| Various environmental stresses occur during the breeding of medicinal plant and affect the normal growth of plants and the accumulation of effective components.Researches have shown that attapulgite could relieve the effects of heavy metals and allelopathic on plant growth.In this paper,seedings of Codonopsis pilosula were used as experimental material to study the effects of copper,cadmium and ferulic acid on photosynthesis,osmotic substance content,antioxidation,biomass and seed germination,including the alleivation of attapulgite on adverse effects.The main findings are described as follows:(1)The effect of cadmium stress on plant PSⅡ has obvious concentration and time effects,which could reduce photochemical efficiency and increase nonphotochemical quenching of PS Ⅱ.The application of 10 mmol/L Cd stress in different proportions of matrix for 48 hours,the adding of the applititude at 1/50(V/V)has the most obvious effect on stress relief.At the same time,the decrease of chlorophyll content and the increase of MDA,soluble protein content,POD,CAT and APX enzyme activities caused by cadmium stress were alleviated.(2)The effect of copper stress on the photochemical efficiency of PSⅡ also has a significant concentration effect,reaching a very significant level at 6 mmol/L.At the same time,the effect of copper stress reduced chlorophyll content,increased the content of soluble sugar,soluble protein,MDA and the activity of POD,CAT and APX.Under the stress condition,the adding of proper amount of attapulgite could effectively alleviate the adverse effects.(3)The effect of ferulic acid(FA)on seed germination was not obvious at low concentration,and higher than 1 mmol/L prolonged seed germination time and affected seed vigor.If there exist FA in the soil before sowing,the photochemical efficiency and biomass of the seedlings both are low concentrations promote and high concentrations restrained.The inhibitory effect occurs when the concentration reaches1 mmol/L.If FA stress is encountered in the seedling stage,the chlorophyll fluorescence will deepen with the increase of concentration and the prolongation of time.The addition of different proportions of attapulgite could alleviate the adverseeffects of FA.On the whole,the effect of 1/50(V/V)on the effect of pre-seedling and seedling stage was the most obvious,and the increase of the three antioxidant enzymes activities of POD、CAT、APX was obviously alleviated by the matrix.In conclusion,appropriate proportion of attapulgite could alleviate the stress of copper,cadmium and ferulic acid in the soil,which could alleviate the inhibition of plant growth ferulic acid during actual planting process.The corrective effect is most obvious when the volume ratio of the attapulgite to the matrix is 1/50. |
