Effects of Exogenous Hormones on the Germination and Seedling Growth of Cunninghamia lanceolata

Cunninghamia lanceolata seeds were selected as the study material. The seeds were soaked for 0.5 h, 1 h and 2 h with five concentrations (50, 100, 150, 200 and 300 mg/L) of IBA, GA3, 6-BA and ABA (50, 100, 150, 200 and 300 mg/L), respectively, and the seed germination rate, germination potential and seedling growth were determined. The results showed that: (1) Different concentrations of exogenous plant hormones and different soaking times had significnat differences on seed germination. The highest germination rate was 94.7% and the highest germination potential was 55.3% when GA₃ concentration was 100 mg/L and soaking time was 1 h. (2) There were no differences in the seedling growth under different soaking times of exogenous plant hormones, however, there were significant differences in different concentrations. Different concentrations of IBA, GA₃ and 6-BA promoted the growths of seedling height and diameter of Cunninghamia lanceolata, and different concentrations of ABA promoted the roots growth.