Micropropagation and ex vitro rooting of wolfberry

Abstract

An accurate protocol for the in vitro propagation of a commercial wolfberry (Lycium barbarum L.) cv. Nixia 1 has been developed through axillary shoot proliferation. Driver and Kuniyuki Walnut (DKW) medium supplemented with 6-benzyla- minopurine (BAP; 0.5 mg/L) and sucrose 3% w/v gave the best results compared with other basal media tested, with significantly improved production of multiple shoots direct from nodal segment explants, resulting in an average of 6.73 shoots/explant with an average of 7.45 nodes/shoot that would potentially form new explants. Rooting of shoot explants was carried out both in vitro and ex vitro with 0.5 and 1 mg/L of indole-3-butyric acid (IBA), with or without adding putrescine (160 mg/L). In all cases, rooting efficiency resulted very high, and putrescine was effective only when combined with a low concentration of auxin. Plantlets were hardened off in jiffy pots under greenhouse conditions, with a survival rate of more than 90%. Ex vitro rooting, performed by dipping in an aqueous solution of IBA 100 mg/L, is the preferred technique not only because rooting and acclimatization are very high but also reducing micropropagation to one phase is more economical.