In Vitro Propagation and Nuclear DNA Content of Tripleurospermum Insularum (Asteraceae) – A Critically Endangered Insular Endemic Species From Turkey

Abstract Tripleurospermum insularum Inceer & Hayirlioglu-Ayaz (Asteraceae) is a critically endangered endemic species in Turkey that is face the risk of extinction as a result of the fragmentation of its habitat as well as overgrazing and trampling of its natural population. However, the protocol for micropropagation of this threatened species has not been developed yet. Here, its regeneration ability on MS media supplemented with different plant growth regulators were evaluated using nodal segments. The higher number and length of shoot per explant was achieved with the addition 4.6 µM ZEA and 0.5 µM IAA to the culture medium. Besides, the highest node number of shoot per explant was obtained from MS medium supplemented with 4.6 µM ZEA and 0.5 µM IBA. Flow cytometric analysis also revealed that most of the in vitro developed shoots of T. insularum possessed similar nuclear DNA content as well as ploidy level as initial material and plants from natural population. In vitro rooting of shoots was achieved at 100 % efficiency containing 2.9 µM IAA. Rooted and well-developed plantlets were initially acclimatized under greenhouse conditions and then moved to the botanical garden, where they matured and flowered. Finally, 76% and 74% survivals were achieved during the acclimatization process, respectively. This is the first report of a successfully developed micropropagation protocol of threatened T. insularum for its ex situ conservation.