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Plant growth-promoting rhizobacteria

Tonygreen

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I think we are missing out and have been experimenting with legume inoculants. My main goal is to try to find an inoculate with the right strain of bacteria that will produce nitrogen fixing nodules.

again, here is the girls science project that got me thinking more...

http://www.pbs.org/newshour/rundown...-science-fair-bacteria-enhanced-plant-growth/

I have only tried twice with two different products but this last time I seen some deffo differences. This is my gg4 cut, you can see she stacked spears for me this time. Usually when I grow her she is the more traditional looking clumpier fat chunks we see. I haven't dont enough testing or controls in place to say for sure it was the inoculate. I didnt find any
nodules that I could see though but again didnt inspect well enough yet...




I talked a little bit about this before but wanted to post an updated thread and ask again if anyone else has experience's or thoughts to share?

Those teenage chicks already got nodules to form on wheat roots and proved huge increase in yields. Looking to duplicate in cannabis.
Are we missing out? Couldnt find much more than basic info on the girls shit but lo and behold I study was published here earlier this spring...

Isolation and characterization of plant growth-promoting rhizobacteria from wheat rhizosphere and their effect on plant growth promotion
Afshan Majeed,1 M. Kaleem Abbasi,corresponding author1,* Sohail Hameed,2 Asma Imran,2 and Nasir Rahim1

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4362341/


So whats up? I'm not suggesting we are growing wheat but if they got colony forming bacteria and nitrogen fixating nodes to form on wheat roots we got a fighting chance?

Anyway more testing to come in a more controlled environment than my tent.:tiphat::laughing:
 

Only Ornamental

Spiritually inspired agnostic mad scientist
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Are you using organic or mineral fertilisers and are you growing in soil or hydro? Especially in the case of inorganic soil-less, I don't see any reason why the plants should grow much bigger/faster regarding nitrogen fixation. Unless the bacteria excrete growth promoting chemicals... in which case you could as well add them in pure form. Might be tossing a coin which way you'll get better (= growth according to your likings) AND reproducible growth.
 

Tonygreen

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im looking specifically for colonies forming nodes on cannabis roots like they do on legumes and how the girls got to grow on wheat to potentially increase yield.

Water only soilmix...

Excrete growth promoting chemicals? Not sure you read the literature I posted to understand how this theory works?
 

Only Ornamental

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Ah, right! Problem is that legumes have a very unique set of N-fixing bacteria; since not too long ago, the believe was that legumes are the only plants having N-fixing bacteria. The second plant family are certain cereals which also seem to form nodes (I say seem because I'm not entirely sure that they A) form nodes similar to legumes cause I don't know everything and B) there are also N-fixing bacteria not forming nodes). On the other hand, several bacteria species are now know which don't form nodes but still fix nitrogen and/or which associate with plant other than legumes and cereals...

On poor soil or with non-fertilised high-perfomance crops, fixing nitrogen alone already increases yield though certain strains achieve plant growth promotion by other means as well. One of which is the production of indoleacetic acid and/or ethylene.
You might find THIS publication useful. Amongst other mechanisms, phosphate solubilisation, siderophore production (solubilisation/sequestration of iron and sometimes other metals), and secretion of antibiotics and other substances harmful to plant pathogens play possible roles in plant growth promoting effects. Many of these are independent of node formation and hence independent of plant species! Nodes are a special link allowing that very special symbiosis between N-fixing bacteria and legumes but are also the reason why these bacteria are useless with nearly any other plant. Hence, node-independent or non-node forming bacteria would be preferable.
 

Tonygreen

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Thanks for the link!

I am going on the theory that they are not as useless for every other plant as thought. Im sure people were shocked to find the girls got nodes on wheat as well, which they did. So I am going through testing inoculants to see if it can be duplicated in cannabis.

Might be a long shot but who thought they would grow on wheat?
 

