In vitro protocol for bud induction from adventitious roots of purple sweet potato (Ipomoea batatas (L.) Lam)

Abstract A new efficient in vitro plant regeneration system characterized by rapidly sequential organogenesis using leaf explants has been developed in sweet potato [ Ipomoea batatas L. (Lam.)]. The optimal regeneration plant response was obtained in the varieties Ning Purple Potato No. 1 with a four-step protocol: The first stage was callus induction of leaf explants for 40 days on MS medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) (0.8 mg L -1 ), the second stage was adventitious roots being induced from callus on solid MS medium with 0.6 mg L −1 6-BA and 0.3 mg L −1 NAA, A different proportions combination of of 6-BA and NAA could induce adventitious roots. The third stage was adventitious buds being induced from adventitious roots, solid MS medium with 2.0 mg L −1 ZT, 1.0mg L -1 KT and 1.0 mg L −1 GA 3 produce a maximum of number of adventitious shoots after 12 week. In the third stage the combination of hormones and the longer induction time was important. the fourth stage was acclimation of nutrient solution. The key of this method was that refining seedlings does not require humidity control and there is no need to pre-open the flask to acclimatize. We had developed an efficient protocol to generate plants. As the method is simple, rapid and consistently reproducible, it may be of value in germplasm maintenance and gene transfer studies.