A technique of micropropagation is

Somatic embryogenesis is formation of embryoids or somatic embryos from vegetative cells or tissues through micropropagation, during which embryoid are either directly formed or formed via callus formation.

(1) Fusion of protoplasts of two different cells, which shows both plasmogamy and karyogamy, is called protoplast fusion.

(2) Embryo rescue is done in embryo or seed culture to allow the underdeveloped, non-viable embryos formed in incompatible crosses to turn into viable embryos or plants to obtain rare hybrids or hybrids of incompatible crosses. 

(3) Somatic hybridisation is fusion of protoplasts of two genetically different varieties of plant species to obtain
hybrids.