• Horticultural Science & Technology
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• v.33 no.1
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• pp.18-23
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• 2015

Time-specific responses of flower bud differentiation were investigated in 'Shinko' (Pyrus pyrifolia Nakai) pear grown at different altitudes from July through December 2013 to determine their suitability as scions in a top-grafting system. Flower bud initiation and bud necrosis were monitored on each of three sections of one-year-old shoots: terminal, middle, and basal. Flower bud differentiation s tarted in September in the highlands of the Lishan area, and in J uly in the lowlands of the Zhoulan area. In Lishan, flower bud differentiation was higher in the middle and basal segments; during leaf fall, however, flower bud differentiation occurred rapidly in the terminal segment. In Zhoulan, flower buds began to differentiate from the terminal section of the shoot, and severe flower bud necrosis was noted. In July, flower buds developed normally; however, in early August, some of the buds at the basal segment showed browning. During leaf fall, some flower buds showed symptoms of necrosis with rapid and complete browning. Flower bud necrosis began at the basal segment and progressed rapidly towards middle and terminal sections. Before leaf fall, flower buds fell off when scales swelled. The terminal and middle parts of the current-year shoots, with some flower buds, collected in October or later from the Lishan area could be used as scions for top-grafting of 'Shinko' pear. Each grafting scion was a 3-5 cm shoot with one flower bud. These results suggest that scions from the terminal and middle segments of stems of 'Shinko' pear from the Lishan area can be used as scions whereas those from Zhoulan area show necrosis and might not be suitable as scions.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.264-268
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• 2007

Flower and fruit characteristics, in 'Hongro' and 'Galaxy Gala' apples, were investigated by bearing branch lengths and flower bud position such as blow 5 cm, $10{\sim}15cm$ and above 20 cm length with terminal bud, and above 20 cm length with axillary bud for investigation on possibility of alternative use of long bearing branch and axillary bud in case of die-back of spur flower bud. In flowering characteristics by flower bud position in the above 20 cm length, the terminal bud was later and was short in flowering period, and also was little in number of flower per bud. Fruit weight, number of seeds, and sugar-acid ratio, in characteristics of ripening fruit, were more the blow 5 cm and $10{\sim}15cm$ length, but soluble solid and malic acid contents was the opposite tendency. In fruit characteristics by flower bud position in the above 20 cm length, the terminal bud had high tendency expected far number of seed in 'Hongro' and Hunter a value of 'Galaxy Gala' apple but had not significant difference. Correlation between fruit weight and number of seed was high. As the results, value of alternative use of long bearing branch in apples had a little expected for fruit weight, especially was more 'Galaxy Gala' and the axillary bud.

• The Korean Journal of Zoology
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• v.19 no.3
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• pp.113-122
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• 1976

The rate of $^{3}H$-thymidine uptake induced by MMS in asynchronous HeLa $S_3$ suspension cells was decreased in direct proprotion to dose increase. The combined treatment of BUdR or IUdR with MMS was more effective in reducing the rate of $^{3}H$-thymidine uptake. MMS-stimulated $^{3}H$-thymidine uptake was detected in synchronized $G_2$ stage cells of HeLa $S_3$ suspension cultures following treatment with thymidine double shock. BUdR and IUdR greatly enhanced MMS-stimulated $^{3}H$-thymidine uptake. IUdR was found to be a more effective sensitizer than BUdR in this respect.

• Journal of Plant Biology
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• v.38 no.2
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• pp.143-151
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• 1995

Addition of plant growth hormones [0.01 mg/L NAA and 0.2mg/L benzyladenine (BA)] to a woody plant medium stimulated the adventitious bud formation of poplar explants during culture. Endogenous IAA content increased rapidly at the initial culture stage and then decreased, being followed by rapid increment again at the late culture. But the content of trans-zeatin riboside (t-ZR) increased continuously during the culture. Cytoplasmic soluble proteins were analyzed by one- and two-dimensional SDS-PAGE. Increased amount of 40 kD band was detected by one-dimensional electrophoresis using Coomassie Blue staining during the culture and two distinctive proteins whose mol wt is 40,000 were detected by two-dimensional electrophoresis using autoradiography and these proteins were synthesized continuously prior to the adventitious bud formation. When the midvein segments were transferred to the actinomycin D-containing medium, the spots of adventitious bud-related proteins(ABRPs) did not disappeared but weakened in intensity. So, it is concluded that genes coding for the ABRPs are regulated to some degree at the transcriptional level. Also, they were not observed in BA-free medium, suggesting that these proteins be regulated by cytokinin, which made then possible to form the adventitious bud.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.1-20
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• 1974

