Callus induction and browning inhibition of Crocus sativus L.

Callus induction from corms,sterile buds and young leaves of Crocus sativus L.was studied,and the browning and contamination in the callus induction were also explored.Results indicated that with the sterile buds and young leaves as explants,the percentage of callus inducement was higher and the inducing time was shorter than that with corms as explants,but the browning took place easily in callus.The bigger corms(≥20 g) were suitable for the callus induction.Moreover,the longer corms were stored,and the faster calli were induced.The percentage of callus inducement was over 70% within 30 d by using Murashige and Skoog(MS) medium supplemented with 2.0 mg/L 2,4-D and 0.5 mg/L 6-BA.Inoculating explants to fresh media in succession could effectively reduce the browning,whereas media with the addition of activated carbon and polyvinylpyrrolidone were ineffective to diminish the browning.Washing corms with running tap water overnight before sterilization were effective for reducing surface epiphytic microorganisms significantly and depressing the rate of contamination.