The problem of necrosis and senescence in tissue culture is overcome by

Options

A. Spraying cytokinins
B. Spraying auxins
C. Suspension culture
D. Subculture

Answer

To address the problem of necrosis and senescence in tissue culture, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Necrosis and Senescence**:
- Necrosis refers to the death of tissue, while senescence refers to the aging process of the tissue. Both issues can adversely affect the success of tissue culture.

2. **Role of Plant Growth Regulators**:
- Plant growth regulators are substances that influence plant growth and development. They can help in managing issues like necrosis and senescence.

3. **Cytokinins as a Solution**:
- Cytokinins are a class of plant growth regulators that promote cell division and growth. They are particularly effective in preventing necrosis and delaying senescence in tissue cultures.

4. **Application of Cytokinins**:
- To overcome necrosis and senescence, cytokinins can be sprayed onto the tissue culture. This application encourages the cells to divide and remain healthy, thus preventing tissue death and aging.

5. **Comparison with Other Regulators**:
- While auxins are also plant growth regulators, their primary role is in promoting shoot growth rather than directly addressing necrosis and senescence.

6. **Conclusion**:
- The most effective method to overcome the problems of necrosis and senescence in tissue culture is to spray cytokinins.

### Final Answer:
The problem of necrosis and senescence in tissue culture is overcome by spraying cytokinins.

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