In vitro propagation of Royal Irises (section = Oncocyclus) in Palestine

Abstract

Palestine is a region rich in plant biodiversity. Despite that, several species are threatened due to various factors including overgrazing, human activities and intensive agriculture. As a part of the species, Iris species from section Oncocyclus are considered threatened species according to the IUCN red list. As a tool to protect and conserve these species, a protocol of in vitro propagation of Palestinian Royal Irises is developed. This study contains four phases: first, selection of suitable explants and establishment of irises from the embryos on an aseptic culture. Second, in vitro shoot proliferation and regeneration, followed by in vitro shoot multiplication. Third, in vitro rooting. Finally, hardening of plantlets in the greenhouse gradually. The highest embryo germination percentage was 100% on a half-strength MS medium without PGRs. The best shoot regeneration was obtained on half-strength MS medium supplemented with 0.5 mg/L or 1.0 mg/L of BA while the best rooting results were on half-strength MS medium supplemented with 0.5 mg/L IBA. Plantlets were acclimatized in peatmoss:sand (2:1) substrate with a survival rate of 75% - 100% after 4 weeks from transfer to pots. This method was efficient in overcoming seed dormancy in irises.