Haploid plant cultures are produced from

Haploid plant cultures are produced from Pollen grains.
Haploid culture is an in vitro technique used to produce haploid (cells have half the number of chromosomes) plants.
Blackslee in 1922 first reported the natural occurrence of the haploid condition in Datura plants, due to parthenogenesis.
Haploid plants can be produced through in vitro culture of male gametophytic cells at the microspore or immature pollen developmental stage.