In vitro development of microcorms and stigma like structures in saffron (Crocus sativus L.)

Abstract

Saffron is an important spice derived from the stigmas of Crocus sativus, a species belonging to the family Iridaceae. Due to its triploid nature it is sterile and is not able to set seeds, so it is propagated only by corms. The natural propagation rate of most geophytes including saffron is relatively low. Anin vitro multiplication technique like micropropagation has been used for the propagation of saffron. In the present study, various explants were cultured on different nutrient media supplemented with various concentrations of plant growth regulators to standardize the best media combination for obtaining optimum response with respect to corm production and development of Stigma Like Structures (SLS). Highest response (60%) was observed with half ovaries on G-5 media supplemented with 27μM NAA and 44.4μM BA followed by 55% on LS media with 27μM NAA and 44.4μM BA. Maximum size (1.3 g) of microcorms were obtained from apical buds on the LS media supplemented with 21.6μM NAA and 22.2μM. Stigma Like Structures were developed from half ovary explants both directly and indirectly. Maximum number (120 indirectly and 20 directly) and size (5.2 cm) of SLS were obtained in G-5 medium supplemented with 27μM NAA and 44.4μM BA followed by 100 indirectly and 20 directly and 4.5 cm long on LS medium supplemented with 27μM NAA and 44.4μM BA.