Basic genetics explained

[KiefSweat]

yea thats the one, I was amazed at the detail in some of it.

If you could run pcr tests would the herm/intersex plants show up as males with a larger data size? I suppose that could be one way to test some basic sexual genetics on the plant.

 

[mofeta]

how many generations do you need to go to start seeing vigor loss and depression?

It depends on context.

If you are using the insane vigor that can be seen in the first gen in wider crosses as your standard, that drops off right away.

Aside from that, it depends on what you are working with. In some examples it is not really much of a problem, but some are a bitch. Its all in the selection process, that relies on having enough to choose from. Once you clean something up, it is pretty smooth sailing.

All things considered, IMO, this is a trivial problem (inbreeding depression) compared to carrying out selections on a truly large scale. In fact, I think that the ability to properly evaluate many many individuals is the only non-trivial obstacle in weed breeding.

Guys grow huge numbers all over the world, all the time, that's not a problem. All the breeding techniques necessary are found in books, they had been developed for the most part before I was born and I'm 50, so that is not a problem.

How do you accurately sift through 1,000,000 individuals for non-visible traits? Wow all I can come up with is refining machine testing until it can accurately identify the same one I would if I had the lifetime to spend smoking each one.


Selection, selection, selection.

Plant Breeding = Variation + Selection

These are two very different, but complimentary things.

Variation implies presevation of raw material, and generation of new traits through epistatic interaction, and with enough numbers, mutation. This requires techniques that are tailored to this end. There are a number of them, and they are well known to anyone versed in the art.

Selection is just that. It's corollary is rejection. It too requires methods tailored to end up with what you want. These methods are also well developed and not that complicated.

I shake my head when I see people saying "xxxxx breeding technique is bad". There is no "bad" technique (within reason of course) just ones improperly applied in a context that is inappropriate.

One to one mating is an inappropriate method of preserving diversity. Random open pollination is an inappropriate method of creating homozygous lines. A screwdriver is not "bad" because it doesn't drive a nail very well.

(ha ha I just thought I would put in some of my thoughts that were more than tangentially related to the OP, although they are more along the lines of "Basic Breeding Explained")

 

[Sam_Skunkman]

It depends on context.

If you are using the insane vigor that can be seen in the first gen in wider crosses as your standard, that drops off right away.

Aside from that, it depends on what you are working with. In some examples it is not really much of a problem, but some are a bitch. Its all in the selection process, that relies on having enough to choose from. Once you clean something up, it is pretty smooth sailing.

All things considered, IMO, this is a trivial problem (inbreeding depression) compared to carrying out selections on a truly large scale. In fact, I think that the ability to properly evaluate many many individuals is the only non-trivial obstacle in weed breeding.

It is not trivial when you self a single plant, line for 3+ generations you get so many problems that some times the work can not be completed, I should know.
-SamS

Guys grow huge numbers all over the world, all the time, that's not a problem. All the breeding techniques necessary are found in books, they had been developed for the most part before I was born and I'm 50, so that is not a problem.

How do you accurately sift through 1,000,000 individuals for non-visible traits? Wow all I can come up with is refining machine testing until it can accurately identify the same one I would if I had the lifetime to spend smoking each one.

You might be able to find something linked to what ever you are looking for with genome tilling?
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC514099/pdf/pp1350630.pdf
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC514099/
-SamS

Selection, selection, selection.

Plant Breeding = Variation + Selection

These are two very different, but complimentary things.

Variation implies presevation of raw material, and generation of new traits through epistatic interaction, and with enough numbers, mutation. This requires techniques that are tailored to this end. There are a number of them, and they are well known to anyone versed in the art.

Selection is just that. It's corollary is rejection. It too requires methods tailored to end up with what you want. These methods are also well developed and not that complicated.

I shake my head when I see people saying "xxxxx breeding technique is bad". There is no "bad" technique (within reason of course) just ones improperly applied in a context that is inappropriate.

One to one mating is an inappropriate method of preserving diversity. Random open pollination is an inappropriate method of creating homozygous lines. A screwdriver is not "bad" because it doesn't drive a nail very well.

Do people even want homozygous lines? I know of none created except for our experimental work.
-SamS

(ha ha I just thought I would put in some of my thoughts that were more than tangentially related to the OP, although they are more along the lines of "Basic Breeding Explained")

x

 

[mofeta]

It is not trivial when you self a single plant, line for 3+ generations you get so many problems that some times the work can not be completed, I should know.
-SamS

I admit that some are quite difficult, and I have less experience than you. Have you tried making parallel lines from a selfed individual?

1. generate S1 seeds
2. separate S1 seedlot into 4 groups, randomly
3. proceed with savage inbreeding in each group, SEPARATELY
4. When problems arise, allow flow between the 4 separate populations

Although the 4 lines are very similar (duh), they are different enough to fix any problems I have seen (good enough anyway, allowing completion of project is "good enough" to me). But, I think your experience is of a different order of magnitude compared to mine, and I put great weight on your opinion on these matters.

