Abstract
Somatic embryos were induced from in vitro germinating seed-hypocotyls of Catharanthus roseus. The process of embryogenesis has been categorized into a few distinct stages (induction, proliferation, maturation and germination) in which liquid overlaying at varying levels 0 ml (T-0), 0.25 ml (T-1), 0.5 ml (T-2)(,) 0.75 ml (T-3) and 1.0 ml (T-4) was applied on solid medium. It was found that liquid overlaying improved proliferation; maturation, germination of embryos in C. roseus. In proliferation stage, particularly in T-2, torpedo embryo number increased significantly (i.e. 129.6%) as compared to control. Liquid overlaying (T-2, T-3 and T-4) also improved embryo maturation and showed early germination even in maturation medium. It also accelerated normal embryo germination frequency particularly in treatment with T-2 and shortened 'embryo-plantlet' recovery time. Biochemical analyses revealed more proline, protein and amino acid with increasing level of liquid overlaying as it improved embryo induction, development and faster germination.