Abstract:In order to study the mutagenic effect of colchicine on germinating Chinese fir seeds, three sources of Chinese fir seeds were soaked in 0.9% colchicine solution, and then the seeds were sowed. 60d later, the mutation rates of seedlings were calculated, and the cell ploidy in different fractions of mutant seedlings was detected with a flow cytometry instrument. Results showed that mutation rates were different among three sources of Chinese fir seeds soaked with colchicine solution, the highest mutant rate was 23.45%, from full sib Z3#. The mutant seedlings obtained from three sources of Chinese fir seeds all showed a shortened radicle and a significantly swelled hypocotyl. Ploidy detection shown that 57.2% cells from the radicle were aneuploid, 42.04% of the lower and 9.15% of middle fraction of the hypocotyl cells were tetraploid, and all the cells in the upper fraction of hypocotyl and in the total cotyledons were diploid. Seedlings with significantly mutated phenotypic traits and cell ploidy could be obtained by soaking seeds with colchicines solution. The research has laid a foundation for further studies on creating new homologous polyploidy germplasms of Chinese fir.