Hemlady said:I have read just the opposite, that Evergreen is dominant over Dormant.
Stout determined that in diploids evergreen was "dominant" over dormant.
As far as I know, no one has examined the situation genetically in tetraploids. Although the evergreen characteristic, as defined by Stout may be "dominant" over the dormant characteristic, as defined by Stout, in diploids, the situation may be different in tetraploids. In tetraploids characteristics sometimes lose simple dominance and recessiveness (if it was originally present) and become quantitative. It is likely that a majority of characteristics are not inherited in simple Mendelian ways in tetraploids but are inherited quantitatively.
The simple Mendelian dominant and recessive rules and ratios fit well in certain genetic scientific research and in some real-life situations but are often inconsistent in real-life.
In daylilies, particularly in tetraploids, it is unlikely that dominant and recessive categories are any more helpful than simply considering most characteristics as quantitative.
For a simple Mendelian example, lets consider red flower colour versus yellow flower colour. In a diploid daylily red flower colour might be considered dominant to yellow flower colour. A pure-breeding yellow flowered daylily would be genetically yy and a pure-breeding red-flowered daylily would be genetically YY. The seedlings from a cross of the two daylilies would be genetically Yy and theoretically should all be the same red flower colour as their red-flowered parent. In real life the seedlings from such a cross would probably not all be the same red flower colour. They might not even all be red flowered. The problem becomes even more difficult if we looked at the same cross in tetraploids where there are five different genotypes instead of three (YYYY, YYYy, YYyy, Yyyy, yyyy) versus (YY, Yy, yy). Whereas in diploids we might
find YY and Yy to be red-flowered and quite similar, in tetraploids we might find that YYYy, YYyy, and YYYy were three different shades of red or perhaps even pink with YYYy darker red than YYyy which in turn was darker red than Yyyy.
Lets continue with the example. We might consider red flower colour to be dominant to yellow flower colour. But that does not mean that we can describe yellow flower colour as simply recessive. The terms dominant and recessive always imply (if not state outright) to what characteristic. So red flower colour may be dominant to yellow flower colour and yellow flower colour might be recessive to red flower colour but yellow flower colour might be dominant to near-white flower colour.
Back to daylilies in real-life.
It would be nice if we found that red flower colour was dominant to yellow flower colour but in real life in crosses of certain red flowered daylilies with certain yellow flowered daylilies the seedlings might be red-flowered or they might be 'brownish coloured', or described as 'muddy' or drab. Or in crosses of purple flowered daylilies with yellow flowered daylilies we might find that some of the seedlings were 'muddy' or 'drab' coloured. The muddiness or drabness of the flower colour would probably be an indication that the red or purple flower pigments were adding or mixing with the yellow flower pigments and not acting as simple dominants - but more quantitatively or additively.
Characteristics such as number of buds, scape height, leaf length, flowering time, flower size, petal length, petal width, etc., are typically best thought of as quantitative. For example, if one parent has a scape height of 18 inches and the other has a scape height of 24 inches then the seedlings will average a scape height of (18+24)/2 = 21 inches. That does not mean they will all have scapes 21 inches tall but that the scape heights on some seedlings might be shorter than 18 inches and on others any where in between 18 and 24 inches while on yet other seedlings the scape heights might be taller than 24 inches. A simple estimate for seedlings for quantitative characteristics is the average of the values for the characteristics of the two parents.
Stout found that flower doubling tended to not be present when a double was crossed with a non-double (in diploids). At best doubles would be recessive in diploids. However, even that is unlikely to be a simple case as doubling in daylilies is probably a characteristic that may be present genetically but not be visible ( variable expressivity and incomplete penetrance).
Reblooming also tends to not appear when a rebloomer is crossed with a daylily that does not rebloom. However, I consider that probably nearly all daylilies can rebloom given the necessary environment. The problem is that the necessary environment can be impossible to provide in some locations (not enough growing days for example). For a seedling to show rebloom it needs to be grown under optimum conditions of sunlight, temperature, water, fertilizer, competition, length of growing season, etc. When grown optimally I think that rebloom is quantitative - if one cultivar reblooms every 60 days under optimum conditions and it is crossed with a cultivar that reblooms every 120 days under optimum conditions then the seedlings from their cross would on average rebloom every 90 days under optimum growing conditions.