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How many plants do you need to maintain a variety without inbreeding depression?

MagillaG

New member
A post on the subject from Vic High

RRS Improved Breeding for Closet Hacks
Here is a simple model that can help explain how someone with as little as a 400watt garden and a flo clone bench could pull off an improved breeding project utilizing a derivitive of the RRS concept. This is not a strict blueprint, but just a general model that can be scaled up or down depending on the realities of the seed maker. In this case, I will assume that the clone bench is limited to 30 clones and the flower room limited to 20 flowering plants. Purists will find flaws in the model and and their insight is welcome as it can only add depth. However, I request that any that are not interested in the concept of improved breeding techniques to simple limit their participation to read only status. By all means questions about clarification are welcome, but ignorant attempts to discredit are not. As the starter of this thread, I ask the breeder mod to respect this wish and delete any extra "noise". If this isn't possible because of site policy, I will just remove this post and take it to a more selfish location FPRIVATE "TYPE=PICT;ALT="

Hope this enlightens some to the possibilities.

*********************************************

Starting with two unrelated inbred lines, A and B.

1) Grow out the A line and select the top 5 males (Am1-5) and top 5 females (Af1-5) to use later:
a) plant a little over twice the seeds your flower room can handle
b) veg seedlings
c) sex the seedlings
d) select females for flower room and repot into final pots
e) take 4 clones of each of these females
f) flower males and females, may be cramped with the males to start, don't worry
g) just before the males explode, remove, grade, select 5 best.
h) prune these 5 males to remove all flowers and return to veg area
i)harvest females, grade, and identify the top 5
j) keep the best two clones that represents each of the 5 selected females, discard the rest

What you finish with is 15 clones and some sinse to enjoy personally or sell if that is your game. Whatever the route, this step has not cost the grower anything but a bit of space in the flo bench.

2) Grow out the B line and select the top 5 males (Bm) and top 5 females (Bf) to use later: Follow the procedure used in step 1 above.

The net result should be another sinse crop and the flow bench contain 30 clones now.

5 Am clones labelled Am1 - Am5
2 sets of 5-Af clones labelled Af1-Af5
5 Bm clones labelled Bm1 - Bm5
2 sets of 5-Bf clones labelled Bf1-Bf5

3) Making the A and the BA seedlines Take the 5 Am and 1 copy of each of the Bf and Af clones and flower them out (15 total) allowing random pollination. You should end up with 10 seedlots divided into two groups of 5, the A group labelled A1-A5 and the BA group labelled BA1-BA5


4) Making the B and the AB seedlines Take the 5 Bm and 1 copy of each of the Bf and Af clones and flower them out (15 total) allowing random pollination. You should end up with 10 seedlots divided into two groups of 5, the B group labelled B1-B5 and the AB group labelled AB1-AB5.

Be sure to make sure that the end numbers correspond to the same initial female clones. For instance, be sure that AB1 and A1 seedlines are from the same A1 mother. And that the BA1 and B1 seedlines came from the same B1 mother.

The clone bench should be empty now and the breeder should have 5 packs of A seedline, 5 packs of the B seedline, 5 packs of AB seedline and 5 packs of the BA seedline making 20 packs of seed.

5) Grow out and rate the 5 packs of AB seedline. One could do them all at ounce, or divide it up over 6 sinse crops. Nothing wrong with a few sinse crops is there? For this model I will divide the task into the 6 sinse crops.

5a) Grow out as many of the AB1 seeds as your flower room can handle. This usually means planting a little over more than double the number of plants your room can handle and then just selecting the best females for flowering. Make backup clones of each female to be flowered and store them on the flo bench. Now take the number of plants your flowering room can hold (say 20 in this model) and divide this number by 5 and this is the number of keeper plants you want to identify from this crop (say 4). Use a standard score sheet system to score this crop and make notes for future reference if necessary. Identify and select the clones representing these 4 plants and toss the rest. Be sure to label them AB1.

5b-5e) repeat the 5a process for each of the seedlots labelled AB2 to AB5. You have now enjoyed 7 sinse crops and should end up with 20 clones on your clone bench if your flower room can hold 20 plants. There should be 4 of each group, be sure each group is properly labelled from AB1 - AB5.

5f) This is your eighth sinse crop and is where you grow the best of the best of the AB seedline. Randomly arrange these plants in your grow room and then flower them out. Score each plant and use the totals of each group of 4 to score each of the 5 groups. Rank the AB seedlines from best to worst. You can help your decision by referring to the data you also collected in the previous 5 grows. The point is to determine which of the 5 seedlots provided the best OVERALL results, not the best individuals

Your clone bench should be empty again.

