Abstract

Vegetatively propagated crops are exposed to pests every growing season, providing them with the opportunity to feed on the plants and transmit diseases. Meristem culture is an important method to clean for viruses to restore high yields. Media optimizations with different concentrations and combinations of 6-benzylamino purine (BAP) and Naphthalene Acetic Acid (NAA) were tested for their effects on shoot initiation from meristems. This was followed by regeneration and shoot multiplication from nodal cuttings in five elite varieties of sweet potato. There was a highly significant genotype (variety) x environment (media) interaction for all experiments. Concentrations and combinations of BAP and NAA significantly affected the percentage of meristem survival/regeneration and subsequent shoot multiplication. The best combination of the plant growth regulators was NAA (0.1 mg/L) and BAP (1.0 mg/L). For further propagation, shoot numbers per single nodal cuttings were significantly affected by BAP concentrations (p < 0.05) and genotypes. The medium which gave maximum numbers of shoots was ½ MS media supplemented with BAP (2.5 mg/L) and GA₃ (0.5 mg/L). The tallest shoots, with the highest number of internodes, suitable for transfer to soil, was obtained from ½ MS media without any growth regulators for all of the cultivars.

Key words: Media, meristem, multiplication, regeneration, shoot, sweet potato.