防风(Saposhnikovia divaricata)组织培养中的玻璃化现象研究

Studies on Vitrification of Test-tube Saposhnikovia divaricata

以防风茎段为外植体，建立了组织培养再生体系，对防风试管苗玻璃化现象进行了研究。结果表明，与正常苗相比，玻璃化苗形态异常，组织含水量升高，叶绿素含量显著降低，酸性过氧化物同工酶活性减弱。6-BA浓度超过2．0mg／L、光照低于2000Ix、培养瓶内湿度大都极易导致防风试管苗的玻璃化，减少愈伤继代次数，增加培养基内琼脂和蔗糖浓度，可以降低玻璃化率。轻中度的玻璃化苗通过改变培养环境可以恢复正常。优化的防风再生体系为：以嫩茎段为外植体，继代3次左右的愈伤组织诱导出芽，芽继代增殖时，6-BA浓度采用1．0mg／L和0．5mg／L交替使用，培养光照3000～4000Ix。

Stems of Saposhnikovia divaricata were cultured in vitro to establish the regeneration system, and the vitrification of plantlets was also researched. The results indicated that the appearance was different with vitreous plantlets, vitreous plantlets had more water and fewer chlorophaU. The acidic bands＇ activity ofperoxidase （POD） isozymes was decreased. 6-BA concentration being more than 2.0 mg/L, light intensity being lower than 2 000 Ix and high humidity easily induced the vitreous plantlets and the percentage of vitrification could be reduced by cutting down callus＇ ages and increasing sucrose and agar concentration. Mild and moderate vitrification could be reversed by changing cultural condition. The optimized regeneration system was： Tender stems were used as explants; using callus about 3 ages for buds＇ differentiation, and 6-BA concentration was alternated 1.0 mg/L with 0.5 mg/L on subculture： Choosing limht intensity on 3 000-4 000 lx.