Abstract
The single node cuttings of sweet potato (cv. Mokpo #29) plantlets maintained in vitro were cultured with (MF+) or without membrane filter (MF-) under photomixotrophic (PM), hetrotrophic (HT) and autotrophic (AT) conditions. Shoot length was the greatest (11.9cm) in 3$0^{\circ}C$ (HT) treatment and it was the shortest (3.4 cm) in $25^{\circ}C$ (PM) treatment. Nodal explants cultured in 3$0^{\circ}C$ treatment looked more vigorous than those of $25^{\circ}C$ in appearance, and node number was the greatest (10.5 per plantlet) among the treatments. But plantlets grew in 3$0^{\circ}C$ (HT) treatment were observed all overgrown. The size in leaf area was about 2 times greater and shoot length was about 2 times shorter in PM than in HT condition. Percent dry matter of shoots was 5.9% (HT) and 7.4% (PM) in $25^{\circ}C$ treatment and 6.1% (HT) and 7.4% (PM) in 3$0^{\circ}C$ treatment. Plantlets cultured in the MF+ treatments were less succulent than those cultured in the MF- treatment. Vitrified plantlets were examinated 14.8% (both $25^{\circ}C$ and 3$0^{\circ}C$) in PM condition and 22.2% ($25^{\circ}C$) and 31.5% (3$0^{\circ}C$) in HT condition. Sucrose was necessary for the survival of in vitro plantlets. In the sucrose-free medium, explants cultured in the MF- had turned yellow and were dead after 30 days of culture. But explants cultured in the MF+ were alive and produced plantlets with shoot and root (AT). On the other hand, the survival of explants on the MS basal medium (sucrose-free and hormone-free) depended entirely upon the MF attachment.
고구마의 기내 소식물체의 생장촉진 및 순화율을 높이기 위하여 마디를 광혼합영양과 종속영양, 광독립영양 조건하에서 각각 배양하였다. Shoot길이는 3$0^{\circ}C$의 종속영양배양에서 11.9 cm로 가장 길었고 $25^{\circ}C$의 혼합영양배양에서 3.4cm로 가장 짧았다. 3$0^{\circ}C$에서 배양된 마디의 생육이 가장 빨라 마디수가 10.5개로 가장 많았지만 식물체는 도장되어 연약하였다 엽면적은 MF-처리구인 종속영양배양보다 MF+처리구인 혼합영양배양에서 2배로 넓었고 shoot의 건물률도 약간 높게 나타나 함수량이 비교적 적은 편이었다. 투명화된 불량묘는 광혼합영양배양의 경우 $25^{\circ}C$와 3$0^{\circ}C$ 모두 14.8%였고, 종속영양배양에서는 $25^{\circ}C$에서 22.2%, 3$0^{\circ}C$에서 31.5%로 MF+처리구에서 훨씬 적게 나타났다. Sucrose-free배지의 경우 MF-처리구에서 배양 30일 후에 마디절편이 노랗게 변하고 결국 고사되었으나 MF+처리구의 광독립영양배양에서는 정상적인 식물체로 생장되었다. 또한 sucrose와 호르몬이 첨가되지 않은 MS기본배지에서 MF+처리구의 경우 마디절편의 생존율은 양호하였다.