[angelgoob]

I have noticed northern wild-type produces CBD strains. Is this because somehow the UV wavelength the resin protects against has changed in the northern climate because of the sun's angle coming through the atmosphere and the result plants therefore favor CBD because it protects or take less energy for protection?

[oldchuck]

Originally Posted by angelgoob

I have noticed northern wild-type produces CBD strains. Is this because somehow the UV wavelength the resin protects against has changed in the northern climate because of the sun's angle coming through the atmosphere and the result plants therefore favor CBD because it protects or take less energy for protection?

Don't know the answer to your question but it is interesting to think about. Is it mostly northern types that make more CBD? And if so why?

I've started growing some hybrids in an attempt to balance out the CBD-THC ratio. I think it works in the F1 generation but still uncertain about further inbreeding. I've been using a far northern hemp variety called Finola and crossing to different examples of the usual high THC commercial varieties. It ain't your usual stoner smoking weed but it works for me.

[Sam_Skunkman]

Biotransformation of Tetrahydrocannabinol
Muhammad T. Akhtar . Khozirah Shaari . Robert Verpoorte
Phytochem Rev DOI 10.1007/s11101-015-9438-9
Abstract Cannabinoids are terpenophenolic com- pounds consisting of an aromatic polyketide and derived from the geranyl diphosphate C10 terpenoid unit. They are the active constituents in Cannabis sativa and have been utilized in a number of cannabis- based medicines. Biotransformation of cannabinoids is an important field of xenobiochemistry and toxicology and the study of the metabolism of these compounds can lead to the discovery of new com- pounds, unknown metabolites with unique structures and new therapeutic entities. Different fungi, bacteria, plants and animal cells have been used for the regio- and stereoselective transformation of cannabinoids. All of the above mentioned organisms have distinct enzymes which catalyze the conversion of a specific cannabinoid at different positions and thus provide a variety of derivatives. All organisms are able to transform the alkyl side chain where as mammalians are unique in the formation of the carboxy derivatives. This review article assesses the current knowledge on the biotransformation of tetrahydrocannabinol and with particular focus on D9-THC.

[Sam_Skunkman]

Do me a favor and save a few leaves from each of the the parents and some progeny?
I would like to DNA sequence the parents as well as F1 progeny and F2 progeny when you make them, keep tract of the sex of the leafs and what the parents leaves were from male or female plants and who the parents are. Just dry the leaves, place between paper sheets with ID info and I will get them later. I suspect the reason you see CBD up north and more THC at the equator is because at the equator people have been selecting plants for THC, even if just by traditional growers, they can easily remove all the CBD from drug varieties just by saving the seeds of the best ones when smoked, do this for a few hundred years you have high THC varieties, with little to no CBD.
If you do any Cannabinoid or terpene analysis on any of the plants keep a leaf with the analysis info so we can keep the DNA info + Analysis together in one set of data.
Let me know if you save anything...

-SamS

Originally Posted by oldchuck

Don't know the answer to your question but it is interesting to think about. Is it mostly northern types that make more CBD? And if so why?

I've started growing some hybrids in an attempt to balance out the CBD-THC ratio. I think it works in the F1 generation but still uncertain about further inbreeding. I've been using a far northern hemp variety called Finola and crossing to different examples of the usual high THC commercial varieties. It ain't your usual stoner smoking weed but it works for me.

[Sam_Skunkman]

https://biorxiv.org/content/biorxiv/e...56887.full.pdf

Phased Diploid Genome Assembly with Single Molecule Real-Time
Sequencing
Chen-Shan Chin, Paul Peluso1, Fritz J. Sedlazeck, Maria Nattestad, Gregory T. Concepcion,
Alicia Clum, Christopher Dunn, Ronan O’Malley, Rosa Figueroa-Balderas, Abraham Morales-Cruz, Grant R. Cramer, Massimo Delledonne, Chongyuan Luo, Joseph R. Ecker,
Dario Cantu, David R. Rank, Michael C. Schatz.
Abstract
While genome assembly projects have been successful in a number of haploid or inbred species, one of the current main challenges is assembling non-inbred or rearranged heterozygous genomes. To address this critical need, we introduce the open-source FALCON and FALCON-Unzip algorithms (https://github.com/PacificBiosciences/FALCON/) to assemble Single Molecule Real-Time (SMRT®) Sequencing data into highly accurate, contiguous, and correctly phased diploid genomes. We demonstrate the quality of this approach by assembling new reference sequences for three heterozygous samples, including an F1 hybrid of the model species Arabidopsis thaliana, the widely cultivated V. vinifera cv. Cabernet Sauvignon, and the coral fungus Clavicorona pyxidata that have challenged short-read assembly approaches. The FALCON-based assemblies were substantially more contiguous and complete than alternate short or long-read approaches. The phased diploid assembly enabled the study of haplotype structures and heterozygosities between the homologous chromosomes, including identifying widespread heterozygous structural variations within the coding sequences.

