beckygardener said:What is the main reason that the dips are converted to tets? Is it to get more variation in any future hybrids/children of such tets? (Particularly the bloom patterns, colors, etc.?)
Geneticists provide a number of changes that
may happen when a plant is converted. I have seen no evidence of more potential variation in tetraploids than in diploids. Every characteristic that is present in tetraploids is also present in diploids or would be present in diploids if there were as many hybridizers working with diploids as there are working with tetraploids and if those hybridizers produced as many diploid seedlings as they produce tetraploid seedlings.
In general, most (but not all) of the interesting characteristics present in tetraploids first appeared in diploids. Those cultivars were then converted to tetraploids to introduce the characteristic into the tetraploid gene pool. Diploids still continue to be converted to tetraploids.
Tetraploids by default have larger cells so they can have thicker leaves, scapes, petals and so on. Those larger cells can also produce new problems, such as scape blasting, in tetraploids. Although diploids can be selected to have thicker cells any tetraploid automatically has larger cells than its diploid version. Also tetraploids seem to be more successful when self-pollinated (but daylily hybridizers very rarely self-pollinate their plants) than diploids.
New characteristics, that is, new mutations are always much easier to find in diploids than in tetraploids. Genetics in tetraploids is more complex than in diploids and before gene engineering and molecular genetics, professional plant breeders would work with diploids and then convert them to tetraploids rather than attempt to work directly with tetraploids. It is important to note that daylily hybridizers do not work in the same way that professional plant breeders work or for the same reasons.
