Inheritance In Seeds Question

[Sam_Skunkman]

Here are two I started with,

Garden of Invention: Luther Burbank and the Business of Breeding Plants - 10 edition

http://www.amazon.com/The-Garden-Invention-Business-Breeding/dp/0143116894

Principles Of Plant Breeding, 2Ed
by Allard R.W

 

[Tom Hill]

Sativied,

Mating does not forever remain random, as if trapped in a vacume, that is mearly a theoretical reference point to give the maths a base point - a ground zero.

I am fully aware of the various degrees of dominance and have spoken to that previously here. However, answer this, does a recessive allele ever hold the same advantage over a dominant allele as is true in the reverse? No sir, no sir it does not.. Now carry those maths as far as you need to to realize that any advantage small as it may be,, wins in the end.. It's why we named it dominant. Once it is fixed and in place,, there is not the same threat to it's existence as holds true for more vulnerable conditions of genes.

 

[Tom Hill]

bos and calligari's selection methods in plant breeding is far better and much deeper but really what is the point if we can not agree on the implications of the texts lol?

 

[Chimera]

... answer this, does a recessive allele ever hold the same advantage over a dominant allele as is true in the reverse? No sir, no sir it does not...

That's absolute nonsense Tom, you are speaking out of your ass my friend.

Allelic interactions (dominance, recessive, co-dominance) has absolutely nothing to do with how an allele will confer an advantage to the organism. In some cases or environmental conditions, the dominant trait is more desirable, in some cases the recessive is more desirable. These terms simply describe how that particular allele interacts when paired with others in the population, nothing more, nothing less, and you can't make bro.ad generalizations about whether an allele being dominant or recessive is either beneficial or deleterious to the individual.

Cannabis being a (mostly) obligate outcrosser, has maintained a huge variation of alleles throughout her evolution via the near open pollinated mating scheme. This method of reproduction allows point mutations to accumulate and be passed along "in the background' of the visible genetic pool, without being purged from the population. These mutated recessive alleles lie in wait until the environment pulls them to the forefront via a selective advantage, or through a rare homozygotic pairing which might confer an advantage. But it's the environment that selects the allele and its prevalence in the population at any given moment in time, not whether it is dominant or recessive.

A genetic researcher I am working with suggested to me that through the current analysis, cannabis seems to have a SNP rate of 1 base pair substitution in every 100 base pairs. Humans, which are incredibly polymorphic, have SNPs at 1 in 1000 base pairs- so this in an incredibly high degree of polymorphism by an order of magnitude. These various forms provide a genetic flexibility that has allowed cannabis to colonize 6 continents, and this in my submission is due to the plasticity the various alleles within the genome confer.

i have never never seen a seeded female plant throw out variable sized seed outside of development stage so there is just no way i am buying the multiple loci bit brother it is not an option, apologies.

If that is the case, then you aren't sorting your seeds by size or aren't paying attention. Many females create progeny of various sizes; it's how you can easily select for seed size. Anyone can run their seeds through a 2,2.5,3,3.5,4,4.5 millimeter screen set and you'll see pretty clearly that seed size is just another trait that falls within a normal distribution- a classic distribution of quantitative traits, which are governed by multiple loci.

Regardless, a single mother's seeds are related to her own genomic complement. It doesn't say anything about whether those traits are fixed for her, nor does it say anything about how many loci govern the trait. Whether you buy it or not, seed size is not governed by a simply monogenic model of inheritance, and I submit that you have no basis or data on which to make such a claim.

-Chimera

 

[Tom Hill]

finally some balls on the table give me a minute...

 

[Tom Hill]

i am not saying it is advantageous to the organism as a whole i am saying it is advantageous to the allele itself. (this is the case, period, nobody said jack shit about what is more desirable in growing conditions a,b, or c or any of that other shit folk are thinking to put in my mouth - this is the fact less the laws of inheritance have become "nonsense") Or,, did we just pull the word dominant out of our asses? lol... How a particular allele interacts when paired with another is exactly what i am talking about and the type of allele we chose to name dominant we did not do so without reason. Now, follow that to it's inevitable conclusion though you will not read about it in wikipedia or etc we'll actually need to use our brains.

mutant recessive alleles lie in wait someplace outside of a fixed dominant chromosome - and the latter is not subject to alteration by the former. The reverse of course,, is not true. So it does not require more than a third grade education to understand which form of gene has the advantage over the other..

I am all for touting the plasticity of the genome been doing it for years while everybody else was speaking mendelian crap and obligate outcrossers i was talking about strawberries and crossovers but none of this changes the fact,, the dominant allele will prevail (given time of course) over any other form of the gene - it maintains the advantage. Again,, we did not come up with the term out of our asses..

