Mycorrhizae, bacteria, and modern bonsai substrate

wireme

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I think you're right that modern substrates do support microbial/fungal life, but I also came across this quote from a scientific article, which seems to suggest that inorganic, soilless substrates do not support microbial/fungal life to the same degree as regular soil. If you have any sources on this subject, please send them my way--I find the subject fascinating.

"Microorganism population differ significantly between soilless culture systems and the indigenous microorganism type in each soilless system is unique. Organic (coconut-fiber) soilless substrate system had the highest amount of fungi and Fusarium spp., whereas the inorganic substrate (rockwool) contained the highest amount of fluorescent pseudomonads. In addition, aerobic bacteria could be dominant over fungi in inorganic (rockwool) substrate. Soilless substrates lack the diverse biological and microbial communities found in conventional agriculture soil. For soilless culture, a few studies have assessed the usefulness of inoculating plant with microorganisms at early stages but none of them showed a significant positive impact on cultivated crop."



Heya. These days by the time I’m done work and chores I’ve been to done to try to think and reply. Very interesting thread though, I hope to read it soon and maybe reply more.
 

Harunobu

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So I kind of should know this, and I can find out by bare-rooting this cutting, but I rather let them be and be healthy.

I am rooting these cuttings of the azalea 'Matsunami', and I am rooting them inside, under a soda bottle dome, using a growth light and a heat map. And I lifted the bottle today and some of the soil came up. They only have been in there for 6 weeks, which should be enough for them to grow some roots.

1598545385683.png

But you can see in this picture there are quite a bunch of thin white filaments. I feel they cannot be roots. They grow so lateral, too near the soil line, and too long for them to be the roots of the cuttings. The medium is potting mix, kanuma, and perlite. Can some root fungi expert 100% confirm? If so, then with just garden soil and some substrate, after just 6 weeks, without any contact with azalea roots, you can get a whole bunch of mycorrhiza. I also have cuttings that are in peat and kanuma, so no fertilizer (the picture has potting mix soil, which has fertilizer). I could maybe observe if these are similar or different.

Now, temperatures have been high inside (22-28 C), so things grow quick. But this would show how easy it is to get a ton of mycorrhiza supporting an azalea cutting without any special treatments or inoculations.
 

Harunobu

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Well, 5 µm is super-tiny. That's a little larger than a bacterial cell. Are you sure about that and do you have a citation? So those filaments are stings of single cells?

I couldn't get a better picture as a closeup would no longer be in focus on my phone. DSD's second picture is how azalea roots usually look. They are more yellowish, not bright white. I kinda want to check now on another pot of cuttings.
 

Harunobu

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So I had to check so I dug one up. And yes, they are roots.

1598554332420.png

I washed away some of the soil, and the wetness made the roots stick together. But they are roots. Just a lot of very fine transparent ones. I guess I am just a champ at rooting cuttings. Never checked the root system of a 6 week cutting before.

So I guess when you can see mycorrhiza, you are seeing mats of the filaments? And the filament is way smaller than a plant root cell?
 
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Well, 5 µm is super-tiny. That's a little larger than a bacterial cell. Are you sure about that and do you have a citation? So those filaments are stings of single cells?
I was a little mistaking 5 µm is in the lower boundary. It is between 5 and 10 µm which doesn't change the fact that it is "super-tiny" as you wrote.

So I guess when you can see mycorrhiza, you are seeing mats of the filaments? And the filament is way smaller than a plant root cell?
Yes and yes. This smaller diameter explain in part why mycorrhiza is a better way for trees to exploit the soil rather than growing their own cells: to explore the same volume of substrate, mycelium needs to build less organic structures and is thus less costly.
 
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Deep Sea Diver

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I’m doing first repost to 2 1/2” pots anywhere between 45-60 days, so you’re on the verge of pushing really fast.
btw: If you are out in the PacNW you have to watch out for all those spitzenkörpers pushing the hyphae all over your garden!
Cheers
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Deep Sea Diver

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I’m doing first repost to 2 1/2” pots anywhere between 45-60 days, so you’re on the verge of pushing really fast.
btw: If you are out in the PacNW you have to watch out for all those spitzenkörpers pushing the hyphae all over your garden!
Cheers
DSD sends
First repotting plus 3.5 weeks.
Best DSD sends
7CC6DD7B-C4DA-4340-A8FB-1875766A7EA9.jpeg
 
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