• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.51-61
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• 1979

The chromosome behavior and it's synapsis in the meiosis of pollen mother cell were studied on Populus alba L. as a female parent tree, Populus glandulosa Uyeki as a male parent tree and their hybrid, Populus alba x glandulosa. 1. At metaphase I, the number of nuclear plates with early separation chromosome were observed with the lowest proportion of 11.0% in Populus glandulosa and with the highest proportion of 13.0% in Populus alba${\times}$glandulosa. 2. At metaphase II, early separation chromosomes appeared with the frequency of 11.0% in Populus alba${\times}$glandulosa. But the frequency was not different with those of the parental trees. 3. At anaphase I, lagging chromosomes appeared with some high rate of 11.6% in Populus alba${\times}$glandulosa and yet the number of chromosome bridges in populus alba x glandulosa almost were not different with the partental trees. 4. At anaphase II, lagging chromosomes appeared with some high frequency of 10.2% in Populus alba${\times}$glandulosa and the chromosome bridges in Populus glandulosa appeared with the highest frequency in all studied trees. 5. The frequency of abnormal pollen sporad was the highest value of 8.2% in Populus alba${\times}$glandulosa among the studied trees. With the results, it might be assured that the chromosome segregation and it's synapsis behaved normally in Populus alba, Populus glandulosa and Populus alba x glandulosa, and so all the studied trees could produced normal pollens.

• Polymer(Korea)
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• v.30 no.6
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• pp.512-518
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• 2006

A biodegradable polymer poly((R) -3-hydroxybutyric acid) (PHB) was conjugated with a hydrophilic polymer poly(ethylene glycol) (PEG) by the ttansesterification reaction to form the amphiphilic block copolymer. PHB with low molecular weight ($3000{\sim}30000$) was appropriated for the drug delivery materials. High molecular weight PHB was hydrolyzed by an acid-catalyst to produce the low molecular weight one. Amphiphilic block copolymer was formed the self-assembled polymeric micelle system in the aqueous solution that the hydrophillic PEG was wraped the hydrophobic PHB. Generally, polymeric micelle forms the small particle between $10{\sim}200nm$. These polymeric micelle systems have been widely used for the drug delivery systems because they were biodegradable, biocompatible, non-toxic and patient compliant. The hydroxyl group of PEG was substituted with carboxyl group which has the reactivity to the ester group of PHB. Amphiphilic block copolymer was conjugated between PHB, and modified PEG at $176^{\circ}C$ which was higher than the melting point of PHB. Transesterification reaction was verified with DSC, FTIR, $^1H-NMR$. In the aqueous solution, critical micelle concentration (CMC) of the mPEG-co-PHB copolymer measured by the fluororescence scanning spectrometer was $5{\times}10^{-5}g/L$. The shape and size of the nanoparticle was taken by dynamic light scattering and atomic force microscopy. The size of the nanoparticle was about 130 nm and the shape was spherical. Our polymeric micelle system can be used as the passive targeting drug delivery system.

• Korean Journal of Agricultural Science
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• v.28 no.1
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• pp.1-7
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• 2001

In this study we evaluated genetic divergence among six Tongil-type rice varieties and assessed the relationship between genetic distance and hybrid performance in all possible non-reciprocal crosses between them. The 15 F1 hybrids along with the six parents were evaluated for eight traits of agronomic importance including yield in a replicated field trial. The six parents were examined for DNA polymorphism using 120 random decamer oligonucleotide primers. A total of 168 polymorphic variants were generated and based on the polymorphism data, genetic distances (GDs) ranged from 0.157 to 0.383. Heterosis was observed in hybrids for most of the traits, and yield exhibited the highest heterosis among the eight traits examined. The correlation values of GDs with F1 performance were not significant. Also the correlations of GDs with midparent and better-parent heterosis were not significant except for spikelets per panicle. Our results have indicated that GDs based on the RAPDs markers may not be useful for predicting heterotic combinations in Tongil-type rice and are supportive of the idea that the level of correlations between hybrid performance and genetic divergence is dependent on the germlplasm employed.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.712-721
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• 2015

