• Research in Plant Disease
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• v.24 no.1
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• pp.75-80
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• 2018

From 2014 to 2016, Fusarium wilt disease was found on fassionfruit in Iksan and Jeju, Korea. Symptoms included wilting of foliage, drying and withering of leaves, and stunting of the plants. The infected plants eventually died during growth. Colonies on potato dextrose agar were pinkish white, and felted with cottony and aerial mycelia with 35 mm after one week. Macroconidia were falcate to almost straight, thin-walled and usually 2-3 septate. Microconidia were usually formed on monophialides of the hyphae and were hyaline, smooth, oval to ellipsoidal, aseptate or medianly 1-septate, very occasionally 2-septate, slightly constricted at the septa, $3-12{\times}2.5-6{\mu}m$. On the basis of the morphological characteristics and phylogenetic analyses of two molecular markers, internal transcribed spacer rDNA and translation elongation factor $1{\alpha}$, the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was proved by artificial inoculation, fulfilling Koch's postulates. To our knowledge, this is the first report on the occurrence of F. oxysporum on fassionfruit in Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.7 no.1
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• pp.55-65
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• 1991

The study was performed to select a adaptable tree species under stressed field conditions where there are a industrial plants operating with a number of smoke stacks emitting pollutants, such as hydrogen fluoride and sulfur dioxide. As a result of the study, a tree species selected are due to construct a forest belt in a zones near industrial plants to reduce the concentrations of air pollutants. The concentrations of atmospheric hydrogen fluoride and sulfur dioxide were very higher at experimental sites near industrial plants (air-pollution sites) than at control site. The leaves of 7 tree species grown at air pollution sites contained more sulfur and, specially, fluorine than at those control site. Among the tested tree species, Ligustrum japonicum Thunb. and Euonymus japonica Thunb. grown at air pollution sites did not at all break out a foliar injury but appeared to be healthy, as well as those grown at control site. Acer pseudo-sieboldianum Kom., Pinus virginiana Mill., Larix leptolepis Gordon., Pinus koraiensis Sieb. et Zucc., Pinus strobus L., Picea abies Karst and Ligustrum obtusifolium Sieb. et Zucc., however, showed a severe fluoride-type foliar injury such as necrosis on tip or margin of leaves, etc. Fluorine found in leaves was proved to be correlated to sulfur found in leaves whereas index of foliar injury hadn't a good correlation to pollutants found in leaves. It appears that Euonymus japonica Thunb., Ligustrum japonica Thunb., Platanus acerifolia Willd, Chamaecyparis pisifera Endl., Populus tomentiglandulosa T. Lee and Sophora japonica L. grown at both experimental sites had a high value of percent survival whereas Pinus virginiana Mill., Pinus koraiensis Sib. et Zucc., Koelreuteria paniculata Laxm. and Alnus hirsuta Rupr. had an extremely low value of that. In comparison with control site, the percent tree height increments in Chamaecyparis pisifera Endl., Ligustrum japonicum Thunb., Quercus acutissima Carruth., Populus tomentiglandulosa T. Lee, Pinus thunbergii Parl and Euonymus japonica Thunb. and the percent upmost root diameters in Populus tomentiglandulosa T. Lee, Chamaecyparis pisifera Endl., Euonymus japonica Thunb., Ligustrum japonicum Thunb., Betula platyphylla var. japonica Hara and Pinus thunbergii Parl. cultivated at air polluted sites showed very high value above 90%, respectively. A significant negative correlation (r=-0.662) was recognized between the index of foliage injury and the percent collective character, which was the mean of tree characters such as percent survival, percent tree height increment and percent upmost root diameter increment which compared to those at air polluted site with those at control site. Based on the percent collective character Ligustrum japonicum Thunb., Euonymus japonica Thunb., Chamaecyparis pisifera Endl., Populus tomentiglandlosa T. Lee, Betula platyphyla var. japonica Hara and Platanus occidentalis L. have large value about 90%, respectively. Therefore, the results indicate that this tree species are adaptable species in air polluted regions. For better understanding of the adaptable tree species, furthur studies concerning the effects of various air pollutants on the tree growth are required.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.251-257
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• 2001

