Beneficial fungus....?

[camille1585]

Using fungicides on a regular basis is bad since it kills off everything, leaving empty 'dead' potting material. The trouble with that sort of no man’s land is that it's competition free space for which ever fungus arrives first, In pot grown plants, unfortunately that usually means pathogenic types.

For increased nutrient uptake I think that you need myccorhiza which are specific to orchids. Non pathogenic Rhizoctonia solani is one that I know has been found to live in symbiosis nearly exclusively with orchids, and it does help increase plant growth and development, which I assume is due to enhanced nutrient uptake. I don’t know if it’s available commercially though.

But beneficial fungi are not just for nutrition, you are forgetting another important group of them: the ones that protect the plants. Many fungi are good biopesticides, and I think that some can be used successfully on orchids since they don’t form such a tight symbiotic relationship as the orchid specific ‘nutritional’ mycorriza. They colonize plant roots and soil and protect the plant from pathogenic fungi and oomycetes. They do that either by outcompeting that bad guys for space and food, or actively destroying them, often via the production of antibiotics. I’ve seen this ‘battle’ under the microscope, and it is impressive how quickly the invading pathogen is killed off! At the same time they can also stimulate root growth in some plant species.

Trichoderma spp. Are one of the better known fungal biopesticides, and used with success on many crops. I know that some people here use it, I believe that the product is called Rootshield. I did some research to see if it is effective on orchids, and found a study that showed that inoculating Guarianthe skinnerii seedlings with Trichoderma harzianum led to higher survival rates of the seedligns, and they grew better.
Pseudomonas fluorescens is another highly effective one, although it is a bacteria and not a fungus, found in the soil of many many plants. It suppresses many different types of soil borne plant diseases.

[Discus]

This thread has revived my interest in speaking to a local company that researches novel mycorhizal fungi to create commercial products - of course, to be commercially interesting the requisite fungus would have to be able to help a wide range of orchids and be "culturable". Their products are currently all arbuscular mycorhizza (AM), however, they have done quite a bit of research on endomycorhizza (EM) as well.

Now I just need to find some sacraficial orchids somewhere with some associated fungi, and a couple of flasks of different mericloned plants for growth trials...

I wonder if you'd need two (or more?) lines - a terrestrial vs an epiphytic one for example. I vaguely recall reading that the orchid/fungal association was fairly specific - but Camille's suggestion that Rhizoctonia is fairly generalist gives me hope!

This is also interesting.

[camille1585]

All I know is that the Rhizoctonia I mention is mainly on orchids, but I don't know if that was for terrestrials, epiphytes, or both. Trichoderma is the one that has been tested with success on epiphtyes.

I'm really interested in this topic in general (I do research in plant pathology for a living), and I think all these beneficial microbes, whether they associate with plants or not, are part of the chemical free solution to pest management, and also reduced use of chemical fertilizers.

I think this evening I'll have a look at what sort of literature exists on epiphytic orchids and mycchorizal fungi, this is something I would really like to try on my own plants.

[Discus]

Incidentally, these guys in Poland seem to have already developed an orchid myco product - MYKOFLOR - Products - Inoculums. You seem to be able to buy it from this polish site (google translate FTW - although having just spent 2 weeks in Poland I recognise some of the words now...!).

The native european terrestrial guys seem to be doing quite a lot of work on germinating orchid seed with and maintaing mycorhizza in culture, and it appears you can order isolates if you want to play with them - being in the EU will greatly facilitate getting access to both as inside the EU, phytosanitary-type regulations seem fairly lax. http://culturesheet.org/mycorrhiza:t...id_mycorrhizae has some useful links.

[Tsuchibuta]

I wonder if such a product would allow the coral root orchids to be grown outside of their native environment.

[keithrs]

Very good reads!!!

[King_of_orchid_growing:)]

Originally Posted by Tsuchibuta

I wonder if such a product would allow the coral root orchids to be grown outside of their native environment.

Don't mean to be the bearer of bad news, but no, it will not.

Corallorhiza spp. not only depend on the fungi (which may not be part of the Rhizoctonia complex), but a host tree that the fungus is in symbiosis with as well.

No fungus, no host tree, no Corallorhiza.


Orchid mycorrhizae of Thelymitra and Caladenia are part of the Rhizoctonia complex, and are known as Tulasnella.

---------- Post added at 12:11 PM ---------- Previous post was at 12:02 PM ----------

Originally Posted by Discus

Now I just need to find some sacrificial orchids somewhere with some associated fungi, and a couple of flasks of different mericloned plants for growth trials...

I recommend the grassland Eulophias in your country. They are hardy, many of them are not threatened, and they will most likely bounce back from you collecting a root sample for mycorrhizae isolation.

For isolating mycorrhizae, you may have to culture several strains that you gather from the root cutting(s) to do trials in-vitro.

If you're interested in epiphytes, I recommend getting orchids from vendors that come from the orchid's respective countries of origin. The chances are higher that you'll end up with some mycorrhizae hitchhikers.

If you're interested in Disas, I recommend just gathering soil samples that are very close to the roots. I don't recommend disturbing the deciduous Disas while they're in active growth.

Originally Posted by Discus

I wonder if you'd need two (or more?) lines - a terrestrial vs an epiphytic one for example. I vaguely recall reading that the orchid/fungal association was fairly specific - but Camille's suggestion that Rhizoctonia is fairly generalist gives me hope!

Rhizoctonia is a complex. There may be a Rhizoctonia genus in this complex, but there are other genera in the Rhizoctonia complex as well.

Some orchids have different associations.

Rhizoctonia solani is only 1 of those orchid mycorrhizae.

[Tsuchibuta]

Originally Posted by King_of_orchid_growing:)

Don't mean to be the bearer of bad news, but no, it will not.

Corallorhiza spp. not only depend on the fungi (which may not be part of the Rhizoctonia complex), but a host tree that the fungus is in symbiosis with as well.

No fungus, no host tree, no Corallorhiza.


Orchid mycorrhizae of Thelymitra and Caladenia are part of the Rhizoctonia complex, and are known as Tulasnella.[COLOR="Silver"]
Some orchids have different associations.

Rhizoctonia solani is only 1 of those orchid mycorrhizae.

My thought would be to innoculate a media of made of such wood (like mushroom blocks) then grow the Corallorhiza in there.

In theory if you can grow the fungi then you should be able to grow the plant.

[King_of_orchid_growing:)]

Originally Posted by Tsuchibuta

My thought would be to innoculate a media of made of such wood (like mushroom blocks) then grow the Corallorhiza in there.

In theory if you can grow the fungi then you should be able to grow the plant.

You can try it out if you know where the Corallorhiza grows and can recognize which trees the fungus is in association with.

Unfortunately, growing fungus is a whole different skill.

---------- Post added at 12:49 PM ---------- Previous post was at 12:18 PM ----------

I wonder if anyone's given any thought to growing Neottia nidus-avis (Bird's Nest Orchid)...

If I'm not mistaken this achlorophyllous orchid is usually in association with citrus trees. That's a lot more doable than dealing with conifers.

They're a beautiful bronze color too.

My understanding is that some of the seeds of these achlorophyllous orchids have been successfully sown in-vitro before. The problem is when they deflask them to grow them in culture.

[Tsuchibuta]

Alas - Counterproductive, in order to preserve the species you would have to disturb its habitat to obtain the necessary data. In the process likely destroying the species you are trying to preserve.

^ why it would be great if this ready made product would work out of the box.