ISSR-assisted analysis of clonal fidelity supported with SEM and histology using in vitro propagated plants of Moringa peregrina (Forssk.) Fiori— An endangered desert tree

Moringa peregrina is an important indigenous plant found in United Arab Emirates (UAE). It is an endangered species with important nutritive and medicinal properties. Environmental restrictions, urban expansion and unmanaged grazing endanger the plants. In this study, in vitro propagation of M. peregrina was carried out using different explants cultured in various combinations of plant growth regulators. Callus induction was successfully achieved by culturing shoot tip explants in medium containing either 2,4-D alone or in combination with thidiazuron [TDZ], 6-benzylaminopurine [BA] and kinetin [Kin]. The optimal callus induction was recorded in medium supplemented with 2,4-D (2 mg/L) and TDZ (0.1 mg/L) compared to other combinations. Callus regeneration was successfully achieved through culture in Murashige and Skoog (MS) medium containing BA and naphthalene acetic acid (NAA). Direct shoot organogenesis was achieved from nodal explants using MS medium supplemented with TDZ (0.2 mg/L). Histological and scanning electron microscopy (SEM) analyses confirmed the regeneration potential of the friable callus, which exhibited embryogenic spherical cells possessing densely stained meristematic zones amenable to differentiation into shoot primordia. The total number of roots was significantly higher in medium containing NAA when compared to medium containing indole-3-butyric acid [IBA]. The clonal fidelity of the in vitro plantlets developed through direct organogenesis was assessed using ISSR-DNA marker. The similarity indices between the parental plants and their progenies were above 98.2% and indicated that the progenies were highly similar to the mother plant. This technique allows mass multiplication of M. peregrina, hence providing a promising method of conserving the genetic resources for this plant.