aurea x aurea, or aurea x self

[JScott]

I've done some googling, and I can't seem to find a definite, or even an indefinite answer. If two aurea variety plants are crossed, and for the sake of example, let's use Cattleya tenebrosa 'Walton Grange' and say it was selfed, will the offspring all be yellow, or will there be some variation in coloration?

[Roberta]

Those who actually hybridize can shed more light... but line-breeding (that may include different color forms of the species) can give surprises.

I have a Laelia purpurata 'Tipo' x self... L. purpurata 'Tipo' is an awarded plant... the name implies that it is typical, but that turned out to just be a cultivar name. The awarded plant did look like a tipo... pink and white petals based on the award description in Orchidwiz, the AOS award photo in OrchidPro has a dark lip. So I was surprised that the one that I got from the selfing (done by SVO) came out as a beautiful alba. I asked Fred Clarke about it, and he said that about 25% of the selfing did come out white. So... clearly the mother plant had some alba in its ancestry as well as forms with color. Since cultivars aren't registered anywhere, the ancestry is known only to the hybridizer (or in this case, probably multiple hybridizers over some years so probably nobody really knows all that went into the awarded
plant)

With different color forms in the ancestry of the plant, when it is selfed the genetics follow the Mendelian rules. Surprise!

[JScott]

Thank you! That clears things up a bit. I only have a rudimentary understanding of genetics, so I'm not sure how all this works with dominant and recessive traits when breeding orchids, but that's good to know that some variation is possible. Thank you so much!

[estación seca]

Aurea forms (or any other atypical color forms) might be caused by different mutations in different plants. Crossing two plants that have the same aurea mutation and no recessive normal chromosomes would yield aurea progeny.

But if the two plants are aurea because of different mutations, progeny would probably be normal, because they would inherit a normal copy of each gene, one from each parent.

An example: Carter & Holmes offered seedlings of the primary hybrid Maxillaria Memoria Ben Berliner a few years back. They used aurea forms of the normally red-flowered parents, Max. tenuifolia and Max. variabilis, hoping to get yellow-flowered hybrids. The seedlings came out red. This means the parent clones were yellow because of mutations in different genes.

[JScott]

I have a tenebrosa 'Walton Grange' x self, and I was just wondering what the chances are that it might actually bloom out yellow. It's still about two years from blooming. I don't know if this means anything, but the plant itself is considerably lighter green and appears to have little to no anthocyanins like my other tenebrosas, which have a great deal of purple on their new growths. Like I said, I don't know if that means anything, but there it is.

[Fairorchids]

It will most likely come out aurea.

Some years ago, I purchased seedlings of tenebrosa (aurea x alba). They all came out tipo, as the aurea mutation and the alba mutation were not compatible.

[JScott]

Originally Posted by Fairorchids

It will most likely come out aurea.

Some years ago, I purchased seedlings of tenebrosa (aurea x alba). They all came out tipo, as the aurea mutation and the alba mutation were not compatible.

Just an aside, the three Adenium obesum seedlings I got from you last year are just going wild. They were tiny things when I got them (and for the price, I expected them to be, maybe an inch or two tall), but they have done great. They are upwards of ten inches tall now, and I wouldn't be surprised if they bloom next year, if not this year.

So thanks for those, they are doing great, and I am very satisfied. Thanks for the great plants!

[My Green Pets]

Oooh, but what will happen if you self and/or sib cross those seedlings?

Originally Posted by Fairorchids

It will most likely come out aurea.

Some years ago, I purchased seedlings of tenebrosa (aurea x alba). They all came out tipo, as the aurea mutation and the alba mutation were not compatible.

[Jeff214]

Not sure if anyone is interested... but coming from a biochemistry (biosynthesis) point of view...

Genes encode for enzymes that help produce pigments in plants (Enzymes are a type of protein that helps out with chemical reactions.). For example, a starting material might be converted to red pigment by a production line of enzymes ABC. (Just a simplified example. not the actual pathway.)

Starting material -> enzyme A -> intermediate product 1 (not red).
intermediate product 1 -> enzyme B -> intermediate product 2 (not red).
intermediate product 2 -> enzyme C -> red pigment (final product).

If any one of those enzymes are not functioning properly, you may get low to no red pigment production (and an alba or aurea plant).

Say if parent A has functional enzymes AB (alba/aurea) and parent B has functional enzymes BC (alba/aurea). The offspring might inherit functional copies of all the enzymes ABC (red). Just based on phenotype (what is looks like), you can't tell the genotype (the gene make up).

That's just one way how two alba/aureas could potentially make an offspring with red flowers. There's more nuance in the relationship between genotype and phenotype but that's not my specialty.... so I will leave it at that.

[JScott]

Originally Posted by Jeff214

Not sure if anyone is interested... but coming from a biochemistry (biosynthesis) point of view...

Genes encode for enzymes that help produce pigments in plants (Enzymes are a type of protein that helps out with chemical reactions.). For example, a starting material might be converted to red pigment by a production line of enzymes ABC. (Just a simplified example. not the actual pathway.)

Starting material -> enzyme A -> intermediate product 1 (not red).
intermediate product 1 -> enzyme B -> intermediate product 2 (not red).
intermediate product 2 -> enzyme C -> red pigment (final product).

If any one of those enzymes are not functioning properly, you may get low to no red pigment production (and an alba or aurea plant).

Say if parent A has functional enzymes AB (alba/aurea) and parent B has functional enzymes BC (alba/aurea). The offspring might inherit functional copies of all the enzymes ABC (red). Just based on phenotype (what is looks like), you can't tell the genotype (the gene make up).

That's just one way how two alba/aureas could potentially make an offspring with red flowers. There's more nuance in the relationship between genotype and phenotype but that's not my specialty.... so I will leave it at that.

I absolutely am interested. Thank you so much for that information. That is fascinating, and I think you for sharing that.