Effects Of Simulated Acid Rain On Corn Seedlings And Soil Microbes

Using the indoor potted-corn as material. We studied the effects of diferent acidities simulated acid rain on the seed germination, growth and physiological characteristics of seedling leaves, physical and chemical properties,soil microorganisms and soil enzyme activity in rhizosphered soil of Jidan415, ulteriorly analysed the correlation of them;and studied the time-delay effects of Jidan415 seedling leaves after the deal with simulated acid rain, and mensurated the growth and physiological characteristics of seedling leaves of three species of corn(Hei301,Jidan522 and Yindan2) in order to evaluate the best fastness plants in them by using subordination function method. The results are following:1,The simulated acid rain had certain inhibition on the germination rate of Jidan415, and with the intensification of the acidity, there were more and more inhibition; The visible injury was more and more bad with the decrease of pH value, and the injury threshold values of Jidan415 was observed at pH<4.0;With the intensification of the acidity of simulated acid rain, inhibition on the seedling growth of Jidan415 was increased obviously;The chlorophyll content, chlorophyll a/b ratio, dissolve sugar content, catalase activity of Jidan415 seedling leaves and its root activity were significantly declined;but the content of malondialdehyde, the permeability of cell membranes and peroxidase activity of Jidan415seedling leaves were increased with the decline of pH value of simulated acid rain, moreover with the increase of the intensification of simulated acid rain the superoxide dismutase activity of Jidan415 seedling leaves was increased then decreased papidly;The total nitrogen,total phosphorus, total potassium and available phosphorus were firstly increased then decreased with the increase of acidity;the available nitrogen and available potassium were decreased with the decline of pH value;The number of soil microorganisms in rhizosphered soil of Jidan415 was reduced with the simulated acid rain treatment;Under simulated acid rain stress the growth and reproduction of the physiological groups of nitrogen were suppressed obviously;The sucrase activity, dehydrogenase activity were firstly increased then declined with the increase of acidity, but the urease activity was decreased all though;2,Correlation analysis showed:the pH value of simulated acid rain was negatively correlated of different degree with malondialdehyde, the permeability of cell membranes and peroxidase activity, but was positive correlated of different degree with the chlorophyll, chlorophyll a/b ratio, catalase activity, superoxide dismutase activity, dissolve sugar and root activity of Jidan415;the pH value of simulated acid rain was positive correlated of different degree with total nitrogen, total phosphorus, total potassium,available phosphorus, vailable nitrogen, available potassium, soil microorganisms and soil enzyme activity in rhizosphered soil of Jidan415;3,Association analysis showed:the effects of nitrogen physiological microbes groups in rhizosphered soil of Jidan415 seedlings impact on the total nitrogen and available nitrogen were the greatest; azotobacter in rhizosphered soil of Jidan415 seedlings with these fertility factors (total nitrogen,total phosphorus, total potassium, available phosphorus, available nitrogen, available potassium)associated with a greater extent; Jidan 415 seedlings rhizosphere soil sucrase and urease activity had the greatest impact on the total nitrogen and available nitrogen; sucrase activity impact on total potassium content in the whole is minimum; sucrase associated with the total nitrogen is greatest;4,There is certain degree of time-delay indury of simulated acid rain on Jidan415 seedlings;5,In the three species of tested varieties, Jidan522 acid-fast are the strongest, followed by Yindan2, Hei301 weakest.