Effect of light wavelength on in vitro organogenesis of a Cattleya hybrid

摘要

The effect of light wavelength on multiplication, tissue growth and pigment content was studied in Cattleya intermedia X C. aurantiaca microcutting cultures. The initial explants were shoots regenerated from protocorm-like bodies. Modified MS medium containing 5.0 mg-1(-1) BA, 0.2 mg-1(-1) zeatin and 1.0 mg-1(-1) NAA, solidified with Difco agar, was used for adventitious regeneration of shoots and aerial roots. The rate of organ initiation depended on the wavelength of the monochromatic light applied. Red and blue treatments were effective in triggering photoinorphogenesis in the evaluated material. The propagation coefficient reached 11.7 under red light, 10.6 under blue, 8.3 under white and 6.2 in darkness. Total chlorophyll and carotenoid content were highest in cultures illuminated with white light, gradually decreasing from the blue to the red and the far red treatments. Blue light treatment improved the efficiency of micropropagation and benefitted initiation of rhizogenesis and aerial root elongation, and the resulting plants were true to type.