High starch, low sugar yielding genotypes of sweet potato and their micropropagation

Abstract

Sweet potato (Ipomoea batatas(L.)) is considered as the world’s fifth most important food cum vegetable crop. Sweet potato tuber rich in starch, minerals and vitamins supplement food to small and marginal farmers in sweet potato growing countries. Central Tuber Crops Research Institute (CTCRI) at Bhubaneswar harbours a sizable collection of sweet potato germplasm. As it is vegetative propagated crop, the enhancement of genetic base is limited. In the course of the present study, genetic resources of sweet potato were screened for their high starch and low sugar content. Of the 116 different germplasm evaluated for yield, 14 genotypes showed high starch content. Among those 14 lines the five genotypes viz. ST-10, ST-13,ST- 14, T-18, T-23 showed low sugar along with other attributes like high 􀀁 -carotene in orange flesh lines like ST-14, T-23, high anthocyanin in purple flesh genotypes like ST-13, T-18 and high starch in white flesh genotype like ST-10 (21-25% starch). Micro propagation of these valued sweet potato was carried out using five different treatment media having various concentration of growth regulators. The influence of growth regulators was pronounced as well as genotypic influence was also observed. The bud break response period was found least in ST-13 and showed highest percentage of bud break and growth compared to the other genotypes in all treatment media. Results are encouraging for rapid multiplication, propagation and conservation of these high value crops.