• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.588-592
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• 2012

To examine the reason of empty samara production of Chinese elm, Ulmus parviflora, twenty two planted trees in Wonju-si were monitered for three years in terms of their flowering, pollinatiom system and samara characteristics. Inflorescences with bisexual flowers of Chinese elm are developed in the leaf axils on the twigs. Dichogamous flowers are varied with protogynuous and protandrous flower, and stamens in some bisexual flowers are developed in seperated time on a inflorescence or a tree. It is revealed newly that the flower of Chinese elm is out-crossed and partially insect(Apis mellifera) pollinated. The ratios of sound samara are significantly differed among years, the heighest values 65.5% were shown in 2009, lowered 42.9% in 2010, and the lowest 37.5% in 2011. This result might be affected by mean daily precipitation and number of rainy days during the flowering date, and lower temperature during the floral initiation stage, especially in 2011. These findings suggest that Chinese elm has self-incompatibility strategy and much pollination failure resulted in a production of much empty samaras. Further researches on the empty-seed production strategies and pollination system of major tree species might be needed.

• Korean Journal of Breeding Science
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• v.43 no.1
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• pp.50-55
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• 2011

The introduction of doubled haploid (DH) approach into breeding programs has reduced the times and population sizes required for the production of pure lines. We carried out the experiment for development on effective method of producing haploid in wheat. Emasculated spikelets of wheat were pollinated with maize pollen and cultured in the solution containing 40 g/L sucrose and 2,4-D, NAA, 2,4,5-T and dicamba 24 h after pollination, and then incubated until embryo rescue. Fourteen to sixteen days after pollination, the embryos are excised and cultured in half-strength MS basal medium supplemented with 20 g/L sucrose and 1 mg/L NAA. The type of plant growth regulators was found to be most significant in production of haploid plants. The application of synthetic auxins to pollinated florets, stimulates haploid embryo development to a stage where the embryos can be rescued onto nutrient media. The percentage of seeded florets was significantly affected by 100 mg/L 2,4-D, 150 mg/L 2,4,5-T and 50 mg/L dicamba. The percentage of embryos formed was significantly increased by treatment with 2,4-D and 2,4,5-T at 100 mg/L, and dicamba at 50 mg/L, but the treatments with 150 mg/L 2,4-D inhibited embryo development and plant regeneration. The optimum application time of plant growth regulators was 24 hrs after pollination.

• Journal of Apiculture
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• v.34 no.3
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• pp.197-206
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• 2019

Pollination is an important ecosystem service involved in plant breeding and reproduction. This study analyzed the pollination network, which is the interaction between flowering plants and flower-visiting insects in the agricultural landscape. Flower-visiting insects from blossoms of flowering crops and surrounding plants were quantitatively surveyed during summer time. The pollinator species and abundance on each flowering plant were analyzed. A total of 2,381 interactions were indentified with 154 pollinators on 30 species of plants. Species richness of the pollinators was highest in Coleoptera (34%) followed by Hymenoptera (28%), Diptera (28%) and Lepidoptera (10%). Apis mellifera dominated (50%) followed by Calliphora vomitoria (5.3%) and Xylocopa appendiculata among pollinators, and remaining wild pollinators provided complex interaction. Among plants, Platycodon grandiflorum, Perilla frutescen and Fagopyrum esculentum harbored most pollinators and showed highest interaction frequencies. In the modular analysis, Apis mellifera was located as a hub-species which connect the interaction of others, implying most important role in the network. This results provide the basic information on the pollinator species associated with each crop and pollinator habitat in which plant provide the nectar, pollen and habitat resources for wild pollinators.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.145-154
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• 2021

Integrated pest management system in Korean apple has significantly advanced for last few decades. However harmful effects of pesticides threats the ecosystem services of natural enemies and pollinators. Apple require cross-pollination and Insect pollination with diversity and abundance is one of the keys to profitable apple production in quantity and quality as well. Thus crop protection tools are to be administered in harmony to meet the pest suppression and protection of beneficial organisms such as natural enemies and pollinators. Adding onto the established IPM system, integrated pollinator-pest management (IPPM) concept is proposed as the future direction of apple IPM. For this, ecological enginnering of creating habitats for pollinators, landscape management and agroecosytem diversification as well as selective soft pesticide uses on time guided by pest monitoring and phenologyand targeted delivery are further proposed. Recent shift of agroecosystem from climate change and new pest outbreaks require new paradigm of pest management for sustainable agricultural production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.193-197
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• 1994

This study was conducted to investigate optimal time for dissecting out embryos, effect of embryo size on plant generation, and kinds of media and environment in order to establish an effective bulbosum method. The optimum time for dissecting out the embryos for culture was found to be 17 days after pollination, when the size of embryos ranged from 0.8 to 1.0mm in length. Culture of embryos on B5 medium under continuous radiation was considered to be an efficient practice for production of barley hybrids. Haploid embryos, when compared to their counterpart diploid ones, were slower and fewer in plant development in culture.

