星肋小环藻、滇池铜绿微囊藻的春化作用

为认知星肋小环藻（硅藻）春季活动、滇池铜绿微囊藻（蓝藻）春夏大规模暴发的活动规律，通过确定生长温区后进行变温实验，分析低温对2种实验藻的生长影响，其结果为：小环藻的生长温度为9.5～15.0℃，微囊藻生长温度为15.0～31.0℃，生长高温将抑制2种藻的生长；15.5℃以上、9.0℃以下时小环藻停止生长，31.0℃以上、15.0℃以下时微囊藻停止生长；在15.5～17.5℃停止生长后用7.0～9.0℃处理一天后放回生长温度培养，小环藻恢复生长，在31.0～33.0℃停止生长后用7.0～14.0℃处理一天后放回生长温度培养，微囊藻恢复生长，表明特定低温可使处于高温休眠的藻恢复生长，即低温具有解除高温休眠的作用；诱导低温7.5～9.5℃、10.0～14.0℃时，星肋小环藻、铜绿微囊藻的生长与低温诱导强度反相关，与诱导时间正相关；低温可解除高温休眠作用诱导藻生长，同样，高温也可解除藻的低温诱导作用。分析认为：星肋小环藻、铜绿微囊藻的低温诱导作用与植物春化作用一致，因此实验藻具有春化作用，其年活动规律为：经冬季低温诱导，处于休眠的实验藻春季恢复生长，夏季生长高温抑制铜绿微囊藻生长，秋季无诱导低温过程，铜绿微囊藻华可发生但不如春夏。

Verenalization in Cyclotella asterocostata and Microcystis aeruginosa

To study the activities of the Cyclotella asterocostata in spring and Microcystis aeruginosa in Dianchi Lake in spring and summer, on the basis of the experiment to determine the growth temperature, Analyses the low temperature impact on two experimental algae growth. The results show that：the Cyclotella asterocostata growth temperature was 9.5～15.0 ℃, the Microcystis aeruginosa growth temperature was 15.0～31.0 ℃, growth high temperature would restrain the growth of the two kinds of experimental algae. The Cyclotella asterocostata stopped growing when the temperature was more than 15.5 ℃, 9.0 ℃ below, it was the same to Microcystis aeruginosa（more than 31.0 ℃, 15.0 ℃ below）. The stop growing Cyclotella asterocostata will recovery growth after treated with 7.0～9.0 ℃ for a day and back on the growth temperature, it was the same to Microcystis aeruginosa which was treated with 7.0～14.0 ℃. This showed that specific low temperature could make experimental algae recovery growth in dormancy high temperature, low temperature could remove the effect of dormancy high temperature. Two algae growth and the intensity of induction-low-temperature was anti-correlation when the temperature was 7.5～9.5 ℃ and 10.0～14.0 ℃, positive correlation with the reaction time. Low temperature could induce experimental algae growth and high temperature could lift the low temperature induced effect of experimental algae. Analysis that Cyclotella asterocostata and Microcystis aeruginosa had vernalization which is similar to those higher plants, therefore the experimental algae had the vernalization. The annual activity rhythm of experimental algae was： low-temperature in winter induced growing in spring which had stopped growing; high temperature in summer inhibited the growth of experimental algae, because there was no low temperature induction in autumn, algal blooms could occur but not large-scale outbreak.