Journal of Bio-Environment Control ISSN:1229-4675(Print) 2765-3641(Online) 생물환경조절학회지

The influence of growth regulators (NAA and BA) and sucrose concentrations (0, 3, 5, 7, 9%) on in vitro rapid-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] was investigated with single-node or shoot-tip culture of two cultivars (‘Matnami’ and ‘Shinhwangmi’). The survival rate and growth of shoot-tip explant was also investigated under the presence or absence of light (blue and red LED = 7:3, 150±5 μmol·m^-2·s^-1 PPFD) during minimal-growth in vitro conservation at 15°C. Vine length, vine diameter, fresh weight and dry weight were enhanced without callusing of explant in the MS medium supplemented with 0.2-0.5 mg·L-1 BA. The growth of single-node and shoot-tip explants were significantly enhanced with the increase of vine length, number of leaf, number of root, fresh weight, and dry weight in the solid medium containing 5% sucrose and 0.2 mg·L-1 BA. Vine elongation of shoot-tip explants were highest in the liquid medium containing 3% sucrose than the solid medium. The survival rate of minimal-growth in vitro conservation was 100% in 5 months under the presence of light (LED, 150±5 μmol·m^-2·s^-1 PPFD) at 15°C, but the explants in dark condition died in 3 months. The light was absolutely necessary for the in vitro conservation under minimal-growth conditions of virus-free sweet potato plantlets at 15°C, and the high density of explants (10 plantlets per Petri Dish) was increased the efficiency of mass conservation.