Richmond- Lang effect is related to .

Options

A. Auxins
B. Gibberellins
C. Cytokinins
D. ABA

Answer

**Step-by-Step Solution:**

1. **Understanding the Richmond-Lang Effect**: The Richmond-Lang effect refers to the phenomenon discovered by scientists Richmond and Lang in 1967, which is related to the role of a specific plant growth regulator (PGR).

2. **Identifying the PGR**: The PGR in question is cytokinin. Richmond and Lang found that cytokinin plays a crucial role in delaying senescence in plants.

3. **Defining Senescence**: Senescence is the process of aging in plants, which often results in the wilting and yellowing of leaves, known as chlorosis. This process is influenced by the levels of cytokinin in the plant.

4. **Mechanism of Action**: Cytokinins help delay senescence by promoting nutrient mobilization to the leaves and aiding in chlorophyll formation. This means that with sufficient cytokinin, leaves can maintain their green color and vitality for a longer period.

5. **Cytokinin Functions**: Besides delaying senescence, cytokinin is also essential for cytokinesis (cell division) and callus growth in plants. This is why it was initially named "kinetin," derived from its role in promoting cell division.

6. **Conclusion**: Based on the information provided, the Richmond-Lang effect is related to cytokinin, which is the correct answer.

**Final Answer**: The Richmond-Lang effect is related to cytokinin.

---