Preliminary Report on Development of Proper Stigmas and Stigma-Like Structures in Saffron Under In Vitro Conditions

Abstract

Saffron reproduces vegetatively; hence, improvement through breeding is difficult. From the last few decades, the tissue culture and genetic engineering techniques are being exploited for propagation and genetic improvement of vegetatively propagated plants. In the present study, the authors cultured stigmas, tepals, and anthers as explants on different nutrient media supplemented with various concentrations of growth regulators to standardize the media composition for the development of stigmas under in vitro conditions. Best response with respect to the callus formation was observed with anther explants (78.33%) on Murashige and Skoog (MS) medium supplemented with 19.8 µM BAP and 43.2 µM NAA (Z1) followed by moderate callusing with tepals (54.66%) and stigmas (43%) on the same medium. Callusing on MS medium added with 15.4 µM BAP and 54 µM NAA (Z2) was also moderate with all explants. With respect to the development of stigma and stigma-like structures (SLS), the best responses (46.33%) were observed with stigmas on MS medium added with 19.8 µM BAP and 14.6 µM NAA (A1) followed by the formation of only SLS (43%) on Z1 medium. Proper stigma development in Kashmir saffron was reported first time in the present study. The SLS and stigma development were indirect, having an intermediate phase of callus formation. Explants like anther and tepal after callusing did not show further development. However, callus obtained from tepals showed the formation of some leaf-like structures.