Polyembryony

Polyembryony is a phenomenon where multiple embryos develop from a single fertilized egg or from the cells of the embryo sac in plants. This results in the production of multiple offspring that are genetically identical or closely related. Polyembryony occurs naturally in some plant species and can also be induced artificially through tissue culture techniques. It is particularly common in certain fruit crops like citrus, where it can be exploited for clonal propagation, ensuring uniformity and genetic stability in cultivated varieties.

Polyembryony can have various causes, depending on the plant species and the specific mechanisms involved. Some of the common causes include:

 Zygotic: 

In some cases, polyembryony arises from the fertilization of multiple egg cells within the embryo sac, resulting in the development of multiple zygotes. This can occur naturally in certain plant species, leading to the formation of genetically diverse offspring.

 Nucellar:

Polyembryony can also occur through the development of embryos from cells of the nucellus tissue surrounding the embryo sac, rather than from fertilized egg cells. This type of polyembryony is common in citrus and other plant families like Pinaceae (pines).

 Adventitious Embryo Formation:

 Certain environmental or hormonal factors can stimulate the formation of adventitious embryos from somatic cells of the ovule or ovary wall. This can result in the production of multiple embryos from a single seed, leading to polyembryony.

 Genetic Factors :

Polyembryony may have a genetic basis, with specific genes or genetic mutations influencing embryo development and the initiation of multiple embryos from a single fertilized egg or embryo sac.

Hybridization  :

Hybridization between different species or varieties can sometimes induce polyembryony, as seen in some interspecific crosses. The genetic interactions between parental genomes can lead to abnormal embryo development and the production of multiple embryos.

Pathological Conditions:

In some cases, stress, disease, or other pathological conditions may disrupt normal embryo development and lead to polyembryony as a response to the stressor.

    At conclusion we may say that Polyembryony can result from a combination of genetic, developmental, and environmental factors, and its occurrence varies among plant species and cultivars.