A Genetics Conundrum or Fun with Punnett Squares...

[Alaska]

Hello everyone I am in somewhat of a genetics conundrum. As some of you may have read, I have a strain called "alaskan". It is a local clone only that I am in the process of backcrossing. Through the crossings that I have made I can tell certain things about inheritence of the hermi trait, which will be the focus of this thread. I will spell out everythings results, and my though process to reach the conclusions which I am thinking is the best option.

In this situation, I am going to let the letter "H" or "h" represent ther Hermi trait. However, please do not get confused, because with this genetics model, we have a recessive hermi trait. This means that the hermi flowers will manifest in plants that have two "h" chromosomes.

The first cross done was using a ST#3 male. This was the lone male left after culling from the pack. The male plant was trimmed down to one single male flowe, the pollen collected, and applied to the Alaskan strain. About 30 seeds were harvested later(called AST from now on)Due to a storage error, some of the seeds moulded, and only about 10 seeds germinated. Several runts were culled, leaving four females and three males. All three males have been kept and two of the three have been successfully crossed to the alaskan strain for the ABX1D and ABX1F. The third is in the works as we speak.

Of the four females, one was a full blown hermi. One leaned toward the ST#3 heavily, and two were a good mix.

Now, the alaskan does not herm, so I know it must be recessive in the alaskan(or dominant in the line and the alaskan is recessive for it in that line, but that s another story).
The ST#3 male that was used was not grown out to full maturity, so it is not known if it would herm or not, but I suspect becuase of the plant pattern that it would be hetz. for the herm trait.

All this evidence suggest to me that both parents of the AST cross were carrierers of the recessive hermi trait, or Hh. They both carried the trait, and when crossed, the following would result.

The resulting gene pairs would be: HH, Hh, Hh, hh - Only one in four would actaully show the hermi trait. Well, thats what I had, One in four. I know its a small population, but if we examine the other possiblities we see that this is the most likely solution.

[Alaska]

Now, See Figure 2,3, and 4

[Alaska]

Examine Figures two three and four. Figures two and three would not show any hermis in the flowers, just carry the trait, and figure four would give 1/2 hermies, which doesnt' fit the bill either. So, from these simple punnett squares, we can deduce that both the alaskan the the ST#3 male used were Heterozygous recessive for the hermi trait.


Now that you understand the situation, we can begin with the actual question at hand!

[Alaska]

If three different males are used seperatly to the orignal alaskan mom(Hh) then there are three different possiblities genetically for each male. They are as follows:

[Alaska]

With figure 1 there would be 25% hermi, 2 there would be none, and with 4 there would be 50%. If we continue to backcross to the alaskan, we will always have the recessive hermi trait in the immediate offspring.

Even if we try different males until we find a HH male that gives no hermi offspring, when the BX is made, the offspring will continue to have the hermi trait.

See Figure 2.

So, according to the numbers and the punnett sqaures, there is no way to work out the recessive hermi trait with BXing, even if enough test crosses are done and a HH male is used at every cross.

So, here is where the meat and potatoes of the situation comes in. When I have reached BX3 stage, a HH male can be choosen by crossing various males to plants with a known genotype, to find both a male and a female that are HH for the hermi trait. Cross them, and viola, no more hermi triar in the line and it will be at F2 stage from a BX3, which will eventually be taken to F4 or F5 as long as the hermi trait is removed at the first inbreeding.


If anyone has any insights or idears for a better way to remove the hermi trait? Also, during these BX's, other desired traits will be fixed (or attempted to anyway)

Thanks for reading this and thinking about it, and I appreciate the advice

Be safe and enjoy life

Alaska

[cured]

I don't know what to say....But I want to say something. Best
I'll shut up and read along..

[Alaska]

c,mon guys!

A

[suzy cremecheese]

This post was edited you might want to reread it

Interesting thread but it is impossible to determine the stats and punnets from those small numbers. You need a bigger population for any of your hypothesis to be validated.

With the small number of plants you have, assuming that your correct about this being a single recessive allele trait, you can not eliminate the possibilty of figures 1 or 4.

Therefore you must consider figures 1 and 4 when you compute the possibilites for the three dads.

Regardless your correct if your hypothesis about one recessive allele is correct. You cant work the trait out of the line if you continue to use an Hh parent no matter how many generations you Bx.

If you want to work it out of the line via backcrossing use an HH male as the recureent parent and select an HH female from the progeny.

Is it possible to redo the cross on a larger scale?

Also...

