Responses Of Phenolic Compounds In Poplar To Temperature Strikingly Drop In Spring

The experiments were carried out to study the correlations between the change in contents of phenolic compounds(condensed tannin;lignin;total phenol;flavonoid)in different frozen resistance poplars(P.psuedo-simonii×P.nigra×P.nigra CL.' HeilinⅢ';P.psuedo-simonii×P.nigra×P.nigra CL.'A5';P.Xiaohei Huang)and temperature strikingly drop at the stages of germination,budding and leaves beginning opening in spring.1.Temperature strikingly drop induced the increase in the relative membrane permeability and the content of MDA,the change trend was almost identical.Generally,the effect of temperature drop on cell membrane of HeilinⅢwas larger man others,Xiaohei Huang was least.With temperature dropped the contents of soluble sugar were increased,higher in leaves than in branch barks.2.At the same stage,the larger temperature dropped,the more phenolic compounds contents increased;the contents of phenolic compounds in branch barks had a largest change at the stage of germination.In varied phenolic compounds,lignin content had a significant change in P.Xiaohei Huang with strong frozen resistance,condensed tannin and total phenol centents were significant changed in P.psuedo-simonii×P.nigra×P.nigra CL.' Heilin IIP with weak frozen resistance and P.psuedo-simonii×P.nigra×P.nigra CL.'A5' with common frozen resistance,flavonoid content was no significant difference among different frozen resistance poplars.3.The change in leaves and branch barks of poplar was significant in varied phenolic compounds.The contents of condensed tannin and total phenol were higher in branch barks, flavonoid was higher in leaves,lignin was almost same,varied phenolic compounds may play different role in cold resistant system of poplar.