Influence of thidiazuron on callus induction and crocin production in corm and style explants of Crocus sativus L.

Crocus sativus L., mostly famous as saffron, has gained more attention due to its crocin (crocetin ester) pigment responsible for its extensive pharmaceutical properties. In this study, we established two different callus cultures from corm and style explants of saffron to find out the best explant as a suitable source for crocin production. Comparative analyses of total phenolic, flavonoid, carotenoid and anthocyanin contents were also performed in the two callus cultures. For callus induction, different combinations of MS medium with name thidiazuron (TDZ), benzylaminopurine (BA), 1-naphthaleneacetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination were tested. Of the used media, all the combinations containing TDZ and NAA gave 100% callus induction. HPLC-DAD and HPLC-ESI-MS analysis were used for identification of crocin esters in established callus cultures. The highest amount of 0.35 mg g(-1) DW crocin was detected in style originated calli grown on the medium containing 3 mg L-1 NAA +1 mg L-1 TDZ while the corm calli showed the most abundant total carotenoid (0.73 mg g(-1) DW), phenolic (15.04 mg gallic acid equivalent g(-1) DW) and flavonoid (0.76 mg rutin equivalent g(-1) DW) contents. In general, style-derived calli showed longer time survival with a fine texture and good quality compared to corm-derived calli.