Extracting specific genetics from a hybrid cross

Breeder's Lab
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You might have a hybrid with what I could be made up of heterozygous traits possibly like this example AaBbCcDdEe × AaBbCcDdEe. This possible scenario you are looking at is a hybrid with just 5 traits and the various resulting combos. Not saying it can’t be done but this is just with your hybrid cross with itself. If you throw in IBL then the combination might lose your desired phenotype/geno type and have to cross many (desired phenotype X desired phenotype). I am sure this will be confusing but this is what happens when you look for too many traits in just one type and don’t know their allelic transmission. If desired phenotype is heterozygous then it can’t be stabilized.

Punnett Square Pheno-Type.pdf (469.6 KB)

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It CAN be done, no one wants to do it though…

@crunkyeah

I just read an .edu article about selective breeding on heterozygous plants, they suggested mostly what everyone has been saying on here, select the traits from the mother you can see, then to determine if a trait is dominant or recessive you need to “Self,” the plant then watch the resulting offspring. For example, if the plant you want out has broad leaf, If they all display the trait you want, its dominant, if they display a mixed result, then it’s a recessive trait.

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Yes, that is one trait and a great start and you have the data to back it up :+1:! Then you go and ask yourself what is it missing or what additional characteristics does it possess or not and how do I keep them or add them in? Every time I do a cross what happens to the makeup? Back and forth, I am thinking making multiple f2 selections and then taking them in different directions of what characteristics you are after. This keeps desired traits to lower number and be able to lock in without breeding thousands. These F2’s to f3,f4,f5 are all coming from same cross just focusing on different desired traits but within the same family. The different F2’s that have traits you like can be locked in possibly and but missing something other F2’s have. Since you have been breeding other F2’s to f3,f4,f5 you can cross say f5 with certain desirable traits with another f5 that has other desirable traits and see if they blend. You have a inter family hybrid(heterozygous) with all the traits you want. Chance of crossing these stabilized traits and getting a good blend is higher because it is within the same family gene pool. I don’t know if this makes sense? You know what you are looking for just making a plan and let it evolve.

I like what you are doing just like the old saying goes a mob of people is no more an army than a pile of building materials is a house.
:cactus:

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Thats so true :upside_down_face: its pleasure when you create something thats yours creation :dizzy: it has some love and energy in it :green_heart:

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Polyhybrid does change the outcome of the 1st generation of cross, and you’re right it will increase variations. However, even still, it is not the same as inbreeding for 1 generation. Many recessive traits will still be suppressed until it is inbred. Any homozygous dominant trait crossed to any recessive trait will only express the dominant trait and it will not show in the offspring until it is inbred.

Worse, the more you hybridize, the more recessive traits you suppress and the more plants you need to grow in order to recover them. Interesting and uncommon traits are typically recessive. Why? Because if they were dominant, then they would survive into polyhybrids more easily – the great mashing of heterozygous dominant traits.

If you have even 3 recessive traits you want to recover from the landrace, and they were crossed to 3 homozygous dominant traits, then only 1 in 4 plants (in the F2s) will have any given recessive, but only 1 in 4 in 4 in 4 (4 * 4 * 4 = 64) plants will have all 3. If you add males, you need to grow twice as many to identify the recessive traits in each, so 128 plants to secure a mere 3 recessive traits in a single generation.

Now consider than when you cross another strain in there, you are just putting yourself on a treadmill and losing even more recessive traits that you have to try and recover. It quickly gets out of control. 4 recessive traits? 512 plants. 5 recessive traits? 2,048 plants…

Many of these traits will be things you don’t even notice unless you’re really familiar with the landrace parent. Some of the traits you might not even want, and then you have to decide how strongly you feel about sticking to your goal against not wanting a trait you’re trying to preserve.

And this is the point of backcrossing. You will never get there 100%, that is right. The best you can do is look at this project in terms of statistics. What you want to do is steer a population of seeds toward the landrace parent. In my opinion, the best way to do that is to do it through careful, slow selections over many generations.

The point of backcrossing is that it does not have the identical effect as generational inbreeding. You retain the heterozygousness of the backcross parent. This helps you to do three things 1) slowly inbreed to prevent early loss of recessive traits, 2) reinforce the recessive traits you have selected and 3) open up the heterozygous traits for another round of selection.

