Effects Of Cd Stress On Physiological Characteristic And The Regulation Of Silicon Of Sasa Argenteastriatus

In order to explore the effect of Cd stress on physiological characteristics and theregulation of silicon of bamboos, laid a theoretical foundation for bamboos'large-scale cultivation in mining area.A soil culture experiment was conducted withthe experimental materials of potted seedlings of Sasa argenteatriatus to study theeffects of different concentrations of Cd (100mg/kg,400mg/kg,800mg/kg)onphysiological characteristics and the regulation of different concentrations of Si(100mg/kg,300mg/kg,500mg/kg)under the Cd stress. The results showed as follows:1. The effect of different concentrations of Cd on physiological characteristics of SasaargenteatriatusCompared with the CK group, the treatment of higher concentrations(400mg/kg and800mg/kg) of Cd reduced the protective enzyme activities: the activity of superoxidedismutase(SOD) and the activity of peroxidase(POD), the content of soluble protein(Pr), and the chlorophyll relative content (SPAD), increased the content ofmalondiadehyde (MDA) to some extent; Net photosynthetic rate (Pn), Stomataconductance (Gs) and Transpiration rate (Tr) of Sasa argenteatriatus leaves werereduced, intercellular CO2concentration (Ci) was improved, declined chlorophyllfluorescence parameters: PSII maximal photochemical efficiency (Fv/Fm),PSIIpotential activit (Fv/Fo),PSII effective photochemical efficiency (Fv'/Fm'),Actualphotochemical effeciency of PSII (ΦPSII), Electron transport rate (ETR) andPhotochemical quenching coefficient (qP) to some extent, Non-photochemicalquenching coefficient (NPQ) was improved. Generally, The above indexes changealong with the decreasement of Cd stress value and the extension of time, weredifferent significant with Ck in the treatment of the60d. This shows that higherconcentrations leaves to Sasa argenteatriatus generate obvious physicaldamage.However, low concentrations of Cd (100mg/kg) stimulus blade biologicalactivities to some extent. The above indexes change is contrast with the treatment ofhigher concentrations(400mg/kg and800mg/kg) of Cd.2. The regulation of different concentrations of Si under the Cd stress of SasaargenteatriatusCompared with the Cd stress group(without Si), the treatment of Si inhibit thedecline of the protective enzyme activities(SOD,POD), the content of Pr, and SPAD,the increasement of MDA to a certain extent, reduced the change range ofPhotosynthesis parameters:Pn,Gs and Tr to some extent,but no significant effect to Ci The treatment of Si inhibit the decline of chlorophyll fluorescence parameters of Sasaargenteatriatus, reduced the change range of Fv/F0,Fv'/Fm',ΦPSII,ETR and qP,inhibit the increase of NPQ. Treatment of100mg/kg and500mg/kg Si didn't changethe trend of diurnal course of photosynthesis, but which effected the factors of middaydepression, Treatment of300mg/kg Si change the trend of diurnal course ofphotosynthesis,which have a peak on10:00.From10:00to12:00.Pn,Gs and Stomatallimitation valve(Ls) reduced,but Ci almost has not changd. That Suggests300mg/kgof Si significantly reduce the non-stomatal factors. The treatment of Si improved theability of Sasa argenteatriatus to use of light energy. In a word, the treatment of300mg/kg of Si was the optimal concentration. That Suggests proper concentration ofSi treatment can effectively relieve the physical damage of Sasa argenteatriatus underCd stress.