Effective microbes (EM) and paphs

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paphioboy

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This was brought up in the vermicompost thread and I think it deserves a thread of its own, seeing that many people are interested. The use of effective microorganisms (EM) to help orchid growth is interesting because I think what you add is more important than how much. Mainly because most of the epiphytic species do not have a symbiotic relationship with many of the soil-dwelling fungi. Most epiphyte species, in fact, are symbiotic with certain isolates of potentially pathogenic fungi, including Rhizoctonia, Fusarium and Pythium. There are many papers on this, you can Google 'Orchid mycorrhiza'. In contrast, the more common mycorrhizas or beneficial fungi for non-orchid temperate terrestrial plants belong to the Glomerales and Gigasporaceae. Many EM products tend to contain these fungi or other supposedly biocontrol agent species that help protect the plant, like Trichoderma (a known parasite on other fungi).

For the slipper alliance, it is known that most of the naturally-associated fungi belong to the Tulasnella/Epulorhiza and Ceratobasidium group, some of which are unculturable. Epulorhiza is strongly-associated with Paphs. If you add in a different fungus, the additive could in fact be competing with the naturally occurring fungi, and could be detrimental to plant health. Several people here who have used EM products say they get detrimental effects like leaf-spotting, which could be due to use of an incompatible microbe. Interesting to note, one of the papers below (Shefferson 2007) states that some widely-occurring Cypripedium species (calceolus) have a more specific relationship with the symbiotic fungi, whereas other cyp species which have a more narrow habitat (formosanum) are more generalist in their preference of fungal partners.

Some references for those interested in orchid mycorrhiza:
http://www.academia.edu/458826/Studi...nachal_Pradesh

Fungus in Paph thaianum roots:
http://www.scirp.org/journal/PaperDo...?paperID=22189

Fungus in Parvisepalum (no full text, but you get the gist in the abstract):
http://english.kib.cas.cn/rh/rp/2011...321_66672.html

Evolution of fungi in Cypripedium:
http://nature.berkeley.edu/brunslab/...ferson2007.pdf
 

naoki

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I agree that evolution of orchid mycorhizae is very interesting because orchids can control some pathogenic fungi as you mentioned. BTW, I can't access the bottom 3 links (and I'd like to read them, I have the bottom one).

My understanding is that the potential benefits of EM for orchids (I don't know much about this topic, I admit) could be something other than the direct benefit via symbiotic mycorrhizae. For example, could they be beneficial in dealing with the excreted products from roots? Yen et al (2011; HortScience 46:1022-1026) has shown that the acidification of sphagnum moss is likely due to chemicals excretion from roots of Phalaenopsis than from break down of media. I wonder if EM can counteract with this effect, and keep the rhizosphere more stable?

Also, in addition to mycorrhizae, there are lots of endophytic and epiphytic root microbes (fungi and bacteria) on both terrestrial and epiphytic orchids, whose role has been overshadowed by mycorrhizae studies. It sounds like we don't know well about the function of those (some are pathogenic, and others may not interact, but some of them could have benefits). While some of them could be beneficial to orchids, but it seems that EM for soil is probably quite different from something good for epiphytes. As a side note, mutualistic mycorrhizae (or microbes) could be a bit misleading concept, because the relationship between hosts and fungi are not always mutually beneficial depending on the environment. For example, when pot-grown plants have enough access to nutrients and water, plants don't want to waste precious sugar for fungi, right?

With regard to Cyps, are you talking about Shefferson et al (2007: Evolution 61 (6): 1380-1390)? It's an interesting paper (my friend is one of the authors), but I thought that the specificity of C. formosanum wasn't particularly wide (Fig. 1). C. acaule and C. californium appear to associate with much wider range of fungi than the others included in the study. Also, one thing to note is that the fungal range found in the nature may not represent the orchids' CAPACITY to develop symbiotic association with wide range of fungi, right? We do think that plants can have some control of whom they develop association. In certain environment, a particular type of fungi is beneficial, so you may see only a few fungal species associated. But in different environments, orchids might be able to develop association with other fungi (the best fungus is not available or a different type of fugue is better at different condition etc). Is this way of thinking bogus?
 

