• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.345-352
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• 1998

A Korean endemic and evergreen small tree ' Dendropanax morbifera $L_{EV}$.(Araliaceae)' is a component of evergreen forest and mainly idstributein sourthern region and islands in Korea. A local population of D. morbifera which is located between evergreen and deciduous forest within 50m x 50m quadrate was investigated to ascertain the change of population structure, emergence and growth dynamics of seedlings and saplings, and pattern of spatial distribution by the temproal and spatial expansion of population . The result of analysis of population structure by Importnace Value(IV), evergreen forest showed a high species diversity of evergreen tree species such as Cinnamomum japonicum, Machilus japonica, Neolitsea serica, Daphniphyllum macropodum, Ligustrum japonicum, and etc, in middle and under story than in upper story where Camelia japonica and Quercus acuta were dominant. And in conterminous deciduous fores, the major component of evergreen forest in this region, Camellia japonica, Quercus acuta, evergreen tree of Lauraceae and etc. were abundant in only under story. IV of D. morbifera differed from among three story. In comparative analysis of emergence and growth dynamics of D. morbifera seedlings and saplings between evergreen and deciduous forest, emergece and density of seedlings were significantly greater in evergreen than in deciduous forest, and growth of height and basal diameter of seedlings and saplings were slightly larger in evergreen than in deciduous forest. The spatial distribution patterns by Moristia's index mapping of indivuduals using a lattice method of XY axis within this population showed that seedlings(age up to 2 years) and saplings (age>2 years and height<1m) both evergreen and deciduous forest were more or less aggregated apart from mature trees, and thougth intermediate trees(height>1m and dbh<10cm) had a aggregated distribution pattern, mature trees(dbh>10cm were uniform. In conclusion , the expansion of D. morbfera population from evergreen to deciduous forest accompanied with a mumber of evergreen woody species, and also, emergence and recruitment, and growth of seedlings were greatly influenced moisture and canopy by around community structure.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.54-61
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• 2021

This work describe an efficient method for the shoot induction and plant regeneration of seedling-derived apical bud explants of Tilia mandshurica Rupr. & Maxim. The highest rate of shoot induction (82.2%) was obtained when apical bud explants from juvenile seedlings (5 months old) were cultured on Murashige and Skoog (MS) medium containing 1.0 mg/L 6-benzylaminopurine (BAP). However, apical bud explants obtained from mature trees (12 years old) did not produce any shoots, even with BAP supplementation. Among the three cytokinins tested for shoot multiplication (BAP, zeatin, and kinetin), BAP was the most effective; the highest number of shoots per explant (2.1) was observed on MS medium supplemented with 1.0 mg/L BAP. In contrast, the longest average shoot length (3.0 cm) was observed after growth on MS medium with 2.0 mg/L zeatin. No multiplication occurred when apical bud explants were cultured with kinetin-supplemented media. During rooting of in vitro-elongated shoots, the highest rooting rate (100%) was observed in half-strength MS medium supplemented with 0.5 ~ 1.0 mg/L indole-3-butyric acid (IBA) or 3.0 mg/L 1-naphthaleneacetic acid (NAA). During the acclimatization process, plantlets that were rooted on the IBA (0.5 mg/L)-supplemented medium had the highest survival rate (100%) and maximum root length (18.5 cm). These findings suggest that a low concentration (0.5 mg/L) of IBA is appropriate for the rooting and acclimatization of T. mandshurica. Plants were successfully transferred to the greenhouse with a 100% survival rate. This protocol will be useful for the large-scale propagation of Tilia species.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.167-167
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• 2022

Seed production of italian ryegrass has a problem of lodging during ripening and a decrease in quality due to difficulty in drying seeds during harvest. Therefore, in order to produce high-quality Italian ryegrass in paddy fields, it was carried out to reduce the density and solve the lodging problem through transplanting. In this experiment, Lolium multiflorum cv. Kowinearly was transplanted in autumn from a paddy field in Sindong-ri, Gwansan-eup, Jangheung-gun, Jeollanam-do. var. Kowinearly was made into a bed at 90 g/box and stacked in boxes. It was transplanted on October 27th after 2 days of germination at 30℃ and 15 days of seedling and greening. When transplanting, they were transplanted at intervals of 30×14cm. The existing cultivation method, drill seedling, was sowed at a level of 50 kg/ha, and both transplanting and drilling were carried out at a nitrogen fertilization rate of 45 kg/ha. The number of ears during transplant cultivation was 1,016/m² and the drilling tended to be higher at 2,278/m², but this was probably due to the difference in seeding amount. The seed number of an ear tended to be 56% higher in transplantation, which had a significant impact on yield. The seed yield was 2,096 ka/ha in transplantation, which was 21% higher than that of drilling. When looking at the relationship with weed occurrence, there were areas where all the weeds, such as amul foxtail, occurred due to the low density. Even in the same transplanting area, the seed yield was about 1,000kg/ha less in the area where the weeds were abundant. It seems that weed management is important in paddy cultivation. Therefore, it seems necessary to develop an exclusive herbicide for Italian ryegrass cultivation.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.197-205
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• 2015

