This study was conducted to investigate the optimal plant growth regulator level for the shoot formation of Lycium chinense Mill. In vitro plant propagation was developed for leaf explants of boxthorn. Leaf explants were cultured on MS medium supplemented with cytokinins (BA and 2-iP) alone. Plants were successfully regenerated through in vitro culture by using leaf explants of boxthorn grown in the field. After 4 weeks of culture, 58% of shoot formation had developed from the leaf explants. The shoot formation rate of 'Jangmyeong' was highest followed by 'Myeongan', ;Cheondae', and 'Bullo'. The use of 0.2mg/L BA was critical for enhanced production of shoot formation and resulted in 58% of the culture producing shoot formations. Regenerated plantlets transplanted to pots were developed and successfully acclimatized to greenhouse.

Optimmum cultivation period was determined for producing seed bulb of Korean native Allium wakegi Araki in vitro in hydroponic culture. The growth gradually increased during cultivation period. In general, plants grown for 5 months produced significantly the highest bulb number and bulb fresh weight per plant. Raising the cultivation period from 1 to 5 months remarkably increased seed bulb yield.

Allium wakegi Araki was grown at plant spacings of 5, 10, 15, and 20 cm to determine the effect of planting density on the growth and yield. Allium wakegi Araki plants grown at the 5 cm plant spacing had the lowest bulb diameter and bulb weight, while plants at the lowest density (20 cm spacing) had the highest bulb diameter, bulb number, bulb weight and fresh weight. In general, plants grown at narrower spacings produced significantly smaller bulb diameter and bulb weight, but resulted in the highest yields and plants per hectare and lower fresh weights per plant.

This study was conducted to develop the clonal propagation technique through in vitro culture using basal stem explants in Phalaenopsis hybrid grown in vitro. The highest frequency of protocorm-like body (PLB) formation was obtained when basal stem explants were cultured on VW medium containing 30g/L sucrose, 500 mg/L activated charcoal, 150 ml/L coconut water, 1 mg/L NAA, 5 mg/L 2iP and 2.5g/L gel rite. PLBs transferred to Hyponex medium were regenerated to plantlets. Plantlets transferred to plastic pots containing spagnum moss were developed and successfully acclimatized under greenhouse. The flower was bloomingly opened in plants regenerated from basal stem explants. The flower was not different from both mother plant and plant induced through clonal propagation of Phalaenopsis hybrid.

This study was conducted to develop the clonal propagation technique through in vitro culture using by leaf sheath explants of Phalaenopsis grown in vitro. The highest frequency of protocorm-like body (PLB) formation was obtained when explants of leaf sheath were cultured on VW medium containing 30g/L sucrose, 500 mg/L activated charcoal, 150 mVL coconut water, 1 mg/L NAA, 1 mg/L 2ip and 2.5 g/L gelrite. The PLB formation rate of VW medium was highest followed by modified Hyponex medium, and lowest in MS medium. Plantlets induced from PLBs transferred to plastic pots including spagnum moss were well developed.

For the purpose of establishing an efficient propagation through airlift bioreactor system of Zingiber of officinale Rosc. Korean native Seosanjong, the effect of different factors and bioreactor on cultured plantlets were investigated. The highest number of plantlets, fresh weight per plant was obtained from explants when cultured in MS liquid medium including 0.3 mg/L NAA and 2.0 mg/L kinetin for 40 days. A 10 L bottle type bubble bioreactor, compared with 250 mL Erlenmeyer flask, was more efficient, producing 4.7 plantlets or from 1.5 to 1.6 times more than did the Erlenmeyer flask. The results demonstrate the rapid mass propagation of airlift bioreactor to produce normal ginger.

Callus cultures from leaf explants of Gypsophila paniculata L. cv. 'Bristol Fairy' have been tested their growth and morphogenic capacity on Murashige and Skoog medium supplemented with 0.l, 0.5, 1 and 3 mg/L 2,4-D. The frequency of callus formation ranged from 43.3% to 100%. The optimal 2,4-D concentration for promoting callus formation and growth was 0.5 to 3 ㎎/L. 4.2∼ 5.6% of adventitious roots were obtained with the use of 0.1 and 0.5 mg/L 2,4-D. Calli grown well on 1.0 mg/L 2,4-D was the heaviest among the calli grown in various concentrations.

Embryogenic callus cultures of Korean native Seosanjong of ginger(Zingiber of officinale Rosc.) were induced through stem explants taken from in vitro shoot-tip cultures. Among the four concentrations of 2,4-D tested in Murashige and Skoog medium, 0.5 and 1 mg/L of 2,4-D was most effective in inducing embryogenic callus. Leaf explants did not express any new morphogenetic response in all 2,4-D concentrations tested. Plantlets transferred to hormone-free MS medium were developed and successfully acclimatized under greenhouse.