**Figure 8.**

*(i) Growing stage of stevia and (ii) growing stage of chicory.*

Hence, this indicates that sterilisation of plant cells is essential in the *in vitro* process of culturing seeds, and basic steps must be considered during sterilisation. The difference in growth between the sterile and non-sterile plant cells might result from their genetic differences among the two subspecies of the used plants. This result agrees with the findings of Debnath and McRae [60], which explained that different genotypes variably react for shoot proliferation and regeneration in a liquid medium or a semi-solid media in his work on a semi-solid medium between subspecies. Also, the water absorption rate can influence the seedlings' rate during *in vitro* cultivation of plant cells [101].