6a-6f) repeat the entire process from 5) above, but using the BA1 - BA5 seedlines instead.


7) with reference to steps 5a-5f, use the data data collected to determine your two top A seedlines, lets say that A5 ranked tops and A3 ranked second. This means that you can discard lots A1, A2 and lot A4

7a) Grow out as many plants of the A5 seedbatch as you can and select your top 3 males and top 3 females. Maintain clones of these 6 plants on your clone bench, cleartly labelled as Af1-Af3 and Am1-Am3.

7b) Grow out as many plants of the A3 seedline and select the best 2 males and best 2 females, clearly labelling them Af4-Af5 and Am4-Am5.

Now be sure to have two copies of each Af clone for a total of 15 clones on the clone bench. Sound familiar?

8) Now repeat the processes in step 7 but with using the data collected in step6 to choose the top two B seedlines.

Now you should have 30 clones on your clone bench representing:

5 Am clones labelled Am1 - Am5
2 sets of 5-Af clones labelled Af1-Af5
5 Bm clones labelled Bm1 - Bm5
2 sets of 5-Bf clones labelled Bf1-Bf5


Repeat the process in steps 3) and 4) so that you once again have seedlines labelled at A, B, AB, and BA.

You have finished the first cycle of the breeding program and ready to start a second. It hasn't been quick but you have enjoyed alot of sinse along the way and the combined AB and BA seedlines represent a superior F1 seed product. Each step of RRS will just keep making it better.


Now it's time to post, proof, and go back and edit the mistakes, haha.

figure1.jpg.0bfdea55422fc2240b43fb0bb750877f.jpg

figure2.jpg.ec9514833b521cd13567ba2a666d5b69.jpg
 

zif

Well-known member
Veteran
Exactly.

If you have the space you would increase numbers everywhere - more possible moms, more ‘selects’ from them, more males, etc.

But the easiest way to understand the basic idea is to think of each round as selecting a best mom A and mom B to continue their respective inbred lines, where best means the ones who make the most desirable F1 hybrids.

Have fun!

That helps a lot! Thank you Zif!

So, when you say:


Do you mean that I would be growing out the seeds from the selected superior "A" females, that had been pollinated by half of the mixed "B" pollen (and vice versa), and I would then be choosing the single female that made the best offspring when fertilised by the opposite line?

And then I'd complete the cycle by going back to the clones I'd kept of the winning female in each line (A and B), and pollinate each clone this time with the remaining half of its "own" pollen (A with A, B with B) to generate a new test population of A's and B's again. etc..


I'm definitely going to give this a try!
 

Kalbhairav

~~ ॐ नमः शिवाय ~~
Veteran
zif is the dude.

Listen to his wisdom :D
If he had more space/time, no doubt he’d be churning out superior hybrids of some very interesting combinations.
 

aliceklar

Active member
Wow. Mind blown. :whee: I've spent a goodly portion of the past 24 hours thinking about this, googling reciprocal recurrent selection, digging into an old plant breeding genetics textbook, and trying to figure out how to adapt this to my modest grow space. But I reckon its doable, especially if I split some of the stages into more than one grow.

Was wondering, are there any grow journals out there of people actually doing this?

Its a great programme - and will make a whole heap of bud along the way :smokeit: Thanks again zif for suggesting this, and also MagillaG for the detailed example. Awesome stuff.

I'm doing an initial trial grow at the moment of 14 different varieties - from which I'll select my fave four to do the crosses to generate the two F2 populations that will be group A and group B in my RRS programme. Gonna be so much fun.

AK xo
 

q3corn

Active member
Was wondering, are there any grow journals out there of people actually doing this?


Go through the Marijuana Strains and Breeding threads. Particularly anything that talks about making new crosses. the Original Glue subforum had a good amount of documentation on here about making a bunch of the new glue derivatives.
 

romanoweed

Well-known member
ahorator:
but something in me is suspicious if i have 2000 or 1000 Plants open pollinating if that Line would stay exact the same...


Acording i could take a representative pheno of a Line, say its not recessive Traits, open pollinate with 2000, and tada, PERFECT Copy? sounds too good to be true.