PaphMadMan

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The use of effective microorganisms (EM) to help orchid growth is interesting because I think what you add is more important than how much. Mainly because most of the epiphytic species do not have a symbiotic relationship with many of the soil-dwelling fungi. Most epiphyte species, in fact, are symbiotic with certain isolates of potentially pathogenic fungi, including Rhizoctonia, Fusarium and Pythium.
I doubt it is just a matter of formal symbiotic relationships. Every healthy natural environment has a balance of microorgansims that stabilizes over time. That stable mixed population tends to prevent "foreign" microorganisms from moving in and taking over catastrophically. They also tend to moderate fertility - quickly taking up nutrients when they are adundant and slowly releasing them over time as cells die.
 

naoki

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Thanks, LPM. I've seen that one before, but I wasn't sure if it is the same one which Paphioboy was talking about because the paper LPM links is with Paphiopedilum thailandense (=P. callosum, not P. thaianum). It is kind of cool that we are discovering so many fungi which are not similar to any known species.
 

myxodex

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I doubt it is just a matter of formal symbiotic relationships. Every healthy natural environment has a balance of microorgansims that stabilizes over time. That stable mixed population tends to prevent "foreign" microorganisms from moving in and taking over catastrophically. They also tend to moderate fertility - quickly taking up nutrients when they are adundant and slowly releasing them over time as cells die.
This is what I'm wondering about ,... the basic overview. The micro-organism (mo) component in our pots is like a "black box" about which we know very little, but I'm sure that it effects culture, as you point out nutrient buffering is most likely an important factor. With an inorganic subtrate, SH-type culture maybe less so. I also wonder about the "batch culture effect", i.e. what changes in populations during the periods between repotting. In fresh medium there will be some more easily degraded polysaccharides to serve as carbon source than later on, are there changes in mo species populations with time. Do we reach a death phase, where due to limitation in carbon source and "salting up" perhaps, where nutrient release from the death and lysis of "the good guys", substrate compression and rise of anoxic regions, promotes the rise of the "badies" ? I think most of us try to repot before this crisis phase happens, if indeed it does.

The question is how does our fertilisation routine effect the micros, how much and in what balance. Does an all nitrate N-supply slow everything down and extend pot-life? I've just made up my own medium with amino acid chelated trace elements (EDTA free) and the aa's make up about 19% of total N ... am I mad ?

As for orchid mycorrhiza, there is a (2007) review here; http://core.kmi.open.ac.uk/download/pdf/11036795.pdf , which has an interesting section on seed germination with mycorrhiza and it's potential for orchid conservation. It would be great if we could just order a vial of mycorrhiza spores and use them to grow our seed without the need for sterile culture technique, ... but it is also possible that these fungi might just be a bit more touchy about growth conditions than our favourite orchids.
 

paphioboy

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As a side note, mutualistic mycorrhizae (or microbes) could be a bit misleading concept, because the relationship between hosts and fungi are not always mutually beneficial depending on the environment. For example, when pot-grown plants have enough access to nutrients and water, plants don't want to waste precious sugar for fungi, right?

With regard to Cyps, are you talking about Shefferson et al (2007: Evolution 61 (6): 1380-1390)? It's an interesting paper (my friend is one of the authors), but I thought that the specificity of C. formosanum wasn't particularly wide (Fig. 1). C. acaule and C. californium appear to associate with much wider range of fungi than the others included in the study. Also, one thing to note is that the fungal range found in the nature may not represent the orchids' CAPACITY to develop symbiotic association with wide range of fungi, right? We do think that plants can have some control of whom they develop association. In certain environment, a particular type of fungi is beneficial, so you may see only a few fungal species associated. But in different environments, orchids might be able to develop association with other fungi (the best fungus is not available or a different type of fugue is better at different condition etc). Is this way of thinking bogus?
Thanks for your input. Great to see others are interested in discussing this topic. It is true that the relationship between plants and fungi are not always beneficial, but in the context of applying EM products to plants, I suppose the general assumption is that the microbes should be beneficial, but perhaps not when used with a wrong host. That was what I was trying to convey, because the microbes in the products are not the ones naturally associated with the roots of slippers.

Yes, it is the Shefferson paper. My bad, I meant to say calceolus compared to californicum and macranthon var. reyburnense (discussion part), not formosanum. I totally agree with your point regarding fungal capacity, because it also depends on the natural distribution of the host fungus. But if I'm not mistaken, another study in Dend aphyllum/pierardii showed better germination of seeds when the associated fungus is present. PM me your email address, I can send you the other papers..
 

paphioboy

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I doubt it is just a matter of formal symbiotic relationships. Every healthy natural environment has a balance of microorgansims that stabilizes over time. That stable mixed population tends to prevent "foreign" microorganisms from moving in and taking over catastrophically. They also tend to moderate fertility - quickly taking up nutrients when they are adundant and slowly releasing them over time as cells die.
I used the term 'symbiotic' a bit loosely, but yes you are right. It is better to say 'associated fungi', as sometimes the fungus may benefit from the plant and vice versa, as the external environment dictates.
 

paphioboy

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This is what I'm wondering about ,... the basic overview. The micro-organism (mo) component in our pots is like a "black box" about which we know very little, but I'm sure that it effects culture, as you point out nutrient buffering is most likely an important factor. With an inorganic subtrate, SH-type culture maybe less so. I also wonder about the "batch culture effect", i.e. what changes in populations during the periods between repotting. In fresh medium there will be some more easily degraded polysaccharides to serve as carbon source than later on, are there changes in mo species populations with time. Do we reach a death phase, where due to limitation in carbon source and "salting up" perhaps, where nutrient release from the death and lysis of "the good guys", substrate compression and rise of anoxic regions, promotes the rise of the "badies" ? I think most of us try to repot before this crisis phase happens, if indeed it does.

