Question

Fusion product of protoplasts of different plants is called
(a) Synkaryon
(b) Heterokaryon
(c) Parthenospore
(d) None of the above

Answer 1

Hint: When sexual crosses are not possible, protoplast fusion followed by SE regeneration can be used in plant breeding. Protoplast fusion, which involves fusing living cells that have had their cell walls removed to form new living entities, has also been used to overcome pre- and post fertilization barriers.

Complete answer: Somatic fusion, also known as protoplast fusion, is a type of plant genetic modification in which two distinct species of plants are fused to form a new hybrid plant with the characteristics of both.
In 1969, a completely new method for raising hybrids that could not be produced using traditional hybridization methods due to sexual incompatibility was proposed. The fusion of isolated protoplasts is used in this technique. The technique is known as parasexual hybridization because only somatic cell protoplasts were used in this experiment.
There are three steps to it. (i) Protoplast isolation (ii) Fusion of isolated protoplasts (iii) Hybrid protoplast culture to regenerate whole plants For protoplast fusion, polyethylene glycol (PEG) is commonly used. PEG treatment causes rapid protoplast aggregation, which is a precursor to fusion. Fusion between two or more protoplasts is possible.
The formation of a heterokaryon is the result of the fusion of two dissimilar protoplasts. The nuclei in the heterokaryon may fuse during culture to form a true hybrid cell.

Thus, the Fusion product of protoplasts of different plants is called heterokaryon.

Note: Somatic fusion can be used to make potato plants resistant to the diseased potato leaf roll. The crop potato plant Solanum tuberosum, whose yield is severely reduced by a viral disease transmitted by the aphid vector, is fused with the wild, non-tuber-bearing potato Solanum provides, which is disease-resistant, through somatic fusion.