Zygotic meiosis is observed in
algae
Many lower-grade plants have life cycles involving sexual reproduction with the alternating haploid (n) and diploid (2n) stages. A change of ploidy is involved. To return from a diploid stage to a haploid stage, meiosis must occur. When the meiosis occurs in the zygote, it is called as zygotic meiosis. Such type of life cycle is called as a haplontic life cycle. Here, the haploid stage is multicellular and diploid stage is a single cell. A zygotic meiosis is a meiosis of a zygote immediately after karyogamy, which is the fusion of two cell nuclei. This way, the organism ends its diploid phase and produces several haploid cells. These cells divide mitotically to form either larger, multicellular individuals, or more haploid cells.
Many algae ( Chlamydomonas, Zygnema, Chara, golden algae, dinoflagellates etc) show haplontic life cycle and hence zygotic meiosis.