Practice question

Androgenesis results in plants whose nuclear genetic constitution is identical to male parent gamete contribution because development originates from male gametophyte microspore. Microspores formed after meiosis in anther tapetum carry recombined haploid genome representing segregation products of diploid male parent heterozygous loci. Under stress pretreatment cold starvation heat and culture conditions gametophytic program that would normally produce mature binucleate pollen with vegetative generative cells is aborted, sporophytic pathway triggered leading to repeated mitotic divisions forming embryoid or callus inside anther locule. Since no contribution from female genome occurs, regenerated plant inherits solely paternal alleles for nuclear traits such as disease resistance plant height etcetera, while organellar DNA may show biparental leakage depending on species. Initially plants are haploid n requiring chromosome doubling via colchicine to restore diploidy producing doubled haploids fully homozygous for male derived alleles. This feature enables capture of male recombination products in single generation accelerating breeding for traits transmitted through pollen parent without maternal interference.