摘要:The effects of explant source, medium composition and growth regulators were examined in order to optimize the induction and selection of fast growing callus lines of European yew (Taxus baccata L. Washingtonii). Callus cultures were induced from isolated mature zygotic embryos or from segments of juvenile branches. Following two months of growth on induction medium (MS + 3.0 mg/L NAA, 0.5 mg/L kinetin, 100 mg/L arginine, 2.5 % sucrose and 0.8 % agar), callus proliferation was induced in 86.4 % of embryo explants and 100 % of branch-cutting explants. The growth potential of established callus lines was found to vary in response to genetic potential and culture medium composition. The growth rate of stem-derived callus obtained on induction medium was superior to that obtained using all other tested media modifications (duplication time 9.6 days). However, the growth of embryo-derived callus lines was enhanced by increasing the iron content from 27.8 to 55.6 mg/L FeSO4 ∙7H2O in the maintaining MS medium (duplication time for line E2 was 8.5 days). In two out of three embryo-derived lines, tissue growth was further improved by transferring onto modified B5 medium (duplication time for lines E2 end E5 was 4 and 5.7 days, respectively). HPLC analysis confirmed the presence of the anticancer agent cephalomannine in calli grown on B5 medium and a taxane-like substance in calli grown on MS medium.
关键词:callus induction; European yew; MS medium; taxane; zygotic embryo