Preservation of sweet potato (Ipomoea batatas) using slow growth techniques for gene bank

Abstract

Sweet potato (Ipomoea batatas (L.) Lam) is an important food crop in Thailand and its germplasm conservation is mostly in the field. The preservation of plant genetic resources by slow growth technique is a useful method for in vitro conservation of sweet potato genotypes that should be developed to save important accessions of sweet potato germplasm for breeding and genebank. Four genotypes were used (PJ265-1, PJ0106-6, PJ65-3, and PJ284-17) with different pulp colors in three experiments with different concentrations of MS salts (½MS, ¼MS) and sucrose (30, 60, 90 g L-1), using growth regulator (0, 2, 4, 6, 8, and 10 mg L-1 ABA) and using growth retardants (0, 5, 10, 15, and 20 µM ancymidol). The survival (%) was evaluated every three months, the four genotypes of sweet potato were obtained over nine months by using ½MS medium plus 30 mg L-1 sucrose, MS medium plus 2-6 mg L-1 ABA and MS medium plus 10 µM ancymidol. By the way, in vitro plantlets should be subcultured after sixth months.