Find in Library

Black cumin or <i>Nigella sativa</i> L. is a medicinal plant of the Ranunculaceae family that has enormous importance. It has traditionally been used to cure a lot of diseases since ancient times. In the current study, the effects of different auxins on callus induction and subsequent somatic embryo formation of <i>N. sativa</i> L. cv. Black Diamond were examined. The best result of callus induction was observed when cotyledon explants were incubated in a Murashige and Skoog (MS) medium supplemented with 1.0 mg L⁻¹ α-naphthaleneacetic acid (NAA). The formation of somatic embryos was achieved efficiently from cotyledon-derived calli cultured on a 2 mg L⁻¹ Indole-3-butyric acid (IBA)-containing medium. Furthermore, histological analysis of embryogenic calli was used to detect the presence of different developmental stages of somatic embryos. In contrast to the calli and embryos of <i>N. sativa</i> ‘Black Diamond’, which initiated in the dark, light was necessary for the complete differentiation of callus and embryo cultures into shoots/developed plants. Hypocotyl-derived calli and embryos were successfully differentiated on IBA at 2.0, 1.0 mg L⁻¹, and NAA at 2.0 mg L⁻¹. To the best of our knowledge, this work can be considered the first report on the differentiation of <i>N. sativa</i> ‘Black Diamond’ somatic embryos into developed plants. Moreover, the metabolic profiles of secondary products of <i>N. sativa</i> ‘Black Diamond’ callus and embryo cultures originated from the best auxin treatments identified and were compared with that of intact seeds. Callus cultures of <i>N. sativa</i> ‘Black Diamond’ contained thymoquinone (TQ) in a significant percentage of the peak area (2.76%). Therefore, callus cultures could be used as a perfect alternative source of TQ for pharmaceutical and therapeutic purposes. In addition, fatty acids and/or their esters were recorded as the major components in callus and embryo cultures. These vital compounds could be isolated and used for numerous industrial applications.