G
guest3854
Another member here posted this , I forget who , sorry . Also some good reading "Botany An intro to palnt biology " By Nadakavukaren and McCracken
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Breeding for beginners
- Thread starter glasspackedbowl
- Start date
Blue Shark
Member
Hay GPB that's a refreshing bioligy lesson there man. Correct me if I'm wrong, but if I understand it correctly a cross between two pure strains will give the least variation in the offspring.
yes, Idealy an IBL(or pure strain) will make less varriated offspring f1's. But its when then f2's are made that things will change up. Depending on the mother and father picked there could be a larger variation.
a homogeneous f1glasspackedbowl said:
the diagram above is an adaptation on mendel's law
http://www.ndsu.nodak.edu/instruct/mcclean/plsc431/mendel/mendel1.htm
*Note: chaos theorum makes forlorn such laws. as the americans say "shit happens"
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Wacky Tobacky
Active member
wow this brings back memories of being in a biology class and studing that. its been a while....
what do you thing about this then????
what do you thing about this then????
i am basing my following comment on somthing DJ short had reported....
"somewhere between the f1 and f3 generations you need to do a backcross, but knowing when is a breeders secret..." (i hope i didnt' mangle that quote too much)
once you find the hybrid plant with the traits you want...
"If what you want is to have wr plants with the webbed leaf , it could be done in a few steps.
1 - make your wr df cross, can we for simplicity call this our F1.
2 - inbreed the F1s to make your F2s. I the F2 generation all possible combinations will be seen provided you grow out enough to find them.
3 - Grow out a number of F2s its in the F2s you will find the recombinations you seek.
WR plants with webbed leaf.
How many F2s will you need to grow should be the real question, that will depend on gene linkage.
With gene linkage independent assortment is restricted further and may require a very large number of F2s to be grown out."
it is my understanding that in order to develop a population enhanced in those traits you will need to do a backcross and then several test crosses until you find that the offspring are more uniform with respect to a specified trait.
like the guy who posted previously said, you should be able to find that one first plant if you grow out enough F2's, but to develop a stable population MAY require more work with backcrossing and test crossing depending upon the genetic characteristics of the trait you are trying to stabilize with in your population.
like with cherry AK, there is a quote somewhere about how Simon had to do a series of test crosses and back crosses to stabilize that cherry taste.
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thanks for posting i am learning lots from you guys....
3RD rail
what do you thing about this then????
i am basing my following comment on somthing DJ short had reported....
"somewhere between the f1 and f3 generations you need to do a backcross, but knowing when is a breeders secret..." (i hope i didnt' mangle that quote too much)
once you find the hybrid plant with the traits you want...
"If what you want is to have wr plants with the webbed leaf , it could be done in a few steps.
1 - make your wr df cross, can we for simplicity call this our F1.
2 - inbreed the F1s to make your F2s. I the F2 generation all possible combinations will be seen provided you grow out enough to find them.
3 - Grow out a number of F2s its in the F2s you will find the recombinations you seek.
WR plants with webbed leaf.
How many F2s will you need to grow should be the real question, that will depend on gene linkage.
With gene linkage independent assortment is restricted further and may require a very large number of F2s to be grown out."
it is my understanding that in order to develop a population enhanced in those traits you will need to do a backcross and then several test crosses until you find that the offspring are more uniform with respect to a specified trait.
like the guy who posted previously said, you should be able to find that one first plant if you grow out enough F2's, but to develop a stable population MAY require more work with backcrossing and test crossing depending upon the genetic characteristics of the trait you are trying to stabilize with in your population.
like with cherry AK, there is a quote somewhere about how Simon had to do a series of test crosses and back crosses to stabilize that cherry taste.
-------------------------------------------
thanks for posting i am learning lots from you guys....
3RD rail
Reign of Terror
Active member
^^^now this arises a new question.
What is the point in that "backcross"? If you have a cherry pheno AK for instance, wouldnt just inbreed the cherry pheno. Why do a backcross, since its only a pheno. I though that phenos are just expressions and backcrosses wouldnt stabilize this expression, only inbreeding.
Isnt backcrossing a way to introduce new genes into a strain and keep it healthy, or to say for instance have a clone only in seed form? Otherwise, whats the point?
What is the point in that "backcross"? If you have a cherry pheno AK for instance, wouldnt just inbreed the cherry pheno. Why do a backcross, since its only a pheno. I though that phenos are just expressions and backcrosses wouldnt stabilize this expression, only inbreeding.
Isnt backcrossing a way to introduce new genes into a strain and keep it healthy, or to say for instance have a clone only in seed form? Otherwise, whats the point?
like we have been talking about if you have a cherry pheno ak47 and u back cross it to one u have that lets say has a better profile then the f2(meaning it has the cherry flavor but a better yeild or potency) would allow u to take that f2 that got worked down to get the flavor and make it yeild more or be more potent.
