Abstract:
The effects of sucrose concentration and light condition on bulblet-in-tube’s regeneration were investigated.
Results revealed that explants (‘Siberia’ bulb scale) cultured on media containing 3 g.L-1 sucrose induced fast (23.33 days) with the highest inducement rate (88.91%) and most buds (13.78/explants). In 75 days of swelling period, the diameter of bulblet on media with 8 g.L-1 sucrose increased most (350.44%) with best roots formation. Explants provided with 16-h photoperiod light condition (L) differentiated fast (27.60 days) with highest proliferation multiple (6.4). Besides, most of them (67.36%) induced adventitious buds. While plants in continuous darkness condition (D), most of explants (78.69%) developed bulblets directly. After swelling, bulblets induced and swelled in D had the highest diameter increase rate (443.70%) with most (14.53 roots/bulblet) and longest roots (36.82 mm). Interestingly, the bulblets differentiated in L and swelled in D (L-D) only increased to 245.33% with least (7.31 roots/bulblet) and shortest roots (7.96 mm). Carbohydrate contents of bulblet cultured in various light conditions showed significant difference. L condition applied in all phases was best for carbohydrate accumulation of bulblets and L-D (differentiate in light and swell in dark condition) was worst. Endogenous hormones contents of bulblets provided with different light conditions showed slight difference. During dormancy breaking period, all index above exhibited similar change trend with lily commercial bulb and there was slight difference among different bulblets. Ex vitro performances of those bulblets were also compared. The surviving rate in L-L (differentiate in light and swell in light condition) was
66.7% which was also the highest immediately followed by bulblet in D-D (Differentiate in dark and swell in dark condition) (53.3%). The bulblets in L-D survived least (26.7%).
