IMPACT OF FUNGAL ELICITOR AND CULTURE CONDITIONS ON INDUCTION OF CALLI AND ALKALOIDS PRODUCTION IN Narcissus tazetta var. italicus TISSUE CULTURES

The use of plant-derived drugs has been increased throughout the world as a result of health hazards and toxicity associated with the use of synthetic pharmaceutical compounds. Tissue culture techniques are developed as an alternative strategy to produce active secondary metabolites. Fungal elicitation with a combination of tissue cultures optimization is effective strategy to enhance biologically active compounds. Callus cultures of Narcissus tazetta var. italicus (Ker-Gawler) Baker were prepared from bulb explants. They were cultured on a modified Murashige and Skoog medium, supplemented with 3% sucrose, 3mgl-1naphthalene acetic acid (NAA) and1.5mg l-1 benzyl adenine (BA). Five factors included: fungal growth medium, fungal elicitor concentration, fungal age, exposure time, and callus age were optimized to improve alkaloids production. Culture filtrate of Fusarium sporotrichioides Sherbakoff isolated from the rhizosphere of N. tazetta var. italicus was used as a biotic elicitor. Elicitor of F. sporotricoides, grown on Potato Dextrose broth, stimulated alkaloids production by calli (23.4 mg. g -1dry cell) more than that grown on other media. Elicitor concentrations above 20% enhanced alkaloid accumulation significantly particularly at 80% (32.3 mg. g -1dry cell). Fungal ageing was accompanied by a progressive increase in alkaloid contents of calli. Elicitors prepared from older fungal cultures were effective in stimulating calli growth and alkaloid production more than younger cultures. Alkaloids were increased by increasing exposure time. After 15 days exposure time, there was an increase in alkaloid contents of calli by 2.52 – fold compared to the control. Alkaloid production was directly proportional to callus age until the eighth week then declined significantly by ageing. Eight-week-old callus cultures produced maximum amount of alkaloids (39.2 mg. g-1 dry cell) after elicitation for 15 d. In this treatment alkaloid contents increased by 1.8-fold, compared to that produced by 2-week-old callus.