@megdavis Are you going to be working with diploids primarily or tetraploids primarily or both?
I was planning to self-cross and line breed (backcross) to look for recessive traits
Dominant and recessive are relatively simple when working with inbred diploid lines (Mendel worked with peas which are natural inbred lines). When working with outbred daylilies they become more complex. In particular the concepts actually apply to how we measure traits more than to the traits themselves. For example, using inbred lines if I cross a purple flowered plant with a white flowered plant I may find that their F1 seedlings are all purple flowered. Using just my eyesight I may not be able to distinguish the F1 purple flowers from the purple parent. However, if I extract the purple pigment I may find that the F1 seedlings have substantially less purple pigment in their flowers than the purple parent has. When something like this was actually done in petunias the F1 only had about 70+% of the pigment. Using just eyesight the characteristic was a "complete" dominant. Using the quantity of pigment it was a partial dominant or quantitative. If I take the same purple allele and "white" allele and cross them into a number of different inbred lines I will find that the amount of pigment varies in the different lines, possibly both in the homozygous parent and in the F1s. When something similar to this has actually been done it has been possible to find genotypes in which an apparently "dominant" characteristic in some/many inbred lines is "recessive" in others. Each inbred line is the equivalent of one genotype or one genetically unusual genotype. This can be described as background genotype effects or modifier gene effects, etc.
In tetraploids the situation becomes even more diverse. Simple, classical dominant and recessive characteristics are more difficult to identify than in diploids. That may be because there are few situations in diploids where the heterozygote is 100% the same as the homozygote (where the "dominance" is complete). In a tetraploid where there are five possible genotypes at one gene (AAAA, AAAa, AAaa, Aaaa, aaaa) if one measured the amount of pigment present in a flower one might find AAAA - 100%, AAAa - 80% AAaa - 60% Aaaa - 40% aaaa - 0% for example and quantitative inheritance. Finding AAAA - 100%, AAAa - 100%, AAaa - 100%, Aaaa - 100% and aaaa - 0% would be unusual.
I typically suggest considering most characteristics in daylilies to be quantitative/additive (affected by many genes) and for what to expect in seedlings to be based on whether the characteristic involves "making" something. The ability to make something, for example, a pigment, is usually inherited in the seedling but is not necessarily present to the same extent as the parent (depending on the other parent).
