| Studies were conducted to probe into the changes of a-amylase activities and starch contents in fresh leaves of technical maturity, to test the changes of starch contents in cured leaves, to investigate the effects of spraying GA3, BR120 on a-amylase activity and starch content of fresh leaves. The ults were as follows:1. α-amylase activity of fresn leaf increased gradually from foot to top. The maximum a-amylase activity was in top leaf. Starch content raised gradually from foot leaf firstly, then decreased in top leaf, and it's maximum value was in upper leaf. Correlation analysis showed that a-amylase activity and starch content in fresh leaves were significantly negative correlated. Starch contents in fresh leaf and that in cured leaf were positively correlated. The higher a-amylase activity was in fresh leaf, the more starch were degraded, and the lower starch content in fresh and cured leaves were.2. The results of spraying GA3 showed that spraying time had no effect on α -amylase activity and starch content of fresh leaf. Spraying 30mg/L or 50mg/L of GA3 could increase α -amylase activity and then decrease the starch content remarkably. Spraying 10mg/L of GA3 had no effect on α-amylase activity and starch content of fresh leaf. The treatment A2B3 got the highest α-amylase activity and lowest starch content.3. The results of spraying BR120 showed that it could improve a-amylase activity and reduce starch content in fresh leaf significantly. Spraying BR120 in the 7th day after topping could increase a-amylase activity and then decrease the starch content remarkably compared with spraying in budding. When spraying 0.001mg/L~0.01mg/L BR120, the higher concentration was, the higher a-amylase activity was, and the lower starch content was. The treatment A2B3 got the highest a-amylase activity and lowest starch content.
|
PDF Full Text Request