避免黛粉葉莖頂分生組織初代培養內源感染的處理方法

The Methods for Avoiding Endo-contamination of Shoot-tip Explants in Initial Culture of Dieffenbachia

本研究旨在探討黛粉葉無病原培植體之準備與芽體無菌培養之建立。利用不同大小莖頂分生組織作為起始培植體，培養結果於MS基礎培養基含1 mg．L^(-1)NAA及1 mg．L^(-1)TDZ培養12週後，最小之莖頂（0.1×0.25 mm）培植體具有20%的存活率，較大（0.90×1.20 mm）存活之莖頂分生組織培植體，則顯現高繁殖潛力，獲得12.3個再生芽體；另以4種大小黛粉葉腋芽分生組織作為無病原培植體來源，剝除3或4片鱗片數的存活率可達30%-35%，剝掉1片鱗片的分生組織培植體平均每一個反應培植體可達11.2個再生芽體；顯示利用黛粉葉腋芽進行初代培養可避免病原感染，可建立其微體繁殖芽體再生。此外，母株經6週人工乾旱處理之枝梢腋芽，進行精細解剖再切取腋芽培養，結果顯示，剝除2-4片鱗片莖頂培植體之存活成功率可達80%-92.5%，可有效避免初代培養感染微生物。 In this research we described the methods of pathogen-free meristem explant preparation and the shoot proliferation of Dieffenbachia. After culturing different sizes of shoot apical meristem on solidified MS medium with 1 mg．L^(-1) NAA (1-Naphthylacetic acid and 1 mg．L^(-1) TDZ [1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea] for 12 weeks, a 20% survival rate was obtained from the smallest size (0.1 × 0.25 mm) of shoot-tip meristem explant; while 12.3 shoots were regenerated from the largest size (0.90 × 1.20 mm) of shoot-tip meristem explant during initial culture. Moreover, four types of axillary meristem-tip by removing scales were used as explants for aseptic culture. Axillary meristem-tip after 3 or 4 scales removed, used as explant, had higher survival rate of 30%-35%. An axillary meristem-tip explant, with one scale excised, produced 11.2 shoots. Removal of scales from meristem-tip was ideal for the elimination of in vitro endo-contamination in Dieffenbachia. High survival rate (80%-93%) was achieved in axillary bud explants, with 2-4 scales removed, excised from the stock plants that had not been watered for 6 weeks. The methods we described here reduced in vitro endo-contamination and had high shoot multiplication of Dieffenbachia.