Polyembryony

Polyembryony

• It is the development of more than one embryo inside the seed, and the condition is described as polyembryony. It was first noticed by Leeuwenhoek (1719) in the seeds of the Citrus genus.
• It is the occurrence of more than one embryo in a seed, which consequently results in the emergence of multiple seedlings. The additional embryos result from the differentiation and development of various maternal and zygotic tissues associated with the ovule of the seed.
• Polyembryony may be true or false depending upon whether many embryos arise in the same embryo sac or in different embryo sacs in the same ovule.
• In adventive polyembryony, an embryo develops directly from the diploid cell of nucellus and integuments, as in Citrus. In cleavage polyembryony, the zygote proembryo sometimes divides (cleaves) into many parts or units. Each unit then develops into an embryo.
• Polyembryony increases the chances of survival of the new plants. Nucellar adventive polyembryony is of great significance in horticulture.
• Polyembryony offers several advantages, including the production of multiple offspring from a single seed, increasing the chances of survival for the species. It ensures genetic uniformity when embryos arise from somatic tissue, leading to clones that maintain desirable traits.
• This process also enhances the propagation of plants without relying on fertilization, which is beneficial for agriculture.