These studies are conducted to find out inducing factors for the non-sprouting bud which appears in the utility reclaimed hill mulberry held and to establish control method for it since 1971. The results are as follows： 1. In spring, winter bud does not germinate at all on the top of branches or does wither suddenly after or during its germination. Necrosis and browning are appeared in cortex and phloem of non-sprouting bud branch. In autumn, the deterioration of leaves, the abnormal leaves on the top of branch, and browning of veins or petioles are also observed. 2. The soil of non-sprouting bud mulberry Held were found to be sand loom derived from granite rocks. The sub soil of it was very poor in development of root system because it had hard soil and lower pore space ratio. Especially, the sub soil to bring about severe non-sprouting bud had been easily appeared with deficiency of moisture content because of high density solid. 3. Content of soil moisture was significantly lower in the severe non-sprouting bud soil than in the healthy field. The sub soil o( the healthy field contained proper moisture content. On the other hand, the sub soil of the severe non-sprouting bud held contained almost critical moisture content for wilting. 4. The depth of available soil was shallow in the non-sprouting bud than in the healthy fold. The more rate of the non-sprouting bud was severe, the more available soil depth was sallow. 5. Available boron content in soil was affected by moisture content in soil. There was. lower moisture content in the non-sprouting bud field than that in healthy fold during 5, June to 5, September. 6. There was no significant correlation between soil pH and available boron content. On the other hand, the correlation of the content of organic matter and available boron content appeared to be highly positive significance. 7. The quantity of boron was significantly contained more in healthy mulberry field (0.34∼0.43ppm) than in non-sprouting bud field (0.10∼0.28ppm). 8. Boron content in leaves and barks was significantly lower in the non-sprouting bud trees than in healthy trees. 9. The symptom of non-sprouting bud induced from boron free sand culture was similar with that arised in the non-sprouting bud field. 10. The rate of non-sprouting bud was high by the increased application of lime. Considering the facts mentioned the above, author may conclude that the non-sprouting bud of mulberry tree is caused by boron deficiency, but also it is affected by the parent rocks, organic matter, soil moisture content and lime application. 11. The non$.$sprouting bud may be completely controlled by the application of 6∼9kg borax per 10a mulberry field twice a year in spring and summer.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.535-539
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• 2001

To establish the cultural practices of persimmon in heated plastic house, the growth and flower bud differentiation of 4-year old 'Nishimurawase' persimmon tree planted in 80 L pots were investigated. Temperature was kept at above $18^{\circ}C$. The earlier heating induced the earlier flower bud differentiation, while the number of days from bud burst to flower bud differentiation was 70-75 days, which was not affected by the date of heating. The date of flower bud differentiation in 'Nishimurawase' persimmon was May 1, May 21, and June 1 in the plastic house heated from Jan. 15, Feb. 15, and Mar. 15, respectively. The number of flower primordia per bud in the plastic house was 6.2-7.1, slightly fewer than that of 7.8 in the open-field, with the tendency of increasing the number by earlier heating. The days required for the differentiation of the last flower bud primordia from the beginning of differentiation of the first bud were 40-60, and that required for the flower bud differentiation of all buds on the same shoot was 30. The total carbohydrates in shoot increased and the contents of nitrogen decreased, resulting in increased C/N ratio just before flower bud differentiation, and it coincided with the time when the total carbohydates increased above 15%. During two weeks before flower bud differentiaton, The contents of zeatin per 1 g dry matter of shoot drastically increased from $27.2{\mu}g$ to $47.3{\mu}g$, while that of IAA slightly decreased from $188.6{\mu}g$ to $172.4{\mu}g$, and that of GA decreased from $2,225{\mu}g$ to $1,555{\mu}g$.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.202-209
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• 2015

