Question

Optimum pH for protoplast culture is -

• A. 6.5 to 7.0
• B. 5.5 to 5.9
• C. 4.5 to 4.9
• D. 7.5 to 7.9

Hint:

Remember that almost all standard plant tissue culture media (MS, B5, etc.) are adjusted to a pH of \(\sim\)5.8 before sterilization. This is a crucial number to memorize for any plant biotechnology exam.

Answer 1

The Correct Option is B

Step 1: Concept Overview:
This question concerns the optimal pH for in vitro protoplast culture. Maintaining the correct pH is essential for protoplast viability and growth.
Step 2: In-depth Analysis:
Protoplasts lack a cell wall and are therefore vulnerable. The culture medium's pH influences nutrient absorption, membrane integrity, and enzymatic function.
In plant tissue culture, including protoplast culture utilizing media like MS, a slightly acidic pH is required before autoclaving.
The ideal pH range is generally 5.5 and 5.9, with 5.7 or 5.8 being typical.
pH levels under 5.0 may cause nutrient precipitation and hinder development.
pH levels exceeding 6.0 can impair ion availability and encourage contamination.
Step 3: Conclusion:
The ideal pH range for protoplast cultivation is 5.5 to 5.9.