In most flowering plants, seeds are formed when pollen grains fertilize an egg cell. However, some plants have special ways to reproduce without this process, known as Apomixis.

What is Apomixis?

Apomixis is a form of asexual reproduction that mimics sexual reproduction. Instead of merging pollen and egg, the plant produces seeds without fertilization. The embryo develops directly from a diploid cell (a cell with two sets of chromosomes) inside the ovule. Because no fertilization occurs, the offspring are genetically identical to the parent plant. This is common in some species of Asteraceae (sunflower family) and grasses.

Understanding Polyembryony

Polyembryony is the presence of more than one embryo in a single seed. While a normal seed has only one embryo, polyembryonic seeds contain several. This happens when the plant produces extra embryos from different parts of the ovule, such as the nucellus (the tissue surrounding the embryo sac) or the synergid cells. These extra embryos grow alongside the main embryo formed by fertilization.

Examples in Nature

• Citrus Fruits: Oranges and lemons are classic examples of polyembryony. If you plant one seed from an orange, you might see multiple small shoots emerging.
• Mango: Certain varieties of mango also show polyembryony, where the nucellar cells begin to divide and form new embryos.
• Grasses: Many wild grasses use apomixis to reproduce quickly in stable environments without needing pollinators.

Why Does This Matter?

Apomixis is very useful for farmers. It allows the production of hybrid seeds that do not lose their good qualities over generations. Normally, hybrid seeds must be bought every year, but with apomictic plants, farmers could save seeds that stay exactly like the parent plant. Polyembryony is also important because it ensures that at least one embryo is likely to survive and grow into a healthy plant, increasing the chance of reproductive success.