Let that the Very berry suprises(BB) the purple plant has the color but what about yeild and potency. Its hard to keep one trait unaffected while trying to control another trait.
Let that the Very berry suprises(BB) the purple plant has the color but what about yeild and potency. Its hard to keep one trait unaffected while trying to control another trait.
i was gonna post this pic its been in my gallery for while almost since i joinedsteel savage said:Another member here posted this , I forget who , sorry . Also some good reading "Botany An intro to palnt biology " By Nadakavukaren and McCracken
"fixing" a trait...
"fixing" a trait...
when we start talking about backcrossing aren't we talking about "fixing" a trait for subsequent offspring????
for the plants in the diagram the green phenotype...
(based upon what's evident in the f2 population: and when it comes to the numbers we can talk ourselves silly without resolving anything. yes, yes lots of plants...lots of testing...in addition to all the genetic talk in the world we would have to start talking statistics as well...)
...seems to be recessive. so we know that those plants will always produce green offspring unless they are crossed to a dominant color phenotype. we have learned now, and can monitor the progress of this trait through successive generations.
with the purple color it's more of a mystery.
but, if you back cross the purple progeny to the purple mother line (assuming it has been bred to be homozygous). you will have enriched the subsequent population in that purple pheno type, no?
now if you wanted only tall green plants....
if you backcross to the tall plant you are "fixing" the tall phenotype, but the green phenotype will be "skipping" a generation.
and, if you backcross to the green plant you will be "fixing" the green phenotype, but the tall phenotype will be "skipping" a generation.
now, if you begin test crossing between the two lines you MAY be able to produce offspring enrighed in the tall, green phenotype.
but you will have to test several crosses, and there MAY be several pitfalls with respect to the nature of the genes and environmental variations effecting your results.
it would be nice to see someone show some progress along these lines as it happens so we could follow the progress, and know that if you buy a certain seedline you are getting what's advertised.
"show me the offspring" ; "show me the offspring"
but that's the nature of things...i will tell you that as an amature "hack" i would not want to have to live up to that standard.
AND, i would not mind paying someone for all the hard work it would take to produce and document those type of results.
but, when things get that advanced (and what follows is a big concern of mine) greed and business takes over. when that happens you would probably only be able to get those seeds as a "feminized" product. making it very difficult for a closet hack to maintain those genetics without cloning, pay for more seed, or spending years trying to reproduce the original breeders efforts.
that is the nature of things IMHO. a divide is possible, but like what vic said "RIGHT NOW there is just not alot of difference between what the masters (and once again thanks guys, sincerely) produce and what closet hacks are turning out."
BUT, that can and will change.
sorry for the rant at the end.
"fixing" a trait...
when we start talking about backcrossing aren't we talking about "fixing" a trait for subsequent offspring????
for the plants in the diagram the green phenotype...
(based upon what's evident in the f2 population: and when it comes to the numbers we can talk ourselves silly without resolving anything. yes, yes lots of plants...lots of testing...in addition to all the genetic talk in the world we would have to start talking statistics as well...)
...seems to be recessive. so we know that those plants will always produce green offspring unless they are crossed to a dominant color phenotype. we have learned now, and can monitor the progress of this trait through successive generations.
with the purple color it's more of a mystery.
but, if you back cross the purple progeny to the purple mother line (assuming it has been bred to be homozygous). you will have enriched the subsequent population in that purple pheno type, no?
now if you wanted only tall green plants....
if you backcross to the tall plant you are "fixing" the tall phenotype, but the green phenotype will be "skipping" a generation.
and, if you backcross to the green plant you will be "fixing" the green phenotype, but the tall phenotype will be "skipping" a generation.
now, if you begin test crossing between the two lines you MAY be able to produce offspring enrighed in the tall, green phenotype.
but you will have to test several crosses, and there MAY be several pitfalls with respect to the nature of the genes and environmental variations effecting your results.
it would be nice to see someone show some progress along these lines as it happens so we could follow the progress, and know that if you buy a certain seedline you are getting what's advertised.
"show me the offspring" ; "show me the offspring"
but that's the nature of things...i will tell you that as an amature "hack" i would not want to have to live up to that standard.
AND, i would not mind paying someone for all the hard work it would take to produce and document those type of results.
but, when things get that advanced (and what follows is a big concern of mine) greed and business takes over. when that happens you would probably only be able to get those seeds as a "feminized" product. making it very difficult for a closet hack to maintain those genetics without cloning, pay for more seed, or spending years trying to reproduce the original breeders efforts.
that is the nature of things IMHO. a divide is possible, but like what vic said "RIGHT NOW there is just not alot of difference between what the masters (and once again thanks guys, sincerely) produce and what closet hacks are turning out."
BUT, that can and will change.
sorry for the rant at the end.
cheers!
G
Guest
Anyone got some more info/ better explanation on heterozygous and homozygous.