 

[Tom Hill]

If that is the case, then you aren't sorting your seeds by size or aren't paying attention. Many females create progeny of various sizes; it's how you can easily select for seed size. Anyone can run their seeds through a 2,2.5,3,3.5,4,4.5 millimeter screen set and you'll see pretty clearly that seed size is just another trait that falls within a normal distribution- a classic distribution of quantitative traits, which are governed by multiple loci.

Regardless, a single mother's seeds are related to her own genomic complement. It doesn't say anything about whether those traits are fixed for her, nor does it say anything about how many loci govern the trait. Whether you buy it or not, seed size is not governed by a simply monogenic model of inheritance, and I submit that you have no basis or data on which to make such a claim.

-Chimera

yeah,, sounds like you as well as others misunderstood the original question and therefore perhaps my response,, i thought it was covered.. if you are pulling multiple sized seed out of a single female this is only development stage in my experience. and quite frankly if seed size is governed by multiple loci within a population i submit to bird seed and seed oil producers to stop playing around the same as i do medicinal cannabis growers,, and grow from clone.. there is no percentage in unnecessarily complicating complicated problems when the answer is to simplify.

 

[mofeta]

Hi guys

Tom, you ignorant cockbite. (<<<obscure SNL allusion to confuse the youngsters)

Dominance is not an absolute, fixed quality. It exists only in relation to other homologous alleles. The exact same sequence that is dominant over the others today, might not be tomorrow. The first analogy I can think of is cpu speed. The most blazingly fast chip of 10 years ago is now a snail. It has not changed in absolute terms, but in relation to the chips of today, it is slow. The same exact chip was once fast, now it is slow.

On the birdseed/oil thing- pushing the curve over on traits like this is just fine. Cloning would be a colossal waste of time and work for this kind of crop. It is completely different than the finer qualities in kind bud that make clonally propagated crops an ok idea. The reason for this is that there are numerous different allele permutations that can lead to superior yield, but a particular super elite trangressive smoke is the result of a very specific set of instructions that cannot vary even slightly.

 

[Tonygreen]

Now we are talking. Dont mind me ill just be in the corner taking notes and reading while i smoke this fatty

 

[Tom Hill]

Jane you ignorant slut.... (i speak fluent SNL Mofeta )

It is not required to be an absolute.. it merely requires an advantage more than not (let's stop being blind to what an advantage -of any measure- brings to the maths over the long term for fuck sake?),, and it does absolutely fit that paradigm, and that is why these truths to hold true, hence the friggin nomenclature in the first place, duh..

on the seed size thing i mostly agree because i have actually done it seen it been there done that and it is a friggin hell of a stretch to be mentioning seed size (i do not know about oil content) under the same umbrella of quantitative traits as quality of smoke.

its why i threw the "if" in there,, for damn sure there is no reason on a medicinal cannabis forum to be taking such notes on seed size unless you are weighing a count of seed by gunny sack to the gram seed size would be said to fall under mendelian rules by the human eye though my colleagues like to reference things that really have no bearing here - hemp farmer minuscule observations ..

 

[MrBelvedere]

Reading this is like watching Darwin arguing with Mendel

 

[Tom Hill]

really i have not one not two but 3 fucking scientist sitting here trying to argue to me that the term dominance has no virtue, no reason at all we call it that we just yanked it out of our ass lol,, you guys are too much and you are all wrong as can be.. i know i have an ass kicking coming,, but this ain't the time or place lol..

 

[MrBelvedere]

Natural selection vs artificial selection! Everybody won!

 

[mofeta]

Just re-read Chimera's comment, dominance just affects what selection sees, not frequency. It provides a reservoir of variation for quick adaptation (for the most part).

This is elementary though. Discussion of this kind of stuff retards discussion of the really interesting stuff happening these days.

Mendelian and classical genetics is for pansies. If you keep discussing this old stuff I will buy you a dress. Real men discuss molecular genetics.

Who is up for a truly manly discussion of GWAS, GBS, WGP, constructing haploSNPs, Bayesian modeling, L2-regularized logistic regression, LASSO, genome imputation, CRISPR, gene drives, etc?

 

[Tom Hill]

hahaha,, just do not forget what you should already know before jumping ahead and certainly do not think you guys will pass off misinformation on my watch

once again,, wild populations do not exist in some kind of a hardy weinberg utopia (no populations do) natural selection applies:




Calculating the Effect of Natural Selection on Gene Frequencies.

