Effect of Explants Sterilization and Plant Growth Regulators on Embryo Culture of Kepel (Stelechocarpus burahol)

Kepel (Stelechocarpus burahol) is an original Indonesian fruit plant. Kepel is currently hard to find and cultivate conventionally. In vitro culture is a method for kepel propagation. The in vitro culture requires an established protocol for explant sterilization to be successful. For the present, there is no appropriate kepel sterilization method that has been known. This study aimed to obtain a sterilization method for kepel embryo explants appropriate for embryo culture. This research was conducted in September 2018 - January 2019 at the In Vitro Culture Laboratory, Faculty of Agriculture, Universitas Muhammadiyah Yogyakarta. This study used an experimental method arranged in a single factor. Completely Randomized Design with the treatment of various immersion methods of kepel embryo explants divided into 8 levels. They are Sodium hypochlorite (NaOCl) (5% : 5', 5% : 10', 10% : 5', 10% : 10'), Hydrogen peroxide (H₂O₂) (2% : 10', 2% : 15', 3% : 10', 3% : 15') and plant growth regulators 2 ppm 2,4-D + 0,5 ppm BAP, 2 ppm NAA + 0,5 ppm BAP. The results showed that 5% NaOCl for 5 minutes treatment was the best method for sterilization with a percentage of viable explant 88.89%. Then, the percentage of browning 11.11% and 2 ppm 2,4-D + 0,5 ppm BAP was effective in the organogenesis of callus of kepel embryos.