This experiment was conducted to investigate the effect of chitosan on the growth and yield of fall-planted potatoes. The research was carried out in fall-planted potatoes from August 2000 to Aprial 2001 at the height of 250m above sea level in Jeju Island. Soaking for 30 min. of seed potatoes in 200 times diluted solution of 3% liquid chitosan shortened days to emergence by 4 to 6 days. Stem length, number of stems and number of stolons per plant were 56.5 cm, 4.3, and 19.0, respectively, when seed potatoes were soaked for 30 min. in 200 times diluted solution of 3% liquid chitossan. Total potato yield in this treatment reached 2,963 kg per 10a and was significantly greater than in other treatments. Yield of marketable tubers (greater than 30g) per 10a for treatment of seed potatoes soaking in 200 times diluted solution of 3% liquid chitosan and for treatment of foliage spray with 200 times diluted solution of 3% liquid chitosan plus chitosna power (10 kg per 10a) miximg with soil was 2,761 kg and 2,628 kg, respectively. Contents of Mg, Fe and B were the greatest in the treatment of 30 min. soaking of seed potatoes in 200 times diluted solution of 3% liquid chitosanm. The increased contents of these elements are considered to have caused yield increase as a result of increased chlorophyll content for photosynthesis.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.112-117
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• 2013

Phytophthora capsici is one of major limiting factors in production of pepper and other important crops worldwide by causing foliage blight and rot on fruit and root. Increased demand for the replacement of fungicides has led to searching a promising strategy to control the fungal diseases. To meet eco-friendly agriculture practice, we isolated microorganisms and assessed their beneficial effects on plant health and disease control efficacy. A total of 360 bacterial strains were isolated from rhizosphere soil of healthy pepper plants, and categorized to 5 representative isolates based on colony morphology. Among the 5 bacterial strains (GJ-1, GJ-4, GJ-5, GJ-11, GJ-12), three bacterial strains (GJ-1, GJ-11, GJ-12) presented antifungal activity against P. capsici in an fungal inhibition assay. In phosphate solubilization and siderophore production, the strain GJ-1 was more effective than others. The strain GJ-1 was identified as Bacillus sp. using 16S rDNA analysis. Bacillus sp. GJ-1 was also found to be effective in inhibiting other plant pathogenic fungi, including Rhizoctonia solani, Pythium ultimum and Fusarium solani. Therefore, the Bacillus sp. GJ-1 can serve as a biological control agent against fungal plant pathogens.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.229-238
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• 1994

Issues of declining growth and vigor in forests are major concerns in many areas around the world, especially in response to predictions in the 1980s of widespread forest declines. This paper summarizes the current state of knowledge for forests in North America, Europe, and East Asia. Forest declines near point-sources of pollution(such as metal smelters) have been well recognized for a century, but evidence of widespread impacts away from point-sources remains relatively uncommon. In North America, significant forest decline has resulted from high concentrations of ozone near Los Angeles, California, and around Mexico City. Some high-elevation forests of red spruce in the eastern U.S. have declined in the past 20 years ; evidence indicates a role of low-pH fog in reducing they cold-tolerance of spruce. In Europe. most attention has focused on Norway spruce stands that developed yellow foliage, needle loss, and in some cases mortality. This syndrome appears to be related generally to an inadequate supply of magnesium, perhaps coupled with a very high supply of nitrogen. Despite localized areas that show declining trees, overall stand growth and standing biomass in Europe increased from. 1970 to 1990. Much less information is available for East Asia. Many industrialized regions in China have a pH of rain <4.5, and some connections between pollution and forest decline have been suggested. Pollution impacts on forests near cities in Korea include needle chlorosis, reduced needle retention, and declining species diversity. Overall, temperate forests show no widespread declines, and no evidence of substantial effects of pollutants on forest growth or vigor. Small areas showing declining forests may indeed demonstrate pollution impacts, and may provide cause for concerns about future impacts on larger areas.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.50-54
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• 2006

