Somatic embryogenesis and chromosomal stability of regenerants in sweet potato and taro

The in vitro somatic embryogenesis offers a better option for propagation, conservation and improvement especially for vegetatively propagated crops. Sweet potato (Ipomoea batatas) and tare (Colocasia esculenta), the important tropical tuber crops are grown vegetatively. To develop in vitro propagation system for theses crops, experiments are conducted to induce somatic embryogenesis, regenerate whole plant establish regenerants in vivo and assess cytogenetic situation of regenerants. Somatic embryos are produced from the calli derived from sweet potato leaf, petiole, stem and root explants in MS medium supplemented with 2,4-D (0.2 to 0.5 mg/L)and BAP(0.4 to I mg/L). The whole plants have been developed on subsequent culture of embryos or embryogenic calli in MS medium with or without growth regulators. In tare, somatic embryos have been obtained through a callus phase by culturing cormel tips in MS medium supplemented with NAA (0.25 to 0.5 mg/L), BAP (0.25 to 0.5 mg/L) and GA(3) (0.1 to 0.2 mg/L). The embryos develop into the whole plants on transfer to MS medium containing NAA and BAR. Embryogenesis is found to be influenced by genotype, media and explants. The regenerated plants of both the crops are hardened in hydroponics and get established in soil. Root tip cytology has revealed chromosomal stability of regenerants of both the crops.