Effect of Gibberellin and Light on Germination of Seeds in Codonopsis lanceolata Benth

Seed of Codonopsis lanceolata exhibits low germination due to impermeable seed coat. Prolonged seed dormancy can be overcome by the application of gibberellins, as it promotes growth of the embryo and weakens the structures surrounding of embryo. The effects of photoperiod, sugar and gibberellin concentration were investigated at constant temperature for 12 days and 22 days in vitro and invivo conditions respectively. The rate of germination of seeds of Codonopsis lanceolata in wet filter paper in both complete dark and light treatments was significantly lower than that of seed treated with . It clearly indicates that there is significant coat imposed dormancy in the seed of Codonopsis lanceolata. The rate of germination in vivo condition was lower than that of the in vitro condition supplemented with Thus, the physical dormancy due to impermeable seed coat and low level of endogenous gibberellins in the seed was the cause of poor germination rate in Codonopsis lanceolata.