Also, you grow exclusively outside I think, and the lack of environmental controls (like the ones indoors or in greenhouses) out there makes it harder for inbred plants. If I were doing big outdoors breeding, I would probably select for one different vigor trait in each of the paralell selfed lines along with the effects traits that were being selected for equally among the four lines (but seperately though).

You might be able to find something linked to what ever you are looking for with genome tilling?

Yeah wow that is real exciting stuff, genome mining and whole genome sequencing, elucidation of transcriptional and epigenetic codes, etc, man what a time to be alive.

I foresee a time when we will be able to analyze seeds and not even need to grow them to do selections. Of course, if we somehow avoid blowing ourselves back into the stone age, we will not have to breed at all, we will just print the genome/transcriptome/epigenome that we want. We will know what to print by using big computers to simulate various permutations of the information that determines the form and behavior of the plant.

Do people even want homozygous lines? I know of none created except for our experimental work.

Well, I was speaking in a relative sense of course, truly homozygous plants can only be achieved (currently) through DH, I should have said "method to increase homozygosity" in that sentence.

But yeah, I have situations where relatively homozygous populations are quite useful, for the normal reasons plant breeders find them useful. I don't know about other folks, I have not asked anyone. Maybe I will start asking people what they think about this, just out of curiosity.

Thanks for the thoughtful replies. I really enjoy doing this kind of work, and it is fun to talk to other people who enjoy it enough to devote serious thought to it.

 

[Tonygreen]

Yes we would like homozygous plants that breed true. Not everyone is a cash cropper.

 

[mofeta]

Yes we would like homozygous plants that breed true. Not everyone is a cash cropper.

The uniformity of seed lots from homozygous lines, or F1s of homozygous lines, make them excellent for cash cropping.

 

[Tonygreen]

True mofeta, I was thinking of the vigor people talk about so much.

There really are not many options for homozygous lines out here. Im trying to make my own.Other people certainly have much better skill sets and gene pools to do a better job. It will be maybe two years before I have a couple separate lines selfed down to play with.

I would like to see some of these perfect f1's I have seen mentioned

 

[Yard dog]

from what I've seen they have been in "fem" lines. It seems to pop up in a some s1/s2s of bubba and a few other plants. I think the peyote purple had one generation that was almost 90% male. I don't know about hybrids using reversed pollen in that regards it seems to have been on inbred lines.

They say with feral hemp crops that they will revert back to normal sexual ratios after a few generations as well, mathematically it seems possible to do with intersexed plants if your breeding for that trait, unless i'm completely off base with that.

I think that the morph for showing as "male" is on the "xx" side as is evident within monoecious hemp, so even when accessions were proven to contain no MADC2 marker, they could and would still show intersexually (ie with balls), I think a french group recently published some data on this? (perhaps SamS knows?) I'm sure they found the monoecious plants to have their genome roughly the same size as female ("true" xx), I'm only going on the abstract cited a the minute ;

Hemp (Cannabis sativa) has a highly variable sexual phenotype. In dioecious hemp, the sex is controlled by heteromorphic sex chromosomes according to an X-to-autosomes equilibrium. However, in monoecious hemp, the sex determinism remains widely unknown and has never been related to a quantitative approach of sex expression. The present paper aims to contribute to the comprehension of the sex determinism in monoecious hemp by assessing the genotypic variability of its sex expression and establishing its sex chromosomes. Five monoecious and one dioecious cultivars were grown in controlled conditions under several photoperiods. The monoecy degree of 194 monoecious plants was recorded at each node by a figure ranging from 0 (male flowers only) to 6 (female flowers only). The genome size of 55 plants was determined by flow cytometry. The DNA of 115 monoecious plants was screened with the male-associated marker MADC2. The monoecy degree varied significantly among monoecious cultivars from 3.36 ± 2.28 in ‘Uso 31’ to 5.70 ± 0.81 in the most feminised ‘Epsilon 68’. The variation of monoecy degree among cultivars remained consistent across trials despite a significant “cultivar × trial” interaction and partly agreed with their earliness. The genome size of monoecious plants (1.791 ± 0.017 pg) was not different from that of females (1.789 ± 0.019 pg) but significantly lower than that of males (1.835 ± 0.019 pg). MADC2 was absent from all monoecious plants. These results strongly support that cultivars of monoecious hemp have the XX constitution and that their sex expression has a genetic basis.

 

[St. Phatty]

Is Tri-foliate growth good ?

I have a tri-foliate TH Seeds "Sage & Sour". Their Sativa-Afghani cross, crossed with Diesel.

She was feminized and is Trifoliate.

 

[Dropped Cat]

Bump, fucking good thread.

