[dizzlekush]

I'm wondering what is most likely the best legal plant that could be used as a 'model organism' for horticultural experiments intended for applying the information achieved from results on cannabis cultivation? If one wanted to do testing on different types of substrate, EC levels, nutritional demands, timing/concentration of Plant Growth Regulator/phytohormone applications, temperature crop steering, etc. etc. with the intention of using information gleamed from experimentation for cannabis cultivation, what would be the best legal plant to use for testing?

There are multiple benefits of having a separate test plant from cannabis. If growing cannabis illegally, you can refine your growing skills without breaking the law to get maximum yields when you do decide to step outside the law. If living in a state with medical marijuana laws that restrict your grow by plant count and/or square footage, your experiments would no longer be putting you in illegal plant count/area and/or wouldn't be risking any ill effects on your limited harvest. Also having a plant that's harvest isn't of value could be beneficial to some experiments. Examples of this would be quantifying phytotoxicity levels of certain chemicals (e.g. methanol and non traditional [concentrations of] non ionic surfactants), or conducting an experiment on leaching/flushing using common hops where some plants are fed until day of harvest for maximum dry weight, and then other groups are treated with different types/days of leaching, then the cones are harvested dried, cured then burned. Watching quality of burn, smelling the aroma and examining impurities in ash could be used to quantify quality of 'flush' and could be done without losing a profitable harvest.

So back to the original question: Which plant is the best Model Organism r.e. experimentation for cannabis cultivation?

Cannabis is an annual, dioecious C3 dicot, and one of the few plants that are such. All other plants in the Cannabaceae family are perennials, with Cannabis being the only annual, and one of the very few dioecious annuals to exist. Cannabis is hypothesized to have originally been a short lived perennial in the past (like hops currently is) and changed to an annual when global annual weather became less temperate. Ive seen a male cannabis 'tree' that was 4 years old that was kept indoors under 18/6 for 2 years and then moved outside after the breeder had gotten full use of it. It still produced pollen sacks but wouldn't fully mature to pollination. While i have no argument that cannabis should be labeled as an annual, it's my personal opinion the distinction between annual and perennial is the least important distinction when trying to find model organism for cannabis, and that using an perennial as a model organism for cannabis would be more acceptable than using a C4 plant, a monocot, or a non-dioecious plant. If anyone disagrees with this opinion, please feel free to discuss it.

It turns out that if we want a model organism that is also an annual, dioecious, C3 dicot, our options are greatly limited. Here were the choices i found most relevant to our discussion.

Hops (Humulus lupulus) (Perennial)
Images: https://www.google.com/search?q=Humu...OYWJiAK1vLzhCA
Wiki: https://en.wikipedia.org/wiki/Humulus_lupulus
The only perennial in the choices thus far, the null hypothesis victor and the plant to beat. If looking at scientific classification, all plants in the Cannabis genus under federal law are legally "Cannabis sativa" and therefore illegal. So the next highest classification gives us the family Cannabaceae, which also houses the Humulus genus and several species of tree recently re-classified through genetic mapping such as Hackleberry trees, the Trema genus of trees and several other genera of trees. Of these options, hops (Humulus lupulus) is commonly accepted as the closest relative to cannabis, and female hop flowers (cones) are physiologically the most accurate analogue in the known plant kingdom for female cannabis flowers (buds). https://www.theplantlist.org/browse/A/Cannabaceae/
Hops are [likely to be] ~90% genetically identical to marijuana with even a marginally larger amount of base pairs.

For the present study five different cultivars of Cannabis, origiating from France (accession number CJBN 716/85), Afghanistan (CPRO-dlo 883271), Nepal (CPRO-dlo 891191), The Netherlands (S S 241) and Italy (OBN 0148-F), were used. One sample of Humulus lupulus L. coming from Italy (OBN 2801-F) was also used. H. lupulus belongs to the only other genus of family Cannabaceae. For each Cannabis and Humulus cultivars, six individuals were tested....
...The raw PCR fragment obtained for all Cannabis samples and Humulus had a length of approximately 360 base pairs (bp) (Fig. 1).
The DNA from all five hemp samples had an ITS1 225 bp long with a GC content of 58.2%. The hops ITS1 was 226 bp long with a GC content of 56.6%. The five Cannabis sequences obtained are identical.
However, the hops sequence was 90% identical to the sequence of the hemp samples
https://www.google.com/url?sa=t&rct=j...KynxJIVzVUOmMw (PDF)

Spinach (Spinacia oleracea)
Images: https://www.google.com/search?q=Sile...iw=840&bih=449
Wiki: https://en.wikipedia.org/wiki/Spinach...EKSriQKW7v3JCA
A small plant, not growing much more than a foot tall. Probably the most commonly grown out of all of the annual, dioecious C3 dicots. The plant is commonly harvested for its leaves, while we're looking for increased floral production, 'essential oil', and specific phytochemicals.

