Factors Affecting Callus Induction Rate and Formation Time of Mature Seed of Zoysia japonica

The induction rate and callus formation time are the key parameters during the process of callus induction.Mature seeds of Japanese lawngrass(Zoysia japonica) were used as explants to investigate the effect of the factors,including grinding,immersion and the way of transferring explants on the medium,on callus induction rate and formation time.Results are as follows: when the culture medium for callus induction was MS+ 2,4-D 5 mg/L + L-Pro 500 mg/L + sucrose 30 g/L + agar 7 g/L,pH5.8,(1) the callus induction rate was significantly improved after seeds were ground;(2) with the way of transferring explants on medium at random,the induction rate increased;(3) the induction rate was higher when the mature seeds were immersed in water for 72 h.Taken together,these findings suggest that after the mature seeds were ground,immersed in water for 72 h and transferred on medium at random,a little callus appears from explants after seeds were on medium 5～7 d,the callus formation comes to peak at 9～11 d,callus can be in subculture after 14 d,and the callus induction rate are as high as 95.6%.