 

[Only Ornamental]

Is Tri-foliate growth good ?

I have a tri-foliate TH Seeds "Sage & Sour". Their Sativa-Afghani cross, crossed with Diesel.

She was feminized and is Trifoliate.

View Image

Use the forum search, there are quite a few good threads about advantages and disadvantages of whorled leaf pattern aka whorled phylloxaty/phyllotaxis .

 

[Dropped Cat]

Is Tri-foliate growth good ?

I have a tri-foliate TH Seeds "Sage & Sour". Their Sativa-Afghani cross, crossed with Diesel.

She was feminized and is Trifoliate.

View Image

Interesting to note most whorled plants tend to be male.

I wonder if as a rule they should be culled.


I have luck so far with very little or no inter-sex traits in my
ladies I cross.

Have there been examples of hermi plants being desirable at all?

 

[Tom Hill]

Sam,,

You sir have said it yourself,, check progeny to ultimately determine the sexual stability -for lack of a better word- (lower amounts of sexual of modifier genes bringing "hermies") b4 making the call as a cullist,, why then is the opposite not also true? u selections pass up your best individuals bcuz we are stuck in this mindset of corn breeding,, when all that matters,, is this clone we are growing right? So whats with the corn breeding tactics?

 

[Tom Hill]

u have seen with your own eyes ears nose throat and brain what terpenoid profiles can do to a high... u pioneered that realization (hence my cracks about selling folk fa18a's without the guidance systems lol),, u know how complicated the maths are to do that and u know that disease/stress resistance falls under that same category of biometrical genetics (quantitative) affecting sexual expression... Yet u choose to pitch your fork in the sand on this subject almost religiously,, i have been watching and waiting for going on 2 decades now,, and i still dont know why..

 

[Tom Hill]

like its not hard enough to breed tandem selection for like 100+ things,,, so fuck it lets breed for one more that is positively correlated to 100 others hahaha,, let's look up and make sure the sky is still blue..? No man no friggen way it's absurd and it is my solemn duty to say so,, hehehe.. especially bcuz we are talking about strawberries,, not corn..!

 

[KiefSweat]

doesn;t corn also have ten chromosomes?

I've got some questions about how many plants you should use when making seeds.

If i made a f1 hybrid with only one mom and one dad how many plants of each sex do I want to select to make f2s from?

In the future how many males do I want to select for the p1?

 

[Tom Hill]

and corn is also diploid right? but we dont smoke corn ha..?

here is reality,, drug cannabis genetics is a highly complicated being that is often spoken about as if it wasn't.. the whole entire matter -this huge elephant in the room- is never spoken about never confronted.. authors on the subject have utterly FAILED time and time again whether they copy/paste off the internet or ask somebody else to "edit" (read write) their book or avoid the whole subject matter entirely and choose some older copy/paste from the old hemp archives.. none of that hunts in reality. fuck all that..

All numbers questions how many this or that boils down to how rare the traits are that we are trying to capture..

 

[Tom Hill]

Can u dig what i am laying down? it takes like 3 or 4 things for corn to taste good,, a couple more to be good for us,, and a couple more for it to survive..

Drug cannabis? hehehe,, it takes like 50 things to taste good,, another 50 to be good for us,, and a couple more for it to survive..

We grow clones do we not? when we are faced with such insurmountable maths we breed said creature as if it was octoploid,, this is what we have done with drug cannabis - bcuz indeed it is at least that complicated, its all right in front of our face yet we choose to ignore the facts... instead we sit around like a bunch of grumpy old mangos talking about corn breeding lol,, wake me when we wake..

 

[Tom Hill]

Ks,, select as many as you can always this is the only correct answer to that question,, and at the end of the day? we will grow only a handful of select clones like any good strawberry or pineapple or fruit tree or sugar cane farmer,, why? because we can,, and there can be only one so to speak.. this is the true way of things,,, and if it gives 2 seeds an ounce? who the fuck cares if its the best,, that is reality.. I have no idea what these other guys are saying,,, its chinese/greek to me..

 

[Tom Hill]

let me smoke some of that hash that has u answering me in edit mode only hashaha?

I know u get me Sam,, as i have always got u,, yes i agree like begets like,, but no i dont agree that folks we know know what they want hehehe.. using them for herbal production may produce a few seeds,, using them in breeding may produce even less, got a coin to flip?, this is the reality of the matter.. just like when u told folk to look at progeny,, it works both ways,, we just never know so i take maybe not offense,, but a raised eyebrow let's say at such lines in the sand.. i know u can dig where i am coming from..

i do not believe quality is linked to intersex either,, i am a firm believer in traits inherited separately,, but i can count too,, and its a shitload of things we are putting together to make us smile,, after-all,, we are doing more than making rope here,,, if we were just making rope? then let's not take our eye off how strong the fiber,, however if we are making resin? well, u know...-T