| Two sugarcane varieties, GT17 and TT22, were used in this experiment. In the experiment, l00mg/L of ethephon and salicylic acid were sprayed on the sugarcane leaves in different sugarcane varieties at the end of tillering stage respectively. There are two controls, one is sprayed with water on the leaves under the condition of drought stress, the other is under normal conditions. Leaf Samples were collected to assay the oozing percentages in cells, contents of superoxide anion, chlorophyll a and total chlorophyll and POD activity. The gas exchange parameters (net photosynthesis, evaporation, stomata conductance) and chlorophyll fluorescence parameters (Fo, Fv/Fo, Fv/Fm) were analyzed. The results were as followings:1. The ethephon treatment could keep lower oozing percentages as compared with the control under the condition of drought stress. Salicylic acid had different effects in different sugarcane varieties. It made lower oozing percentage hi TT22 but had little effect on GT17.2. The ethepon treatment increased the contents of superoxide anion in two sugarcane varieties, while S A treatment could reduce the contents.3. Both the ethephon and SA treatments could improve POD activity compared with those activities in controls in the condition of drought stress.4. Both the ethephon and SA treatments inhibited the contents of total chlorophyll and chlorophyll a in two sugarcane varieties.5. Ethephon and SA treatments could increase the net photosynthesis in two sugarcane varieties, but decreased the gas conductance and evaporation after within 20 days after the treatments.6. The ethephon and SA treatments could increase the ratio of variable fluorescence to minimal fluorescence and the ratio of variable to maximal fluorescence, but had little effect on initial fluorescence (Fo).7. Both the treatments improved the qualities of sugarcane. |
PDF Full Text Request