Changes In Levels Of Endogenous Hormones After Root-cutting In Roots And Blades Of Quercus Variabilis Seedlings

In the process of vegetation construction,the roots of transplanted seedlings is the most vulnerable during transplanting,which will seriously affect the roots quality of seedlings and afforestation effect.When the roots of forest were damaged,endogenous hormones emerged stress changes.In order to study the stress reaction to root-cutting of endogenous hormones after the damage of root-cutting Quercus variabilis seedlings answer the blades reaction to changes of endogenous hormones in roots and explore the mechanism of root-sourced chemical signal and rootblade interaction.In this paper,1a Quercus variabilis seedlings were used as adopt ELISA method to measure relations between changes of endogenous hormones [such as IAA,ABA,GA3,GA4,ZR,DHZR,Me JA,i PA and BR] and root-cutting [as a stressing factor,setting 3 treatments including 1/2,1/3 root-cutting,and uncut(CK)] in roots and blades of Quercus variabilis seedlings 2 d,15 d,30 d,60 d and 90 d after root-cutting treatment.The main conclusions are as follows:(1)The ABA contents of roots began to increase significantly after the root-cutting of Quercus variabilis seedlings.The ABA contents of roots increased more with increasing proportion of root-cutting;The ABA contents of roots decreased 15 to 60 days after root-cutting treatment.The ABA contents of blades began to increase 15 to 60 days after root-cutting treatment.The ABA contents of roots and blades at rootcutting group basically maintained the same trend as the CK group 60 days after rootcutting.However,Me JA in blades and roots of Quercus variabilis seedlings was lower than that of CK group after root-cutting treatment.1/2 root-cutting group was overall higher than the 1/3 root-cutting group of same period,and whole growth process showed a slowly increasing trend.The largest increasing was 1/3 root-cutting treatment group.(2)As gibberellins(GA4 and GA3),GA4 contents of roots at 1/3 root-cutting group and CK group was greater than that of 1/2 root-cutting group in the same period after root-cutting treatment;30 to 90 days after root-cutting GA3 contents of 1/3 root-cutting group in roots was larger than 1/2 root-cutting group and CK group in the same period.The effect of root-cutting on GA3 and GA4 in blades of Quercus variabilis seedlings was not obvious.Only contents of GA4 in blades was higher than that of CK group 2 to 60 days after root-cutting.(3)After root-cutting treatment,i PA contents in roots of Quercus variabilis seedlings were higher than that of CK group.with decreasing proportion of root-cutting,the difference of i PA contents was greater between root-cutting group and CK group.i PA of blades appeared U-shaped,which was higher than that of CK group 15 to 30 days after root-cutting.ZR and DHZR contents in roots of Quercus variabilis seedling after root-cutting was lower than that of CK group.2 days after root-cutting DHZR was higher than that of CK group.For DHZR,root-cutting group was higher than CK group 60 to 90 days after root-cutting,and 1/2 root-cutting group was higher than the 1/3 rootcutting group;for ZR,30 to 60 days after root-cutting 1/3 root-cutting group was higher than CK group,and 1/2 root-cutting group was lower than the CK group.However,the effect of root-cutting on ZR in blades was not obvious.2 days after root-cutting,DHZR in the blades was lower than that of root-cutting group.It was higher than root-cutting group 30 to 90 days after root-cutting.(4)After the roots of Quercus variabilis seedlings were damaged by root-cutting,IAA contents of roots and blades were lower than that of CK group at the same time,and higher than CK group 90 days after root-cutting.BR contents of Quercus variabilis seedling at root-cutting group were higher than that of CK group.However,BR contents of blades didn't change significantly,and 30 to 60 days after root-cutting the root-cutting group was lower than CK group.(5)After 1a Quercus variabilis seedlings were cutted roots,its height,root tips,weight of roots and blades,total biomass and blades biomass ratio reduced,and lateral roots number and roots biomass ratio increased.at 1/3 root-cutting group the height,root tips,root and blades weight,total biomass,blades biomass ratio and lateral roots number of seedlings were higher than that of 1/2 root-cutting group,However,roots biomass ratio of 1/3 root-cutting group were lower than that of 1/2 root-cutting group.