The Mutagenic Effect of Cunninghamia lanceolata Seed by Colchicine Treatment

The germination rate and mutation rate of the mature seeds of Cunninghamia lanceolata presoaked with 25 mg/L of gibberellin for 24 h were studied by treating with 0.3%, 0.6%, 0.9% and 1.2% colchicine solution for 1d, 2d, 3d and 4d respectively, and the seeds soaked with distilled water were taken as control. The germination rate and mutation rate were observed and counted 3 weeks later, and the mutant seedling growth was observed 9 months later after the treatments. The results indicated that colchicine treatment had a significant influence on seed germination rate and mutation rate, and there was a certain rule of changes in these indexes because of the different colchicine concentration and treatment time. It was showed that the highest mutation rate was resulted from soaking the C.lanceolata seeds for 4 d with 0.9% colchicine. Colchicine concentration and soaking time duration had a significant influence on C.lanceolata seedling height, there was a variation tendency that the average seedling height was firstly reduced and then increased with the increase of colchicine concentration by the same soaking time, while the average seedling height treated by the same colchicine concentration rose up firstly and then dropped afterwards. The change of basal diameter of the C.lanceolata seedling height was consistent with that of the height, and the sprouting treatment inhibited the branching differentiation.