In vitro explant sterilization and bud initiation studies of four strawberry cultivars

Abstract: A series of in vitro experiments were conducted using four strawberry cultivars to investigate their survival response to different disinfectants, explants regeneration response to liquid and solid media, in vitro bud initiation response to BAP enriched media, clonal multiplication response to various BAP concentrations in MS and Knop media and bud initiation response to sugars sources. Highest meristem survival (75%) was recorded in cultivars Osogrande and Toro when treated with 0.5% NaOCl for 15 minutes, however, 75% explants of Chandler survived when treated with 1% NaOCl for 10 minutes. Similarly, maximum survival (58-71%) was observed in Chandler, Osogrande and Islamabad Local when internodal segments were treated with 0.5% NaOCl for 15 minutes. However, the survival percentage of these cultivars significantly varied at different NaOCl concentrations when petioles segments were used as explants. The results of second experiment indicated that highest rate of survival (79.20%) was achieved in Toro when meristems were cultured on solid MS media containing 0.5 mg/L GA₃. In another experiment, maximum percentage (83) of bud initiation was recorded in Osogrande at 0.5 mg/L BAP. Findings of experiment regarding clonal multiplication of in vitro shoots derived from meristem showed that maximum buds formation per culture (25, 20 and 15) were obtained in MS media containing 1.5 mg/L BAP and 0.1 mg/L IBA in cultivars Osogrande, Chandler and Islamabad Local respectively, however, similar buds formation response was varied with the cultivars when knop media was used. Similarly, when sugar sources were studied cultivar Osogrande initiated highest number of buds (20) at sucrose based MS media containing 0.8 mg/L Kinetin and 0.2 mg/L NAA, however, cultivars Chandler and Islamabad Local initiated 15 buds at sucrose based MS media containing 0.6 mg/L Kinetin and 0.2 mg/L NAA.