This is being written for normal people who do not want to deal with punnet squares. There are many sites that will give you a more scientific explanation should you need it.
For a clivia to flower YELLOW all the orange pigment must be missing from the flower. This orange pigment, or anthocyanin is controlled in clivia through 2 or more different genes. These genotypes are called Group 1 and Group 2 in the clivia world.
If you put 2 known group 1 yellows together, you should get a yellow plant
If you breed 2 known group 2 yellow clivia together, you should get a yellow flowering plant.
If you breed a group 1 to a group 2 yellow, all the babies will be orange. Why? Because these genes dont mix. This is why it is important to know the groups when breeding.
Pinks and Peaches work similarly. If you cross a non yellow with one of these yellows, of the same group, and it has background yellow genes, some percentage of the seedlings will be Yellow (Or pink, or peach depending on what you are breeding for and what you are using). Usually 25%.
There have been attempts to breed BOTH genes into the same plant. This has been successful in some of the Victorian Peaches for example. However the only way to know if it is successful is to breed the plants together, grow out ALL seeds, Keep the clear based seedlings, grow and flower those, breed them together, etc until all seedlings come out clear based...and then breed those to a G1 and a G2 and see if the next generation is also all clear based. Even the plants listed on the list below as being both G1 and G2 may not be so in YOUR example of the plant unless yours is an offset (natural clone) or a clone of the original plant that showed these traits.
Although Clivia breeding is hundreds of years old, the information on yellow clivia breeding is not. It is relatively new information, and Yellow clivia used to sell for thousands of dollars even just a decade ago. As we breed these wonderful plants we learn more and more about them.
This is a very basic discussion of "yellow" without looking at any other genes but 2 genes in the whole background of our breeder plants. If you took basic Biology you will remember the geneticists aid, the Punnett Square, which allowed us to make some simple calculations on the percentage of X that would be Y. These are very basic, not complete, calculations based on the simplest of terms, and should only be considered 100% accurate when working with known breeding material.
Now, when you grow clivia Seeds, the base of the plant will either have color or be "Clear"
This is what a Colored based seedling looks like:
This is what we mean by "Clear Base"
See how the first one has distinct color on the back of the plant and the 2nd has no color at all? That is the difference.
Now, Sometimes its not so clear cut.
For instance, this is a cross between Euterpe (A Variegated Euterpe in this case) which is a pink, and Victorian Peach. Note how this seedlings base could be colored...maybe not..sort of hard to tell right?
When you have something like this Often the best answer if you have the option is to look at the rest of the seedlings in the batch, for instance here is one of the seedlings that variegated from the same batch of seeds:
As you can see, this one from the same seed batch is obviously colored. Note how my first colored example had the color on the leaf, and this one only shows it on stem, both are colored base.
Now, that is not to say the first one is also colored but if all the rest of your seeds from the batch look colored and you have one you cannot determine, the best way to guess is on the side of colored. If your wrong, well, maybe you get a nice suprise later :) If some look colored and some dont, the ones that do not are quite possibly clear bases!
When we talk about an unknown, clear based, plant you will always see us list all possible colors from a clear base. Those are: Yellow, Green, Apricot, Peach, Pink. We will generally try to tell you what we think the most likely outcome color wise is going to be as well.
There are some who would rather deal in absolutes, and tell you "This plant that I do not know the parentage of, will be 100% X. That to us is not a truthful statement and we refuse to make that statement.
For instance if we have a plant that is a Solomone Yellow (Group 1) and another plant that is yellow but is stated to be from Nakamura Ghost breeding (Maybe Group 1) and we get a clear based seedling, We will not tell you that this will absolutely be YELLOW, because we DO NOT KNOW THE BACKGROUND of that "Ghost"....And if every single plant that was ever bred like this was going to be yellow...well...all the people breeding for "Blushed Yellows"...they must be all fools. And flowers like Nicollette, That is pure yellow on the inside and orange on the outside...they simply would not exist in that universe of absolutes. These flowers can exist because there is more at play in their breeding than a simple set of 2 rules.
We have bred many different plant and animal species, and the one thing we know for certain is that if you are using a 4-6 box punnett square...you are absolutely not taking everything into account. The background genetics of most clivia flowers have not been fully documented.
For that reason I am adding from our friend Gideon Scheepers who maintains the Clivia Forum A list of all known Group 1 and Group 2 Plants, along with some that he thinks might represent yet another yellow gene altogether that he is calling Group 3.
So, with that said...here is all the gathered knowledge about what is what...what is in Group 1, What is in Group 2, and so forth. When we can we categorize our seeds and plants by their known groups using this list. If we dont know...we dont guess. We are already on Group 3, who knows how many groups there might be :)
|Group 1 Yellows:
Mare's or Howick Yellow
King Hamelin Yellow
San Marcos Yellow
Eshowe or Saunders Yellow
Jim Holmes Yellow
Vico or Smither's Yellow
Kewensis strain yellows
'GTS Delta Cream'
Yellow Daruma G1
Sir John Thouron
Vic Daniels Yellow G1
Pen Henry Yellow
|Group 2 Yellows:
Stella Parish Yellow
Port St John's Yellow
Yellow Daruma G2
TK Yellow GT
Vic Daniels Yellow G2
'Auriel Batten Yellow'
TK Miniature Yellow
TK short BL Yellow
|Group 3 Yellows:
Celtis Kloof Yellow4
Potterill Blush Yellow
Ndwedwe Alpha Thurston6
Ndwedwe Beta Thurston
Oribi Gorge Yellow
Byrne Valley Yellow
Peaches and Pastels
de Villiers Variegated Peach
Ndwedwe Gamma Peach
Anna Meyer Peach
|Group 1:||Group 2:||Unknown:|
1 Dwesa Yellow, Bashee Yellow, Transkei Yellow, Smith's Yellow, Tsolo Yellow, Floradale Yellow are the same plant
2 Natal Yellow, Giddy Yellow, Fred Gibello Yellow, Jardine Yellow,Swellendam Yellow, Holl's Yellow and Stella Parish Yellow are the same plant
3 'Cynthia's Dream' is a cross made by Fred van Niekerk using Natal Yellow crossed with a clone of Cynthia's Best
4 Group 3. There are 4 plants collected in the greater Pietermaritzburg area in the early 1960`s namely; Potterill Blush Yellow, Greendale yellow, Peacevale yellow and Celtiskloof yellow. All of these plants are compatable with one another and produce yellow[or slightly blushed] flowering seedlings when crossed together. These plants have for sake of a better name been called Group 3 yellows in my breeding program . They all flower yellow with a very slight pink blush or tiny speckling on the reverse of the flower, they produce seed pods which ripen red and all seedlings are pigmented but still flower yellow. - Sean Chubb
5 Mvuma Yellow. Another habitat plant which seems to be in her own group is Mvuma Yellow. Fortunately she is semi fertile when selfed and so we are growing on unpigmented seedlings from the selfing. Hopefully these will then be crossed back to the original clone to produce more yellows with the same genetic makeup as Mvuma Yellow. - Sean Chubb
6 Ndwedwe Alpha Thurston a habitat collected plant has been found not to be compatible, does not produce yellow seedlings with any other Yellow except her own seedlings so we have classified her in a group known as Alpha Group. - Sean Chubb
More on this can be seen at http://www.cliviaforum.co.za/forum/index.php?topic=11053.msg79585#msg79585
7 'Butter Yellow'. The very rare 'Butter'(said to originate in the KZN habitat) was also found to be Group 2 and is the breeding source of the deep yellow Group 2 hybrids such a 'Pat's Gold' and 'Golden Fleece'.