Graytail and Rascio:Discussion on strains and root exudates

Graytail;2462302 said:

Rascio;2459643 said:

I've been trying to absorb as much knowledge as I can these last months, and I'm at that exciting stage (well to me anyhow ) when small parts are starting to make sense and even fit together.

Anyhow, I was thinking about different HB grows and the ongoing discussion of adjustments and different responses of the method to different strains, and I might have an interesting idea.

The prevailing view seems to be that tropical strains bred outdoors in soil yield the best results from the little without further tuning. Strains developed indoors,with hydro in mind, may not respond as well or require some adjustments.

Then I was reading some stuff about rain forest soils, and how plants thrive in conditions with almost no nutrients in the soil. The article I was reading talked about how rain forest plants are much more dependent than temperate plants on, you guessed it, mycos and the sfw.

Then I remembered how graytail's Brazilian Amazonia (which I understand to be a new world native indica) really rocked in the high brix soil. It makes sense to me that plants bred under nutrient rich conditions would, over time, become less dependent on their fungal friends only if the change in dependency conveyed an advantage. The possibility that jumps out at me is that plants bred for hydro, or for sterile , nutrient rich soils, produce less exudate, and are selected because the energy saved on exudate, is available for flowers. This may even be the case for landrace strains bred outdoors in soils that are naturally high in nutrients.

My thinking is that maybe different responses to the kit isn't an indica/sativa thing, or even a hydro/soil thing. Maybe the strains that really shine with the kit are the ones that include material from strains that are used to terrible soil. These strains take full advantage of the nutrient gathering capabilities of the mycos.


With this slightly different (or maybe I'm kidding myself and this idea has been hashed out) idea, different breeding strategies come to mind. Maybe the most popular indicas used in modern breeding programs have a relatively weak relationship with their native mycos, compared with the tropical sativas with whom they are crossed. Such crosses could wind up with poor myco relations.

I wonder what other rainforest indicas are out there? Maybe that Brazilian indica would be great stock for indica growth patterns, instead of the more temperate Afghani strains. I'd love to see crosses of that indica with something like original haze, or the tropical sativas it came from.

More than likely you're miles ahead of me on this and I'm just catching up. Whatever it is it's fascinating.

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I was rereading my journal and came across this post, and I think it deserves more discussion. First, I think we're talking about the same mechanism, when I say bacteria and you say fungi. My understanding is that the myco fungi are strictly for the roots themselves. The fungus grows on the surface of fine roots and sends out its own tendrils, which makes the roots far more efficient with a whole bunch more surface area for absorbing nutrients. The roots exude various forms of sugars depending on the plants needs, and bacteria in the area use those sugars to dissolve minerals and provide them in a form the roots, and the fungi, can use. Different bacteria are stimulated by different sugars. I just did some research on root exudates and you're right, there are also fungi that use them.

I overlooked your point about using it for breeding science. Interesting. Also, as far as I can tell, you're also right about plants reducing their exudates when they get nutrients directly. They become "lazy" and adjust to getting nutrients without exudates. So, they'd be strains that didn't produce the full range or full strength of exudates, handicapped so to speak, unable to fully thrive on their own.

I'm not sure what my judgement is on landraces vs highly bred strains. I find myself more interested in the landraces and IBLs because I like a pure sativa buzz and it takes so little indica to ruin it for me. From my experience, purer strains aren't "better". For me, they're a sort of touchmark. I can know from whence this or that particular effect comes. I want to know what a true Thai buzz is like. I want a pure Oaxacan or Highland Columbian. I now know, for instance, what a Brazilian is like. I've grown several simple strains including an IBL, and they all had a certain something in common.

But the same thing should apply to the indicas. The Brasil Amazonia really interested me for that precise reason. I thought, hey, if I'm gonna grow an indica for my own tastes, why not try something a little more exotic and novel than an Afghan? Any of several Kushes would probably be more potent and easier to grow, but I'd like to know what a true Amazonian indica is like.

So ... breeding ... hmm ... If you cross a landrace indica with a highly bred production indica, the result should be a plant that does better in organic soil. But does it hamper the production part? ... I don't know. It's something to look into for sure.

My brief research on root exudates and their reaction to direct nutrients didn't yield a lot, but I did run across a couple good articles.


An excerpt from "Teaming With Microbes" ...

Pacific Horticulture Society | Plants Are in Control

A serious kickass scientific treatise on exudates, that I'm gonna have to read a few times before it sticks, I think ...

Maximizing root/rhizosphere efficiency to improve crop productivity and nutrient use efficiency in intensive agriculture of China

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