The capacity to generate a whole plant from any cell of the plant is called:

The correct option is Totipotency.

Detailed Explanation:
Totipotency is the ability of a single cell to divide and produce all the differentiated cells in an organism, including extraembryonic tissues. In plants, cellular totipotency represents the capacity of a cell (even a mature, differentiated one) to regenerate into a complete, functional whole plant under suitable laboratory conditions (nutrient medium, controlled temperature, and light).

Let us look at the other options to understand why they are different:
1. Micropropagation: This is a method or technique used to rapidly multiply plant stock material to produce a large number of progeny plants using plant tissue culture methods. While it relies on totipotency, micropropagation itself is the process of clonal propagation rather than the cellular property.
2. Differentiation: This is the developmental process by which unspecialized cells undergo structural and functional changes to become specialized cells (like xylem, phloem, etc.) with specific functions.
3. Somatic hybridization: This is a genetic technique that allows the fusion of protoplasts (cells without cell walls) from two different plant varieties or species to produce a hybrid plant containing characteristics of both parents.