Only Ornamental

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Oh yes, I suppose they were VERY shocked! A bit like when they discovered that the earth is round and not flat... but imagine it weren't Columbus or some other dude but a bunch of snotty-nosed girlies who figured that out :) .
I admit, when first reading the article I thought about some yellow press nonsense or April fools. Had to find a more science-based and more reliable source to confirm it. LoL
 

Tonygreen

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Its hard to find but there is more articles with more in depth info on the girls out there.

Here is the page for their project...
https://www.googlesciencefair.com/p...b3d6fd88d47a6eb3c927805255d7f4c7c439fddd9c256

I just have a gut feeling the right strain will also form nodules on cannabis and it could be a door that is not been opened yet...

"...increased barley yields by 74%." more yield sounds good so worth testing out. :)

Maybe we'll shock some people.

You can deffo see some possible affects on the above gg4...

And ah I found the strain they used...

We used one acidic strain (r.leguminosarum) and one basic strain (r.japonicum).

Conclusions

In all test groups seeds treated with r.japonicum and r.leguminosarum germinated faster by approx 50% (p<0.001).
Both bacterial strands increased crop yield by an average of 30% with some results exceeding 70% (p<0.001).
This will be of benefit to agriculture and the developing world as it has the potential to increase crop yields and assist food production in challenging climates.
We can conclude from these results that our hypotheses: ‘If we inoculate cereal crop seeds with Diazotroph bacteria, their germination speed will be increased,’ and ‘If we inoculate cereal crop seeds with Diazotroph bacteria at an early stage, the plant growth will be positively affected,’ have been successfully statistically proven at a 95% confidence level. We are confident in the statistical validity of our results due to our large sample sizes and experimental controls.


Little rugrats popped 10k seeds!
 

Avenger

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Where do they say that nodes were formed/found on the cereal crop roots after inoculation with Rhizobium bacteria?
 

Tonygreen

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Another study showing benefits of rhizobacteria on wheat

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4362341/

Inoculation with Pseudomonas fluorescens showed a significant increase in root weight 19–43%, number of tillers per plant 10–21%, grain yield 15–43%, and straw yield 22–39% of wheat compared to un-inoculated plants



The beneficial effect of Rhizobium and Bradyrhizobium
on legumes in terms of biological nitrogen-
fixation is well known (Werner, 1992). However,
additional reports also indicate that these symbiotic
bacteria have the potential to be used as PGPR with
non-legumes (see below).


http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.476.7505&rep=rep1&type=pdf
 

Only Ornamental

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Here is a very interesting paper showing many ways rhizobacteria can help promote growth directly and indirectly.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4522733/

More than nitrogen fixation...,
Nice find! Thanks for sharing!
Though, several of the described effects are also true for freely living bacteria (e.g. Serratia or Pseudomonas). I like the latter better as they are easier to cultivate (Petri dish) and readily form spores which makes handling, storage, and soil/seeds inoculation way easier. Besides that, many of these are fluorescent and mobile which makes them very funny to cultivate (though they often stink terribly and you ought to be a real nerd to think them very funny to cultivate). Also, the whole garden will profit from these microbes and not just those which form nodes.

Maybe you could buy some inoculates and try them out or search yourself for nodules on different plant roots
A nodule that is actively fixing nitrogen will be pink to reddish when cut open, rather than tan (ineffective) or green (dying).
(by Colorado State University)
and use them to inoculate either seeds (sow quickly) or better young seedlings.

Keep the differently inoculated seedlings well separated from each other and from the untreated control in order to avoid cross-contamination and more so contamination with possible plant pathogens (you may not know for sure if the nodules really contain benevolent rhizobacteria but are in fact tumours or worse are rank growth caused by viruses or nematodes).

Good luck BTW!!
 

Only Ornamental

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PS Maybe you have observed that those studies were often done in poor eastern countries (e.g. Middle East, India) where access to fertilisers is limited and the gain from bacteria as natural 'fertilisers' and 'PGR' is considerably higher compared to plants grown under near-optimal conditions (which is likely the case with your plants :) ).
 

Tonygreen

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The girtls theorize ""The great thing about our theory is [that] any crop that contains a flavonoid can trigger bacteria. It'll work the same," Judge said."