To improve the breeding efficiency of oriental pear, heritability, correlation and frequency distribution of fruit ripening date were analyzed using 4,035 seedlings obtained from 15 families between 13 parental cultivars. Although variation of fruit ripening time was higher in most early-ripening parental cultivars than in late-ripening parental cultivars, according to analysis of average, standard deviation, and coefficient of ripening variation for ten years, fruit ripening time obtained from all parental cultivars was inherited narrower and more stable variation than others fruit trait, with 0.92-3.41 in coefficient of variation. The heritability of fruit ripening time was calculated to be over 0.8 in almost all crosses and average fruit ripening time of seedlings from cross combinations could be predicted based on that of the parental cultivars due to its superior heritability relative to other fruit traits. The average ripening time was earlier than the mid-parental value in families obtained from cross combinations using at least one late-ripening cultivar as parent, indicating that the early-ripening trait was more likely to be dominant compared to the late-ripening trait. By contrast, average ripening time was clustered in families of crosses not only between mid-season and early-season cultivars, but also between mid-season and mid-season cultivars. There was highly significant relationship (at 0.68) between mid-parental and progeny mean fruit ripening time. The correlation between fruit ripening time and fruit weight was also highly positive and thus, the mid-parental fruit ripening time could be a potent criterion for indirect selection of fruit weight.

• Journal of Plant Biology
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• v.7 no.2
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• pp.14-16
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• 1964

The origin of cultivated Prunus yedoensis Matsumura has been controvertial among botanists. This plant has been reported grown wild in Mt. Hanla. During the crossing experiment on the P. yedoensis and its putative parent performed from April 7 to 19 in Mt. Hanla, the writer studied morphological and physiological characteristics of various species of Prunus and assumed that the wild P. yedoensis may be a hybrid between P. subhirtella var. pendula form. ascendens and P. donarium.

• Polymer Science and Technology
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• v.1 no.1
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• pp.16-29
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• 1990

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.801-807
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• 1994

Lactose substituted styrene monomer, N-(p-vinylbenzyl)-D-lactonamide(VLA) was prepared by coupling the lactose lactone with p-vinylbenzylamine. The carboxyl group of biotin was activated with N-hydroxysuccinimide in the presence of N, N'-dicyclohexylcarbodiimide. Subsquently, biotin substituted styrene monomer, N-(p-vinylbenzyl)-biotinamide(VBA) was prepared by amidation of the activated biotin with p-vinylbenzylamine. Poly(vinylbenzylactonamide-co-vinylbenzylbiotinamide), p(VLA-co-VBA) were synthesized through radical polymerization from the synthetic monomers(VLA-VBA) by using various mole ratio. The percentages of yield were 67~71%. The copolymers were found amphlphilic which had hydrophilic lactose, hydrophobic vinylbenzyl and biotin site within the structure. IR and $^{13}C-NMR$ analysis on the monomers and copolymer were carried out.

• The Korean Journal of Mycology
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• v.16 no.4
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• pp.247-252
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• 1988

The uptake of isolated Lyophyllum ulmarium chromosomes by Ganoderma applanatum protoplasts was induced with polyethylen $glycol+CaCl_2+glycine$. Uptake products of chromosomes by protoplasts showed micro-and macrotransgenome type. The former was slowly growing and unstable, the latter was outgrowing and stable mycelial colonies which made thick hyphae of width and segregation of mycelial colony on GCM containing benomyl. A comparison of macrotransgenome type was using isozyme analysis of esterase. The enzyme pattern of two transformants was distinct in position and quantity compared with parents.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.179-184
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• 2004

A doubled-haploid (DH) population was developed through anther culture of F$_1$ plants obtained from a cross between a japonica cultivar, 'Nagdongbyeo', as male parent and a indica cultivar, 'Samgangbyeo', as female parent. Segregation modes for plant length, culm length, panicle length, third internode length, and days to heading in the DH lines showed nearly normal distribution with wide range of variation. A molecular map with 136 simple sequence repeat (SSR) markers was constructed using the DH population. The total map distance was 1,909 cM and the average interval of marker distance was 14 cM.

• Polymer(Korea)
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• v.36 no.2
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• pp.149-154
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• 2012

The amphiphilic copolymer by the conjugation of biocompatible chitosan and antioxidant lipoic acid was studied as a drug delivery carrier. The amphiphilic copolymer was self-assembled to form nanoparticles in the aqueous solution. 5-Fluorouracil widely used as an anticancer drug was encapsulated inside the nanoparticles by a solid dispersion method. The degree of branching of lipoic acid on chitosan was controlled to obtain the optimal condition for the drug delivery carrier. The sizes of nanoparticles were about 250 nm by the dynamic light scattering. The encapsulation efficiency of nanoparticles were about 10%. The copolymer with 42% degree of branching showed the best performance as a drug delivery carrier.