Cryopreservation of sweetpotato (Ipomoea batatas) and its pathogen eradication by cryotherapy

Sweetpotato (Ipomoea batatas) ranks as the seventh most important staple crop in the world and the fifth in developing countries after rice, wheat, maize and cassava. Sweetpotato is mainly grown in developing countries, which account for more than 95% of total production of the whole world. Genetic resources, including cultivated varieties and wild species, are a prerequisite for novel sweetpotato breeding in both conventional and genetic engineering programs. Various cryopreservation protocols have been developed for shoot tips and embryogenic tissues. The former explants are preferred for long-term conservation of sweetpotato genetic resources, while the latter are valuable for sweetpotato genetic improvement. This review provides update comprehensive information on cryopreservation of sweetpotato shoot tips and embryogenic tissues.