Effects of medium components and subculture period on plantlet regeneration of creeping bentgrass

Mature seeds of creeping bentgrass were used as explants to study the effects of 2,4-D concentration,combination of 2,4-D and 6-BA,and sucrose concentration on callus induction and the effects of subculture time,6-BA concentration,sucrose concentration on plantlet regeneration. The results showed that combination of 2 mg·L-12,4-D and 0. 1mg·L-16-BA produced the best result with 94% callus induction rate,and 30 g·L-1sucrose gave the best result,callus induction rate being 82%. During regeneration process,1 mg·L-16-BA could bring the best differentiation frequency(62%) and 40 g·L-1sucrose resulted in the highest plantlet regeneration frequency(52%). The callus after the second time subculture(40 d after explants were laid on medium) gave the highest differentiation frequency(71%) which began to decline as subculture prolonged. After the fifth time subculture(100 d),only 18% differentiation frequency was obtained.