Callus cultures in plant regeneration systems are sometimes useful for conservation. Moreover, they are capable of new variants. What do you think about secondary metabolite production from callus mediated regeneration systems? Is it feasible to try new variants in vitro which may provide more secondary metabolites than mother plants? I think, questions should alternatively be extended over duration of callus cultures, if the new variants are the case. "Have you ever tried/seen or read any study to check metabolite profiling of the regenerants (regenerated plantlets) derived from different callus culture periods?"