Breeding for Light

Breeder's Lab
#21

I need actually to do a disclaimer:

  • There is in my opinión an abismal difference between “breeders” and “pollen chucking” and I am neither far to be part of the second category.
  • Breeding to me entails " large" selection with numbers that are far above any grow space I could never image.
  • I am not a commercial grower but a semi self sufficient grower
  • I consider I won’t never able to do nothing close to this discussion, nevertheless I consider these sites are exactly to discuss also similar topic, with a passion for questioning and challenge limits and possibilities.

I hope no one will get upset if this or other threads are out of standard knowledge and are questioning crazy alternatives.

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#22

If you make seeds to me you’re a breeder. There are varying degrees of work that would differentiate some breeders from others but I urge you to not discount your breeding efforts as they are actual breeding efforts.

Most “breeders” aren’t working population sizes with any sense of credibility. You’re good bro.

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#23

@Sbeanonnamellow i think thats a good point and I’ve often thought the same.

Id be interested in your opinion on population sizes breeders should be using. I completely agree with you on this and am interested on hearing others opinion

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#24

Sorry I don’t want go OFF TOPIC.

I am in love with Luther Burbank and other plant breeders like Carol Deppe, and John Jeavons work ( not cannabis) and I consider a base of real breeding large specimen selection.
This text I have highlighted in my books and I share to better explain my point of view.
Also I consider breeding a matter of statistic and small population ( we should define how small) doesn’t allow for effective statistic data.

Marijuana Botany by Robert Clark - Chapter 3

"The most important part of Burbank’s message on selection tells breeders to choose the plants “which are approaching
nearest the ideal,” and REJECT ALL OTHERS! Random pollinations do not allow the control needed to reject the
undesirable parents. Any staminate plant that survives detection and roguing (removal from the population), or any stray
staminate branch on a pistillate hermaphrodite may become a pollen parent for the next generation. Pollination must be
controlled so that only the pollen- and seed-parents that have been carefully selected for favorable traits will give rise to
the next generation.
Selection is greatly improved if one has a large sample to choose from! The best plant picked from a group of 10 has far
less chance of being significantly different from its fellow seedlings than the best plant selected from a sample of
100,000. Burbank often made his initial selections of parents from samples of up to 500,000 seedlings. Difficulties arise
for many breeders because they lack the space to keep enough examples of each strain to allow a significant selection. A
Cannabis breeder’s goals are restricted by the amount of space a to keep enough examples of each strain to allow a significant selection. A Cannabis breeder’s goals are restricted by the amount of space available. Formulating a well defined goal lowers the number of individuals needed to perform effective crosses.

Another technique used by breeders since the time of Burbank is to make early selections. Seedling plants take up much less space than adults. Thousands of seeds can be germinated in a flat. A flat takes up the same space as a hundred 10-centimeter (4-inch) sprouts or six-teen 30-centimeter (12-inch) seedlings or one 60-centimeter (24-inch) juvenile. An adult plant can easily take up as much space as a hundred flats. Simple arithmetic shows that as many as 10,000 sprouts can be screened in the space required by each mature plant, provided enough seeds are available. Seeds of rare strains are quite valuable and exotic; however, careful selection applied to thousands of individuals, even of such common strains as those from Colombia or Mexico, may produce better offspring than plants from a rare strain where there is little or no opportunity for selection after germination"

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#25

Whenever possible, breeders should be using thousands of plants in my opinion.

Fortunate for us, a significant amount of that work has been done across mellenia. Now we get to sit on the shoulders of giants able to make some great reflections of stuff with random 1:1 matings and come across like the all mighty cannabis savior. Albeit, doing so from within the hybridization impasse pushes those legendary reflections further away.

Most modern cannabis breeders will search through dozens of plants for a female representation but don’t often if ever seem to put the same emphasis on selecting and choosing the most desirable male. Progeny testing sire lines against one another is a significant part of the breeding work that I feel gets sorely overlooked. So many breeders making crosses where the male input is immediately retired and little if any progeny testing for that male even done to begin with.

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#26

Robert Clark is a G!

I agree that it depends on space and I think the muddy genetics of cannabis makes it even more difficult. Selecting for multiple characteristics just makes the plant count grow exponentially.

I’m very curious about how breeding would’ve gone without prohibition. I dont know if we’d be spending as much time pheno hunting if there had been opportunities to more freely create true breeding strains

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#27

Not my thread but I don’t think it’s off topic at all. Wonderful contributing comment! It’s helpful because now when I see your posts and comments within the community I’ll think “@Rhizome knows whatsup!”

