Embryo culture and callus induction—MS medium supplements For immature embryos, MS medium is essential for initial morphogenesis and enhanced callus development when additionally supplemented with which components?

Introduction / Context:
Morphogenesis from immature embryos often requires a rich hormonal and organic environment. Beyond mineral salts (MS medium), supplemental organic additives like coconut milk and growth regulators such as GA3 can promote cell division, callus proliferation, and subsequent differentiation.

Given Data / Assumptions:

• Target explants are immature embryos with high developmental plasticity.
• MS salts provide baseline nutrition; additives modulate morphogenesis.
• Desired outcome is robust callus and organogenic competence.

Concept / Approach:
Coconut milk provides vitamins, amino acids, sugars, and natural cytokinins; GA3 influences embryonic growth and elongation. Their combination is historically noted to enhance early morphogenesis and callus vigor in several species.

Step-by-Step Solution:

Verification / Alternative check:
Comparative cultures with and without coconut milk/GA3 show improved callusing and subsequent morphogenesis in many protocols.

Why Other Options Are Wrong:

• GA3 alone may not match the stimulatory effect achieved with coconut milk.
• Adenine or adenine+kinetin can help in some cases, but the question emphasizes the proven pair for initial morphogenesis and callus enhancement.
• Activated charcoal adsorbs regulators and may reduce effective hormone levels at this stage.

Common Pitfalls:
Using excessive GA3 can reduce organogenesis; concentration and timing are crucial.

Final Answer:
GA3 and coconut milk