The influence of light spectrum on morphogenesis of orchid germs in vitro

The aim of the study is to reveal growth and developments specificities of orchid (Cymbidium hybridum F1) germinant in vitro cultured early in the ontogenesis in relation to various light spectra. Chromatic and achromatic luminous tubes (Philips, TLD 18 W) were used as lighting sources. 4 light patterns were tested: control group - colorless (white) light WL; group 1 - WL with addition of red WL+RL, group 2 - WL and blue WL+BL, group 3 - WL and green WL+GL. The authors showed that during C. hybridum F1cultivation in type breeding ground, morphometric growth indexes of root and leaf and wet weight of germs raised with the increase of red light part in PAR (photosynthetically active radiation) flux, thought stem length was twice bigger under the mix of colorless and green light, and also blue light addition to achromatic emission aided the reduction of germ parameters, in contrast with control group. Growth characteristics of plants, cultivated under photoculture conditions, can be adjusted by light with varied spectral content