Analysis Of Phenolic Acids In Forest Soil And Allelopathy Of Phloridzin To 8 Forage

Silvopasture systems is a multi-level artificial vegetation formed by the organic combination of forest and grassland(forestry and animal husbandry),which is an advanced land management method.The trees and grassland growing together will secrete allelochemicals and interact with each other.In recent years,there are more and more researches on allelopathy,but most of them are aimed at the effects of self toxicity or exogenous allelochemicals on fruit trees.This study aimed at the analysis of phenolic acid allelochemicals in different garden plants and fruit trees,aiming to detect the composition of soil phenolic acid allelochemicals and analyze its allelopathy to grassland.This study is divided into three parts:In experiment 1,the soil of four kinds of fruit trees and four kinds of garden plants were selected as the test materials,which were apple,grape,pear,peach,amygdalus triloba,platycladus orientalis,rosa xanthina and syringa aromaticum.Analysis of phenolic acids in different plant soils by ultrasonic extraction and HPLC.The results showed that cinnamic acid,benzoic acid,p-hydroxybenzoic acid,chlorogenic acid and ferulic acid are common phenolic acids,which exist in all tested soils.The total amount of phenolic acid in orchard soil was significantly higher than that in garden plant soil.The content of phlorizin in apple orchard soil was the highest,and the range of phlorizin content was 41.40 to 169.07 mg/kg.In experiment 2,the allelopathy of phloridzin on the germination of 8 forage seeds was selected.Set 5concentration gradients of 50 mg/L,100 mg/L,200 mg/L,400 mg/L and 600 mg/L,eight kinds of forages are white clover,red clover,lotus japonicus,chicory,ryegrass,tall fescue,orchardgrass and kentucky bluegrass.The results showed that the germination rate,germination potential,germination index,germination delay,germination irregularity and other phenomena appeared after the treatment.There are obvious phenomena of "low promotion and high inhibition" in orchardgrass and red clover.The other herbages show a trend of stronger inhibition of seed germination with the increase of concentration.The order of allelopathy inhibition effect of different concentrations of phloridzin was ryegrass > tall fescue >kentucky bluegrass > chicory > lotus japonicus > white clover > red clover > orchardgrass.In experiment 3,the allelopathy of phloridzin with different concentrations on the growth of 8 kinds of seedlings was studied.Set 5 concentration gradients of 50 mg/L,100 mg/L,200 mg/L,400 mg/L and 600mg/L,eight kinds of forages are white clover,red clover,lotus japonicus,chicory,ryegrass,tall fescue,orchardgrass and kentucky bluegrass.The results showed that the growth of grass seedlings was mostly inhibited after treatment.The length of root decreased,the content of chlorophyll decreased,the activity of antioxidant enzyme decreased,the content of MDA increased,the plant was low and the growth trend became poor.Red clover has the phenomenon of "low promotion and high inhibition",white clover,orchardgrass and chicory all show the trend of stronger inhibition of seedling growth with the increase of concentration.The order of allelopathy inhibition effect of different concentrations of phloridzin on 8herbage seedlings was ryegrass > chicory > white clover > lotus japonicus > tall fescue > orchardgrass >kentucky bluegrass > red clover.In conclusion,phloridzin,p-hydroxybenzoic acid,cinnamic acid,benzoic acid,chlorogenic acid and ferulic acid are common phenolic acids in soil.The inhibitory effect of phloridzin on ryegrass was the strongest,while that on orchardgrass and red clover was the weakest.In order to grow grass in the forest garden,it is necessary to consider the planting of orchardgrass and red clover.