Posted on Nov 19, 2022 5:08 AMMy second Iris cross also used Tall Bearded Iris (Iris 'Saffron Drift') (SD) as the pod parent (as mentioned in my previous post, it doesn't produce pollen for me) after seeing how vigorous the first lot of seedlings from it were.
I was again aiming to introduce some of the colour from
Tall Bearded Iris (Iris 'Handshake') (HS), especially since SD usually produces much taller bloom stalks than HS under my conditions.
Three of the five seedlings flowered this year for the first time. All three need further evaluation before I decide what to do with them. The variation was initially quite surprising, but after more research and thinking about it, I have a working hypothesis that explains the results thus far.
Seedling #1 is an eye-catching bitone that fades with age.
Seedling #2 actually flowered last and was quite late (I wasn't expecting it to bloom this year). I think it is a lovely pastel, with pale lemon standards and ivory falls (with a faint Debby Rairdon pattern).
Seedling #3 was quite surprising when it opened. The bud initially looked like it might be a green, but when it opened it was a crystal white with just green veining on the hafts. It also has the least ruffling of any the seedlings.
How could this much variation arise from the cross? From my previous cross of 'Saffron Drift' X 'Hell's Fire', I worked out that SD probably carries two copies of the dominant anthocyanin inhibitor (IA) gene and at least two of the standards inhibitor (IAs) gene as well. If my supposition is correct, then in the SD X HS cross the seedlings could end up with any of the six possible combinations of the IA and IAs genes (e.g. 0-2 IA and 0-2 IAs). This would partially explain each of the seedlings:
- Seedling #1 would have inherited 0x IA and 2x IAs from SD.
- Seedling #2 would have inherited 2x IA from SD.
- Seedling #3 would have inherited 2x IA from SD.
But what about seedlings #3 being white and hence lacking both anthocyanins and carotene pigments? Given that HS is a plicata with a white ground colour, I have to suspect that it carries exactly two copies of the carotene inhibitor gene (IC) based on the seedlings thus far:
- Seedling #1 inherited 2x IC from HS, as the colour seems to be purely anthocyanin.
- Seedling #2 inherited 1x IC from HS. Combined with the Debby Rairdon gene from SD, that would explain the pale yellow.
- Seedling #3 inherited 2x IC from HS, resulting in white.
If my hypothesis is correct, then the remaining seedlings (and if I start the remaining seeds) could produce any combination of white, yellow and violet on either of the standards and falls. If I get a darktop seedling, then that would suggest that HS also carries the ICf gene (carotene inhibitor on the falls) and the falls of Seedling #2 is not just the Debby Rairdon pattern from SD.
Any comments on my suppositions are most welcome!
