Biology · Biotechnology and Its Applications · NEET
Without a cell wall. NCERT says naked protoplasts are still "surrounded by plasma membranes". So the wall is digested away, but the plasma membrane stays intact. This is a very common trap: the cell is 'naked' only in the sense of losing its wall, not its membrane.
Because it is made by fusing two somatic (body) cell protoplasts, not by fusing gametes (egg and pollen). Normal sexual hybrids form when male and female sex cells fuse. Here two ordinary body cells are fused directly, so the offspring is a somatic hybrid and the process is somatic hybridisation.
The plant cell wall (cellulose) is digested by wall-degrading enzymes such as cellulase. Once the wall is gone, the naked protoplast surrounded only by its plasma membrane can be released and later fused with another protoplast.
It was a scientific success but a commercial failure. NCERT states clearly that pomato "did not have all the desired combination of characteristics for its commercial utilisation." NEET often tests this exact line, so remember pomato was made but was not usable as a crop.
Traditional breeding needs two plants that can cross sexually (compatible gametes). Somatic hybridisation fuses body-cell protoplasts, so it can combine characters from plants that may not breed sexually. That is why it offers vast potential for making new varieties in vitro.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
A protoplast is a plant cell from which the cell wall has been enzymatically digested, leaving a naked cell that is still bounded by its plasma membrane.
It is the process of fusing protoplasts from two different plant varieties, each with a desirable character, to form a hybrid protoplast that is grown into a new plant called a somatic hybrid.
Pomato is a somatic hybrid made by fusing a tomato protoplast with a potato protoplast. It was successfully produced but lacked the right combination of characters for commercial use.
It shows how tissue culture techniques can combine characters from plants that may not cross sexually, and pomato is a frequently tested named example of an in vitro-made variety that failed commercially.
Cellulase and other wall-degrading enzymes digest the cellulose cell wall to release the naked protoplast.
