the protocol for surface strerilization is depending on your plant matarial and time. I am using two streilization type (for anther culture) same time.
1st. ethanol 96% for 1 min.
2nd. HgCl2 %0.1 for 10 min.
3th rinsed with sterile (autoclaved) distilled water 3 times
but you have to search best sterilization protocol for your plant material.