Breeding for beginners - Page 3 - Breeder's Laboratory - International Cannagraphic Magazine Forums

04-25-2006, 10:12 PM

Another member here posted this , I forget who , sorry . Also some good reading "Botany An intro to palnt biology " By Nadakavukaren and McCracken

Blue Shark · 04-30-2006, 02:38 AM

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.

glasspackedbowl · 04-30-2006, 03:56 AM

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.

DocLeaf · 04-30-2006, 07:37 PM

Quote:

Originally Posted by glasspackedbowl

yes, Idealy an IBL(or pure strain) will make less varriated offspring f1's.

a homogeneous f1

the diagram above is an adaptation on mendel's law
https://www.ndsu.nodak.edu/instruct/m...el/mendel1.htm

*Note: chaos theorum makes forlorn such laws. as the americans say "shit happens"

Wacky Tobacky · 04-30-2006, 09:34 PM

wow this brings back memories of being in a biology class and studing that. its been a while....

solrebl · 04-30-2006, 09:44 PM

Yeah wish I still had my genetics textbook....

Guest423 · 07-08-2006, 01:16 PM

nice thread, i'll be saving this info for the future, thanks

3RD_Rail · 07-08-2006, 05:30 PM

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 · 07-08-2006, 05:51 PM

^^^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?

Possum · 07-08-2006, 08:09 PM

ask simon...

04-30-2006, 03:56 AM	#23
glasspackedbowl Medical Test grower. Inquire within... Join Date: Sep 2004 Location: Cloud City Posts: 2,080	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. __________________ Campolina (cappaccino X Annac) Akita (stankonia x Annac) These are available from seedbay! Stankonia is my Spicy strain. Get them while there there to get! BIG Thanks ro Ronley for donating them! 215/sb420 Compliant Medical patient! R.I.P. Daltron he has passed away! space! Breeding for Beginners Hill Temple Indica ...... Grat3fulh3ad's G13xSDv3 ..... FemaleSeeds White Widow .... Stankonia CP and White Rhino
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07-08-2006, 05:30 PM	#28
3RD_Rail New Member Join Date: Jun 2006 Posts: 7	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
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07-08-2006, 08:09 PM	#30
Possum Member Join Date: Jul 2004 Location: Temazcal Posts: 109	ask simon... __________________ "everybody knows the dice are loaded, everybody rolls with their fingers crossed. that's just the way it goes, everybody knows."
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04-25-2006, 10:12 PM	#21
guest3854 Guest Posts: n/a	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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04-30-2006, 02:38 AM	#22
Blue Shark Member Join Date: Nov 2005 Posts: 77	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.
	Quote

04-30-2006, 09:34 PM	#25
Wacky Tobacky Is Back in Action Join Date: Jan 2006 Posts: 626	wow this brings back memories of being in a biology class and studing that. its been a while....
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04-30-2006, 09:44 PM	#26
solrebl Member Join Date: Mar 2006 Posts: 111	Yeah wish I still had my genetics textbook....
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07-08-2006, 01:16 PM	#27
Guest423 Banned Join Date: Feb 2006 Posts: 3,304	nice thread, i'll be saving this info for the future, thanks
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07-08-2006, 05:51 PM	#29
Reign of Terror I am the Ruler of Horror...the Reign of Terror. Join Date: Mar 2006 Posts: 582	^^^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?
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