关键词: 菊花, 光周期敏感性, FT类似基因, 实时定量RT-PCR

Abstract: A FT-like gene named CmFT（Genbank accession No. GQ925916）was cloned by RT-PCR and rapid amplification of cDNA ends（RACE） using Chrysanthemum morifolium Ramat.. A predicated 525 bp open reading frame was deduced in the cloned sequence，which encoded 174 amino acids. By alignment analysis，the deduced amino acid sequence contained two critical residues and conserved region，both of which identified as diagnostic of true FT. The gene was proposed to belong to FT subfamily by phylogenetic analysis. Fluorescence quantitative RT-PCR system followed by SYBR GREEN was established to examine the expression of CmFT under different part of mature tissues and different photoperiod treatments. CmFT gene expressed highest in flower buds，next in stem and lowest in leaf. Expression of CmFT under the short day（SD）treatment was significantly high than that under long day（LD）. Abundance of CmFT indicated a diurnal rhythm in SD-grown plants，so that its levels showed a decreasing trend under light，a rise during night and the maximal level before the coming of light. Under
the LD treatment，the expression level tended to be zero. The results suggest that CmFT is associated with
photoperiod sensitivity and may function in regulating photoperiodic flowering in Chrysanthemum.

Key words: Chrysanthemum, photoperiod sensitivity, FT-like gene, real-time quantitative RT-PCR