Question

If you squeeze a seed of orange, you might observe many embryos of different sizes. How is it possible? Are these embryos genetically similar or different? Comment.

Answer 1

In Citrus seeds, polyembryony occurs due to adventive embryos developing from nucellus cells alongside the zygotic embryo. These adventive embryos develop asynchronously, resulting in embryos of different sizes within the same seed. Adventive embryos are genetically identical to the parent plant because they arise from somatic nucellus tissue, while the zygotic embryo is genetically different. Hence, multiple embryos of various sizes coexist; most are clones except the sexually formed one, explaining both size variation and genetic similarity.