What is the kind of development that takes place in the zygote in organisms with diplontic and haplo- diplontic life cycle?

Schematic representation of development of zygote in &diplontic life cycle:-

In this type of life cycle, Diploid zygote, germinates by mitosis to form unicellular or multicellular diploid sporophyte.All seed-bearing plants i.e. gymnosperms and angiosperms, follow this pattern.

schematic representation of zygote in haplo-diplontic  life cycle:-

As shown in figure, the zygote undergoes mitotic division to form multicellular diploid sporophyte which produces spores by meiotic division. This type of development is present in many pteridophytes.