Pea Flower Colour Genetics

[Silverleaf]

After some discussion recently about colour, I thought it might be a good idea to collect some pictures together to illustrate the effect of different alleles on pea flowers that I've grown.

I'll keep adding to it as I discover more combinations. To be continued....

[Silverleaf]

+
Wild type purple flower


This is what the "natural" pea flower would look like - basically it's the default appearance when no genes are acting on the flower. The wing petals are maroon and the standards mauve, deepening in intensity and then becoming more blue as the flower ages. The pictures shows two flowers from the same plant at different ages.

The colours are due to red/purple anthocyanin pigments which you can also see in the leaf axil rings, stems, foliage, pods, and seed coat (assuming the plant has the right genetics to express colour in these areas).

[Silverleaf]

a
White flowers, no anthcyanin production


The recessive allele a blocks the production of anthocyanins throughout the whole plant, so there's no coloured axil ring, no purple/red on the pod surface or seed coat, and flowers are white. An aa plant could be carrying loads of different exciting colour genes and you'll never see them because this allele "blocks" them, like if you took all an artist's paints away and made them draw a rainbow with only white paint!

Many commercial varieties are white-flowered, especially sweet-tasting shelling peas, because apparently the white colour and the sweet taste appeared together at the same time. I don't know if this is coincidence or not. Either way it's so common that if a variety description doesn't specify flower colour I assume it's white.

[Silverleaf]

ar
Violet flowers


This gene increases the proportion of bluish anthocyanin pigments in the flower, giving this lovely violet colour. It may look similar to the above picture of wild type flowers, but in person it is easy to distinguish between the two. Pigment in other parts of the plant is affected in the same way, so the axils and other areas show violet instead of purple.

[Galina]

cr for crimson flowers. Here a couple of Unity flowers. Hope you don't mind that I added these. Such a stunning colour.,

[Galina]

b for pink flowers. A picture of Elisabeth flowers

[Galina]

Can't find a separate header for Mr Fixer and the beg gene, so will put a photo here. The wings are exceptionally pretty and faintly stripey. Mr Fixer is a crown pea. The stems have now thickened and a top tuft of flowers is just developing.

[Silverleaf]

I had forgotten how nice that begonia pink is!

[Jang]

Yes, it's very lovely.
I gather a lot of crown peas have pink/salmon flowers. I'm wondering whether it's varying shades of pink and various genes at play or whether there is some kind of genetic connection between pink flowers and crown form

[Galina]

One of the Visionary plants from the conservatory stretched to over 2ft, and the two that were planted outside are doing well, so I decided to plant it out. It instantly responded with flowers! Without a bottle it is at risk, but at least I hope to get pollen and do crosses. What a beautiful flower. It is violet, due to the ar gene which is also called caerulicans. Additionally Visionary has the cov gene which makes the leaves darker and possibly also the flower. This is a beauty.

[Silverleaf]

Very nice work! You can really see how dark and blueish the leaves are there and the flowers are really dark too. Let's hope you get some successful crosses, it really is too fantastic a colour to be hidden away in tiny short plants!

[Galina]

Today I made a cross specially for you Silverleaf. Visionary (pollen) x Telephone. 3 flowers - fingers crossed

[Silverleaf]

Yay! Come on little peas, we're counting on you!

[Galina]

ce and rub genes in peas Beacon and Scholar. One Scholar plant was in my donation of Beacon seeds with very different flower colours. As the seeds I received were originally grown adjacent, I was very lucky to accidentally receive both genes.
https://www.growingfoodsavingseeds.c...ession-ji-1860

[Jang]

Interesting. I imagine it’s a continuum but how successful or easy have you found May or June sowing to be in an average (if there is one) English/Welsh summer?

[Galina]

I don't sow in May or June. Those times are so busy with beans, squash and other crops that there is not time for peas. No experience.

[Jang]

Yes, practicalities are worth considering! I had considered my pea sowing to be over in March until I became interested in Jaerert, and then another, and then..... But there is a time to stop.

[Galina]

gf green flowers in Nightmist
https://www.growingfoodsavingseeds.c...ne-x-nightmist

I can edit this post but not add a photo to a comment Hence a very late PS.

I just have a gf green flowered pea in the garden. What I did notice, following on from our discussions, is that gf, is just a chlorophyll modification, not like other flower colours that require A. This pea has white axil rings, not a single sign of anthocyanin anywhere, but the flowers are different from the usual white. They are smaller and yellowish green.

[Jang]

I have my first non-white flower which is very exciting! It's on Clarke's Beltony Blue.

Based on this very helpful thread, I'm assuming this is the wild default colouring for pea with no gene acting upon the flower colour.

What I'm unsure of (amongst lots of things I'm unsure of!) is what the implications for breeding are in terms of flower colour if there is no gene for flower colour. .

