[PDX Dopesmoker]

Originally Posted by PDX Dopesmoker

Thanks Sam,
I was just wondering about that same topic a couple days ago with respect to how harvest state affects cannabinoid ratios. I can only assume that the results in this article might be particular to the type of lighting they use.
That 0.6% THCA in the leaves of the young plants makes me wonder how many seeds it would take the get high harvesting at 2 weeks post sprout. If you get about 0.1g dry weight per plant then you'd need about 2000 seeds to extract a gram of THC (if you could find a way to squeeze the THC out of those little leaves with reasonable efficiency). 26 harvests a year on one light using nothing but paper towels for growing media in a room no taller than a shoebox sounds almost economical until you factor the $100,000/harvest seed expense (assuming you only run top gear from quality breeders).

I was trying to get a better look at a mutated seedling and spotted those two week trichomes. I never knew they were there that early before or even thought about it until I read Evolution of the Cannabinoid and Terpene Content during the Growth of Cannabis sativa Plants from different Chemotypes and now here they are in the photo.
Makes me wonder how much of an indicator early trich coverage is of later production.
The mutation in this photo is the 2nd node is sprouting asymmetrically

[troutman]

Originally Posted by PDX Dopesmoker

I was trying to get a better look at a mutated seedling and spotted those two week trichomes. I never knew they were there that early before or even thought about it until I read Evolution of the Cannabinoid and Terpene Content during the Growth of Cannabis sativa Plants from different Chemotypes and now here they are in the photo.
Makes me wonder how much of an indicator early trich coverage is of later production.
The mutation in this photo is the 2nd node is sprouting asymmetrically

View Image

Could be lots of spider mite eggs.

Just joking.

[PDX Dopesmoker]

Originally Posted by troutman

Could be lots of spider mite eggs.

Just joking.

Imagine you think you've just put together some nice sift from two week old sprouts. It took $10,000 of seed to make that half gram and now you're gonna enjoy it for every penny's worth. You lay the sand on the screen and fire it up expecting the powder to melt, bubble and give you a fat, terpy hit - instead you get nothing and you look down in the bowl and see a spider egg omelet.

[zif]

Originally Posted by PDX Dopesmoker

you look down in the bowl and see a spider egg omelet.

I'm stuck 1/2 way between the satisfaction of nuking a generation of the borg and the disgust of inhaling the mushroom cloud!

All kidding aside, I think the 'young plants' in the article are rooting/just rooted clones. They suggest the high testing early on is a result of slow growth in relatively mature tissue. When the plants shift to rapid growth, they fall back down the THC per unit weight curve. Reminds me of (Mel Frank's - I think in the Insider's Guide?) suggestion to keep moms in perpetual veg under low light, just harvesting and smoking the growing tips. Obviously never caught on, but would save you the $k's of seeds!

[weedaholic721]

Affinity and Efficacy Studies of Tetrahydrocannabinolic Acid A at Cannabinoid Receptor Types One and Two

https://doi.org/10.1089/can.2016.0032

Abstract

Introduction:*Cannabis*biosynt hesizes Δ9-tetrahydrocannabinolic acid (THCA-A), which decarboxylates into Δ9-tetrahydrocannabinol (THC). There is growing interest in the therapeutic use of THCA-A, but its clinical application may be hampered by instability. THCA-A lacks cannabimimetic effects; we hypothesize that it has little binding affinity at cannabinoid receptor 1 (CB1).

Results:*The THCA-A reagent contained 2% THC. THCA-A displayed small but measurable binding at both hCB1*and hCB2, equating to approximate Ki*values of 3.1μM and 12.5μM, respectively. THC showed 62-fold greater affinity at hCB1*and 125-fold greater affinity at hCB2. In efficacy tests, THCA-A (10μM) slightly inhibited forskolin-stimulated cAMP at hCB1, suggestive of weak agonist activity, and no measurable efficacy at hCB2.

