Abstract:

Induction of autotetraploidy Paulownia forunei from the pre-cultured leaves of the diploid with different concentrations of colchicines on the double (liquid and solid) media MS+NAA 0.1 mg·L^-1+BA 18 mg·L^-1 through chromosome numbering of the plant tip cells was conducted, and DNA content in leaf cell were investigated. The results indicated that a more significant difference of explant survival and shoot induction rates and non-significant difference of tetraploid induction rate occurred among various treatments with colchicines, a significant difference of tetraploid induction rate occurred within the treatment time of explants with colchicines, and a more significant difference of shoot and tetraploid induction rates occurred for the time of explants precultured. The tetraploid induction rate might reach 20.0% from the explants pre-cultured for 12 d and treated with 5 mg·L^-1colchicine for 72 h on the double media among the nine experiments. Moreover, leaves of the tetraploid seedlings were larger and thicker than those of the diploid ones, and the stomatal size and density on the leaf larger and thicker than those of the diploid respectively.

Key words: Paulownia fortunei, leaf, colchicine, tetraploid