The Effects Of Ethephon On Photosynthetic Characteristics In Different Sugarcane Varieties

Abstract:Four sugarcane varieties, namely, earlier-maturing variety ROC2O, early-maturing variety GT11,intermediate-early variety ROC1O and intermediate GT17 were grown under the normal growing condition in the field .The plants were sprayed with lOOmg/L of ethephon on the leaves at early growth stage. The control were sprayed with water. After being treated , gas exchange characteristics , two critical photo-enzyme in C4 pathway ,contents of chlorophyll in leaf +1 and N-. P. K in leaf +3 were measured. Simultaneously, the major agronomic characters were investigated.The followings were the main result of our experiments1.The ethephon treatment could obviously improved the net photosyntheticate of sugarcane , especially, have an obvious effect on GTJT and ROCTO.2.We could dtew the conclusion that ethephon treatment could improve the slope of the light response curve of net photosyntheticate to PPFD. This indicated that plants treated by the ethephon had a higher ability to utilize the photosphere than the control.3.The diurnal curve of the photosynthetic ate in sugarcane was single pex curve .The max value emerged at about 11:00 oclock. Ethephon treatment did not changed the trend, but the max values of photosyntheticate were higher in the ethephon treatment than in the control.4.The ethephon treatment could promote the activities of PEPC and NADPalic enzyme, having a higher photosynthetic ability than the control.5.The ethephon treatment increased the contents of chlorophyll in leaves.6.The ethephon treatment increased the contents of nitrogen and phosphor in leaf+3, but had little effect on potassium ,as compared with the control.