The Study On Physiological Characteristics And Leaf Color-emerging Of Leaf-colored Plants Of Prunus Under Soil Drought Stress

A pot experiment was conducted with the leaves of 3-years old Prunus seedlings,with artificial controlled soil water content using weighting method.Four different levels of water stress were applied to examine the effect of water stress on physiological characteristics and leaf color emerging.The water stresses were the control(soil water content 18.11%),light stress(soil water content 14.72%),medium stress(soil water content 11.32%)and severe stress(soil water content 7.92%).The effect of physiological characteristics and leaf color-emerging under soil drought stress was studied by analysis the changes of relative conduction rate,leaf water potential,leaf relative water content,the activity of anti-oxidation enzyme,osmotic adjusting matters,photo synthesis characteristics, pigment and color parameters.The drought resistance ability was evaluated comprehensively by using subordinate function method.The main results were shown as follows:Relative leaf water content,leaf water potential,net photosynthesis rate,transpiration rate were decreased allow with the prolonged treatment under soil drought stress.Relative conduction rate,the content of praline and the activity of POD were increased allow with the prolonged treatment under soil drought stress.With water stress aggravating,the activity of SOD decreased at first and then increased,at last decreased.The content of soluble sugar increased at first and then decreased,the content of soluble protein decreased at first and then increased.With water stress aggravating,net photosyntheses rate and transpiration rate decreased,stomatal conductance increased at first and then decreased, intercellular CO₂ concentration decreased at first and then increased.With water stress aggravating,the content of anthocyanin,Chlorophyll,flavonoids, caronetanoid were increased at first and then decreased,L^*-value and b^*-value were decreased at first and then increased,a^*-value was increased at first and then decreased. Anthocyanin was the main pigment of three spices by partial correlation analysis and the main reason of the changes of leaf color-emerging of three spices.The increase of the activity of PAL and the content of soluble sugar of plant promoted the accumulation of anthocyanin and flavonoids,and enhanced ornamental value of red-leaf plant.After rewatering,the activities of SOD POD,and the content of proline were enhanced,it indicated that the drought resistance ability of three spices was enhanced. The drought resistance ability was evaluated comprehensively by using subordinate function method,and the result was Prunus×cistenena 'Pissardii'had stronger drought resistance ability,Prunus cerasifera Var.arropurea was in the middle,Prunus wrasifers 'nigra' had poor drought resistance ability.Five drought resistance ability indexes of relative leaf water content,leaf water potential,praline,SOD and net photosynthesis were confirmed by comprehensive comparation of physiological characteristics.