I think this is Key to breeding. Have a good crasp but still am not sure
I think this is Key to breeding. Have a good crasp but still am not sure
Azra3l
Member
Hi,
-His position on the chromosom called a locus
-The protein it will produce. There are several version of a gene that are called alleles.
Cannabis is generally a diploid with 9n + 2n chromosoms. If in a pair of chromosoms at the same loci:
-the alleles are coding the same protein, it's homozygous
-the alleles are coding two different protein, it's heterozygous
About Mendell's law, I think that you must remember that it will work under certain limits which are :
-total dominance. But most of the time the dominance is not total and for exemple with Green and purple you can get Green, Purpple and all the in-between
-genetic interactions. A character can be controlled by several genes. Let's imagine that duckfoot's leaves are controlled by two genes one define short leaves and the other one the shape of leaves. If the two genes are not present at the same time, the leaves will be normal. Thus, a very different ratio of phenotypes then the one we would have predicted
-the independant transmission of genes which is true if the genes are not on two close loci on the same chromosoms. In the other case, you will get a slightly different ratio depending on the distance between your loci (and thus the probability of recombination through the cross-over)
Cheers
Let's make it simple. A gene is a piece of DNA that'll define an hereditary information. A gene can be define by:
-His position on the chromosom called a locus
-The protein it will produce. There are several version of a gene that are called alleles.
Cannabis is generally a diploid with 9n + 2n chromosoms. If in a pair of chromosoms at the same loci:
-the alleles are coding the same protein, it's homozygous
-the alleles are coding two different protein, it's heterozygous
About Mendell's law, I think that you must remember that it will work under certain limits which are :
-total dominance. But most of the time the dominance is not total and for exemple with Green and purple you can get Green, Purpple and all the in-between
-genetic interactions. A character can be controlled by several genes. Let's imagine that duckfoot's leaves are controlled by two genes one define short leaves and the other one the shape of leaves. If the two genes are not present at the same time, the leaves will be normal. Thus, a very different ratio of phenotypes then the one we would have predicted
-the independant transmission of genes which is true if the genes are not on two close loci on the same chromosoms. In the other case, you will get a slightly different ratio depending on the distance between your loci (and thus the probability of recombination through the cross-over)
Cheers
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the chart above in post 32 is cool but can anyone get further into detail and wtf does punett square right mean in the f2 slot? im lost after the f1 
btw nice post azra!
what i mean to ask is can anyone illustrate a how-to flow chart from s1 to f5?
btw nice post azra!
what i mean to ask is can anyone illustrate a how-to flow chart from s1 to f5?
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G
Guest
Yeh, dopest that chart is letting me understand breeding a little more.
Thanks Maj. Pothead
I think punett square right is in ref. to the F2 generation on the right side of the chart that shows the 16 different combonations of gene "codes" (if thats the right word).
Now i got a shit load of questions,
You see i have been trying to grow a purple plant and i live near the equator it seams that the gene for turning purple is linked to the gene for shity yelds so after about 9 different strains i found 2 durbun posion females worth crossing both of them are 1foot tall.
I crossed 1 to a 6 footer skunk male and the other to a 9foot delat male. i am about to get a lot of seeds
My first question is these strains should show hybrid vigor. But what exactly is hybrid vigor?
I know its been explaned before but i ent no "brain" so you got to talk in laymans terms to me. To my understanding hibrid vigor is the expresion of all the domanant genes of the parents in the first (F1) offspring.
And if this is so all the F1 plants would appair to be Clones but in reality have different gene "codes" (That word again)
Thanks Maj. Pothead
I think punett square right is in ref. to the F2 generation on the right side of the chart that shows the 16 different combonations of gene "codes" (if thats the right word).
Now i got a shit load of questions,
You see i have been trying to grow a purple plant and i live near the equator it seams that the gene for turning purple is linked to the gene for shity yelds so after about 9 different strains i found 2 durbun posion females worth crossing both of them are 1foot tall.
I crossed 1 to a 6 footer skunk male and the other to a 9foot delat male. i am about to get a lot of seeds
My first question is these strains should show hybrid vigor. But what exactly is hybrid vigor?
I know its been explaned before but i ent no "brain" so you got to talk in laymans terms to me. To my understanding hibrid vigor is the expresion of all the domanant genes of the parents in the first (F1) offspring.
And if this is so all the F1 plants would appair to be Clones but in reality have different gene "codes" (That word again)
yes it refurs to this pic and says that these are all possiblitys from crosing f1's together
bajanbudder said:
Yes they will look very simular as clones would(enviromentl strees may make these vary slightly but not much) But the next batch will only show vigor if that plants genes are for a vigorus plant. Hope that makes sence.
Vigor is the plant expressing its traits and all of them and the dominate wins out making it vigorus in that way.
Were all learning here. Hope we can figure this out.
This is why nirvanas f2 might not be the same plant actually the seeds from them can make 16 different types of plants. Making it hard to find that picture perfect portrail of the original strain.
