Problems Concerned with Haploid Production,Tissue,Callus,Diploid Cells,Tetraploid Cells,Anther,Pollen,AntherCultureTechnique

	Problems Concerned with Haploid Production - Although haploids have been raised mainly from anther culture of a large number of species, this technique has not proved successful in respect of all genotypes of crop species. A number of problems are encountered with the induction of haploids. 1. Anthers often fail to grow in vitro or the initial growth is followed by abortion of the embryos. 2. The tissue or callus developing from the anther generally comprises a chimera of diploid, tetraploid, and haploid cells.
3. Selective cell division must take place in the haploid microspores, con comitantly restricting proliferation of unwanted diploid and polyploid tissues. Selective cell division is often impossible. 4. Formation of albinos in anther cultures, especially with cereals can neither be avoided nor the loss of plants due to albinism reduced. 5. The technique of inducing haploids in vitro is not economically viable due to low success rate. 6. Callus derived from anther or pollen in a medium supplemented with growth regulators is usually detrimental for haploid production.
7. It is difficult to isolate a haploid from a mixture of haploids and higher ploidy levels since the polyploids outgrow the haploids. 8. Doubling of haploids is time consuming and may not always result in the production of a homozygote. Double haploids sometimes exhibit segregation in their progeny. 9. The anther culture technique works well on plants belonging to only a few families, of which Solanaceae is one. 10. The frequency of embryoids obtained is often very low.