Biomass expansion factors and stem density values were commonly used in converting stand volumes into total carbon stocks for the purpose of national inventories of greenhouse gas emissions and carbon sequestration. The objective of this study was to examine the influence of stand age classes on aboveground and total biomass expansion factors, and stem density values in Chamaecyparis obtusa species. A total of 25 representative sample trees based on the three different stand age classes were destructively sampled to measure green weights and dry weights of the major four(root, stem, branch and foliage) portions of C. obtusa species grown in Jangseung-gun of southern Korea. According to the results of this study, as stand age classes increase, total biomass expansion factors tended to be decreased with the ranges from 3.64 to 1.44, while the stem density values tended to be slightly increased with the ranges from $0.35(g/cm^3)$ to $0.44(g/cm^3)$. There were statistically significant differences in biomass expansion factors and stem density values between stand age classes, but became nearly constant after 30 years old for C. obtusa species. This information could be very useful to improve a national-scaled inventory of greenhouse gas emissions and carbon sequestration for the C. obtusa species by applying different biomass expansion factors and stem density values.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.619-628
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• 1995

Crude aqueous extracts from dried leaves, stems, roots, and flowers from both field grown and greenhouse grown alfalfa plants inhibited alfalfa seed germination and seedling growth. The degree of inhibition was greater in the field grown plant extracts. Flowers extract of field grown plant most inhibited alfalfa germination and seedling growth. In the concentration study, the highest concentration of extract (9.0%, w/v) significantly inhibited total alfalfa seed germination by 50% as compared to control. In partitioning study using pot hydroponic culture of plant biomass into leaves, stems, root, LAR products of LWR and SLA exhibited significant variation among four species. This result support that the inhibitory effect of autotoxic substances presenting in alfalfa tissue may be possible interference with the patitioning of biomass into leaf component relative to the total biomass produced by the alfalfa plant. Toxicity of extract was not reduced by adding activated charcoal, Dowex-50W, amberlite to the extract. Toxic substances existing in most plant tissues but mainly above ground foliage are water soluble and stable and may persist in old alfalfa fields. Thus, it is recommended to remove as much as possible of the above growth parts, especially vegetative stage, before one tries to re-establish alfalfa in former field of alfalfa.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.148-152
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• 1999

This study was carried out to develop new cultivars of Z. serrata showing yellow fall leaf. Z. serrata which had yellow fall leaves were selected and then examined for contents of leaf anthocyanin and chlorophyll. In addition, for the progeny test, selected trees were grafted. Of 21 trees having yellow autumn leaves, three individuals, 'S-4', 'S-14', and 'J-32' were finally selected. They contained high level of anthocyanin with higher level in the leaves. Once developed, the yellow color remained till late autumn. Grafted plants of the selected strains showed high grafting efficiency and vigorous growth. Yellow foliage color were found to be maintained in the grafted trees. The tree 'S-4' was 7 m tall and 6 m in crown width, whereas 'S-14' and 'J-32' were 6 m tall and 4m in crown width. The soil pH of the survey sites ranged from 5.9 to 7.24. However, other soil characteristics did not show much difference among the sites with regard to inorganic nutrients including $N,\;P_2O_5,\,CEC,\,K^+,\,Ca^{2+}$, and $Mg.^{2+}$ 'S-4', 'S-14', and 'J-32' clonal lines developing yellow fall leaf were selected as new cultivars and propagated by grafting.

