Dennis616 said: one surprise to me is that despite the greater genetic possibilities with tets it is easier to get changes with dips. Good to know.
A simplified example based on single gene characteristics inherited simply (not necessarily a good example for daylilies but used to show why diploids are easier to manipulate genetically). Suppose I have found a blue diploid daylily b/b but it is only present in one plant and that plant has a scape only six inches tall S/S. I want to put the blue flower on a plant that has a scape 24 inches tall s/s but it is red B/B. I cross the two plants and all the F1 seedlings are short reds B/b S/s. I cross two of the F1 seedlings together (luckily for me for this example they are compatible). 1/16 of the F2 seedlings will be blue with 24 inch scapes b/b s/s.
The same example but in tetraploids. Blue is now b/b/b/b S/S/S/S and the 24 inch scape is s/s/s/s B/B/B/B. All the F1 are short reds B/B/b/b S/S/s/s. There are three extreme situations I could have in the F2 in the tetraploids. I might find that 1/1296 on average are 24" and blue. Or I might find that 1/256 are 24" and blue. Or unfortunately I might find that there are never any seedlings that 24" and blue.
In the diploids 1/16 is produced by 1/4 x 1/4. However in tetraploids 1/4 becomes 1/36 or 1/16 or never. It is partly because of the greater genetic possibilities that finding specific genotypes becomes rarer and therefore more difficult.
