The correlation between temperatures and flower colour in Schlumbergeras

[Mrs.Green]

I know there is a correlation between the temperature and the flower colours in Schlumbergeras . It’s to my understanding that the pigment called anthocyanin causing some of the red colours in flowers, have a stronger effect in coooler temperatures?

If this is correct,when is the flower colour ‘decided’ so to speak? When it’s a small bud, halfway or is it an ongoing process,as long as the flower is ‘alive’?

Being fond of Schlumbergeras ,a Schlum with yellow flowers is on my wishlist. Off course I want the colour to be as strongly yellow as possible. Apart from the fact that this will depend on which cultivar I may get my hands on, what do I have to do to make sure that the environmental factors are the best? When the goal is a deep yellow colour?

I guess the same goes for Schlumbergera gaertneri( formerly R.gaertneri ) ?

[RorBurg56]

From my limited knowledge it might be betalain pigments in most cacti and that cold temps probably do cause colour intensification. I dont know anything about changing flower colours but would have thought it might relate to solar intensity though?

[One Windowsill]

Mr Subjunctive was usually trustworthy for this sort of information.

Temperature is, along with light, the other part of the trigger for plants to start setting buds. If you leave your plants outside during the summer, bring them in once the night temperatures start getting down around 50-60F (10-16C). Some plants have been known to survive temperatures as low as 40F/4C, but that isn't guaranteed. Plants with lighter-colored flowers, if exposed to temperatures below 50F/10C, are known to produce flowers which are more pink than usual:16 this is temporary, and will only happen again if the cold exposure is repeated.

16 One source says 70F/21C is enough to cause pinking, but that sounds really wrong to me: all the other sources more or less agree that they won't even set buds unless they get below about 55F/13C.

https://plantsarethestrangestpeople.blo ... a-cvv.html

They would be betalain pigments as anthocyanins are not produced by any species of the Cactaceae.

[DaveW]

There was an article years ago in the British Cactus Society Journal on temperature and flower colour for the white flowered Schlumbergera's, but I can't find it now. Evidently if buds set in the wrong temperature the white flowers can gain a pink tinge, but can't remember the temperatures concerned now. I suppose other colours may vary the same but you do not notice colour variation in red or other coloured flowers as much, but do if it is supposed to be pure white but another time gets a pink tinge.

From the Web:-

"A colour shift of a white Christmas cactus can also be due to slightly different environmental conditions. They may be pure white at warm temperatures, but take on a pinkish cast when it turns cool."

[Mrs.Green]

Thank you very much RorBurg56, One Windowsill and DaveW So there isn’t much hope of intensifying the yellow colour on a future yellow flowering Schlum. then, if I understand this right? I will have to rely on getting a cultivar with the ‘right’ colour fom ‘birth’ so to speak. Thank you One Windowsill for a great link!

[DaveW]

Possibly on a pale colour like white or yellow temperature variations could be more noticeable, even if not on deeper colours?

[Mrs.Green]

Possibly on a pale colour like white or yellow temperature variations could be more noticeable, even if not on deeper colours?

Thank you DaveW I have only seen one cultivar with yellow flowers on offer here in Norway. Unfortunately the colour seems to be quite pale and judging by the answers here, there isn’t much hope of ‘freezing’ it to my liking

[DaveW]

Looking on the Internet this is the yellowest I can see, obviously a white centre tipped with yellow petals. The problem as always is how correct for colour the photograph is? You can really only tell when you see the actual flower and as we all know flower colour density can vary year to year.

https://www.bing.com/images/search?view ... ajaxserp=0

Whilst that shows the typical zygomorphic flower of S. truncata types, this one has the "flower in flower" with the spreading bottom petals of the S. russeliana types.

https://www.bing.com/images/search?view ... 11&iss=VSI

[Shane]

Evidently if buds set in the wrong temperature the white flowers can gain a pink tinge
[...]
From the Web:-

"A colour shift of a white Christmas cactus can also be due to slightly different environmental conditions. They may be pure white at warm temperatures, but take on a pinkish cast when it turns cool."

