The formation of pomato is an example of:

The correct answer is Option (4) → Somatic hybridization

Option (1) Micropropagation — Incorrect. Micropropagation is producing thousands of plants through tissue culture from one parent. All of them are genetically identical to it (somaclones). No two plants are combined.

Option (2) Totipotency — Incorrect. Totipotency is the capacity of a cell or explant to grow into a whole plant. It is a property of plant cells that tissue culture uses, not a method of making a hybrid.

Option (3) Tissue culture — Incorrect. Tissue culture is the growing of plant parts in a nutrient medium under sterile conditions. The hybrid cell is grown this way, but the step that makes a pomato has its own name.

Option (4) Somatic hybridization — Correct. A pomato was made by fusing a protoplast of tomato with a protoplast of potato. The hybrid is made from body (somatic) cells, not from gametes, and so the process is somatic hybridisation.

NCERT Extract:
Biotechnological Applications in Agriculture – “… Scientists have even isolated single cells from plants and after digesting their cell walls have been able to isolate naked protoplasts (surrounded by plasma membranes). Isolated protoplasts from two different varieties of plants – each having a desirable character – can be fused to get hybrid protoplasts, which can be further grown to form a new plant. These hybrids are called somatic hybrids while the process is called somatic hybridisation. Imagine a situation when a protoplast of tomato is fused with that of potato, and then they are grown – to form new hybrid plants combining tomato and potato characteristics. Well, this has been achieved – resulting in formation of pomato; unfortunately this plant did not have all the desired combination of characteristics for its commercial utilisation.”