Micropropagation via somatic embryogenesis of Iris pallida Lam. ecotypes

Abstract

Iris pallida LAM., which has characterized the economy of small and medium-sized Tuscan farms for decades, is one of the most typical rustic species of the Mediterranean landscape. I. pallida essence is widely used in the perfumery sector for the indicative smell of violet caused by its high content of irones, ketone compounds accumulated inside the rhizome during their storage phase. One of the main critical aspects of its cultivation is the vegetative propagation method, traditionally carried out by rhizome transplanting, which does not allow obtaining a sufficient number of plants to encourage its cultivation. The state of the art indicates the micropropagation of I. pallida via somatic embryogenesis as the most effective propagation method, using immature flower components as starting tissue; however, there are no studies aimed at comparing the responses of different ecotypes of I. pallida to this technique. In this study, I. pallida clones of HE, VIC and BA ecotypes were obtained via somatic embryogenesis, starting from bud (young and immature) and leaf explants, monitoring all the development steps from callus to plantlets production, and testing clones adaptation to field conditions, using a modified acclimatization protocol. The results highlighted the different responses of the ecotypes to the in vitro protocol and demonstrated the effectiveness of somatic embryogenesis in producing I. pallida plantlets with a chromatographic profile overlapping with the donor plant; this alternative propagation method could allow to produce plantlets without sacrificing sealable rhizome.