Micropropagation Protocol of a Threatened Species: Cistus crispus L.

Cistus crispus is an endemic species exclusive of the province of Messina (Italy) and recorded with the status of "Threatened" (T), in the Italian Red List. The aim of this study was to increase knowledge on the propagation for protection and reinforcing of the species. Apical and nodal microcuttings, in situ collected, were sterilized for in vitro introduction. The aseptic explants, were used to establish in vitro cultures. To determinate the optimal medium for shoot multiplication, microcuttings were cultured on gelled Murashige and Skoog medium enriched with increasing concentrations (0, 0.3, 0.6 and 1.2 mg L-1) of three different cytokinins: benzylaminopurine (BA), kinetin (Kin) and dimethylallylamino purine (2iP) separately, in a factorial experiment. The highest multiplication rate (5.5 shoots/explants/month) was achieved with Kin 0.6 mg L-1. The microshoots were also tested to determinate the optimum conditions for in vitro rooting on the same substrate MS (macro-and micro-nutrients), with different concentrations (0, 0.5, 1.0 and 2.0 mg L-1) of two auxins indole acetic acid (IAA) and indole butyric acid (IBA). The best performance of rooted plants was scored on 1.0 mg L-1 IAA, the rooting rate was approximately 4 roots/plant in almost 3 weeks. The plants acclimated ex vitro in 20 days and provided a higher percentage than 80%.