In one generation, a new species of plants is generated. There is no gradual evolution of parent to daughter species. And the new species are incapable of crossing with the parent. I would like to address some questions about polyploidy and the role it plays in evolutionary theory and would especially like to hear from some biology types whose genetics courses were taken a more recently than mine. I am not as strong in genetics as I am in other areas, so let me know if I have it wrong somewhere.
Polyploidy involves doubling the number of chromosomes.
In normal reproduction of eukaryotic cells, the chromosomes must double and then separate. In the case of polyploidy, the cell division after doubling does not take place and one is left with a cell of double the number of chromosomes. But this will be two identical sets, without any new information. If you had 23 pairs you will now have 46 pairs. They are similar apples to the non polyploid root with a larger fruit.