The effect of natural selection on gene frequencies can be quantified. Let us assume a population containing
36% homozygous dominants (AA)
48% heterozygotes (Aa) and
16% homozygous recessives (aa)
The gene frequencies in this population are
p = 0.6 and q = 0.4
The heterozygotes are just as successful at reproducing themselves as the homozygous dominants, but the homozygous recessives are only 80% as successful. That is, for every 100 AA (or Aa) individuals that reproduce successfully only 80 of the aa individuals succeed in doing so. The fitness (w) of the recessive phenotype is thus 80% or 0.8.
Their relative disadvantage can also be expressed as a selection coefficient, s, where

s = 1 − w
In this case, s = 1 − 0.8 = 0.2.
The change in frequency of the dominant allele (Δp) after one generation is expressed by the equation

s p0 q02
Δp = __________
1 - s q02
where p0 and q0 are the initial frequencies of the dominant and recessive alleles respectively. Substituting, we get

(0.2)(0.6)(0.4)2 0.019
Δp = ________________ = ______ = 0.02
1 − (0.2)(0.4)2 0.968
So, in one generation, the frequency of allele A rises from its initial value of 0.6 to 0.62 and that of allele a declines from 0.4 to 0.38 (q = 1 − p).
The new equilibrium produces a population of

38.4% homozygous dominants (an increase of 2.4%) (p2 = 0.384)
47.1% heterozygotes (a decline of 0.9%)(2pq = 0.471) and
14.4% homozygous recessives (a decline of 1.6%)(q2 = 0.144)
If the fitness of the homozygous recessives continues unchanged, the calculations can be reiterated for any number of generations. If you do so, you will find that although the frequency of the recessive genotype declines, the rate at which a is removed from the gene pool declines; that is, the process becomes less efficient at purging allele a. This is because when present in the heterozygote, a is protected from the effects of selection.

i did not need to look too far to find what i was looking for- http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/H/Hardy_Weinberg.html - and neither should anybody else it should be right there in your brains next to the common sense of our every day lives.. for damn sure i should not have to be pushing rocks uphill to make a point that should already be quite commonly known..

nerds....

 

[Tonygreen]

This is better than the republican debate.
so is our drug type in those recessives since it is not the dominant wild type?? And did I throw away all my small seed stock for nothing?

Apparently people made yeast that produces thc so we're all fucked. So much for all this hard work.

 

[Tom Hill]

it's over bro,, even sloppy drunk and on my worst day.. Dollars to donuts half of them did not even check it out the other half crapped their pants upon realizing i was correct and one guy did not even bother to read the frigging thread. go figure.

 

[mofeta]

You are misinterpreting your own example.

The term s (selection coefficient), or the inverse w (fitness or selective advantage) varies due to environment (selective pressure), and has nothing to do with whether the allele under selection is dominant, recessive, etc.

In the example the guy gives, s is .2 for the recessive allele as a given in the example. He could have made the dominant allele unfit just as well. It was arbitrary in order to demonstrate the equation. He was not saying that recessive alleles are always unfit.

As a side note, I really, really dislike the dictionary function that italicizes words in our posts. Totally fucked up. Hate it.

 

[Tom Hill]

Goodness Gracious..

You are misinterpreting your own example.


As a side note, I really, really dislike the dictionary function that italicizes words in our posts. Totally fucked up. Hate it.

Uuhhhh,, excuse me? The very mention,, the very notion!

I have misinterpreted nothing sir. The example i gave is a correct mathematical lay-out of the typical ascent of the wild-type allele (the common and generally if not always - dominant) earning it's definition and increasing in frequency within a wild population (a reminder the example is one of natural selection) - in fact doing exactly what you had just previously stated did not happen!

Yes, we could swap recessive or mutant for dominant or wild-type with regards to fitness but that would be silly, as it is outside the norm -a mere exception, not the rule- when speaking of wild-type alleles, wild populations, natural selection, or any of that.

Wild-type alleles are not only generally dominant, but are of higher fitness values as well - hence their definition as the norm, indeed hence their very existence and frequency shifts towards them within these types of populations in the first place.

Yes there are several exceptions and degrees of dominance poly genetic inheritance and we can go on all day. But that the dominant allele prevails in the often instance of complete dominance, well, that is some serious friggin genetic mathematical judo over the long term. And that is a thing a mutant recessive hiding in corners and dark alleys simply can not lay claim to.

I am afraid the argument is quite solid, i'm afraid we are quite safe from your rebel forces here

PS, i can't stand that function that italicizes words either i thought it was only mine doing it and was looking for how to turn it off.. nobody needs somebody or something else emphasizing words for them.

 

[jefe noche]

"i'm afraid we are quite safe from your rebel forces here "

"Allow me to demonstrate the firepower of this FULLY, operational Death Star!"