Factors Affecting Haploid Production - A number of factors influence androgenesis in vitro. The genotype of the donor plant plays a significant role in determining the frequency of pollen plant production. Anther wall factors also support pollen embryo development.

Histological studies support this view. As induction of the pollen into embryoids occurs most easily within the confines of an anther, the anther wall seems to provide a nursing effect. There are two schools of thought regarding the role of the anther wall. One is that it may have a stimulatory effect on the growth of pollen embryos (probably due to the presence of enhanced levels of some amino acids such as glutamine and serine); the other view holds that it may emanate some inhibitory substances into the culture medium thereby blocking the growth of more pollen into embryos.

It helps in the removal of inhibitors from the agar used for gelling the medium. Another role assigned to activated charcoal is the adsorption of 5­hydroxymethylfurfural, a product of sucrose dehydration during autoclaving, assumed to bean inhibitor of growth in anther cultures.

Certain organic supplements added to the culture medium often enhance the growth of anther cultures. Some of these include the hydrolyzed products of proteins such as casein (found in milk), nucleic acids, and others. Coconut milk obtained from tender coconuts is often added to tissue culture media. It contains a complex mixture of nucleic acids, sugars, growth hormones and some vitamins.

The physiological state of the parent plant plays a role in haploid production. Success in haploid induction is in part dependent on knowledge of the physiology of the pollen yielding plant. In various plant species it has been shown that the frequency of androgenesis is higher in anthers harvested at the beginning of the flowering period and declines with plant age.

Certain physical and chemical treatments given to flower, buds or anthers prior to culture, can be highly conducive to the development of pollen into plants. The most significant is cold treatment.
The developmental stage of pollen greatly influences the fate of the microspore, Androgenesis occurs when a microspore or pollen is induced to shift from a gametophytic pathway to a sporophytic pathway of embryo formation.

Anthers of some species (Datura, tobacco) give the best response if pollen is cultured at first. mitosis or later stages (postmitotic), whereas in most others (barley, wheat, rice) anthers are most productive when cultured at the uninucleate microspore stage (premitotic). Anthers at a very young stage (containing microspore mother cells m tetrads) or a late stage (containing binucleate, starch filled pollen) of development are generally ineffective, albeit some exceptions are known.