cybersix said:Many thanks Sue (as always!) for your post.
You're very welcome.
cybersix said:The key is finding if all daylilies seeds have dormancy or not, I think.
I'm not sure if you mean your seeds or daylily seeds in general? Daylily seeds in general do not all have seed dormancy. For your own seeds the only way to find out is to start them conventionally, i.e. just plant them in normal seed starting medium, don't do anything to them first. If they all germinate in a week or two they did not have seed dormancy. If they germinate over several weeks or months then the later ones did have seed dormancy. Then you would know that you need to be prepared for seed dormancy the next time.
cybersix said:It explaines the different kind of dormancies among plants; then, it says that the genera hemerocallis always have the same type of dormancy and it needs (obligatory) stratification.
I've seen that article before and it is incorrect, stratification is not obligatory for all daylilies but it speeds up germination. They will still germinate if not stratified (there may be exception but nobody's ever studied that) but it can take a long time for some of them. If you'd like to read the original research on daylily seed dormancy from the 1950's try these links:
The second article only has the abstract online for free but most of the important information is summarized there in any case. The full article is 15 pages long and a lot of the information is on the first link above by the same author.
cybersix said: The only thing I knew before entering ATP was that diploids can germinate soon after harvesting, while triploids needs a cold period (the article is written by an italian hybrydizer and he uses dry chilling).
This is incorrect. The seeds I mostly experimented with were diploid and about 25% would germinate immediately while 75% were dormant. See also Griesbach's experiments in the links above. I don't recall keeping any statistics for tets but the usual comment one hears is that dormants benefit from stratification and evergreens do not. This also is probably not correct but has not been studied. Also does it mean the foliage habit of the parents or the foliage habit of the seedling itself?
Dry chilling does not break daylily seed dormancy. If the seeds germinated well after dry chilling they may not have been dormant in the first place. The other possibility is that chilling while fresh (when the seeds are not internally dry) may break dormancy but I think it is most likely that the seeds were not dormant to start with. A daylily seed may be dormant at one time and not at another, seed dormancies can wear off during storage for example. There are also other factors like the air temperature when they are started and so on.
cybersix said:So I'll start giving for a fact that all daylilies seeds have dormancy.
That's the safest way
cybersix said:Now, what I can't find it's osmopriming related to dormancy, as you say.
I did find something when I looked for that earlier this morning, but it was for thermodormancy and photodormancy. I've sometimes wondered if the former might apply to daylilies sometimes, but in Griesbach's testing they didn't respond to light/dark.
cybersix said:So did you find different seeds dormancy in your experience?
In my main testing I did I used naturally pollinated pods from a diploid species-type (it is either Hemerocallis lilioasphodelus or closely related but was not labeled) so that they were genetically as close as I could get them. Those were what I mentioned above as germinating 25% without stratification while the other 75% responded to damp chilling. I'm not sure if I can get enough of those now to try osmopriming but I will look. I know I can get enough of another species-type daylily but it flowers much later so unlikely to have been self-pollinated.
You might also find this article from the American Hemerocallis Society's Journal of interest:
cybersix said:It's a bit of a double work for me, understanding correctly english articles then understanding the gardening terminology LOL.
You do very well indeed!