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#28

Couldn’t have said it better if I tried!

It is nice we are finally getting to the point with marker assisted breeding where can choose traits, they’ve got a decent QTL map for terpene synthases i saw at the Cannabis Research Conference this past summer.

I have a feeling that a lot of the disease resistance genes got lost because of how breeding was done. The differences in stress tolerance genes between bred plants and wild plants is substantial and has universities scramble to collect feral hemp in hopes of increasing resistance/tolerance traiys

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Shaggy's Fantasy Island (A virtual exclusive cannabis community, of sorts.) (Part 2)
#29

I think it’s largely due to bringing plants indoors during the late 70’s and early 80’s due to prohibition pressures and the advancement of indoor lighting technology.

It effectively removed many selective pressures these populations has previously been encountering season by season. I’d imagine modern indoor cannabis would show much less endophyte diversity than more antiquated types, especially those acclimatized to regional climates.

You mention seeking regional IBL’s in another thread. That’s the shift in my opinion. Going from those regional IBL’s that were grown outdoors across full term seasons to indoors static 12/12 on a timer. The regional endophyte relationships getting lost to the more sterile indoor environment. Without those selective pressures the genetic switch to activate those genes falls out of favor.

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#30

Absolutely right! When you finally tell me you got an advanced biology degree I am not going to be the least bit surprised.

One of my overarching research goals is to try and introduce local IBLs for different growing regions. Provide genetic maps and phenotype classifications. That would allow for local breeders to still play with different crosses but also have a clear way to screen and retain locally important traits. I think it helps the cannabis community at large and would help to insulate small size growers from crop failure or loss. Its a big task for sure, but its not impossible

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#31

Nah I just read and weed a lot.

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#32

Hahaha respect that!

The best part for me is you not just reading but clearly understanding what you read and being able to apply it. Thats a skill we are losing it seems at times

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#33

Sorry I need to add a bro-science comment regarding breeding for light.
I found an interesting article about " How much cloud affect photosintesis irradiance" and this test during two cloudy days.

IMG_20231230_204932
IMG_20231230_204932918×1095 104 KB

Let’s back for one second to the idea of strains that need less light and let’s take into consideration Netherland where there are 32% of sunny days ( approximately) during summer and 68% of cloudy days.
If we assume that the sun produce 2,000umol a cloudy day give the plant 1,000. 50% in light reduction.

it makes me think that also in these conditions the strains developed in Netherland for short summer countries are actually developing very good.
Of course someone could perfectly argue that if you take the same strain and you grow it in Spain it will grow much much better ( is it true actually?)

Have you heard about VIC high works? I guess she/he was from here originally ( probably I am crossing data).

Another comment is related with light intensity and altitude.
What we can say about those landrace strains that are growing at 1,000m Vs those that grow at see level? I don’t think the sun intensity, radiation’s, etc is the same… Not sure which reflections bring this to the table.

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#34

@ThePotanist @Sbeanonnamellow

You rock both!!!

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#35

You ask all the best questions

#36

Yes, can be. Here is an example spectra of the sun mid-day partly cloudy northeastern US late spring.

In this sample the PAR (400-700nm) measured as 1580 umol / m^2 s as captured by a spectrophotometer:
image

The solar irradiation will vary by location, environmental conditions, calendar date, and time of day.

For instance, here is what the DLI looks like based on latitude and day-year (estimated daily light received in Mols:

image

And how the amount of irradiation varies based on time of year, this is Ecuador (graph is rotated clockwise):

image

And, here is Sydney:
image

etc…

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#37

Brilliant Northern.
Definetly tonight I won’t sleep :slight_smile:

Can you clarify the following?

1580 umol is not this a value perfectly achievable by LED lights?

#38

You can achieve that but you’d probably want co2 supplementation as that may be a limiting factor.

My suggestion is to not go for that intensity indoors until you have several grows at a reduced intensity under your belt (if not already). That is a high intensity which brings with it other difficulties, such as heat. Also bare in mind, that the light intensity hitting the plant leaves (starting from the top towards the bottom) will be significantly different than the sun intensity (the rule of squares) … when using overhead lighting.

In addition, the yield -v- efficiency decreases with intensity such that double the intensity does not mean double the yield … in addition to any limiting factors (such as CO2).

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#39

From one thing know ten thousand things

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#40

Why even bother answering when @Northern_Loki is just spitting facts!!

Great answer, great pics!

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