IDK if you caught it in the op but i have been trying innoculants. One i didnt notice a difference and one my glue i showed in those pics stacked up like crazy when it usually is more clumpy buds for me.

Perhaps the germination affects could help on older seeds as well.

Very interesting possibilities.
 

Avenger

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I read most of the info, I believe. But I did not read anything in the articles on the girls science project, where they found nodules on the wheat plant roots. Am I missing it?

can you show me? :thank you:
 

Tonygreen

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could have easily mis-spoke, i often do. Coulda swore one of the articles mentioned it, maybe not.

Im reading other studies that are saying the genetic framework possibly needs to be in place in the plant for colony forming nodules to appear... not sure learning as i go.

Found a study that references cereals having the framework in place but the genes are possibly not active.
I'll throw up some more papers im reading when i get home.

http://link.springer.com/article/10.1007/BF02187430#page-1

http://onlinelibrary.wiley.com/doi/10.1046/j.1469-8137.1999.00352.x/abstract

Interesting stuff about induced para nodules and subsequent nitrogenase activity...

http://www.ncbi.nlm.nih.gov/pubmed/1299838

Finding quite a few interesting studies as i go...
Quite a few use 2, 4 – dichlorophenoxyacetic acid to induce nodulation?
 

importedtermite

New member
I just recently had to do some literature research on the rhizobia-legume symbiosis. Root nodules are lateral root organs and as such are formed postembryogenically. Many plants have a symbiosis with soil bacteria but not many have an endosymbiosis with nitrogen-fixing bacteria. The most common example is of the legume species that include peas, beans, peanuts, lentils, and others. An example of bacterial endosymbiosis found outside of legume species is the actinomycete Frankia and its relationship with plants such as Alnus glutinosa (alder tree) and Casuarina glauca. Those plants along with legumes belong to the same Eurosid 1 clade, in which nodulation emerged several times independently. Even though they don’t share a common origin for nodule formation there is still a lot of overlap in the genes controlling actinorhizal and legume nodules. Here’s a nice figure showing the differences in legume and actinorhizal nodule formation:

science


Now there’s a multitude of factors that are required for nodule formation but some of the more important things needing to occur are:
• Flavonoids released by the plant
• Bacteria sensing the flavonoids triggering nodD activation and host-specific lipochito-oligosaccharide (Nod Factors) secretion
• Membrane-localized LysM receptor kinases on the root epidermal cells that can distinguish between different Nod Factors
• Root tip curling forming a niche for the rhizobia microcolony
• Hydrolysis of epidermal cell wall and formation of an infection thread
• Cell differentiation and mitosis of root cells to form a nodule primordium and eventually organelle-like symbiosomes
• Calcium-mediated activation of a central regulator called calcium-calmodulin-kinase (CCaMK) and several other downstream genes
These are just a few of the interactions which allow for nodule formation, it’s a much more complex reaction than that. This is a figure of the pathways involved in nodule development and infection:

science


A few things to consider when attempting to form nodules on a new species would be the Nod Factors secreted from the bacteria and the LysM receptors on the epidermal cells of the root. These are host-specific and are different for each symbiosis. I am not familiar with the receptors on the cannabis root system but I’m sure there could be a way to modify the plant to produce those specific receptors.
Another thing that should be noted is the trouble of getting the plant to not initiate an immune response to the infection. Legumes contain genes called Nodulins that are involved with nodule formation. There are “early” and “late” genes that are expressed at different times. The early genes are involved with bacteria recognition and nodule formation. On the other hand, the late genes code for nodule function and nitrogen-fixation. Leghemoglobin is also needed for nodules to be made. Similar to hemoglobin in our blood, this molecule binds to oxygen and localizes it so that it doesn’t interfere with the nitrogenase enzyme complex. Auxin, cytokinin, and ethylene also seem to play an important role in nodule formation as well. I can go further into those in another post if you’d like or if you want to read some of my sources you can find them here:

http://www.sciencedirect.com/science/article/pii/S1931312811002903
http://www.ncbi.nlm.nih.gov/pubmed/17746918
 
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