Effects Of Antibiotics On Adventitious Shoot Regeneration From In Vitro Leaves Of Pear Cultivars

Genetic transformation using Agrobacterium tumefaciens provides a means of comprehensive and effective. Effects of Ampicillin (Amp), Carbenicillin (Carb), Cefotaxime (Cef), Kanamycin (Km) and Neomycin (Nm) on callus induction and shoot regeneration from the leaves of Pyrus communis 'Bartlett' , Pyrus communis ' Cornice' and Pyrus pyrifolia 'Shenbuzhi' were studied. The results were as follows:1. From shoot regeneration rate and shoot per leaf, the optimal inducing medium for shoot regeneration of each cultivar was respectively as follows:For 'Bartlett': NN69+IBA0.1mg/L+TDZ0.9mg/L was the optimal inducing medium, rate of shoot regeneration is 69.26%.For 'Shenbuzhi': NN69+NAA0.1mg/L+TDZ1.6mg/L was the optimal inducing medium, rate of shoot regeneration is 76.67 %.For 'Cornice': MS+IBA0.1mg/L+TDZ4.0mg/L was the optimal inducing medium, rate of shoot regeneration is 66.67%.2. From callus induction rate, shoot regeneration rate, shoot per and death rate, effects of antibiotics on callus induction and shoot regeneration from the leaves of pear were studied. The results were as follows.-(1) Ampicillin hadn' t significant effects on the rates of callus induction and shoot regeneration from the leaves of 'Shenbuzhi' within concentrations at 50-300mg/L, but the rates of callus induction and shoot regeneration was greatly restrained when the concentration of Ampicillin was at 500mg/L. The influence on callus induction and shoot regeneration from the leaves of 'Cornice' was small when the concentrations of Ampicillin were at less than 1 00mg/L, but redifferentiation from the leaves of ' Cornice'was thoroughly restrained when the concentration of Ampicillin was at 500mg/L. The influence on callus induction and shoot regeneration from the leaves of 'Bartlett' was small when the concentrations of Ampicillin were at less than 500mg/L.(2) Callus induction and shoot regeneration from the leaves of 'Bartlett' was significant inhibited when the concentration of Carbenicillin at more than 200mg/L. Carbenicillin hadn' t significant effects on the rates of callus induction from the leaves of'Shenbuzhi' within concentrations at 50-200mg/L, but shoot regeneration from the leaves of 'Shenbuzhi' was significant inhibited. Redifferentiation from the leaves of'Shenbuzhi' was thoroughly restrained when the concentration of Carbenicillin was at 400mg/L. Redifferentiation from the leaves of 'Cornice' was significant inhibited when the concentration of Carbenicillin was at 50mg/L.(3) Cefotaxime hadn' t significant effects on callus induction and shoot regeneration from the leaves of 'Bartlett' within concentrations at 50-300mg/L, but shoot regeneration from the leaves of ' Bartlett' was restrained when the concentration of Cefotaxime at more than 400mg/L. The influence of Cefotaxime on callus induction and shoot regeneration from the leaves of 'Shenbuzhi' and 'Cornice' was small.(4) Kanamycin thoroughly inhibited shoot regeneration from the leaves of 'Bartlett' and ' Shenbuzhi' when the concentration of Kanamycin was at 20mg/L. Shoot regeneration from the leaves of ' Cornice' was thoroughly inhibited when the concentration of Kanamycin was at lOmg/L.(5) Shoot regeneration from the leaves of 'Bartlett' was significant inhibited when the concentration of Neomycin at lOmg/L. Shoot regeneration from the leaves of'Bartlett' was thoroughly restrained when the concentration of Neomycin at 60mg/L. The influence on callus induction from the leaves of ' Shenbuzhi' was small when the concentrations of Neomycin were at less than 40mg/L, but shoot regeneration from the leaves of 'Shenbuzhi' was significant inhibited. Shoot regeneration from the leaves of'Shenbuzhi' was thoroughly inhibited when the concentration of Neomycin was at 80mg/L. Redifferentiation from the leaves of ' Cornice' was thoroughly restrained when the concentration of Neomycin was at 20mg/L.