Abstract:

To establish an efficient tissue culture system for rapidly propagating Cyclocarya paliurus, axillary buds from the stem segment were used as explants and cultured on WPM medium. Effects of the different types and concentration of plant growth regulator on the germination of axillary buds and proliferation of multiple shoots were studied. The results showed that all nine hormone combinations promoted germination of axillary buds to some degree, among which the most suitable hormone combination was 6-BA 3 mg ·L^-1+2ip 1 mg·L^-1+NAA 0.1 mg ·L^-1, with 83.33% germination rate, the best growth state, but inducing only single bud in every treatment. Multiple shoots could be induced when the single bud was cultured in medium with TDZ, the optimal hormone combination was TDZ 0.1 mg·L^-1 +NAA 0.1 mg ·L^-1, and the germination rate and multiplication coefficient reached up to 100% and 7.33 respectively. With addition of 2.0 mg ·L^-1 GA₃, the elongation of multiple shoots was efficiently improved, and the shoots were healthy and strong, which provided a good foundation for rooting later. The study provided a basis for establishing rapid propagation system for Cyclocarya paliurus with tissue culture , and provided technical reference for developing rapid propagation of other forest species.

Key words: plant growth regulator, Cyclocarya paliurus, axillary buds, germination, multiple shoots, proliferation