I always assumed white flower variants (of normally colorfully flowered plants) arose from the plant having lost the gene(s) to make pigments to color the flowers. But if they do make the pigments sometimes, that really calls that assumption into question

[Mrs.Green]

Looking on the Internet this is the yellowest I can see, obviously a white centre tipped with yellow petals. The problem as always is how correct for colour the photograph is? You can really only tell when you see the actual flower and as we all know flower colour density can vary year to year.

https://www.bing.com/images/search?view ... ajaxserp=0

Whilst that shows the typical zygomorphic flower of S. truncata types, this one has the "flower in flower" with the spreading bottom petals of the S. russeliana types.

https://www.bing.com/images/search?view ... 11&iss=VSI

Thank you DaveW As you mentions, can one trust photos or as in this case ( https://www.shutterstock.com/nb/video/c ... -with.html) video? The cactus in this video seems quite deep yellow but would it really look like this IRL?

[quote=DaveW post_id=390742 time=<a href="tel:1642110554">1642110554</a> user_id=5831]
Evidently if buds set in the wrong temperature the white flowers can gain a pink tinge
[...]
From the Web:-

"A colour shift of a white Christmas cactus can also be due to slightly different environmental conditions. They may be pure white at warm temperatures, but take on a pinkish cast when it turns cool."

I always assumed white flower variants (of normally colorfully flowered plants) arose from the plant having lost the gene(s) to make pigments to color the flowers. But if they do make the pigments sometimes, that really calls that assumption into question
[/quote]

Thank you Shane

Speaking of Schlumbergera flowers, this ‘Angel Dance’ ; https://www.seedlingsandcuttings.eu/ind ... _pathway-2, is described as being an albino. The question is, if it really is a true albino, why is it only the flowers that are affected by albinism? Breeding stable albino ‘markings’ isn’t that easy to my knowledge? With stable I mean the albino ‘markings’ placed exactly the same place on each individual? If this ‘Angel Dance’ is a true partial albino, one would be tempted to belive it could only be multiplied by cuttings, to keep the desired albino( ?) blooms?

[Aeonium2003]

Doesn't look albino to me. If it was albino even the stems would be free of Chlorophyll.

I suspect it is an Anthocyanin free plant.

[RAYWOODBRIDGE]

Hi DaveW ;long time since we spoke, I cannot find the BCSS thread either, but just been onto Schlumbergera.net and they list below 16c (60f) as being the point at which colour change can happen within the bud.
Mrs Green ; the only true Schlumbergera species with deep yellow flowers is S. lutea.
Hope this helps

[One Windowsill]

There was an article years ago in the British Cactus Society Journal on temperature and flower colour for the white flowered Schlumbergera's, but I can't find it now.

Was it this one, page 9 for temperature information?
https://www.jstor.org/stable/42795051

Frank Süpplie "The care and cultivation of schlumbergera hybrids" CactusWorld Vol. 28, No. 4 (December 2010), pp. 235-245 (11 pages)

Just one hour of temperature drop from 18°C to 8°C was enough to pinken a white or yellow variety.

As they like humidity, a large open-topped aquarium/terrarium would keep them from cold draughts and keep higher humidity around them.

Sulphur deficiency can reduce the intensity of yellow flowers in Brassica and Physalis - https://www.botany.one/2021/10/flowers- ... -see-them/

[DaveW]

That would be the article, thanks Windowsill. I thought it was even further back than that. I presumed that pale colours like white or yellow would be more noticeable if any pink crept into their colouration due to temperature variation, or if flower colour intensity varied year to year.

Nice to hear from you again Ray. I wonder if the yellow truncata types could be a lutea cross? Possibly the white truncata crossed with lutea?

[One Windowsill]

That would be the article, thanks Windowsill. I thought it was even further back than that.

I did think the layout looked quite old-fashioned for a 2010 article. It would not look out of place in a 1960s book. This is not a criticism.