청색에서 진보라색으로 변형된 2가지 type의 변이체가 형성되었다. Sodium azide를 처리한 경우 적정농도는 80$\mu$M였고 60일 배양 시 전반적으로 30~50%의 균일한 생존률을 보였고 초장이 아주 작고 다분얼성 변이체를 형성하였다. 형성된 shoot의 길이를 비교하여 보면 sodium azide, MNU의 경우에서는 약 1.0cm내외인 반면 colchicine의 경우 0.5 cm내외로 저조한 길이 생장을 보였다. RAPD에 의한 돌연변이체의 확인에서 농도가 가장 높은 500$\mu$M에서 변이 band가 관찰되었으며 돌연변이 계통에서 새로 형성된 band의 수는 MNU에서 2개 NaN3에서 1개로 전부 3개 (8.1%)의 변이 band가 나타났다.

• 한국환경과학회지
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• 제22권2호
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• pp.187-193
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• 2013

Dry matter allocation characteristics of Calystegia soldanella, grown in pots, was analysed to assess its plasticity in response to water-stressed conditions. As water was withheld leaf water potential between the two watering treatments was similar during the first 6 days, followed by a rapid decrease in water-stressed plants. The minimum leaf water potential was -1.50 MPa on day 15 and the maximum leaf water potential was about -0.5 MPa on day 0 in water-stressed plants. In well-watered plants leaf water potential was maintained almost consistently throughout the experiment. There was no significant difference in plant dry weight between the two watering treatments for 9 days after the start of experiment and that was remarkably increased thereafter, compared with that remained without any increase in water-stressed plants. In dry mass partitioning, however, the water-stressed plants showed a great plasticity, showing that there were 1.81, 1.35 and 0.81 times increase in root, stem and leaf, respectively. Dry mass partitioning in well-watered plants varied from 2% to 5%. The difference of dry mass partitioning between the two watering treatments was reflected in leaf mass per unit area (LMA) and root/shoot (R/S) ratio. LMA in water-stressed plants was lower than that in well-watered plants, while R/S ratio in water-stressed plants was higher in well-watered plants. This means that the water-stressed plants reduced its leaf area and increased dry mass partitioning into root and stem during the progress of soil drying. These results indicate that Calystegia soldanella inhabiting in sand dune cope with water stress with high plasticity which can adjust its dry mass partitioning according to soil water conditions.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.919-924
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• 2014

Ambient ionization can be achieved by generating an electrospray directly from plant tissue ("leaf spray"). The resulting mass spectra are characteristic of ionizable phytochemicals in the plant material. By subtracting the leaf spray spectra recorded from the petals of two hibiscus species H. moscheutos and H. syriacus one gains rapid access to the metabolites that differ most in the two petals. One such compound was identified as the sambubioside of quercitin (or delphinidin) while others are known flavones. Major interest centered on a $C_{19}H_{29}NO_5$ compound that occurs only in the large H. moscheutos bloom. Attempts were made to characterize this compound by mass spectrometry alone as a test of such an approach. This showed that the compound is an alkaloid, assigned to the polyhydroxylated pyrrolidine class, and bound via a $C_3$ hydrocarbon unit to a monoterpene.

• Nuclear Engineering and Technology
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• 제28권6호
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• pp.583-593
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• 1996

An elastic stiffness formula of a leaf type holddown spring(HDS) assembly with a uniformly tapered width from $w_0$ to $w_14$ over the length, has been analytically derived based on Euler beam theory and Castigliano's theorem. Elastic stiffnesses of the tapered-width leaf type HDSs(TW-HDSs) designed in the same dimensional design spaces as the KOFA HDSs have been evaluated from the derived formula, in addition, a parametric study on the elastic stiffness of the TW-HDSs has been carried out. Analysis results show that, as the effects of axial and shear force on the elastic stiffness of He TW-HDSs have been 0.15~0.21% of the elastic stiffness, most of the elastic stiffness is attributed to the bending moment, and that elastic stiffnesses of the TW-HDSs have been about 32~33% higher than those of the KOFA HDSs. It is found that the number of leaves composing a HDS assembly could be lessened by one under the conditions that the TW-HDSs have been adopted in KOFA.

• Journal of Plant Biology
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• 제4권1호
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• pp.21-24
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• 1961

The strains of fungus which belong to Coniothyrium genus were isolated from leaf spoot of Yucca. The isolated strain can grow easily and forms characteristic colonies on Saido's soy agar. There are definite differences, according to other authors, (By Miyake et Hara 1911) Pycnidio-spore are usually formed ellipsoidal, dark brown, 4$\times$2. 5-4. $O\mu$ in size, whereas isolated strains are globose, yellowish brown, 2.8-4.2$\mu$ in diameter. The positive inoculation test can be attained by burned petridish method, preserving it in incubator at 28$^{\circ}C$, and the pycnidio-spore can be reisolated from the inoculated portion. (Photo.7) Up to the present day there is no report for leaf spot of Yucca caused by Coniothyrium sp.. Comparing the writer's isolate with those fungi described(leaf spot of alloe, rose canker and elm canker etc.) hitherto, there are no accordance in the symptom and especially in morphological charactgers and Pathogenicitys.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.542-546
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• 2009

Leaves are the major biomass-producing organs in herbaceous plants and mainly develop during vegetative stage by activities of shoot apical meristem. There is a strong correlation between leaf number and bolting, a characteristic phenotype during the transition to reproductive phase in Arabidopsis thaliana. In order to study interactions between leaf number and bolting, we isolated a Landsberg erecta-derived mutant named multifolial (mfo1) that produces increased number of leaves and bolts at the same time as the wild type. Through positional cloning and allelism test, mfo1 was found to be an allele of a previously reported mutant, altered meristem program1-1 (amp1-1) that is defective in a glutamate carboxypeptidase and bolts earlier than its wild type, Columbia ecotype, with the increased number of leaves. The bolting time differences between mfo1 and amp1, despite the same phenotype of many leaves, suggest the existence of genetic factor(s) differently function in each ecotype in the presence of mfo1/amp1 mutation.