Pollen Grain Evolution

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Two basic methods are used:
 

excised anthers are cultured on an agar or liquid medium, and the development occurs within the anther;

the pollen is removed from the anther, either by mechanical means or by natural dehiscence of the anther, and the isolated pollen is cultured on a liquid medium.

It may take 3-8 weeks for haploid plantlets to emerge from the cultured anthers. In different cases it has been reported that activated charcoal has a stimulatory effect on the initiation of embryos from haploid anther tissue. The removal of inhibitory substances from the agar is considered to be a factor. Another possibility is adsorption by charcoal of 5(hydroxymethyl)-2-furfural, a degradation product of autoclaved sucrose.
 

Anther and haploid  plantlets on a solid medium containing activated charcoal	Anther and haploid  plantlets on a liquid medium containing activated charcoal	Anther and haploid plantlets on a double layer medium. The solid lower part contains charcoal while the upper liquid layer  contains the growth regulators

Timing of androgenesis in tobacco anthers