It takes a LOT of plants to recover something close to a parent after a single cross. You don’t need to grow all of those plants in a single generation, but you can slowly and gradually move your seed populations in the right direction over many generations if you choose a slow method of bottlenecking and gradually work to improve your statistical chances.

I agree. That is a very difficult project. There are many more manageable projects you could do, and lots of interesting landrace options to choose that would have a much more straightforward path to success.

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Yeah… what he said. ^^^

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The 1:1 ratio observed when back-crossing F1 to P1 and the 1:2:1
ratio observed in F1 to F1 crosses are the two basic Mendelian
ratios for the inheritance of one character controlled by one pair of
genes. The astute breeder uses these ratios to determine the
genotype of the parental plants and the relevance of genotype to
further breeding.

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Wow everyone, thanks for the food that keeps my brain moving forward!
@Cactus - Thanks for that website! That tool is pretty useful for breeders! All we need to do is figure out which alleles are dominant and which are recessive…which I’m sure takes a good chunk of time and energy. Really cool to look at though! I want to say that generally my breeding outlook is… pop them all and see what I like best. Sometimes I like plants that just grow a certain way. I’m not really looking to isolate certain traits or anything like that. I’m just going to select the best females I can, and pick the best male to breed to them all. My hope is that with several females I’m not bottlenecking anything, and by choosing my favorite male, that I will be able to create some really good progeny seeds to search through.

@Dr.VitaminGreen - I’m not sure I want to self every mutant I have in order to check out the recessive traits. I think I would rather let the progeny tell me what’s going on with them. The time that it takes to grow out ‘selfed seeds’ is the probably around the same as regular seeds. Flowering, veg time, and all that will be the same as well. I will be working with 1 male only every time I breed, so I should be able to see traits from the mothers. Additionally I will be keeping mothers and only flowering clones, so if I need to I can test progeny against the mother. I plan on doing with with terpenes mostly. I have some really good smelling moms that I want the progeny to smell like. In the selection process I will try to get smells that are closer to her than to the father.

@Faithisyours - I definitely feel your vibe on this one! When I smoke people up with bud I’ve grown and they’re like “wow that stuff is amazing!” it makes me all warm and fuzzy inside. I can only imagine how breeders feel when they see tons of reviews of their strains of people giving them 5/5 feedback. In due time, I want to be able to present to the world a beautiful strain that it hasn’t seen before and everybody loves.

@Lefthandseeds - First off thanks for the detailed responses! I totally get what you’re saying with needing to inbreed to show recessive traits. I totally get that. Most of what I was saying earlier was that even with what we could consider the most simple cross… an IBL to another IBL from the same kind of region… we’re still going to get lots of variation breeding them together, especially if we’re talking multiple males and females with different phenotypic expressions. On top of all the crazy complex mathematics on how many plant numbers we would need to run to find X amount of recessive traits, we have no idea which alleles are dominant in both strains. I’ve read landrace crosses generally tend to dominate modern hybrids. Something about the vigorousness of the strain to survive in the wild against the elements is the theory,

My planned cross is going to be Lagkitan male crossed to BerryFreak, Duckweb, Drunken Bastard, Imperium X, and of course to (hopefully) 8-12 stable Lagkitan females. I don’t even want to think about the craziness that could be in Lagkitan F2 seeds with 6 different phenotypes. As far as all the crosses go I’m hoping for really only 2 recessive traits, natural purpling not induced by cold, and the leaf shape of the mutant. Every other trait I will pick my favorites out of the bunch that I sprout and I’ll see what they hold! I imagine after a couple of years of breeding and growing my own, I will be a bit more knowledgeable about how the different traits express themselves.

As far as the whole backcrossing thing goes. I think I understand the point of backcrossing but in this specific example, since we will never know what the Krasnodar pollen donor was like… there’s no point in backcrossing. The only thing we could do is try to get close to the original CBD Cake mom who started the project. It’s frivolous in my opinion, especially with the amount of time involved.

@V4vendetta - I completely get what you’re saying after looking at the tool Cactus posted! I will use this information when I do get to sprout my own seeds.

For everyone else to wants to scramble their own brain, sometimes I’ve pondered the possibilities of crossing a red/pink pistil CBD variety with a naturally purple mutant like Frisian Duck. Oh boy the combinations of crazy you could find in those F2 seeds.

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Keep me posted Brother want to know what you find out! Everything will boil down; take good notes will want to read them!!

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