This study was performed to identify the effect of fertilizer application and planting method on growth and yield of 'Seolhyang' strawberry during seedling raising. According to the concentration of fertilizer applied, the height of daughter plants was the highest at an EC of $0.8dS{\cdot}m^{-1}$. Leaf number and crown diameter were greatest at an EC of $0.6-0.8dS{\cdot}m^{-1}$. In the first measurement, root number was highest in non-fertilizer application, while root weight was heaviest in non-fertilizer application and EC $0.4dS{\cdot}m^{-1}$. The higher the concentration of fertilizer applied as culture media, the lower the growth rate. Thirty days after planting on the main field, plant height and number of new leaf were highest at an EC of $0.8dS{\cdot}m^{-1}$. However, no significant difference was found in leaf length and width and chlorophyll content according to fertilizer application. Marketable yield of 25 g or higher was greatest in EC $0.6dS{\cdot}m^{-1}$. In contrast, no significance was found in total marketable yield at an EC of $0.4-0.8dS{\cdot}m^{-1}$. Aconsistent pattern was exhibited in the growth of 1-5 harvesting flower clusters according to planting method. The length of leaf and flower cluster was short and chlorophyll content was low, when bed soil was removed 100% in harvesting of the first flower cluster. In all treatment, leaf length was shortened until harvesting of the second and third flower cluster, but rapidly lengthened in harvesting of the third and fourth flower clusters. Moreover, the length of flower cluster had a increasing tendency from harvesting of the third flower cluster. However, chlorophyll content was reduced continuously until harvesting of the fifth flower cluster, and was lowest in harvesting of the fourth flower cluster without removal of bed soil. Total yield was greatest in treatment of crown removal in bed soil between November and May. Late marketable yield between March and May was highest in treatment of 100% bed soil removal, followed by treatment of crown removal. Marketable yield of 25 g or higher was greatest in treatment of crown removal between December and February, while greatest in treatment of 100% bed soil removal between March and May.

• Research in Plant Disease
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• v.20 no.4
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• pp.245-252
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• 2014

The study was performed to establish an efficient screening method for resistant cucumber to Fusarium oxysporum f. sp. cucumerinum. The isolate KR5 was identified as F. oxysporum f. sp. cucumerinum based on molecular analyses of ITS and TEF genes and host-specificity test on cucurbits including melon, oriental melon, cucumber, and watermelon. Then four cucumber and two rootstock cultivars showing different resistance degrees to the Fusarium wilt pathogen KR5 were selected. And development of Fusarium wilt of the six cultivars according to several conditions, including incubation temperature after inoculation, inoculum concentration, root wounding, and growth stages of seedlings, was investigated. Disease severity of Fusarium wilt on the resistant cultivars was changed with incubation temperatures after inoculation. The resistant cultivars showed the higher resistance when inoculated plants were kept at 25 or $30^{\circ}C$ than at $20^{\circ}C$. Among four different growth stages of the seedlings, seven-day-old seedling represented the most difference of resistance and susceptibility to Fusarium wilt. From above results, we suggest that an efficient screening method for resistant cucumber to F. oxysporum f. sp. cucumerinum is to dip the non-cut roots of seven-day-old seedlings in spore suspension of $1.0{\times}10^6-1.0{\times}10^7$ conidia/ml and to transplant the seedling into a non-infected soil, and then to incubate the inoculated plants in a growth room at $25^{\circ}C$ for 3 weeks to develop Fusarium wilt.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.313-319
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• 2012

Mass production method on artificial seedling production of hard clam Meretrix petechialis was developed indoor culture system. Spawning of adult clam (SL $65.8{\pm}8.4mm$) was induced using the combined method of air exposure and water temperature raising. The fertilized eggs were developed to D-shaped larvae after 17.7 hours at $27^{\circ}C$ and hatching rate was 6.1%. Shell length (SL) of D-shaped larvae was measured to be $131.4{\pm}2.6{\mu}m$ and thereafter the larvae grew to the settled spats with SL $190.2{\pm}7.5{\mu}m$ in 4 days. Estimated survival rate of settled spats was 48.1%. Spat collection on 130,000 spats with SL $0.19{\pm}0.01mm$ performed conducted by sand bottom circulation filtering method. Collected spats grew up to $3.1{\pm}0.8mm$ in 46 days, $6.6{\pm}1.8mm$ in 87 days, and $10.5{\pm}0.9mm$ in 114 days. The relative growth between SL and shell height (SH) was calculated to be SH = 0.8501SL + 0.0196 ($R^2=0.9987$) during the whole spat period. During spats rearing, they were suffered from one time of mass mortality at SL 3.1 mm, but 51,000 spats were finally survived with the rate of 39.2% at 114 days of spat rearing in indoor tank system.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.200-205
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• 2016

