Abstract
The present study includes identification the effect of green laser (Nd-YAG) of wavelength 532nm, power 87mw and red laser (He-Ne) of 650nm wavelength,power5mw.at exposing period 10,15,20,25,30 minutes on callus initiation , protein content and regeneration of Silybum marianum L.plants the effect of laser was clear by decreasing the time needed for callus induction, and to increasing the fresh weights of callus. The results showed that there are an increase in the protein contents reached to 0.570,0.707 µg/gm of leave's and cotyledonary leave's callus respectively at 25 min. exposing time to Nd-YAG laser.The results proved the suitability of 30 min. exposing period for hypocotyls and roots since the protein content was 0.750 and 0.410 µg/gm. Moreover, red laser (He-Ne) has possessed a positive effect since the highest protein content of leave's, hypocotyls and root callus was 0.481 ,0.548 and 0.484 µg/gm. respectively at 30min. exposing time.while that of cotyledonary leaves was 0.537 µg/ gm at 25min. exposing period.
