ABSTRACT
Objective: To clone the dihydroflavonol 4-reductase (DFR) gene from the capitulum of Chrysanthemum morifolium and study its expression at different stages of flower bud differentiation period, and in different periods of flowering in different tissues. Methods: Two pairs of primers were designed according to the reported DFR gene sequences of C. morifolium, target fragments were amplified by RT-PCR, connected, and transformated, then positive cloning was detected by PCR and then sequenced. Results: Sequencing results showed that 1 152 bp sequence was acquired with the largest open reading frame of 1 029 bp, which encoded 342 amino acids. Blast comparison was carried out on NCBI. The gene had higher homology compared with the DFR from other species. The sequence of DFR gene was cloned from C. morifolium. Quantitative PCR showed that the gene expressions were different at different stages of flower bud differentiation period, and in different periods of flowering in different tissues. The highest expression of DFR gene was at day 50 of stages of flower bud differentiation period; And in flowering the highest expression of DFR gene is in tubular flowers in the period I and the lowest expression is in the receptacle in period II. Conclusion: The DFR gene of C. morifolium cv. 'Hangju' is cloned. The expression of DFR gene is different both in time and in space. The highest expression is in the period from the buds mature to the capitulum open completely.