This study was conducted in order to investigate the effects that the difference of planting time by a method of cultivation in the non-heated greenhouse and the open field with spring planting had on growth and yield. With regard to the tested variety of Momordica charantia, variety 'Dragon' (Japan Yae 農藝) was selected. And 3 treatments on March 20, April 5 and April 20 for the greenhouse cultivation and 3 treatments on April 20, May 5 and May 20 for the open-field cultivation 1 month later than those for the greenhouse cultivation were planted by the randomized complete block design, and 4 secondary vines were trained. In the results of examining 15-day average atmospheric temperature after planting according to the methods of greenhouse and open-field cultivation and planting time, it was shown that there was a tendency for atmospheric temperature inside the greenhouse to decrease as the planting time was moved up. In particular, the average atmospheric temperature was $16.7^{\circ}C$ when seedling was planted on April 20 in the open-field cultivation, which was approximately equal to $17.0^{\circ}C$ of the average atmospheric temperature when a seedling was planted on March 20 in the greenhouse cultivation. With regard to the date of first harvest by the method of cultivation, it was shown that there was a tendency for the date of first harvest to be earlier in the greenhouse cultivation than in the open-field cultivation, and the date of first harvest was moved up as a seedling was planted earlier for the planting period. The number and weight of harvested fruits per plant showed a tendency which was almost similar to that of total number of harvest days and number of harvests. Thus, the number of fruits was 189 and the weight of fruits was 31,649g in case of the greenhouse cultivation and planting on March 20, which were maximum. In case of planting on the latest planting date : May 20 in the open-field cultivation, the number of fruits was 77 and the weight of fruits was 12,502g, which were at a level of 40% of those of planting on March 20 in the greenhouse cultivation 2 months earlier. The total yield per 10a was 10,228kg in the greenhouse cultivation and was 2.2 times as heavy as 4,607kg in the open-field cultivation with regard to the method of cultivation. For the planting period in the greenhouse cultivation, it was 10,539kg and 10,517kg in planting on March 20 and April 5, which was higher by 9% than 9,629kg in planting on April 20. And in the open-field cultivation, it was 4,785kg in planting on April 20 and 4,872kg in planting on May 5, which was higher by 15~17% than 4,163kg in planting on May 20. Taking the above results into account, it is considered proper to plant Momordica charantia from March 20 to April 5 for the greenhouse cultivation and from April 20 to May 5 or thereabouts when a risk of late frost is gone for the open-field cultivation in southern area.

• Korean Journal of Plant Resources
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• v.9 no.2
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• pp.113-119
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• 1996

This study inverstigates growing seedling of onion for 91 farmhouses at Muan, Hampyeong and Sinan which are major areas of production from Jan. to Apr., 1994 to enhance the research effect of onion and then the following results are obtained. Over 60% of the farmhouses have cultured onion continuously over 11years. Early mature variety cultured is over 9 varieties and among them Kinkyu variety is cultured most frequently. Late mature variety is over 13 and Changyongdaego, Bonganwhang and Chunjudaego varieties are cultured most. Most of the farmhouses used seeds less than 6 dl at small area less than $40m^2$ and especially in the case of early variety ,they purchased it at seed stores with 15,000-20,000 won/dl and sowed them with broadcasting method. Amount of fertilizer level of onion seed is ranged from nonfertilizer level to $16.8g/m^ and most of the farmhouses employ molding after seeding with straw and compost and they did not use thinning. Irrigation is performed by 1-4 times before sprouting of onion seed and most of the farmhouses transplant long nursery plant over 46 days hand weeding is used.

• Journal of Plant Biology
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• v.13 no.1
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• pp.1-12
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• 1970

The Nongkwang variety was sown directly in the field by the three methods of dibbling, drill seeding and broad-casting in non-, low- and high-salty areas, and compared with the growth of transplanted rice in each areas. The yield of rough rice was increased remarkably by direct sowing when compared with that produced by transplanting inboth salty areas, but in non-salty area, the former was decreased significantly. There was no significant difference in the yields of rough rice resulting from three seedling methods of direct sowing in each area. The direct sowing method was predominated in number of panicle, weight of panicle, ratio of matured grains, milling recovery percentage, and straw weight in both salty areas, and dicreased in panicle weight and ratio of matured grain in nonsalty area.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.256-257
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• 2006