Question

The pH of nutrient medium in plant tissue culture is adjusted between
A. 3 – 4
B. 4.1 – 4.8
C. 5 – 5.8
D. 6 -7

Answer 1

An adequate pH is required for the nutrient medium for the proper growth and development of the cultured cells. The pH is adjusted using dilute sodium hydroxide, dilute potassium hydroxide and dilute Hydrochloric Acid.

Step by step answer: Most tissue culture media had a pH adjusted between 5 and 5.8, which Is the adequate range for the proper division and development of the cells in the culture media, as it affects the uptake of ions. Appropriate pH range also plays a vital role in providing the proper stability to the agar gel present in the medium, which functions as a solidifying agent, as the gel will not be properly set. Adequate pH should be set before the sterilization process begins.
-pH range of 3 -4 and 4.1 – 4.8: Generally for pH values between 5, the agar in the medium fails to gel properly thus affecting the consistency of the culture medium, and proper absorption of ions also fails to take place. Hindering the division and development of the cells in the media.
-pH range of 6 – 7: For a pH range above 6, the agar in the medium gets hard, which is also not favorable for the development of the cells.
Thus, Option C is the correct answer, a pH range of 5 – 5.8 is adjusted in the nutrient medium in plant tissue culture.

Note: The media used in plant tissue culture consists of a variety of nutritional compounds, which are vital for the differentiation, growth, and development of the cultured cells. The media are composed of various macro (example: Nitrogen, Phosphorus) and micro ( Zinc, Boron ) nutrients, organic nutrients such as vitamins, amino acids, carbohydrates, various hormones. The culture should be protected from infections, adequate temperature and osmotic potential are also very important.