In this study, we investigated the cumulative effect of low temperature on bud dormancy release and bud break characteristics in 'Campbell Early' grapevine (Vitis labruscana B.) cuttings grown in water culture. Additionally, we observed the development of buds while exposed to low temperatures in an attempt to improve our understanding of dormancy and bud break. The shoots were collected 120 days after full bloom (DAFB; leaf abscission period), and the accumulated chill unit (CU) value was calculated by reducing the temperature to $7.2^{\circ}C$ at 125 DAFB. The rate of bud break was 100% in shoots collected at 150 DAFB, The period until the first bud break was two times longer than in the shoots collected 165 DAFB, and bud break speed was significantly reduced. These results indicate that buds are released from endodormancy after 165 DAFB, because at this point the bud break was complete (bud break rate 100%) and it occurred in a very short time period. During this period, when the low-temperature accumulated value was 321h and 442CU according to the CH and Utah models, respectively. Furthermore, the survival rate of main buds decreased rapidly after 165 DAFB, and survival rate of accessory buds was maintained at more than 90% without seasonal differences. The rate of flower bud formation of main buds was much higher than in accessory buds (1:0.23) before the release from endodormancy at 150 DAFB. The final ratio of accessory buds to main buds was high, 1:1.54, at 255 DAFB. Correlation analysis of each investigated factor revealed that bud survival rate and bud formation rate were related only for the main buds, and there was a close relationship between the survival rate of main bud and time. In addition, the survival rate of main buds was positively correlated to the rate of flower bud formation.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.228-234
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• 2015

Using either the apical or axillary bud of the endangered species Abeliophyllum distichum Nakai, we tested the effect of bud position and culture method on shoot proliferation and rooting. In shoot proliferation, the axillary bud explant was more effective than the apical bud and the effect was fostered by BA treatment, whereas no differences were observed in shoot elongation by the explant position. Spontaneous rooting was observed in the MS basal medium and resulted in conspicuous differences in the explant position : more than 80% in apical bud explant and 28% in axillary bud explant was achieved, respectively. The positional effects were also observed in BA pre-treatments: generally vertical culture method appeared to be better in shoot proliferation, growth, and rooting than that of the horizontal culture method regardless of the BA pre-treatment duration. The highest shoot multiplication was achieved through the vertical culture method with axillary bud explant, whereas the best shoot elongation and rooting was obtained using the vertical culture method with the apical bud explant. Apical bud explant was superior to axillary bud explant in ex vitro micro-cuttings and revealed a significant difference in shoot growth and root development. The above results suggest that explant position and culture method influence the efficiency of micropropagation for a rare and endangered plant Abeliophyllum distichum.

• Korean Journal of Plant Tissue Culture
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• v.28 no.3
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• pp.171-178
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• 2001

This study was investigated to establish a regeneration system of plant via adventitious bud formation from leaf explant cultures of strawberry (Fragaria ananassa Duch). Effects of plant growth regulators (2,4-D, BAP), agar sucrose and myo-inositol on adventitious bud formation were investigated. When the leaf explants were cultured on MS medium supplemented with 0.1 mg/L 2,4-D and 3 mg/L BAP, the adventitious bud formation was most promoted. The adventitious bud formation was not induced from leaf explants cultured on MS medium containing 2,4-D alone. Adventitious bud formation was enhanced to almost 3 times on medium with low level of agar concentration (0.4%) in comparison with those on the medium with high level of agar (1%), but almost of shoot was vitrificated on the medium. Therefore, the normal adventitious bud formation from leaf explants was most effective on the medium containing 0.05 mg/L 2,4-D,1 mg/L BAP, 0.8% agar, 30 g/L sucrose and 100 mg/L myo-inositol. Thus, the mass propagation of healthy strawberry could be established using leaf explants.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.58-64
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• 2008

This study was carried out to determine the availability of development rate(DVR) model for predicting bud break time of 'Niitaka' pear. In addition, the study also assessed the effect of an increase in temperature on predicting bud dormancy breaking time in winter season. The DVR model, which was developed for 'Kosui' pear, illustrated that the bud break time(e.g., Dec. 12-Dec. 19) of 'Niitaka' pear observed in the field corresponded to the predicted bud break time by DVR model. This result indicates that the bud break time of 'Niitaka' pear can be predicted by DVR model tuned for 'Kosui' pear. As the temperature increased during the winter season, the bud break time was delayed. Chilling requirement deficiency for the bud break time is expected in Jeju Province when the temperature increased above $4^{\circ}C$ in winter season.