光周期对春石斛开花及多胺含量的影响

以春石斛为试材，研究光周期对其开花及多胺（腐胺、亚精胺和精胺）含量的影响，以期了解春石斛开花的光周期特性以及期间能源物质多胺的变化规律。结果显示，春石斛短日照处理植株开花较长日照处理的提前约18d，为称量性短日照植物；同时，短日照处理植株的花芽多，开花量犬，花径较长日照大。不同光周期诱导开花过程中，春石斛叶片内腐胺含量最高，波动较大，短日照处理下基本维持比长日照高的水平。亚精胺含量其次，且随生长发育逐渐升高，短日照处理下一直保持比长日照高的水平。精胺含量最低，变化不大，短日照下保持与长日照相同或略高的水平。由此推测，春石斛为称量性短日照植物，高水平的腐胺和亚精胺可能与春石斛花芽的形成有关。

Effects of Photoperiod on Flowering and Polyamine Contents of Nobile-Type Dendrobium

In order to know the flowering characteristics of the nobile-type Dendrobium as well as the changes of polyamines under different photoperiods, flowering and contents of endogenous putrescine （Put）, spermidine （Spd） and spermine （Spm） in the leaves of Dendrobium during flowering were studied. The results were as follows, the first flowering time of Dendrobium under short-days （SD） was earlier than that under long-days （LD） by 18 days. What＇s more, plants had more flower buds, flowers and longer flower diameter under SD than LD. Flowering under different photoperiods, the content of Put in the leaves among the 3 polyamines was the highest and changed in a large scale during development, while mostly the content of Put under SD was higher than that under LD. The content of Spd was next to the Put which increased with the development of the flower bud and maintained a higher level under SD than LD. The content of Spm was the lowest and little change could be found during the flowering process and between different photoperiods. The results suggested that the nobile-type Dendrobium was a facultative short day plant and the flowering of which might be related to high contents of Put and/or Spd.