| In order to shorten sprouting time of Hydrilla verticillata winter buds and increase the rate of forming plantlets in eutrophic water bodies, experiments were carried out to examine the sprouting rates of H. verticillata winter buds and growth of the seedlings after the winter buds were treated with GA and IAA. The concentrations were 0, 50, 100,150 and 200 mg/L and the soaking time were 12 h and 24 h. Results showed that proper combinations of concentration and soaking time of GA and IAA could significantly accelerate the sprouting of winter buds, increase the height, dry weight and root number of seedlings. However, all the treatments had no significant effects on shoot number. Sprouting of winter buds was apparently accelerated after soaked in IAA concentrations of 100 mg/L and 150 mg/L for 12 h and 50 mg/L for 24 h,as well as in GA concentrations of 150 mg/L for 12 h and 50 mg/L for 24 h (P<0.05), but was significantly inhibited after soaked in IAA or GA concentration of 200 mg/L for 24 h (P<0.05). This indicated that sprouting of winter buds was susceptive to the concentration and soaking time of GA and IAA. IAA concentrations of 50 mg/L and 100 mg/L had stronger promoting effects on height of seedlings than GA (P<0.05), and IAA concentrations of 100 mg/L and 150 mg/L were more beneficial to dry matter accumulation (P<0.05), while rhizogenesis of the seedlings may be more promoted in GA concentrations of 150 mg/L for 12 h and 100 mg/L for 24 h than IAA (P<0.05). The results indicated that, soaking winter buds in IAA and GA concentration of 150 mg/L for 12 h would produce satisfying effects in application. |
