Page 146 - phytochemistry general program

Nutritional components of tissue culture media .1

Essential components of P.T.C. media

Support system (solidifying Agents)

Solidifying agents are used to create semisolid or solid media. Agar is mostly used
to solidifying agent in preparation of semi-solid PTC media. However, agarose,

gelrite and phytagel are sometimes used.

The media used in PTC should provide the explants with all the nutrients and
elements needed for growth. Media for PTC is composed of macro- and micro-

mineral nutrients, in addition to, organic nutrients

Inorganic salts (Mineral elements) .1

Cultured plant tissues require a continuous source of certain inorganic elements.
Aside from carbon, hydrogen and oxygen, the elements required can be

categorized into 2 categories.

a. Macronutrient elements These elements are added in large concentrations
(millimolar concentration) as K, N, P, Ca, Mg and S. Nitrogen is added in the
largest amount, it is present as either nitrate or ammonium ion, or a combination of
the two ions. It is preferred to use nitrate rather than ammonium ion because of its
comparative lower toxicity. Magnesium is added as (Mg SO4. 7H2O) which

satisfies both the magnesium and sulphur requirements.

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