Molecular basis to understand polyploidy.

Polyploidy which is defined as an increase in chromosome number by an exact multiple of the haploid chromosome number is a typical characteristic of plant species but can also be found in almost all organisms from protists to humans. In the plant kingdom, since the reproduction can occur vegetatively, polyploid cells have time to settle down from the evolution point of view as a stable genetic system. So, 30 to 70% of angiosperms, including many important crop plants, are estimated to have polyploidy in their lineages. The success of polyploid species in plants has been attributed to their ability to colonise a wider range of habitats and to survive better in unstable climates compared with their diploid progenitors, presumably due to increased heterozygosity and flexibility provided by the presence of additional alleles.