Rapid and efficient callus induction and plant regeneration from seeds of zoysiagrass (Zoysia japonica Steud.)

摘要

A rapid and efficient in vitro culture system has been established in zoysiagrass (Zoysia japonica Steud.). Embryos isolated from mature seeds were used to induce callus, which improved callus formation and shortened the culture period. A high concentration of 2,4-dichlorophenoxyacetic acid (5 mg L−1) in combination with low concentration of 6-benzyladenine (0.2 mg L−1) was proved to be suitable for callus induction in zoysiagrass. Eight types of calli were observed; friable callus was the most regenerable type. Shoot regeneration efficiency was improved by using 1 mg L−1 of thidiazuron with 1-naphthaleneacetic acid (0.05 mg L−1) and gibberellic acid (0.1 mg L−1). Zoysiagrass shoots continued to grow in MS medium, and rooted in half-strength MS medium. With this system, it appears the duration of in vitro regeneration could be shortened to 16 weeks for zoysiagrass, i.e. from inoculation of embryos to regeneration of plantlets with shoots and roots.