Direct Shoot Organogenesis from Lycium chinense Miller Leaf Explants and Assessment of Genetic Stability Using ISSR Markers

An efficient in vitro direct shoot regeneration system has been described for Lycium chinense Miller using leaf explants. Influence of various parameters such as growth regulator concentration, explant type, effect of basal salt type, Murashige and Skoog (1962) medium (MS), Schenk and Hildebrandt (1972) medium (SH), Gamborg et al. (1968) medium (B5), and carbon sources (sucrose, maltose, and fructose) on the regenerating shoots has been studied. Micromorphological studies and genetic fidelity of regenerated shoots were assessed and compared with those of the donor plants. Among the different concentrations of plant growth regulator (PGRs) tested, MS supplemented with lower concentration of 6-benzylaminopurine (BAP) (0.5 mgL(-1)) and thidiazuron (TDZ) (0.5 mgL(-1)) increased the frequency of shoot. Comparatively, indole-3-butyric acid (IBA) was more effective in the regeneration and growth of the root system. A higher number of root formation (6.67 +/- 1.25) was observed when the rooting medium comprised half-strength MS salts supplemented with 3% sucrose. The surviving plantlets were gradually transferred to the greenhouse and natural soil. More than 90% of the plantlets survived and matured within 85 days. Similarity in the band patterns produced by inter simple sequence repeat (ISSR) primers confirmed the genetic stability and uniformity between the regenerated and donor plants. The present optimized direct shoot regeneration system may be useful for mass propagation and improving the genetic traits in L. chinense.