Establishment of Efficient Surface Sterilization Protocol on Different Types of Field Grown Strawberry Explants (Fragaria x ananassa Duch.)

Abstract

The present study was conducted to develop the effective disinfection protocol for the in vitro micropropagation of strawberry (Fragaria x ananassa Duch) with the use of shoot tips, runner tips, nodal segments and leaf segments as explants. The explants used in this study were surface sterilized using antibiotics, fungicides and other sterilants for different time durations. Although using the same sterilants, the most effective and successive way of using sterilants is different upon the time duration for each sterilant. In this study, two sterilization protocols were used and each protocol included same fungicide and antibiotics concentrations for the same time durations but there were slightly different concentrations and time durations of other sterilants. The present investigation revealed that the most effective way of sterilization protocol which were observed on the nodal segments while treated with protocol II including (10ml/L) fungicide solution for 2 hours, (500mg/L) concentration of ciprofloxacin for 1 hour, (20%) chlorox solution with two drops of Tween 20 for 5 mins, (70%) ethanol solution for 5 mins and (0.1 %) mercuric chloride solution for 4mins. However the same sterilants using the same sterilization time did not give raise the survival rate for runner tip explants, because these treatments resulted in tissue necrosis and contamination and then finally the death of the explant materials. And also, the explants of shoot tips and leaf segments were not shown the effective result compared with using nodal segments. So, for the micropropagation of field grown strawberry, the sterilization protocol II was suite for the nodal segments used as explants for the culture initiation on MS basal medium.