Abstract: The effects of different cadmium ion concentrations on callus induction, growth and plantlet regeneration of creeping bentgrass were studied. When cadmium ion concentration in medium was below 2.50 mg/L, the induction frequency was higher than that of control. The induction frequency reached up to 83.3% when cadmium ion concentration in medium was 2.50 mg/L, indicating that low cadmium ion concentration may have stimulating effect on callus formation. As cadmium ion concentration increased, the induction frequency remarkably declined and callus formation was completely inhibited when cadmium ion concentration was over 50.00 mg/L. In the early days of the callus growth (0~30 d), the calli on the medium containing 12.50 mg/L cadmium ion were morphologically largest, and further prolonged growth (30~45 d) exhibited that one lower concentration (2.50 mg/L) gave stronger stimulating effect. During regeneration, regenerated seedlings grew best on the medium where 1.25 mg/L cadmium ion concerntration existed.

Key words: cadmium ion, callus, creeping bentgrass, plantlet regeneration