Research on the Relationship between the Root Activity and Leaf Ageing,Photosynthetic Rate of Rice after Heading Stage

[Objective] The scientific basis for good-quality and high-yielding production was provided through the experiment.[Method] Rice variety—Wuyongjing No.8 being taken as experimental material,the variation of root activity,leaf ageing and photosynthetic rate of upper three leaves after heading stage was investigated based on the different planting density and fertilization measure in order to mold the different rice yield population and master the effect of variation of root activity on leaf ageing and photosynthetic rate after heading stage.[Results] The result showed as follows: after heading stage,the relationship of the root activity with the activity of SOD and POD,the content of chlorophyll and field photosynthetic rate of upper three leaves was positive;with MDA was negative,which suggested that in high root activity the upper three leaves in the population was ageing slowly after heading stage and the content of chlorophyll decreased slowly,resulting in the strong ability of upper three leaves in the utilization of light energy,which promoted the rice population with high photosynthesis for high-yielding formation.[Conclusion] The activity of SOD and POD could be promoted,the content of MDA could be reduced and the aging processing could be delayed for the construction of high-yielding rice population based on the vitality root system after heading stage.