Are you sure that your hermies are the result of a single allele? Are you sure the expression of the trait is not impacted by environment? If you get some reasonable numbers to work with some statistical analysis, like a goodness of fit test, would help you determine if your results gel with your punnet squares... assuming your hypothesis is correct.

If anyone has any insights or idears for a better way to remove the hermi trait? Also, during these BX's, other desired traits will be fixed (or attempted to anyway)


If you really like this variety forget about other traits fix the heminess first and then work on improving the results.

[Agent-Smith]

I like this thread.....I'll be coming along for the ride. :teeth:

[Space Toker]

whoa, granted I am new to this site as of minutes or hours ago, but none of that genetics stuff makes sense to me! But I will check back as I am a biologist by trade! Yeah, did I mention I am f'd up? But I do have a degree and ity should be good for something so have to check back with a clearer head! Forgiv me! For every jackass you knew or secretly wanted to be, I am your hero! :D
I will check this in better state of mind and I thank you to forgive me for now!
PEACE

[suzy cremecheese]

I read your posts a little more carefully and edited my original post accordingly. Just in case you missed it you might want to reread it now.

[Cuzin_Dave]

Leaving aside issues like Ne, and whether or not hermaphrodism is actually a heritable trait, one always has to worry about heterozygous carriers of lethal or sub lethal traits. In a heterozygous state say Xx the lethal recessive alleles are masked and cannot fully express themselves. The formula is fairly simple (1/n + 1) ^ 2 , where n = the filial generation number. Let's say you are dealing with generation F100, the homozygous recessive would still occur with a frequency of .0001. The heterozygous carriers would occur with a frequency of 1/n + 1 at generation F100 or .01.

[Agent-Smith]

Hey Cuzin Dave check your PMs please.

I'll delete this later today. :teeth:

[Space Toker]

whoa this is way over my head, I graduated with a biologist degree and genetics always baffled me, go figure! And I really want to learn as it is important to my love of wildlife AND the herb, but it is still all a hyroglypic puzzle to me! Of course it would have helped to have professors other than the type that Ferris Buehler had, but anyway.... officially lost... OK PEACE

[Cuzin_Dave]

Punnet squares have to do with the independent probability of certain genotypes appearing in a given population. Take the instance of a tetra hybrid (4 way). Intuitively, one knows that at F2 there will be 2^8 or 256 genotypes that could be graphed on a Punnet square grid. From that, one could deduce that there would be the square root of 256 or 16 gross phenotypes.

[Space Toker]

thanks for trying to clear that up man, for now I am still too dense for it to register but I will have another crack at it later. THANKS!

[Alaska]

Ahhhhhh, discussion :)

I don't have the battery power to answer all replies ind. right now, but thanks to all!

Hey suzy, nice crossing over avatar :) and thanks for the thoughtful response.

Glad someone else agrees with me, and even gladder to get a few others thinking about the subject.


The cross can be repeated(with a diff male, as the orignal ST male is gone), but since it is working with a clone only if one of the males I have currently is proven to be an HH (or even an Hh, as this thread has shown it makes no difference in this instance.) than I can take the next BX step,


Even though some might disagree with the methods, to truly BX this clone as no true sisters or brothers of it exist, I will have to do 3-4 bx's then remove the hermi triat when it is taken to the F2 generation from bx3

Any other recommendations are welcome

BTW, I recently sprouted about 40 ABX1D seeds and 25 ABX1F seeds, which will not be cloned but go straight into flowe when big enough, to see if these males are Hh, HH or hh.

Thanks for tuning in all and be safe
Alaska

[BravoC.D.]

i read simons of serious on how to grow seeds and loks for yor desired traits and from what i read your have to pop atleast 250 beans to find that one that u so seak. after that u cross again and look for 2x that which starts to get complicated not to mention enough space for a such a grow. i wish we could all do this ourselves. i'm sure there are some cash cropers that could do so but they go one way.

[Cuzin_Dave]

Bravo, you are correct. A cash cropper would most likely be growing production clones and pretty much disregard issues like genetic stability or the actual quality of the breeding that went into the plant being grown. Not different really, from people eating a steak at a restaurant, as they seldom ask about the breeding the of the animal that made the steak. Breeding is important, but it is more of an arcane academic pursuit than something likely to captivate the average consumer.

[BravoC.D.]

Cuzin_Dave, stuff like that gets me intrigued my good man. hey i have said the same thing with the whole cow your eatting deal. i read on how they choose their males and all to cross them with females in what not. that stuff got complicated but it gets you movtivated into doing such with plants. enjoy your strains for me, bravo

[Bram]

:popcorn: