In vitro regeneration of exotic fruit dragon (Hylocereus undatus) from stem fraction

Hylocereus undatus, commonly known as dragon fruit, is one of the most popular exotic fruits due to its high quality and market value. This fruit is facing different constraints, such as loss of seed viability and various diseases that affect production because the seed and cutting methods are followed to create a new generation. In vitro plant regeneration is a promising technique to overcome these barriers with explants. An efficiency of this protocol was established in dragon fruit using MS + 2.0 mg/L BA + 2.0 mg/L Kin. with explants, stem fraction. Eighty percent explants were responded for shoot initiation treated with 2.0 mg/L BAP in combination with 2 mg/L Kin. The highest number of shoots and the maximum shoot lengths were observed in this medium inoculation after 90 days. Shoots were transferred to media containing ½ strength of MS with root induced PGRs. Ninety percent of the in vitro raised shoots were responded for rooting treated with 2.5 mg/L IBA inoculation after 30 days. The highest number of roots and the maximum root lengths were recorded at 2.5 mg/L IBA. The response of inoculated explants or in vitro raised shoots were positively correlated with the number of shoots and roots respectively. The average shoot and root lengths were negatively correlated with each other resulting in root lengths increasing by decrease of shoot lengths. The healthy shoots with well rooted plantlets were transferred to natural condition where about 80% plantlets were found to be acclimatized.