• Structural Engineering and Mechanics
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• v.75 no.2
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• pp.175-191
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• 2020

In this study, multi-story structures are actively controlled using metaheuristic algorithms. The soil conditions such as dense, normal and soft soil are considered under near-fault ground motions consisting of two types of impulsive motions called directivity effect (fault normal component) and the flint step (fault parallel component). In the active tendon-controlled structure, Proportional-Integral-Derivative (PID) type controller optimized by the proposed algorithms was used to achieve a control signal and to produce a corresponding control force. As the novelty of the study, the parameters of PID controller were determined by different metaheuristic algorithms to find the best one for seismic structures. These algorithms are flower pollination algorithm (FPA), teaching learning based optimization (TLBO) and Jaya Algorithm (JA). Furthermore, since the influence of time delay on the structural responses is an important issue for active control systems, it should be considered in the optimization process and time domain analyses. The proposed method was applied for a 15-story structural model and the feasible results were found by limiting the maximum control force for the near-fault records defined in FEMA P-695. Finally, it was determined that the active control using metaheuristic algorithms optimally reduced the structural responses and can be applied for the buildings with the soil-structure interaction (SSI).

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.495-498
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• 2008

A new spray chrysanthemum cultivar, 'Golden Festival' was released by National Horticultural Research Institute (NHRI), Rural Development Administration (RDA), Korea in 2007. It was selected from the progenies of open-pollination of 'Torbay' in 2002. Trials were conducted from 2005 to 2007 for evaluation and selection of this cultivar, including shading culture in summer and retarding culture in autumn. The natural flowering time of 'Golden Festival' is late October, but year-round flowering is possible by shading and lighting treatment. The cultivar is semi-double type flowers with bright yellow petals and green flower center. Flower neck and stem are very hardy. The diameter of flower is 56.5 mm. The number of flowers per stem and petals per flower are 12.0 and 93.5, respectively. The days to flowering under the short day treatment is about 50 in spring season.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.37-37
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• 2018

We use two different methods for laboratory propagation from seed of lady's slipper orchid(Cypripedium macranthos Sw.); immature seed which also called green capsule or fully mature seed about 120~130 days from pollination. In green capsule culture, the seed pods should be collected within precisely right time. The right time of seed collection could be diverse under the wether conditions or nutritional factors of the plants. In fully matured seed culture, the more complicated procedures are needed to break the dormancy of the seed; thermal or chemical treatment. The seedlings in this study were easily germinated from immature seeds in Harvais medium; 53 days after pollination(DAP) in Cypripedium pubescens, DAP 65 in C. parviflorum and C. macranthos. The germinated seedlings were transplanted to hormone free media immediately to avoid abnormal growth of seedlings. When the seedlings have roots with a minimum length of around 2-3cm and have visible dormant buds, the seedlings were removed from the flask and stored in refrigerator for vernalization. To examine the correlation of seedlings and maternal plants, the 125 seedlings of C. macranthos were transplanted in the soil bed at a distance of 20-100 cm from mother plants on April 20. The survival rate of seedlings were 92% in 20 cm distance from the ripe plants, and 56 % in 100 cm distance. The seedlings which were transplanted near mother plants showed vigorous growth in plant height, leaf width, and especially dormant buds. Considering the existence of mycorrhiza which is a symbiotic association between a fungus and the roots of a orchid vascular, the various fungus from mother plants could affect the growth of the seedlings. These results indicate the possibility of high and stable production and practical industrialization of endangered lady's slipper orchids.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.50-56
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• 1964

1. Five varieties of kenaf, Hibiscus cannabinus L., were used for study the influence of various patterns on flowering and fertilization. e statistical analysis on the percentage of flowering in given time gave highly significant different patterns among five varieties examined. Korean local kenaf was flowered very early, whereas Everglades 71 flowered very late. Both Guatemala 38F and Guatemala 2A introducedf rom Guatemala were flowered intermediately to compare with Korean local and American varieties. 3. The data indicate that low temperature was given delayed flowering time which means the flowering time was closely related with temperature having the flowering time was accelerated more or less early by high temperature. 4. It was shown that the fertilization after pollination was needed for five to six hours. 6. It was examined that the adequate crossing time between different varieties on the kenaf was the time of heavy flowering.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.48-53
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• 2000

This study was carried out to investigate the growth characteristics and propagation methods of Prunus species as woody landscape plants. Both the flowering time and the survival rate of grafting were investigated. The results are obtained as follows: The total of flowering period of Prunus species in Kyonggi province area lasted for about 26 days. The flowering time of the species overlaps. These observations suggest that the possibility of interspecific pollination among Prunus species is very high in the kyonggi province area. The total number of flowers in the species in area was in as follows decreasing order : (1) Prunus yedoensis >Prunus pendula var. ascendens > Prunus subhitella > Prunus sesrulata for. fugenzo > Prunus leveillenana var. pendula. The number of carpels in each flower ranged from 0.3 for Prunus subhirtella to 1.8 for Prunus serulata for. fugenzo. In the caseof Prunus sesrulata for. fugenzo, the carpels appeared to be degenerated and thus losted their function. However, there exist two tyoes of Prunus subhirtella. While one type had normal carpel, the other had the degenerated one. The survival rate of grafting was investigated on May 19. Eighty there percent of the plants survived when the grafting was made in the greenhouse in January whereas the plants grafted in nursery in March survived less in that Prunus suhirtella showed 64%, Prunus leveilleana var. pendula 47%, Prunus sesrulata for. fugenzo 43%, Prunus yedoensis 62% and Prunus pendula var. ascendens 24%, respectively. Therefore, it suggested that high humidity and optimal temperature appeared to incase the survival rate of the grated plants. We therefore propose here that grafting should be done in the greenhouse that both humidity and temperature could be controlled to enhance the efficiency of grafting. This will enable as to perform grafting in winter as well.