• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.141.2-142
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• 2003

A flexuous rod-shaped virus was isolated from Cucurbita pepo leaves showing green mosaic and puckering symptoms at Anseong, Korea. Based on the biological tests, electron microscopy, and reverse transcription-polymerase chain reaction (RT-PCR), the isolate was identified as Papaya ringspot virus type Watermelon (PRSV-W). In the biological test, host range of PRSV-W was limited in the families Cucurbitaceae and Chenopodiaceae. Most susceptible cucurbit species, such as Cucurmis lanatus, Cucurmis sativus, Cucurbita pepo, and Citrullus lanatus, responded to mechanical inoculation by PRSV-W that induce green mosaic, malformation, puckering, and narrow laminae. The local lesion symptoms were produced on the inoculated leaves of Chenopodium maranticolor and C. quinoa PRSV specific primers which amplifies the part of the coat protein (CP) genes, generated a 648 bp product from 6 isolates of PRSV-W, but no amplification had been detected in other viruses including CMV, CGMMV, KGMMV, ZYMV and WMV. In electron microscopy, PRSV particles were flexuous, approximately 780 nm in length and 12 nm in width. PRSV-W is one of the worldwide viruses which has the great economic importance in cucumber, melon, squash, watermelon, and other cultivated cucurbits with ZYMV and WMV. This is the first report of PRSV-W on cucurbits in Korea.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.93-105
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• 2015

This study was performed to analyze genetic relationships of the four major cucurbitaceous crops including watermelon, melon, cucumber, and squash/pumpkin. Among 120 EST-SSR primer sets selected from the International Cucurbit Genomics Initiative (ICuGI) database, PCR was successful for 51 (49.17%) primer sets and 49 (40.8%) primer sets showed polymorphisms among eight Cucurbitaceae accessions. A total of 382 allele-specific PCR bands were produced by 49 EST-SSR primers from 24 Cucurbitaceae accessions and used for analysis of pairwise similarity and dendrogram construction. Assessment of the genetic relationships resulted in similarity indexes ranging from 0.01 to 0.85. In the dendrogram, 24 Cucurbitaceae accessions were classified into two major groups (Clade I and II) and 8 subgroups. Clade I comprised two subgroups, Clade I-1 for watermelon accessions [I-1a and I-1b-2: three wild-type watermelons (Citrullus lanatus var. citroides Mats. & Nakai), I-1b-1: six watermelon cultivars (Citrullus lanatus var. vulgaris S chrad.)] a nd C lade I -2 for melon and cucumber accessions [I-2a-1 : 4 melon cultivars(Cucumis melo var. cantalupensis Naudin.), I-2a-2: oriental melon cultivars (Cucumis melo var. conomon Makino.), and I-2b: five cucumber cultivars (Cucumis sativus L.)]. Squash and pumpkin accessions composed Clade II {II-1: two squash/ pumpkin cultivars [Cucurbita moschata (Duch. ex Lam.)/Duch. & Poir. and Cucurbita maxima Duch.] and II-2: two squash/pumpkin cultivars, Cucurbita pepo L./Cucurbita ficifolia Bouche.}. These results were in accordance with previously reported classification of Cucurbitaceae species, indicating that watermelon EST-SSRs show a high level of marker transferability and should be useful for genetic study in other cucurbit crops.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.189-194
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• 2002

Many researches in the past have shown that a majority initial cracking in concrete are caused during early age period. Therefore, the close examination of early age concrete behavior under various stress conditions is necessary to fully understand the cracking mechanism of concrete. In this study early age cement paste specimen is axially strained up to 20% of its original length by laterally reinforcing it. This type of test is called "Tube Squash Test" and has been previously used to apply up to 50% axial strain on concrete. Microscopic analyses (XRD, FESEM, EDS and DSE/TG) are performed on 20% axially strained early age cement paste specimen. The analysis results show that the microscopic structures and material characteristics of 20% axially strained cement paste remained same as the unstrained cement paste.

• The Korean Journal of Malacology
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• v.4 no.1
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• pp.42-49
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• 1988

The chromosome of Cipangopaludina chinensis malleata Chunchon area in 1988 was analysed by using aceto-orcein squash techniques of spermatogonial tissues to obtain mitotic and meiotic chromosomes. The chromosome cycle did not differ, in general, from that found in other snails, C. chinensis malleata has 18 diploid chromosomes and they were identified and classified into 2 groups. The mitotic chromosome complement of this species consists of 2 pairs of metacentric and 7 pairs of submetacentric chromosomes, Spermatogonial metaphase chromosomes range in length from 4.10 ${\mu}{\textrm}{m}$ for the largest pair to 2.20 ${\mu}{\textrm}{m}$ for the smallest pair.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.1
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• pp.1-12
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• 2006

The rheological characteristics of an ink relate to its performance on the press and to the printing quality such as ink stability, transfer characteristics, mottle, squash, misting, dot gain, and so on. For lithographic print, the emulsification of ink is an important factor to determine the product. And also the rheological characteristics of the emulsified ink should be investigated. Thus, in this study, the effects of the changing molecular weight of rosin modified phenolic resin on the water-pickup ratio of neat inks were studied. And then rheological properties of neat inks and emulsified inks with changing molecular weight of rosin modified phenolic resin were analyzed by using rotational rheometer.

