Sports

MissyWeitzel

I received a tuber of Zoey Rey from a wmds friend. It's not something I would have picked to grow and this is my first year with it. The first few blooms were the fuschia and yellow blend just like all the photos online. Now I have this bloom opening up and it is definitely a much different color. I traced the stem down and it is coming off the main stalk of the same one Zoey Rey plant I have. This is the first bloom on this particular stem/stalk. Of course I have a lot of questions.

In order to know if this is a sport and not some weather/stress related color change, do I just need to confirm future blooms on other stems are the normal fuschia/yellow?

If it is a sport, is there a set of criteria to determine whether I should or should not try to save it?

Is there a master list somewhere of dahlia sports and their origin?

Teddahlia

Sports are treated like seedlings by the ADS. They are not allowed into a trial garden until the third year of being "stable" . Sports are a common breeding tool used by plant breeders. They can be induced by chemicals or radiation or most commonly without any human intervention. Most of the naval orange varieties sold are "sports" from trees that had a branch with "better " or "different" oranges. I am talking about naval oranges that do not make seeds so cannot have seedlings. I personally am wary of sports since they are caused by a loss of genetic material and what other genes were lost and they may have something to do with plant performance. One person stated that color genes are are located in a place in the plant cells that is the first to sport and other genes are not likely to be affected. Just because he has a PhD in genetics does not make that true. ☺

MissyWeitzel

Teddahlia thank you, Ted. Very helpful!

Bessie

Teddahlia has this PhD in genetics written any papers or books? I'm really curious to learn more.

Teddahlia

Bessie The person who started the dahlia breeding site on Facebook has a PhD in genetics and was a professional orchid breeder. He has never said much about flower color on Facebook however. Dr. Virginia Walbot from Stanford University grows dahlias and has been teaching a "dahlia" class at Stanford that includes information on dahlia color. Somehow I have not been admitted to Stanford and have not taken her class. I took a dahlia judging refresher class a month ago and one of the candidate judges did take her class. He speaks "biochemistry" and said a few things that were meant to tease an old man(me) . For example we talked about transposons and variegated dahlias and what I have learned about them is reasonably correct. He said however, a graduate student he knows is studying another color pattern in dahlias and it is caused by a heretofore unrecognized genetic anomaly that is similar to transposons but different. He detected from my facial expression that he had exceeded my depth of knowledge and then when the big words were bouncing off of me like giant raindrops he quit talking about it. Color in dahlias is a fascinating subject. However, it can be said that if you cross two dahlias that are the same color you increase the odds of getting that color. Knowing the chemical pathways in the formation of the color pigments is certainly interesting but it may be just a bit more than a breeder needs. Having said that, purple is an interesting color in dahlias and with some chemical knowledge you may be able increase the breeding success a few percentage points if you know a bit of the basics.

Bessie

Teddahlia thanks! I guess I'll need to scour the research papers to learn more nerdy details about Dahlia genetics. I've never joined Facebook, as this forum is the only place I interact with strangers (or better called Dahlia friends) on the Internet. The Stanford breeding class has a webpage that I looked at a few years ago, before I knew the names of any common dahlias. The page didn't have the details I was looking for.

Teddahlia

There is lots of information on flower color on the internet and most of it applies to dahlias. Facebook site for breeding dahlias has 7,500 members and as you may guess most of those people know very little about breeding dahlias. I post much more detailed information on dahlia addict and more pictures too.

MissyWeitzel

It's me again back with more questions.

Do sports always have the same foliage and plant habit of the original cultivar? Or can characteristics other than color change in a sport?

Teddahlia

Sports are genetically "damaged" dahlias. Radiation(background radiation in your garden can be enough) or some chemical has destroyed some of the DNA. There can be multiple changes to the plant along with the color change but that is less common. One science person said the color genes are exposed and are easily damaged. Who knows? I personally believe that there is ancillary damage in most sports.

bloomhjelm

Speaking of multiple changes, I believe I've seen three different growers on social media with color and petal form sports of Czarny. Maybe you all have seen some of these too. Very interesting how this breakdown is similar -- maybe because the genetic lineage is so narrow and recent in the US.

Teddahlia

"....maybe because the genetic lineage is so narrow and recent in the US." This is a case of the genes that make the dark color not being stable in the long run. Same process as a sport and in this case the gene(s) that cause the over production of the anthocyanin pigment are fragile and are easily either damaged by ambient radiation or just are too unstable to survive reproduction for several generations. One will have to make sure you get good stock and growers may have to cull many plants.
Note: I was working the classification table at a recent show and it came up for classification. I watched the other senior judge color classify it. Czarny is the darkest black red flower I have ever seen. And remember the science graduate student who chose to write a "research" paper on black dahlias. It was about 40 pages long and the conclusion was that black dahlias just make more anthocyanin pigment.