Plant Regeneration of Zoysiagrass from Embryo‐Derived Callus

Abstract

Tissue culture methods could enhance development of improved cultivars of zoysiagrass (Zoysia japonica Steudel). A tissue culture system for callus induction and plant regeneration of zoysiagrass was developed. Embryos were aseptically excised from seeds and over 90% produced callus. Embryogenic callus was produced on Murashige‐Skoog (MS) agar medium supplemented with 2,4‐D (2,4‐dichlorophenoxy) acetic acid, but not on N6 medium. A 2,4‐D concentration of 1.0 mg L−1 resulted in greater callus production than higher concentrations. A 16‐h photoperiod of fluorescent light (65 μmol photon m−2 s−1) increased callus production over dark conditions. Direct elimination of 2,4‐D and dark callus induction resulted in greater regeneration frequency and a higher number of plantlets per callus than gradual elimination and light callus induction. Normal plantlets were transplanted to soil and grown to maturity in the field, where overwinter survival was exhibited.