• The Plant Pathology Journal
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• v.23 no.4
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• pp.233-238
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• 2007

Twenty five isolates of Sclerotinia sclerotiorum were recovered from different infested fields of vegetable along the heavily cultivated crops in Jordan valley. Cellulase and pectinase activities of those isolates were detected using CMC and pectin agar media, respectively. Diameter of the clearing zones on those media represented the level of such enzymatic activities, characteristic of each isolate. The virulence of those isolates was studied using a squash (Cucurbita pipo) cultivar under a greenhouse condition. The significance of correlating the enzymatic activity with the virulence of the isolates was ascertained and discussed.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.08a
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• pp.68-82
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• 1999

CHilling tolereance of plants are closely correlated with the degree of fatty acid unsaturation of membrane lipids. We studied the effects of low-temperature photoinhibition on the photochemical efficiency of photosystem II in terms of fatty acid unsaturation of thylakoid membranes lipids isolated from chilling -sensitive plants and chilling -resistant ones. To directly test the chilling tolerance of photosynthetic machinery in relation to membrane lipids, we further compared wild type tobacco plants with that of transgenic tobacco plants, in which the sensitivity to chilling had been enhanced by genetic modification of fatty acid unsaturation of chloroplast membrane lipids. The transgenic tobacco plants were found to contain reduced levels of unsaturated membrane fatty acids after being transformed with cDNA for glycerol-3-phophate acyltransferase from squash. The functional integrity of photosystem II during and recovery of photosynthesis from low-temperature photoinhibition will be discussed in connection with the degree of fatty acid unsaturation of chlorophast membranes lipids.

• Steel and Composite Structures
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• v.14 no.5
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• pp.473-491
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• 2013

The primary objectives of this paper are to describe the buckling patterns and to determine the squash load of steel plate-concrete (SC) walls. The major variables in this study were the width-thickness (B/t) ratio and yield strength of surface steel plates. Six SC walls were tested, and the results include the maximum strength, buckling pattern of steel plates, strength of headed studs, and behavior of headed studs. Based on the test results, the effects of the B/t ratio on the compressive strength are also discussed. The paper also presents recommended effective length coefficients and discusses the effects of varying the yield strength of the steel plate, and the effects of headed studs on the performance of SC structures based on the test results and analysis.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.10a
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• pp.133-137
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• 2003

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.185-196
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• 2019

Abstract. This research was conducted to figure out the optimal size of the plug cell and seedling raising period in 'Nongwoo' and 'Nonghyeop' cultivars. In the first experiment on effect of plug cell size on growth of squash, seedlings were transplanted into hydroponic cultivation beds at different growing stages: Those in 32-cell trays with 3-4 true leaves at 25 days after sowing, those in 50-cell trays with 2 true leaves at 15 days after sowing, those in 105-cell trays just before a true leaf development, and those in 162-cell trays with only cotyledons at 8 days after sowing. In the second experiment on effect of seedling raising period on growth of squash, it was conducted to have different sowing dates. But the same transplanting date, based on the results of Experiment 1, and compared the differences in growth and fruit productivity as affected by plug cell size in the same way with experiment 1 including the cultivars and environmental conditions. After setting the transplanting date in advance, the number of days for sowing were calculated back for each treatment. In the first experiment, plant height was the greatest in 105-cell trays followed by 162, 50 and 32-cell trays in both cultivars. The best fruit quality was found in different treatments depending on the cultivars, although it was the lowest in 32-cell trays in both cultivars. The fruit quality was not significantly different among those from cell sizes. Therefore, when raising seedlings in 105-cell trays, the period of raising seedlings can be shortened as compared with the conventional 32-cell trays, and this change could reduce the workforce required for growing and transplanting seedlings. In the second experiment, after transplanting, shoot height and leaf width in the first measurement in both cultivars were greater in the 32-cell treatment. However, the last measurement after four weeks showed no significant difference in plant height, but significantly greatest leaf width in the smallest cell treatment, even as compared with that in 32-cell treatment. In case of 'Nongwoo', length and weight of the first harvested fruit showed the highest values in the treatment of 105-cell trays. In case of 'Nonghyeop' the 162-cell treatment along with the 105-cell treatment showed greatest length and weight of the first fruits. From these results, zucchini plug seedlings can be raised in plug trays with reduced cell sizes than the conventional 32-cell trays with improved fruit productivity.