Propagation of saffron (Crocus sativus L.) through tissue culture: a review

Saffron (Crocus sativus L.) is the most expensive spice in the world. This plant species is propagated vegetatively through the formation of daughter corms from the mother one. Unfortunately, many factors hamper the efficient propagation of saffron through this traditional practice. For example, the low production rate of daughter corms and the risk of fungal infection, which also affect the daughter corm quality. Therefore, the conventional propagation method cannot meet the demand for planting material. The use of biotechnological tools, particularly the in vitro culture techniques, can be of great benefit for saffron propagation. Hence, in recent years, various regeneration systems through somatic embryogenesis and organogenesis were established for saffron using different explant types, medium components, plant growth regulators (PGRs), and culture conditions. In the present review, the most relevant advances and main achievements made in saffron micropropagation are reported, and the major bottlenecks encountered during in vitro culture of this species and that restrict the commercial production of saffron corms and plantlets are discussed.