Cryopreservation of Encapsulated Axillary Buds of Clitoria ternatea (L.)

Clitoria ternatea is a brain revitalizing legume, with immense pharmacological value including antimicrobial, antioxidant and anticancer. The lack of a commercial cultivation has led to its' over collection from the wild to meet the demand of herbal pharmaceutical sector and the species is now rare in the wild. Hence, the plant needs to be conserved. Cryopreservation of the species would supplement the conventional conservation strategies in the field or seed bank.

The objective of the study was to evolve an efficient and simple protocol for the cryopreservation of Clitoria ternatea using an encapsulation-dehydration technique.

An in vitro culture system via axillary shoot proliferation was developed using nodal segments in MS medium and optimization of the levels of cytokinins and auxins. Calcium alginate encapsulated axillary buds were subjected to 0-5 h of dehydration, to determine the optimum drying time and moisture content for effective cryopreservation.

The beads dehydrated for 4 h to 20.1 % moisture content had 60 % survival after freezing in LN, of which 65 % regrew. Based on RAPD analysis, the plants regrowing after cryostorage were genetically stable.

A simple and efficient cryopreservation protocol has been established for C. ternatea using an encapsulation-dehydration technique, and this could be effectively utilized for germplasm conservation of this species.