Discussion:*The presence of THC in our THCA-A certified standard agrees with decarboxylation kinetics (literature reviewed herein), which indicate contamination with THC is nearly unavoidable. THCA-A binding at 10μM approximated THC binding at 200nM. We therefore suspect some of our THCA-A binding curve was artifact—from its inevitable decarboxylation into THC—and the binding affinity of THCA-A is even weaker than our estimated values. We conclude that THCA-A has little affinity or efficacy at CB1or CB2.

---------


Very interesting study with helpful results. They have showed the even THC-A reference standards contain decarbed THC, thus proving the reason many crystalline THCA samples are coming in well over 100%. There are other great nuggets in there for anyone who exacts and isolates THCA. I found their hypothesis of THC-A-B being a main constituent in THCA crystalline that is currently being isolated fron Cannabis lacking any backup. It occurs in much too low amounts.

[Sam_Skunkman]

A few more I hope I did not post already?

https://online.liebertpub.com/doi/pdf.../can.2016.0040
Identification of Terpenoid Chemotypes Among High ()-trans-D9- Tetrahydrocannabinol-Producing Cannabis sativa L. Cultivars
Justin T. Fischedick



Pharmacogenetics of Cannabinoids
Szymon Hryhorowicz1• Michal Walczak • Oliwia Zakerska-Banaszak •
Ryszard Słomski • Marzena Skrzypczak-Zielinska
Eur J Drug Metab Pharmacokinet
DOI 10.1007/s13318-017-0416-z

[Sam_Skunkman]

And a classic that explains the problems maintaining Cannabis landraces in a closet.
1,000 males and 1,000 females are required to avoid serious gene loss, because Cannabis is an dioecious obligate outcrosser.
-SamS

Theor Appl Genet (1993) 86:673-678
Statistical genetic considerations for maintaining germ plasm collections
J. Crossa , C. M. Hernandez , P. Bretting , S. A. Eberhart , S. Taba

[Gr33nSanta]

Originally Posted by Sam_Skunkman

I hope for several intersex tests, one for intersex genes and one for stress related intersex expression, I assume they are not the same.
If intersex plants have intersex genes like male and female sex chromsome genes, they can be found, If stress is required to express intersex then the genes that allow intersex expression with stress can be found, I hope.
I am looking, as are others...
-SamS

any news on this?

I think all plants would have the genes for stress induce intersex because I have never heard of anyone not being able to reverse a female with CS.

[Sam_Skunkman]

I have found many female individuals that I could not reverse by stress, as well as a few that could not be reversed with STS. Why I do not know for sure.
No new news on tests for intersex be they stress induced or just intersex regardless of the environmental conditions. I am still hoping this will happen soon as the DNA tests for male seem to work fine but to assume all that are not male are female is a big problem when some of the "females" are intersexed and cause the same problems as a real male.

Who wants to have to examine all plants daily to assure the seeds started are true female and not just an intersexed female that DNA tests as a female but is not without problems.

Remember that when you DNA test males and then assume all the other plants are female that will include intersexed and monoecious, they test as Female even if they express more male flowers then female flowers.
-SamS

[Gr33nSanta]

Originally Posted by Sam_Skunkman

I have found many female individuals that I could not reverse by stress, as well as a few that could not be reversed with STS. Why I do not know for sure.
No new news on tests for intersex be they stress induced or just intersex regardless of the environmental conditions. I am still hoping this will happen soon as the DNA tests for male seem to work fine but to assume all that are not male are female is a big problem when some of the "females" are intersexed and cause the same problems as a real male.

Who wants to have to examine all plants daily to assure the seeds started are true female and not just an intersexed female that DNA tests as a female but is not without problems.

Remember that when you DNA test males and then assume all the other plants are female that will include intersexed and monoecious, they test as Female even if they express more male flowers the female flowers.
-SamS

interesting... well for me the testing to know the males does not matter, the way I grow I think testing for males is ludicrous, I can have all my seedlings in 1 gallon pots along the edge of my flower room and within 2-4 weeks have all of them ''showing sex''

However, what I am truly interested is that at least try to have females that are true females.

I am semi-against feminized seeds but if using CS allows me to spot a true female that might be a step in the right direction.