Annual Mercury(Mercurialis annua)
Images: https://www.google.com/search?um=1&h...iw=840&bih=449
Wiki: https://en.wikipedia.org/wiki/Mercurialis_annua
The only annual of the Mercuries, hence the name. Most commonly found dioecious (the form we want, female specifically) but can occasionally be found monoeocious or hermaphroditic. Roughly the same size as spinach.

It is evident that the floral dichotomy shown by dioecious plant species results from modification during development of a perfect flower by suppression of one or other organ sets. Comparison of male and female flowers from the various dioecious species reveals that the timing during flower development of the suppression event is enormously variable between species.
In a number of dioecious species, including Mercurialis annua (Durand and Durand, 1991), Cannabis sativa (Mohan Ram and Nath, 1964), Spinacia oleracea (Sherry et al., 1993), and Humulus species (Shephard, 1999), the divergence of the male and female developmental pathways occurs extremely early in floral development and the inappropriate organs are not initiated; in all these species the male flowers resemble perfect flowers whilst the female flowers are strikingly different. In most species, however, both sets of sex organs are initiated and the inappropriate set of organs develops to some extent before abortion.
https://www.google.com/url?sa=t&rct=j...r9EEuSrT6bZ_YQ (PDF)

Ill add more info and species as i do more research. With our current understanding, the null hypothesis will be that Hops (Humulus lupulus) is the best model organism for Cannabis-related experimentation, due to genetic & physiological relations between the two. Now I'm wondering what others think the best legal 'Model Organism' for cannabis experimentation might be. Your thoughts, reasoning, and literature to back up your opinions are always appreciated.

[dizzlekush]

Arabidopsis thaliana is the most commonly used model organism for such types of experimentation but would most likely be a very inefficient model organism for cannabis study due to lack of [genetic] similarities

...Medicinal Genomics founder Kevin McKernan says he estimates the size of the C. sativa genome to be about 400 million bases – roughly three times the genome of that other weed, the model plant Arabidopsis thaliana."
https://blogs.nature.com/news/2011/08...TWT_NatureNews

Arabidopsis thaliana has ~125 million base pairs to marijuana's estimated 400 million, which is just one exmple of one of the many reasons why we need to find a better model organism for testing.

[MrFista]

If it were me I'd save myself a lot of time and go straight to the science databases for information on growing hemp - surely the closest relative.

There are farms of it in Sth Island NZ, and surely in many other places over the world. The fact we know it is used for building, textiles, food, fuel etc etc implies a solid body of knowledge is out there somewhere's already. Find it!

[dizzlekush]

Originally Posted by MrFista

If it were me I'd save myself a lot of time and go straight to the science databases for information on growing hemp - surely the closest relative.

There are farms of it in Sth Island NZ, and surely in many other places over the world. The fact we know it is used for building, textiles, food, fuel etc etc implies a solid body of knowledge is out there somewhere's already. Find it!

Thanks for bringing up a good point. However collecting research on ALL forms of cannabis (fiber hemp included) is something i have already been doing for some time now.

The point behind this particular thread is to find a legal substitute plant that one could do their own experimentation on instead of on precious, illicit cannabis. Experimentation that hasn't already been done, published, publicly shared or whatnot.

Personally i think hops is the obvious choice but im no botanist, that's why i made the thread.

[Sheriff Bart]

well theres a few things to look at
studying molecular and cellular mechanisms vs. whole plant morphology and growth
when looking at molecular (including genetics) and cellular mechanisms, the more simpler, the easier it is to work with, becuase you only want to investigate 1 thing at a time, and so with less genes overall, the easier it is to manipulate the organism and achieve the mutants you want, etc. etc. less things to cause interference, etc. etc.

