The present research aimed to evaluate the effect of different light spectra on seed germination and initial in vitro development of Phyllanthus tenellus Roxb. Furthermore, N concentration was evaluated in plant development. Seeds were sterilized and inoculated in solid MS medium. Seeds and plantlets were maintained under the following light treatments: white (control), blue, green, red and white plus UV-A. Seed germination was observed under light and darkness. Under red light, germination showed the greatest percentage (12%) after 12th week, considered very low. Germination rate also increased under red light. Rooting was favored by red light (80%) and white light (71.4%), and reduced under blue light (51%). As results from blue light exposure plantlets presented the highestnumber of leaves. MS medium reduced to half of NH4NO3 and KNO3 solution improved rooting and revealed the best conditions to in vitro establishment of P. tenellus cultures.
