Encapsulation, short-term storage, conservation and molecular analysis to assess genetic stability in alginate-encapsulated microshoots of Ocimum kilimandscharicum Guerke

Abstract

This article demonstrates the plantlet regeneration from alginate-encapsulated shoot tips of Ocimum kilimandscharicum Guerke. The best gel complexation for encapsulation of shoot tips was achieved using 3 % sodium alginate and 75 mM calcium chloride. Re-growth ability of encapsulated shoot tips explant was evaluated after storage at 4 and 25 °C for 30, 45, 60, 75 and 90 days. Preservation at 25 °C being significantly more resistant compared to that stored in 4 °C. Maximum shoot re-growth (83.33 %) was recorded on 0.7 % agar solidified full strength MS basal medium supplemented with 1.0 mg/l BA. Micro shoots, recovered from encapsulated shoot tips (capsule) were best rooted on ½ strength MS medium containing 1.5 mg/l IBA. Complete plantlets (with shoot and root) were transferred to plastic pots containing soil: vermiculite (1:1) showing 79.53 % survival rate in field condition. The genetic stability of synseed-derived plantlets (following 4 and 25 °C of storage) was assessed and compared with mother plant using two PCR based molecular markers namely random amplified polymorphic DNA and inter-simple sequence repeat. Both types of markers revealed high degree of monomorphism, similar to those of the mother plants.