• Korean journal of applied entomology
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• v.7
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• pp.39-51
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• 1969

The study involved determination of resistance levels of spider mites ta argano-phosphates using topical application and slide dip techniques; laboratory serening tests of alternative acaricides using an O/P resistant strain and a field trial of the screened materials. 1. Strains of Tetranychus were from Timaru(TR), Havelock Narth (HNR), Lincaln (LN). Germany (GR, GN). Comparisons of the resistant strains and normal strains at the LD50 and LC50 levels were as follows : (a) Using the topical application tochnique; with Parathian. resistant levels of the GR. TR and HNR strains of T. urticae were respeativuly, 1035. 484 and 452 times as resistant' as the LN strain. (b) Using the slide dip technique; with Phosdrin, resistant of GR, TR and HNR strains of T. urticae were 635, 274 and 266 times greater respeativuly, than the GN strain. 2. The laboratory sereaning tests were carried out far their contact plus stomach and residual effect to assess the toxicities of eleven alternative materials which would be used far control of O/P resistant strain of T. urticae. The acaricide groups represented were 3 organo-chlorines (Spidex, Kelthane and C 8514), 2 nitrophenyls (UC 19786 and Morocide), 2 cyclic carbonates(Eradex and Morestan). I carbamate (UC2004 7A), 1 mixture of carbamate and orano-chlorine and 2 other chemicals (C 8677 and M2527). From all acaricide tested. Kelthane and Morocide were the most effective, folowed by Spidex and M2527. Morestan, C8514. C8677 and RS 143 were intermediate, but Eradex, UC 19786 and UC 20046A were poor. 3, The number of sapmles required for estimation of the population in the field evaluation of acaricidal effects was one giving the highest practical precision. It was decided, after preliminary sampling trials. to use samples of 30 leaves per replicate which gave a $5.7\%$ standard error. 4. In the field trials, Morocide applied at the $0.05\%\;and\; 0.04\%$ a. i. conc. to black currant trees gave excellent control of O/P resistant population of T. urticae for about 12 days, but Morocide 0.025 and Kel thane $0.02\%$ a. i. cone. gave efficient control for about 6 days. In other words. first applications of Kel thane ane Moroeide gave very high degrees of control of O/P resistant population of the two-spotted spider mite. However, the results indicate that secondary application would sometimes be necessary. There was no foliage damage of black Currants and strawberries by either acaricides at the concentrations used. Acknowledgment ... The authors are grateful to: Dr. R. P. pottinger, Senior Lecturer in Agricultural Zoology. Lincoln college. New Zealand. for his helpful assistance in aiding with the organization of thd field work. Department of agriculture officers for mite colonies. Mr. D. A. Slade, Technical Advisor. Fruitgrowers' Federation (now at Massey University) for his assistance and provision of mites for testing. Mr T. McRae of Timaru for permission to use his crops for field tests. The following chemical companies and I or their New Zealand agents for so readily supplying samples of acarides; Ivan Watkins-Dow Limited. Fruitgrowers Chemical Company Limited. Henry H. York & company (New Zealand). Shell Oil (New Zealand) Limited.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.1-5
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• 2007

The Precesses for leaf development in dicotyledonous plants are surprisingly complex, while the mechanism of controlling and coordinating them is poorly understood. To characterize the fundamental features of the leaf development of Arabidopsis, we first attempted to isolate mutants that alter leaf morphology. Here, leaf morphological mutant of Arabidopsis, lanceolatal (lan1) which has small and narrow leaves have isolated and characterized. To clarify the function of LAN1 in organ development, we characterized lan1-7 mutant using an anatomical and genetic approach. The lan1-7 mutant had reduced size of foliage leaves and reduced dimensions of stems. A reduction both in cell size and in cell number was evident at the cellular level in the lan1 mutant, revealing that LAN1 gene appears to affect cell division at an earlier stage and cell elongation throughout the development of leaf primordia. from the analysis of heterogeneous plant with lan1 mutation and 35S-AG transgenic plant, AG gene is revealed to regulate leaf morphology under the control of 35S promoter. Thus, MADS-box gene was revealed to have some relationship to that of LAN1 gene at certain stage in leaf development processes.