Asexual Reproduction in Plant - Agamospermy

Agamospermy:

• The creation of an embryo without fertilisation and meiotic division is known as agamospermy.
• This means that plants in this category reproduce through seeds, but embryo production does not entail meiosis or syngamy.
• Agamospermy excludes both parthenogenesis and apogamy

Types of Agamospermy:

Agamospermy is classified into three types: diplospory, adventive embryony, and apospory. 

1. Diplospory: Archesporial differentiates to create a megaspore mother cell in this way, but this megaspore mother cell gives rise to an embryo sac without meiosis. This embryo sac is diploid and a diploid embryo is generated without fertilization from the diploid egg of this embryo sac. Diploid parthenogenesis is another name for diplospory. Example: Parthenium, Taraxacum.
   
   
2. Adventive Embryony: An embryo is generated in this way from any diploid cell [nucellus or integuments] of the ovule excluding the embryo sac. This diploid cell functions similarly to a zygote. Adventive embryos are formed from nucellus (such as Citrus, Mangifera, Opuntia, and Mamillaria) and integuments (e.g., Spiranthus australis). 
   
   
3. Apospory: It was discovered by Rosenberg in Heiarcium plant. In this method, embryo sac or female gametophyte is directly formed from any diploid cell of the sporophyte except megaspore mother cell without meiosis. In this, gametophyte always remains diploid. E.g., Heiarcium, Ranunculus and Rubus.