Purple pod colour seems to be either Pu or Pur. Is there any way of telling which it is and does it in practice make any difference?

These are rather fumbling questions but I'd really like to share my photo of my first non-white pea flower

[Galina]

Really lovely photo Jang. Yes that is a correct assumption, it is the wild colour. What is harder to understand is that white is not a different colour but is also one of the colours, which has been suppressed. If the 'breaks are off' by crossing with a non white pea any colour could be hiding under the white (but most likely the common two tone purple like above).

Flower colour and pod colour are different genes. For fully purple pods you need both pu and pur not either, and Clarke's will have both of them. https://hsl.gardenorganic.org.uk/see...s-beltony-blue

You can tell whether or not pur is present. Because pur is the gene that colours the funiculi red. Funiculi are the tiny strands of plant material which connect the peas to the pod. I have seen fully green pods that had red funiculi suggesting that one of the purple genes was present, the pur gene, but only the one. Clarke's will definitely have red funiculi. Just a matter of noticing them when shelling.

[Jang]

Many thanks, Galina. All questions answered, and more besides. And thanks for the tip re funiculi. I look forward to much funiculi-spotting a little later on.

[Galina]

You wrote "What I'm unsure of ................. is what the implications for breeding are in terms of flower colour if there is no gene for flower colour". Forgot to answer. There is a gene. Dominant gene A. We need to go to the gene list again http://data.jic.ac.uk/pgene/?validate=20. Fill in the even numbers for access, then type A top left, Up pops 'a' and a description of both A and a. I quote for 'a' "Absence of anthocyanin production. 'A' is necessary for general anthocyanin production in flowers, axils and seeds" So recessive gene a stops anthocyanin (the purple wild colour is stopped and flowers are white) and dominant gene A enables anthocyanin (purple flowers). If you cross a white flowering plant with a purple flowering plant, in the F1 generation the flower colour is dominant purple, in the F2 generation, we have one quarter white and three quarters purple flowers. This was one of Mendel's experiments. https://www.ncbi.nlm.nih.gov/books/NBK22098/

[Galina]

Further comment about gene A. It does not just enable anthocyanin in purple flowers, but also in pink flowers, in the crimson flowers of Kärrboda, the blueish flowers of Visionary and so on. A also enables anthocyanin expression in places, other than flowers. For example the leaf axils. A can get modified by other genes which exist together with A. For example the b gene modifies the A gene to make flowers pink and leaf axils pink. Your Clarke's has purple leaf axils, not pink, because gene b is not present. So A is generally involved to enable anthocyanin, but it needs A and further genes to modify the influence of A, so that you do not get the wild flowers, but other flower colours.. If you have for example the b gene, but not the enabler A gene, then a is in operation which means you will not see the pink flowers and leaf axils, because all colours are suppressed by a.

[Jang]

I shall need to read your second comment here when my mind is fresh and more alert. But thank you very much for the detailed info which I hope to be able to get my head round before too long.
But I actually have problems with the first hurdle which is accessing the information you quote from JIC. I'm used to using the site and have printed off parts of it to refer to so I'm fully aware of its central importance. But maybe I'm missing a trick as when I type A in the top left. as you say, I get much less information and only a without A . Is there something else I could be doing?

[Galina]

As to photos, I find more often than not I have to go back and correct. Sometimes it appears twice and I have to delete one of the copies it seems to have made, but as you know my photos are sometimes invisible to anybody but me, so having them twice at least makes sure they are there.

[Jang]

My problem is that I can't find any reference to A at all on the JIC website. I haven't found any explanations for genes, only columns for phenotype, class, subclass etc as on my photo.

[triffid]

It's late, so apologies if I'm misunderstanding your problem and being obtuse - but have you clicked on the magnifying glass icon to the left? It opens a new page with greater detail on the gene/s in question.

[triffid]

I think the reason they haven't elucidated more on A dominant is because it's not responsible for one single phenotype but is rather a prerequisite for other alleles to express particular phenotypes (observable characteristics). There is either colour or no colour, this is determined by the A gene at the A locus

For example, the other flower colours, not just wild-purple, require A. Purple pods require A. Red-purple stipule rings and the red funiculi Galina mentioned require A. Any and all anthocyanin pigment in the plant is produced because A is present. Only when you have two of the recessive allele, aa at the A locus, do you get white flowers and the associated 'plain' plants. Not because a encodes any colour of its own, but because the allele which is required for colour is absent.

If you go to the middle menu, scroll down to 'Flower and generative apparatus', then to 'Colour', and hit search, there will be a list of all the known colours. Those of which involve anthocyanin modification will require A at the A locus. If A is absent, the plants will have white flowers, yet still carry the colour-modifying genes at their respective loci, though they are impotent until A is introduced via cross-breeding.