Study on regeneration system optimization of Zoysia japonica cv. Zenith in vitro

Mature seeds of Zoysia japonica cv. Zenith were used as explants for callus induction. The result showed that the optimum medium of callus induction was MS medium containing 4.0 mol/L 2,4D. The frequency of callus induction was 69.9%, and the rate of embryogenic callus was 28.78%. Embryogenic callus contained two callus types. Type I was yellowy, wettish and granular(27.36%) and TypeⅡwas yellow, thirsty and granule(1.42%). During callus subculture, the embryogenic callus could maintain the plant regeneration capability by increasing agar concentration. The optimum differentiation medium was MS medium plus KT 4.0 mg/L or 6BA 3.0 mg/L and the ratio of shoot differentiation was over 90%. The suitable rooting medium was 1/2 MS medium and the rooting ratio was 100%.