目的 研究不同 p H值对东北红豆杉和南方红豆杉愈伤组织生长和紫杉醇含量的影响。方法 采用不同p H值的 B5培养基培养两种红豆杉愈伤组织 ,测定生长率、PAL 活性和紫杉醇含量。结果 不同红豆杉愈伤组织所需最适 p H值不同 ,而有利于愈伤组织生长的 p H值均不利于 PAL 活性的提高和紫杉醇的积累。即 :愈伤组织生长快时 ,PAL活性将下降 ,紫杉醇含量也减少。结论 p H值明显影响红豆杉愈伤组织的生长及次级代谢水平 ,从而影响了紫杉醇的合成与积累

Object To study the effect of pH on callus tissue growth and paclitaxel content of Taxus cuspidata Sieb. et Zucc. and Taxus chinensis var. mairei (Lemee et Le 'vl.) Cheng et L. K. Fu Methods The callus tissues were cultured on B5 medium with defferent pH values, and the growth rate, PAL activity and paclitaxel content were determined. Results Different callus tissues of taxus need different optimum pH values. The pH values, which could promote callus growth significantly, were all inhabitory to PAL activity and accumulation of paxlitaxel. Conclusion pH had great influences on the growth of the callus and the level of secondary metabolism, thereby the synthesis and accumulation of paclitaxel were affected.