The question is how does our fertilisation routine effect the micros, how much and in what balance. Does an all nitrate N-supply slow everything down and extend pot-life? I've just made up my own medium with amino acid chelated trace elements (EDTA free) and the aa's make up about 19% of total N ... am I mad ?

As for orchid mycorrhiza, there is a (2007) review here; http://core.kmi.open.ac.uk/download/pdf/11036795.pdf , which has an interesting section on seed germination with mycorrhiza and it's potential for orchid conservation. It would be great if we could just order a vial of mycorrhiza spores and use them to grow our seed without the need for sterile culture technique, ... but it is also possible that these fungi might just be a bit more touchy about growth conditions than our favourite orchids.
I don't think fungus-plant (I'm talking slippers here) associations can be generalized due to species-specific interactions, some of which are quite specialized, as shown in the journal link you provided. I am not too sure how the associated fungus WITHIN roots can be affected by the external environment, as some of the Rhizoctonia and Epulorhiza isolates associated with paph roots form specialized compact structures (pelotons) inside the root. So even if the external mycelium is killed off by changes in the outside environment, I presume the fungus still remains alive within the root..
 

Ray

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The basic concept espoused to me by the Inocucor folks is less symbiotic, and more in the direction Kirk mentions: by establishing a stable population of "good bugs", they work to keep the "bad bugs" at bay.

In my mind, "good" can mean they do something beneficial to the plant, or merely that they do nothing bad to the plant, and prevent others from doing so.

They are the first to acknowledge that they don't know specifically what chemical interactions may be going on that affect the plant, but observations suggest something is going on.
 

PaphMadMan

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... I also wonder about the "batch culture effect", i.e. what changes in populations during the periods between repotting. In fresh medium there will be some more easily degraded polysaccharides to serve as carbon source than later on, are there changes in mo species populations with time. Do we reach a death phase, where due to limitation in carbon source and "salting up" perhaps, where nutrient release from the death and lysis of "the good guys", substrate compression and rise of anoxic regions, promotes the rise of the "badies" ? I think most of us try to repot before this crisis phase happens, if indeed it does.
Most natural environments would have a seasonal addition to the forest floor and litter - a time of maximum leaf accumulation, etc. - "fresh media". Less so for some true epiphytes, but even in the trees it accumulates to some extent. Often a rainy season too - a time when media gets "flushed". Micro-organisms will obviously cycle too. The equivalent of regular repotting and flushing is part of the natural cycling.
 
A

ALToronto

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This reminds me of the discussion we had a while back about mosses and lichens. Could it be that these primitive plants are the 'intermediary' between the EMs and roots in epiphytic plants? We don't really know how the mosses and lichens work, we just know that orchids do better with them than without them.

Another thought - are any of these EMs part of leaf fungi? If so, it would make sense if terrestrial slippers benefitted from them - they get their nutrients primarily from leaf litter.
 

gonewild

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This reminds me of the discussion we had a while back about mosses and lichens. Could it be that these primitive plants are the 'intermediary' between the EMs and roots in epiphytic plants?
That is exactly what I was saying about mosses and lichens.... It's mainly mosses, lichens and the microbes that supply nutrients rather than dissolved minerals falling free in water. Mosses and lichens secret nutrient compounds or elements for the plant and microbes act as the bridge. During those discussions I suggested that excess nutrient salts (K) may inhibit the microbe population and in effect reduce the nutrients available to the plants or kill off beneficial microbes that help the plants resist bad microbes.

Using EM solutions may repopulate the the good microbes and that is why some people see positive results and other do not. But the benefit of adding EM may be short lived if the elevated nutrient salt levels are too high.
 

Trithor

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by establishing a stable population of "good bugs", they work to keep the "bad bugs" at bay.

In my mind, "good" can mean they do something beneficial to the plant, or merely that they do nothing bad to the plant, and prevent others from doing so.
My understanding too
 
A

ALToronto

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Inocucor called me back! I had a very nice conversation with Jan Kral, their VP of Sales, whom Ray mentioned in an earlier post. I'm sending him a link to this discussion.

So I will be getting a small sample bottle of their 'water amendment', as they're required to call it in Canada. I'm happy to share with anyone who comes to the next SOOS meeting in January. Very excited to try it out.
 

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