Submitted to: Congress on In Vitro Biology
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/1998
Publication Date: N/A
Technical Abstract: Studies are underway to produce structures in tissue culture that will yield the important biochemical constituents naturally found in the stigmas of autumn crocus. Explants of floral tissues were evaluated for the proliferation of stigma-like-structures (SLS) by culture on 5 basal media supplemented with different combinations and concentrations of hormones and vitamins. Optimum proliferation of SLS was observed on a CR3-B5 medium using half-ovary explants. Initiation of SLS occurred 50-60 days afer inoculation and explants on CR3-B5 had less browning, higher response per explant, and faster subsequent growth of SLS. The periodic removal of brown tissue, all non-SLS, and the sub-dividing of the ovaries into sectors allowed for production of SLS up to 1.5 years with 3 harvests. Harvested SLS were dried for 30 min at 80C. The presence of crocin, crocetin, picrocrocin and safranal in SLS was estimated by comparing TLC and HPLC profiles of SLS and naturally occurring stigmas. Commercial inaccessible standards - crocin and picrocrocin - were obtained by TLC of the natural saffron extract. To quantify the important secondary metabolites, HPLC was used. A new method of safranal quantification was developed. The concentration of each compound in SLS samples was the same or higher than in natural saffron. Work continues to optimize the in vitro culture conditions for SLS production and explore the possible use of callus and suspension cultures.