2021 年 86 巻 4 号 p. 367-374
The purpose of this experiment is to select Cyclocodon lancifolius (Roxb.) Kurz strain with a high yield and quality to enhance environmental tolerance. Therefore, we report the first case of polyploid induction in C. lancifolius. The treatment of seed and in vitro shoot tips with colchicine was explored as a means of inducing polyploid, and polyploidy was effectively identified by chromosome counting. After successful induction of polyploid, the optimized in vitro culture for polyploid plants was investigated via a complete combination experiment. The results showed that seeds were not suitable for polyploid induction. The shoot tips were treated with 0.05% colchicine solution for 36 h and then transferred to Murashige and Skoog (MS) medium supplemented with 0.1 mg L−1 6-benzylaminopurine (6-BA), 1.0 mg L−1 α-naphthaleneacetic acid (NAA) and 0.05% colchicine for 60 h. Finally, rooting culture was conducted in the above medium without colchicine, yielding the highest induction rate (25.42%), without chimerism. Compared with diploid plants, autotetraploid plants had more distinctive characters, such as larger and darker green leaves, more obvious veins, thicker stems, and more developed root systems. Furthermore, in MS medium supplemented with 1.0 mg·L−1 NAA and 0.01 mg·L−1 6-BA, tetraploid shoots formed complete plantlets through one-step culture, with above 7.0 multiplication coefficient and 100% rooting rate. The survival rate was 100%. The induction system for the autopolyploid of C. lancifolius was successfully established, which provided an experimental basis for breeding heredity and variety improvement.