when you move to something like floral production, and whole plant growth, you are pretty much goin to have to grow the plant you are interested in learning about because the subtleties in how plants react overall compared to when studying molecule and cellular aspects are going to build on each other and data will lose relevancy quickly

even with hops, which are quite similar genetically, the growth of hops is rather different and distinct givin that it is a large vine and controlled cultivation of it is goin to be difficult, and then you run into another problem, the high degree of hybridization, polymorphism and selection that has occured in the cannabis, and humulus, and other plant, species. that is, cannabis has been extensively bred and has had natural and human selection applied to a level that comparing one type to another is like apples to oranges, they are the same plant at the genus and species level, but their growth habits are so distinct already. sativa subspecies obviuously arent going to produce as much floral mass as indica subspecies, etc. etc. and even diff cultivars will have large variability in nutrient uptake ability, pH responsiveness, stress related responses, the list goes on

and im not sayin that you cant draw similarities, you just have to understand that between two diff plants the total amount of things affected by say phytochrome and the degree to which they are effected is going to be vastly difference. even minor changes in repsonse to various hormone levels will result in larger changes on the whole plant growth scale. these are things you just have to keep in mind, imo.

[mad librettist]

if you are thinking of going organic, another consideration is which plants will conveniently leave a container of soil in great condition for growing cannabis.

so far, stellaria (chickweed) seems to be the most effective. it loves sun and if you get it to flower your veg room is in good shape. you can just keep cutting it back, and leaving it in the pot, and the soil grows.

[Crusader Rabbit]

Urtica dioica, the European Stinging Nettle has a dioecious subspecies. The species is naturalized all over the world.

Nettles are perennial and grow each year from rhizomes. They're wind pollinated and have a similar growth form and habit to Cannabis.

edit;



Of course though it is stinging nettle with all the problems that entails.

"The leaves and stems are very hairy with both non-stinging and stinging hairs (trichomes), whose tips come off when touched, transforming the hair into a needle that will inject a mixture of chemical compounds that cause a painful sting or a sensation of "pins and needles."

But those stinging hairs are homologous to the resin bearing trichomes on Cannabis, which could open some experimental possibilities.

[MrFista]

This is a hard question to answer Dizzlekush. What model plant for cannabis? I think the idea has merit, I'm just hard pressed to think of what plant might best serve your purposes.

Perhaps you need an array of cannabaceae first. Trial a bunch with the same conditions as some actual cannabis to determine which plant behaves closest to cannabis (phenotypic expression to environmental cues).

You follow? One round (set up a few conditions) could determine your model, then you can experiment away without fear using a model you've already tested the usefulness of.

[Oregonism]

Didn't even think about the Urtica, but it is a perennial dioecious, so again gene structure comes into play. At some point the two plants have been taxonomically intertwined, but not in current taxonomic structure.
The cannabaceae family would yield some interesting candidates, hops [Humulus], hackberry [Celtis].

What about reading thru some H.Y. Mohan Ram. He dealt mainly with embryology, but he covered a lot of work and his philosophy was to be well rounded in science in general not just your specialty. From that conclusion maybe he identified a candidate that shared embryonic morphology, just throwing that out there as another starting point, discuss.

[plastochron]

first off, i have to say that this is an excellent question and that your logic is pretty spot on. i have done a great deal of research on this issue. as far as the importance of different traits you mentioned, i think that the most important are c3 photosynthesis, herbaceous, and short day photoperiod are the most important. also you want to make sure to find a model plant that produces secondary metabolites that are derived from the same pathways as cannabinoids and terpenoids (DOXP, MEP, MVA pathways). furthermore, it is preferable that these chemicals are secreted and accumulated in trichomes on inflorescence. it is also important to keep in mind what you are trying to study. of course hops is genetically the most closely related, but their growth forms are so dissimilar that i would not recommend using hops. plants in the mint family are also tempting to use because they accumulate lots of terpenes and essential oil. unfortunately most of these plants are either perennial, long day photoperiodic, or both. i thought about using Salvia officianalis for a study, but the logistics of uniformly harvesting the flowers seemed to like a burden. Another plant i considered was Artemisia annua. the main reason i decided against using Artemisia (as well as some other different plants) is that its response to certain hormones was opposite of cannabis's response to those hormones. all factors considered, at the end of the day i decided to use Chrysanthemum morifolium because it is: herbaceous (and can be grown as an annual), c3 photosynthesis, short day photoperiod, accumulates terpenes (in floral trichomes from MVA and MEP pathways), it has a similar response to GA and GA-inhibitor application as cannabis, and lastly (but certainly not leastly) cuttings are cheap and easily available and harvesting and quantifying the part of the plant we are interested in (the flower...) is easy. honestly i wish i had found another plant that would be a better model and be easily accessible, but for right now cut mums will have to do.