Development of Micropropagation Protocol Supporting Sustainable Production of Jackfruit (Artocarpus heterophyllus Lam.)

This study was conducted to develop a micropropagation protocol for 'EVIARC Sweet' jackfruit to support production expansion. Fruiting trees and grafted plants were used as source of shoot tip or nodal explants sterilized using different levels of sodium hypochlorite (NaOCl) with or without chloramphenicol. Shoot growth was evaluated on Murashige and Skoog (MS) medium with or without 1-5 mg/L benzyl aminopurine (BAP), 0.1-0.5 mg/L indole butyric acid (IBA) and/or 0.25-0.5 mg/L gibberellic acid (GA3). Most promising sterilization method was NaOCl at 2.5% for 10 min in the first passage and at 0.5% for 10 min in the second passage. Shoot tips from grafted plants had higher survival than those from mature trees but they produced phenolic exudates that caused tissue browning. Shoot tip cultures on MS medium with 3 mg/L BAP+0.5 mg/L GA3+0.1 mg/L IBA produced multiple shoots (2-3 per explants) with better growth than on MS alone or with 5 mg/L BAP. The shoots were micropropagated at the rate of 6-7 shoots per explant in six weeks but browning was a problem which was not minimized by using carbonadded medium or by frequent subculturing. The shoots did not also produce roots. These constraints should be addressed in future research.