Loss of genes in interspecific crosses

[triffid]

All of the 'Angel' vines are in bloom and none have reddish flowers.

I have been trying to grasp the contents of the following study, and if I understand correctly, there shouldn't be 100% white flowered progeny if the previous gen was 100% red flowered (unless this gen was homozygous for ga?).

https://journals.ashs.org/jashs/view...l?rskey=gGgwEQ

So if one can breed a line of Sal/Sal V/V Ga/Ga this would be stable for 'china rose' flowers?

Input would be much appreciated!

[Galina]

I am afraid this is beyond my comprehension. I lost it when gametophyte factors came into play and I could not make head nor tail of any of the explanations of that word or what it means in this context. Neither do I understand the differences between all the shades of pink mentioned. Or whether china rose is remotely like the pink that Angel is supposed to be on the photo from HSL. It would appear that non of the progeny should be entirely white flowered and your Angels are white.

I am still somewhat surprised that even if HSL got Angel seeds with this photo, they would not have grown it for themselves at least once before offering it to the public for the first time. Had they done so, they would have got the same result as you, no doubt. I would not have expected a bean with those flowers to produce seeds with a white background either, like the Angel seeds you had. White seeded runner beans are also white flowered.

Time for contacting HSL methinks.

[triffid]

Not really, deleting Galina's post is outrageous and that email is absolutely dancing around the issue without addressing it. Subsequent research? How does that work when I've been told it is 'most definitely' the way it appears in the catalogue? Something like that doesn't get explained away with 'subsequent research'. I can't claim to most definitely have a PhD in Quantum Mechanics on my CV (I grew it myself for two years, you know?) and when queried, announce that subsequent research indicates to me that I didn't actually write the thesis. I'm either lying or made a huge mistake. And they're still not admitting a mistake, and are providing no explanation of how the error arose. No personal response for me - two weeks of silence after I've been told my observations are 'quite the mystery'.

[Galina]

It seems that it took the second report to get them looking at it. That set off research and that will lead to corrections in future catalogues.
It's a result of sorts. A mistake sort of acknowledged.

[jayb]

Very poor, particularly when given who they are, their resources and responsibilities. You kind of expect more from them.
Similarly, I contacted them several years back about a tomato I suspected wrongly named, I didn't even get an acknowledgment.
It does make me wonder how much they overlook.

[jayb]

I'm afraid the article is over my head at the moment and I don't feel able to make a meaningful response or colour prediction.
To be honest I'm still trying to grapple with bean pod colours.

[triffid]

If I'm understanding correctly, the Sal gene responsible for red pigment, which originates with P. coccineus, is blocked by another gene ga, which originates with P. vulgaris.
If ga/ga is present in hybrid pollen, it blocks the pollen grains which carry the Sal gene, thus limiting flowers with red pigment in subsequent generations.

[Galina]

This is how I understand it. ga blocks pollination, but in a way that leaves no apparent gaps in the pod. It may be more blocking than just limiting it to less than normal Mendellian ratios.

[Galina]

Unfortunately I don't have many photos of the F2 of my first interspecies cross, but these amazing apricot hues and somewhat distorted flower shapes and not a bit of red to be seen. Further generations have more normal vulgaris colours, but still a little more strongly coloured. After F4 they were essentially vulgaris colours. I have never seen red again.