"shure i would have to do it in neutral enviroment, but appart from that, im not shure "
 

CannaZen

Well-known member
but you preserve the best traits when it evolves. you can cull still plants once one learns what to watch for and still get those results.
 

@hempy

The Haze Whisperer
Breeders like Nev that created lines few have matched to date used a selected male and selected female in breeding a set line.


The last thing i would do if i was working with a poly hybrid after selecting a female from 20 or more seeds would be to open pollinate her.You are trying to stabilize what makes that plant special and limit the undesirable traits of her sisters you culled finding her in a pack or 3 of seed.


I inbreed a Thai line years ago 10 generations saw no loss of vigor or quality made a few seed each year and just germinated the seeds i made next spring and selected a male a fem and repeated it each season as we did not keep clones back then.


Thai i have now is inbreed 7 years again no loss of vigor or quality.


Males play a important roll a subject few seam to interested in.
 

Brother Nature

Well-known member
An acre with at least 1000 plants would be an incredible place to start. But, a lot has been done with much less, finding what works for what you want will be the ticket, it takes time, dedication and work. You have all those things down and method will matter less. You've at least asked the right people though :D.
 

mexcurandero420

See the world through a puff of smoke
Veteran
1000 female & 1000 male at least, but someone over here send me info , where a hemp breeder used 10 males & 150 females to maintain an ibl hemp variety.
 

JockBudman

Well-known member
Personally I think there's a difference between a breeder and a closet hacker here. So obviously a breeder would be runnin 1000-2000 plants, open pollinated tae preserve the line and all that, but that's no practical for a closet hacker like me.

I'm doin the best I can with what I've got so here's the way I'm doing it.

I've got 5 zamaldelica on the go the now - 3 boys and 2 girls. My plan is to collect all the pollen together from all the boys then impregnate all the girls and play with the f2 lines sometime in future.

That won't result in a true maintenance of the variety, but when you consider I'm working with under 20 plants at a time, usually 10 at most, it'll take me years and years to grow out even all the f2 seeds from that simple cross, let alone work the lines etc. And it'll take longer than that even, as I constantly mix and try different varieties.

I'll be doing 10 packs of Old Timers Haze, Panama and Honduras over the next few years, "open pollinating" in the same sort of way. There's going to be seeds upon seeds for me to grow for years yet and I haven't even mentioned my skunk and Afghan crosses and backcrosses I've made/am currently making.

I guess the point I'm making is that the approach the average home grower would take is very different from that a large scale grower and breeder would take. When you consider space, plant counts and the fact many of us still live under oppression and prohibition, open pollinating a ten pack of a variety you like is probably enough for the average tent owner and would give enough seeds to find sporting plants to line breed with. Which would still be maybe 5-10 years of work :D

Anyone who lacks space but doesn't have to worry about plant numbers, should Google the "bonsai sultan" method.
 

Tynehead Tom

Well-known member
In the past I relied on a friends licensed medical grow plant count to do selections as he only grew a 1/4 of his count and let me use the rest for selection. He benefited in being able to select prize clones for his flower runs.
These days I have my own licensed grow and can do 147 plants at a time indoors and 56 outdoor. So over winter I do my pheno hunts thru lines I'm working in an effort to have selections made for the greenhouse. I keep my selected males in clone form but also have isolation boxes and over winter I collect jars of pollen from the ones that make the grade.

In the greenhouse I pull the selected females in between weeks 3 and 4 and isolate them indoors. Pollination takes place in isolation and then they get the spray down and returned to the greenhouse the next day.
I do pollen chucks all the time just to see what comes from the proginy but I also work very hard at selection for the lines I am actually working in a long term breeding program. It can take me all winter just to sift thru 3 or 4 hundred seeds though so I make my selections as ruthlessly as I can
 

troutman

Seed Whore
Breeders like Nev that created lines few have matched to date used a selected male and selected female in breeding a set line.

If you want an Elite strain you have to go with a 1:1 mating system like Nevil did.

But this thread is about maintaining genetic variation and a 1:1 mating system won't do that.

Don't forget that Nevil was also playing with purer lines than most people today who use Dutch genetics that are all mixed Hillbillies. ;)

P.S. I'm happy have lots of Landraces and Heirlooms to breed with. :biggrin:
 

El Timbo

Well-known member
Personally I think there's a difference between a breeder and a closet hacker here. So obviously a breeder would be runnin 1000-2000 plants, open pollinated tae preserve the line and all that, but that's no practical for a closet hacker like me.

It would be nice to think so Jock...
 

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