Study on selection and sterilization of explants of Banksia serrata in tissue culture

Banksia serrata is one of the perennial woody species belonging to Proteaceae family.Its surface is densely tomentose,resulting in extremely high pollution rate of explants in tissue culture.The effects of explants types,seasons,bud positions,and sterilization method on explants survival were studied.The results show that the optimal months to take explants were from October to December,with the pollution rate below 30% and the survival rate of 63.3%.The optimal explants were cut from the upper part of semilignified softwood stems.The best sterilization method was that the explants were washed with 1 000 times dilution of carbendazim for three times,and then dipped in 4% NaClO + 0.01% Tween 80 for 12 min,and the explants pollution rate was reduced to 26.7%.However,both alcohol and HgCl2solutions killed the explants in a short time,and was not suitable for explants disinfection.