[Sativied]

Originally Posted by Sam_Skunkman

I suspect the reason you see CBD up north and more THC at the equator is because at the equator people have been selecting plants for THC,

Is that not likely mainly from the uvb levels limiting the choice? Higher at the equator, higher at higher altitudes too, longer uvb season, less ozone blocking it in the tropics etc.

Pate proposed in 1983 already the difference between the drug and fiber variety was from selective pressure brought about by uvb radiation.

https://onlinelibrary.wiley.com/doi/1...757.x/abstract
"The concentration of Δ9-tetrahydrocannabinol (Δ9-THC), but not of other cannabinoids, in both leaf and floral tissues increased with UV-B dose in drug-type plants. None of the cannabinoids in fiber-type plants were affected by UV-B radiation."

And Chemical ecology of Cannabis, https://www.druglibrary.org/olsen/hemp/iha/iha01201.html

My point is, maybe they never really had the opportunity up north to select for high thc instead of cbd. While near the equator cannabis evolving to a higher thc variety was at most sped up by humans but would have happened regardless.

[oldchuck]

Cool question, Sativied. What's the answer? More and better research? I think so.

[Sativied]

There does seem to be a correlation, and I do think causation too. Besides cannabis there is a lot of research on the effect of uvb on secondary metabolites. Thc absorbs uvb and if you look at the things uvb can do to plants it makes sense the ones with high thc in high uvb areas could have been the best plants in other aspects too. Uvb damage includes reduced biomass, reduced pollination germination (Campbell et al., 1975; Caldwell et al., 1979; Flint and Caldwell, 1984), auxin inactivation and makes it harder for the plant to compete with weeds. Things a basic farmer would have selected against even if only interested in the seeds, or even fiber..., but would obviously make a difference in natural selection too. Wrap a layer of thc around the ovule, the by trichs most protected area, affecting pollination rates positively and then the difference could relative quickly change a population. The whole point is to protect the seed, and appearantly the pollination, in order to reproduce.

UV also causes dna damage and the resulting repair process is a main source for mutations. I.e. Arguably, statistically, a plant species would need longer to evolve and adapt to less damaging environmental factors.

I don't have enough data and there is some conflicting research but it appears that in any case THC is a more flexible screening compound against uvb than CBD. A high THC plant can direct more energy into creating more thc when needed/signaled. CBD contents is not increased when uvb is increased. That flexibility of a high THC plant may have given it a major advantage in areas with high uvb and/or long uvb seasons, and possibly uvb peaks throughout evolution.

[Sam_Skunkman]

Pate worked for me for 2 decades we ran several grow outs in my greenhouse he designed that tried to prove that UVB improved Cannabis in any way. We could not, We used 3 different clones one CBD and two drug varieties we had 4 examples of each each of the 3 clones they were set up so the first set of three were 1 meter from the UVB lights, the next set was 3 meters, the next set was 6 meters, and the last set was a control with no UVB. They were all in 10 liter pots the same size, about 3 feet when started, with the same soil and watering. The closest to the lights got badly fried, the second set was lightly fried, the third set, not really harmed and the 4th set just controls. We ran the lights first in veg then in flowering. We used GC-FID to measure the cannabinoids and terpenes and weighed the total biomass, and flowers and stems and leaf fraction of the dry plants after harvest.
RCC and I did organoleptic analysis on the two drug varieties Skunk #1 and a Thai?, the no UVB plants were the best. The closest row to the lights were much less weight and resin, the second row was lightly harmed in a similar way. None of the UVB plants had any more cannabinoids or terpenes or more weight. I did try.
-SamS

[neverforget4/20]

Originally Posted by Sam_Skunkman

Pate worked for me for 2 decades we ran several grow outs in my greenhouse he designed that tried to prove that UVB improved Cannabis in any way. We could not, We used 3 different clones one CBD and two drug varieties we had 4 examples of each each of the 3 clones they were set up so the first set of three were 1 meter from the UVB lights, the next set was 3 meters, the next set was 6 meters, and the last set was a control with no UVB. They were all in 10 liter pots the same size, about 3 feet when started, with the same soil and watering. The closest to the lights got badly fried, the second set was lightly fried, the third set, not really harmed and the 4th set looked the same as controls. We ran the lights first in veg then in flowering. We used GC-FID to measure the cannabinoids and terpenes and weighed the total biomass, and flowers and stems and leaf fraction of the dry plants after harvest.
RCC and I did organoleptic analysis on the two drug varieties Skunk #1 and a Thai?, the no UVB plants were the best. The closest row to the lights were much less weight and resin, the second row was lightly harmed in a similar way. None of the UVB plants had any more cannabinoids or terpenes or more weight. I did try.
-SamS

very informative. Im wondering if you used any meter to measure the UVB you were getting at those distances. Is it possible that the plants were already receiving UVB through the greenhouse ?

Also could there have been an issue with hardening off the plants to uv exposure?