Abstract
This study was undertaken to develop an efficient propagation technique for mature Betula davurica. Using aseptic materials taken from in vitro culture, the effects of media and plant growth regulators on shoot proliferation and rooting were investigated. DKW medium turned out to be the best in shoot proliferation among the media tested. Whereas axillary buds were better culture material than apical buds in proliferation of shoots, apical buds were slightly better than axillary buds on shoot elongation. Neither 1 /2 MS nor WPM medium seemed to be suitable for shoot multiplication or elongation. When the explants were cultured on 1/2 MS medium, shoot elongation was retarded by forming big callus at the base. In the case of WPM, shoots could be formed normally, but they exhibited slow growing. NAA was so effective on in vitro rooting that more than 80% rooting could be achieved on half-strength DKW medium supplemented with 1.0 mg/L NAA after 4 weeks in cultures. Ex vitro rooting using elongated shoot was also applicable to rooting and acclimatization. Rooted plantlets were successfully acclimatized in an artificial soil mixture and grew normally. The results demonstrate that efficient mass propagation of mature B. davurica can be done through tissue culture.
아배양을 통한 물박달나무 성숙목의 기내증식은 DKW 배지에서 양호하였다. 이 배지는 다른 두 배지보다 줄기증식 및 줄기생장이 양호하여 물박달나무의 적정 배지로 생각되었다. DKW 배지에서 액아배양과 정아배양에는 큰 차이는 없었으나 증식에는 액아배양이, 생장에는 정아배양이 다소 양호하였다. 한편 1/2 MS 배지에서는 절편기부에 callus가 직경 1.0cm이상 지나치게 형성되어 줄기신장을 억제하였고, WPM에서는 줄기형태는 정상이나 생장이 저조하여 물박달나무의 아배양 배지로는 부적당하였다. 발근은 NAA 처리가 IBA 보다 효과적이었다. l/2 DKW 배지에 1.0 mg/L NAA 처리로 80%의 기내발근 되었으며 유도된 뿌리수도 많았다 얻어진 줄기는 직접 기외삽목도 가능하였는데, 이 같은 결과는 물박달나무 성숙목의 효율적인 기내번식이 가능함을 시사한다.