Fungal contaminants observed during micropropagation of Lilium candidum L. and the effect of chemotherapeutic substances applied after sterilization

Lilium candidum L. is a species which grows in the South West Anatolia region of Turkey. It is a bulbous plant with beautifully scented flowers and is used in the floral industry. The bulbs are produced by using traditional propagation and in vitrotechniques. Micropropagation is a rapid propagation technique, but the greatest problem is contamination with fungi and bacteria. Antibiotic and fungicide treatments were done after sterilization for micropropagation of L. candidum. Fungal contaminants formed during the culture were determined. Bulb scales were used as explants (5 - 10 mm width) and were cultured in photoperiodic conditions (16 h light, 8 h dark) or complete darkness. Bulb scales rinsed in water were surface sterilized, then solutions containing chemotherapeutic substances (Benomyl, Nystatin, Streptomycin, Penicillin) in different combinations were applied for 30 min and subsequently were cultured in MS medium with supplement 0.1 mg dm-3 NAA + 0.01 mg dm-3 BA. During the experiment, fungal contaminants were observed in full treatments. Determined contaminants were identified according to their morphological and cultural characteristics by cultivation and were comprised of: Fusarium, Penicillium, Alternaria, Rhizopus, Cylindrocarpon and Aspergillusspecies. The most effective treatment against fungal contaminations was achieved by utilizing a Benomyl (100 mg dm-3) + Nystatin (100 mg dm-3) treatment combination.   Key words: Contaminating microorganisms, Lilium candidum, bulb scale, in vitroculture, treatment, antibiotic, fungicide.