豆梨和杜梨砧木根系中多胺代谢与高温胁迫的关系研究

目的]探讨豆梨(Pyrus calleryana Dcne)和杜梨(P.betulaefolia Bunge)砧木根系中多胺代谢与其耐高温胁迫的关系,对维持根系正常代谢具有重要意义。方法]以豆梨和杜梨实生苗为试材,比较了45℃处理下2种砧木叶片落叶率的变化,以及在30和45℃下供试材料根系内源多胺种类、形态和含量变化。结果]豆梨达到65%落叶率的时间比杜梨早8 d;2种砧木根系中均存在游离态和结合态腐胺、己二胺、亚精胺和精胺4种内源多胺;高温胁迫导致2种供试材料的游离态和结合态腐胺、亚精胺及精胺的含量均升高,其中杜梨根系中游离态腐胺、亚精胺和精胺含量,以及结合态精胺含量显著高于豆梨。结论]多胺代谢变化与供试材料的耐高温胁迫能力有密切关系。

Research of the Relationship between Endogenous Polyamine Metabolism in Roots and High Temperature Stress of Pyrus calleryana Dcne and P.betulaefolia Bunge

Objective] The aim was to discuss the relationship between endogenous polyamine metabolism in roots and high temperature stress of Pyrus calleryana Dcne and P.betulaefolia Bunge,which had an important significance of maintaining normal metabolism of roots.Method] The seedlings of Pyrus calleryana Dcne and P.betulaefolia Bunge were used as experimental materials,the changes on defoliation rate of two rootstocks under 45 ℃ were compared,and content changes of free and conjugated polyamines in roots of two rootstocks under 30 and 45 ℃ were analyzed.Result] The results showed that the time when defoliation rate appeared over 65% in Pyrus calleryana Dcne was 8 days earlier than that in P.betulaefolia Bunge.Four kinds of polyamines,free and conjugated putrescine（Put）,hexanediamine（Hex）,spermidine（Spm）,spermine（Spm） existed in roots of the two rootstocks.High temperature stress leaded free and conjugated Put,Spd and Spm content to increase,and content of free Put,Spd,Spm and conjugated Spm in P.betulaefolia Bunge was significantly higher than those in P.calleryana Dcne.Conclusion] The research indicates that there are close relationship between endogenous polyamine metabolism change and high temperature tolerance of different experiment materials.