Influence of Photo period and Gamma Irradiation on Shoot Development and Chemical Composition of Yucca elephantipes Regel Plant in Vitro

In-Vitro propagated plant lets of Yucca elephantipes were placed under different photo periods (24/0, 16/8, and 0/24 L/D) for two months after cultured on MS medium supplemented with 40 g/l sucrose. Growing explants of Yucca elephantipes cultured on MS medium placed under photo period 24/0 L/D gave the highest shoot length and best proliferation than other treatments especially in subculture 3. Exposure to gamma irradiation at doses 0.0, 5 ,10, 20 and 40 Gy, and placed on the same conditions .Irradiated plantlets exhibited changes in shoot growth especially on photo period at 16/8 L/D than others, also with gamma irradiation at dose 20 Gy. Using gamma irradiation at level of 20 and 40 Gy stimulated both leaf shape and thickness of stem. The contents of total phenol, total saponin and some unsap contents were increased with increasing gamma irradiation