Materials and methods
Plant material
Seeds of Sinningia speciosa were surface-sterilized with 70 %
(v/v) ethanol for 1 min and 2 % (v/v) sodium hypochlorite
solution for 10 min, then rinsed three times in sterilized water.
FIve seeds were placed on 25 ml of agar- solidified culture
medium in Petri dishes (100 x 15 mm). The basal medium
consisted of salts and vitamins of MS (Murashige and Skoog,
1962) medium and solidified with 0.7 % (w/v) agar. The
medium was adjusted to pH 5.8 before adding agar and then
sterilized by autoclaving at 121 °C for 20 min. The seeds were
germinated in a growth chamber at 25 ± 1 °C under standard
cool white fluorescent tubes with a flux rate of 35 μmol s-1 m-2
and a 16-h photoperiod.