RELATIONSHIPS BETWEEN TILLERING AND ACTIVITIES OF PEROXIDASE, IAA OXIDASE AND ACID INVERTASE IN STALKS OF SUGARCANE SPRAYED WITH ETHEPHON AT EARLY TILLERING STAGE

摘要

Aims: To investigate the relationship between the tillering and the activities of peroxidase, IAA oxidase and acid invertase in sugarcane stalks correlated with foliar spray of ethephon at early growth stage. Methods and Results: Two sugarcane varieties ROC16 and ROC22 were employed for foliar application of different concentrations of ethephon at tillering stage, and the enzyme activities of peroxidase, IAA oxidase and acid invertase in the stalks were measured at different time after treatment. Theexperimental results showed that the treatment with 100mg/L ethephon increased the activities of IAA oxidase and peroxidase in the stems of sugarcane plants. In general, it was obvious that the activities of IAA oxidase and peroxidase in the top internodes were higher as compared with those in the base internodes. The treatment with 100mg/L ethephon was the most efficacious in all treatments. The acid invertase activities were different as for different varieties after the plants were treated with ethephon. For ROC16 treated with ethephon, the acid invertase activity of top internodes was higher than that of base internodes from beginning to end of the experiment. The treatment with 100mg/L ethephon recorded higher acid invertase activity than that ofthe control in the base internodes. For ROC22 treated with ethephon, the acid invertase activity was close to that of the control. The treatments with 100mg/L and 400mg/L ethephon recorded lower acid invertase activities than that of the control in thebase internodes. The activities of IAA oxidase, peroxidase and acid invertase at late tillering stage were higher in ROC22 than in ROC16 after treatment with ethephon, which showed the same tillering performance of the two sugarcane varieties. It was suggested that the activities of the three enzymes were closely related to the tillering in sugarcane. Significance of Study: The experimental results provided some references for in part illustrating the biochemical mechanism of the stimulating effect of ethephon on tillering of sugarcane plants.