The Introduction And The Research On Drought And High Temperature Stress With Phlox Paniculata

In this experiment we use two different colours of Phlox paniculate: 'Jincaizi'and 'Fenyan'a s experimental materials, study their growth rules and discuss their drought resistance and high temperature resistance on exterior, physiological index in Shanxi Jinzhong region. Our objective is to study the effect of morphological character and physiological index of Phlox paniculata which is under drought and high temperature stress. The result will provide theory evidence of Phlox paniculata in popularization and application in Shanxi Province in the future. Our experiment drow the following conclusions:1. Field testing showed that Phlox paniculata express well adaptability in Jinzhong area. The florescence of 'Jincaizi' lasts 128 d, the full bloom period 'Jincaizi' lasts 45d; The florescence of 'Fenyan' lasts 116 d, the full bloom period 'Fenyan' lasts 54 d. Their period of growth lasts about 230 d.Their ornamental effect is very well, have high value to popularization and application.2. In the experiment of drought stress, the fancy points in 50%,35% and 20% of soil relative water content have big difference with the control, the lower of soil relative water content is, the more serious of fancy points are. Comprehensive analysis eight physiological index in relative water content of leaves, POD activity, SOD activity, proline content, soluble protein content, chlorophyll content, MDA content and relative conductance of leaves, we found as the soil relative water content become less and the treatment days increase, each physiological index amplitude of variation become large compared with contrast. We also found 'Jincaizi' is better than 'Fenyan' in drought resistance through comprehensive analysis of membership function.The drought make the Pn, Cond, Tr become descend. And the fall range is bigger as the level of drought deeply. The Ci become descend in the level of 65%,50% in soil relative water content during experiment period, stomatal limitation is reason for the descend of Pn. On the level of 35%,20% in soil relative water content, the Ci become descend at earlier stage, in this period stomatal limitation is reason for the descend of Pn; the Ci become ascend at later stage, in this period non-stomatal limitation is reason for the descend of Pn.3. High temperature stress make POD and SOD activity, soluble protein and chlorophyll content in Phlox paniculata ascend at first, and then descend. The relative conductance of leaves and the content of proline and MDA become ascend. The physiological index range large in the temperature of 40?/24? and 45?/27?, We also found 'Fenyan' is better than 'Jincaizi' in heat resistance through comprehensive analysis of membership function.The Pn, Cond, Tr of Phlox paniculata become descend as the temperature become higher. The Ci is descend in 30?/18?,35?/21? and 40?/24?, stomatal limitation is reason for the descend of Pn in these treatments; The Ci is ascend at 45?/27?, non-stomatal limitation is reason for the descend of Pn in this treatment.