EFFECT OF PLANT GROWTH REGULATORS AND ORGAN TYPE ON CALLUS INDUCTION, GROWTH DYNAMIC, POLYPHENOL, FLAVONOID AND TANNIN CONTENT IN MILK THISTLE (SILYBUM MARIANUM L.GAERTN.) TISSUE CULTURE

Milk thistle (Silybum marianum L. Gaertn., Asteraceae) is an annual or
biennial, broadleaf plant native in North African and Mediterranean with
highly valued medicinal properties. The active compound in S. marianum is
silymarin; which is an isomeric mixture of flavonolignans which used in
pharmaceutical industries. Milk thistle is the most commonly used herbal
product for chronic liver disease and may be beneficial for reducing the
chances for developing certain cancers. Plant secondary metabolites, which
have been extracted from in vivo grown plants, were used for a long time but
the general trend new is to extract these secondary metabolites from in vitro
grown plants. We cannot ignore the importance of using tissue culture
techniques which gives the ease of almost all of plant researches, also there
are so many other reasons such as protection from weather and from
diseases, pests, soil problems and obtaining mass quantities with low cost.
As obtaining secondary metabolites from milk thistle plants is
considered a tedious process, it became clear that replacing this by obtaining
these products from in vitro might be better, so our successful attempt was
made to produce calluses and extract the active ingredients from them. The
result of the experiment showed that significances differences were found in
the influence of organ and medium type on callus initiation, growth dynamic
and chemical content from polyphenol, flavonoid and tannin. The best
medium for callus induction was MS3 (supplemented with 2 mg Kin/L + 2
mg/L NAA) for leaf organ and MS1 (1.5 mg/L 2,4-D + 1.5 mg/L BA) for
stem node organ. The highest callus fresh weight was 300.4±9.66 mg/culture
and that achieved on MS3 from leaf organ. Stem node callus grow on MS3
showed the highest content of polyphenol and flavonoids while the leaf
callus grow on MS1 and MS3 showed the highest content of tannin .