• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.409-412
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• 2019

We investigated the development of a micropropagation protocol for multiplication of calla 'Gagsi' by using shoots as explant. The callus was induced on Murashige and Skoog (MS) basal medium containing cefotaxime antibiotics (25, 50, 100 mg/L). Also, MS basal medium with NAA 0.5 mg/L and BA 1.0 mg/L was used. The callus induction and browning rates were compared by treatment supplemented cefotaxime 25, 50 and 100 mg/L in basal MS medium. The callus induction rate was 10.5 % and browning rate was also, 10.5 % on the MS containing 25 mg/L. In the MNB containing cefotaxime, the callus induction rate was 34.5 % and browning rate was 27.0 %. The cefotaxime experiment has been widely used in previous studies. It is thought that it will help establish the mass multiplication system by positively affecting the growth and browning reduction of calla plants.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.325-329
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• 2018

There are two kinds of calla belonging to the Zantedeschia spp. depending on the growing condition. Between them, various colored calla with flower shape and flower color are very popular as cut flowers. However, colored calla is very low in natural reproduction rate, and it takes a long time to obtain a flowering bulb. So it is urgent to establish a large breeding system of good varieties. In this study, various plant growth hormone treatments were carried out to improve the growth of the plants in calla. Root formation was the highest at 81.5 % in basal MS medium, and the formation of shoot and multiple shoots were the highest at 100.0 % and 36.4 % in the combined treatment of BA 2.0 mg/L and IBA 1.0 mg/L, respectively. In fresh weight, the highest growth rate was observed with 11.2 times increase in BA 2.0 mg/L single treatment. Auxin and cytokinin mixed treatment were widely used in previous studies and positive effects on the growth of calla plants will help to establish the micro-propagation system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.44-57
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• 2003

Seasonal variations of bacterial abundance and production, heterotrophic nanoflagellate (HNF) abundance and HNF ingestion rates on bacteria using FLB together with environmental variables were investigated at intervals of a month in Kyeonggi Bay from December 1991 to November 1998. Bacterial abundance and production ranged from 0.38$\times$10$^{9}$ ~ 3.25$\times$10$^{9}$ cells 1$^{-1}$ (average 1.19$\pm$0.69$\times$10$^{9}$ cells 1$^{-1}$ ) and from 1.51 to 20.4 cells 1$^{-1}$ h$^{-1}$ (average 6.04$\pm$ 1.88$\times$10$^{6}$ cells 1$^{-1}$ h$^{-1}$ ), respectively. Bacterial abundance and production showed no differences at the high tide and low tide, and bacterial abundances were not different with depth, but bacterial production decreased with depth. Seasonal variation of bacterial abundance showed almost similar fluctuation pattern to those of DOC (dissolved organic carbon). HNF abundances ranged from 388 to 4,374 cells ml$^{-1}$ (average 1,344$\pm$130 cells ml$^{-1}$ ), were high in March, April, July and August. HNF abundance showed no difference between the high tide and low tide, and was not different with depth. The ingestion rates of HNF on bacteria were 1.0 to 6.3$\pm$10$^{6}$ bacteria 1$^{-1}$ h$^{-1}$ (average 3.12$\pm$0.55$\times$10$^{6}$ bacteria 1$^{-1}$ h$^{-1}$ ), resulting ingestion rates of HNF removed 19.4 to 141.4 %(average 62.3$\pm$12.0%) of bacterial production. Ingestion rates and grazing pressure of HNF on bacteria showed high correlation with HNF abundance. Although we cannot exactly discussion about seasonal variation of bacteria community in this study area where physical and chemical parameters were very complex, the results indicate that bacterial abundance and production were mainly controlled by resources supply as dissolved organic carbon and chlorophyll-a(bottom-up) except March which bacterial abundance and production uncoupled chlorophyll-a because of low dissolved organic carbon and low temperature, and were controlled by HNF grazing pressure(top-down) in the warm seasons except the winter.