Pathways of development

Pathways of pollen development in anther culture or pollen culture are given below.

  • Pathway I
  • Pathway II
  • Pathway III
  • Pathway IV

Pathway I

Uninucleate pollen grain divides equally into two equal daughter cells. Both of these cells undergo divisions to give rise to a proembryonic mass. This proembryonic mass either directly (through embryo formation) or indirectly (through callus formation) may give rise to a haploid plant.

Examples – Datura

Pathway II

Uninucleate pollen grain divides unequally to yield generative and vegetative cell. Callus / embryo originate from vegetative cell alone, while the generative cell degenerates immediately or after undergoing one or two divisions.

Examples – Datura, tobacco, wheat, barley, chillies.

Pathway III

Uninucleate pollen grain divides unequally to yield generative and vegetative cell. Generative cell undergoes successive divisions to develop callus / embryo, while the vegetative cell does not divide or divides only to a limited extent forming a suspensor like structure

ExamplesHyoscyamus niger

Pathway IV

Uninucleate pollen grain divides unequally to yield generative and vegetative cell. Callus / embryo develop by repetitive divisions of both of these cells.

Examples – Datura

Factors influencing pathways of development, in Anther or Pollen culture

  • Genotype
  • Growth hormones
  • Culture medium
  • Growth (physical) conditions
  • Stage of pollen development
  • Pretreatments

Applications – Merits of pollen culture enlist merits, demerits and applications of the concept.