Investigation on the interaction of plant growth regulators and ultrasound treatment on the in-vitro regeneration of Lilium ledebourii Boiss.

: Lilium ledebourii Boiss. Is one of the rare species in the lilium genus which have ornamental and medicinal value. Due to the importance of increasing propagation of bulb and secondary metabolites production in tissue culture of Lilium ledebourii, the use of ultrasound as a physical stimulus with growth regulators as a chemical stimulus, if be effective on micropropagation and secondary metabolites increase in Lilium ledebourii, it can be effective in that proliferation and development of vegetative regions and also use it as a medicinal herb. Therefore, this study was performed to aim of evaluate the effect of NAA and BA and ultrasound waves on micropropagation Lilium ledebourii and total phenolic content as one of the secondary metabolites in Lilium ledebourii. For this purpose, two types of bulbs and scales explants after exposure in an ultrasonic bath with a frequency of 35 kHz in times 0, 5, 10, 20 and 30 seconds were cultured on MS medium containing different concentrations of 0, 0.01, 0.1 and 1 mg l-1 NAA and BA alone or in combination with each other. This experiment was done based on completely randomized design with 4 replications. Scale explants was sensitive to stress caused by ultrasound and was damaged. Generally ultrasonic treatment have not significant effect on regeneration in explants bulb and scale, but in case of the content total phenolics, that effect was significant and the best duration for exposure ultrasonic for increasing total phenolics in two type explants was 10 and 20 second. Also among hormonal compounds, most of the content of total phenolics in both explants was obtained from 1 mg l-1 NAA + 1 mg l-1 BA. Based on the data comparison, the best hormonal compound for bulbs proliferation and rooting bulb xplants was compound 0.1 mg l-1 NAA + 0 mg l-1 BA and 0.1 mg l-1 NAA + 0.01 mg l- 1 BA respectively. The MS medium containing the 1 mg l-1 NAA + 0 mg l-1 BA and 0.1 mg l-1 NAA + 0.01 mg l-1 BA had the best response for bulb production in scale xplants. As well as for rooting of bulbs regenerated from scale, 1mg l-1 NAA + 0 mg l-1 BA was the best.