What is polyploidy?

Polyploidy is the process of genome doubling that gives rise to organisms with multiple sets of chromosomes.
In other words, polyploidy is the condition in which a normally diploid cell or organism acquires one or more additional sets of chromosomes.
The fusion between isolated somatic protoplasts under in vitro conditions and subsequent development of their product to a hybrid plant is known as somatic hybridization.

Somatic fusion, also called protoplast fusion, is a type of genetic modification in plants by which two distinct species of plants are fused together to form a new hybrid plant with the characteristics of both, a somatic hybrid.