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andromonoecious

Symbiosis

andromonoecious
18 years ago

Most trees, and indeed the majority of terrestrial plant species by some estimates, are thought to have obligate symbiotic associations with various mycorrhizal fungi (i.e. Pinus spp. and Suillus). In the case of an ailing bonsai plant would it not be prudent to inoculate the surrounding soil with spores of known symbiotic fungi? And, is it not perilous to expect a soil mix or organic mix to have a fungal diversity capable of accommodating a wide variety of plant species native to different parts of the world?

Comments (15)

  • andromonoecious
    Original Author
    18 years ago

    In response to this posting, I received a personal email from Lucy suggesting this topic is inappropriate for discussion on the Bonsai Forum due to the technical nature of the questions. Perhaps I should rephrase the questions. Directly addressing the care and health of bonsai trees, is the fungal flora an important consideration when selecting or preparing a soil or organic mix? I fail to see how this is too technical for this forum.

  • gerald
    18 years ago

    You are quite right and........, inocculating, especially after barerooting is essintial. Gerald

  • andromonoecious
    Original Author
    18 years ago

    Thanks for the response, Gerald. So, when possible, should a person use a small amount (perhaps very small amount) of soil from the rhizosphere of a naturally growing or healthy planting as a source for inoculation? Of course, in doing so there are risks of introducing unwanted organisms so selecting "healthy plantings" as a source would be essential and, at the same time, difficult to assess.

  • lucy
    18 years ago

    Mycorrhizae are recommended (in my experience) only for conifers, but of course you are free to do whatever you want with your plants. And next time someone sends you a private message, why not respect that privacy?

  • tapla (mid-Michigan, USDA z5b-6a)
    18 years ago

    It's been tough sleddin' for Lucy here lately. Even I'm a little surprised that someone would unilaterally decide what is/isn't appropriate for forum discussion. This is an oft discussed issue and is certainly of interest to, and worthy of discussion in, any container growing circle where media/plant knowledge is anywhere above the "Oh! What pretty plants!" level.

    I left this response to a similar question on the container gardening forum. It may not answer your questions directly, & it may not even interest you. ;o) But I'll offer it up, FWIW:

    "In order for a mycorrhizal symbiosis to form and be an advantage to containerized plants, quite a few cultural conditions need to be appropriate. The composition of the container mix would need to support the growth of the fungi. Container temperatures would need to remain cooler than many of us will be able to maintain. Fertilizer nutrient concentrations appropriate for plant material might easily be sufficient to prevent successful mycorrhizae formation. Anti-fungal applications also destroy mycorrhizae just as readily as they kill unwanted fungal pathogens. Finally, your watering regimen is extremely important, as over-watering is not only harmful to your plants, but to their aeration-sensitive symbiotic fungi as well.
    I haven't used mycorrhizal inoculations in my containers, but I usually observe the existence of the fungal relationship in spring when I repot (Spores are airborne, and if soil conditions are appropriate, it will colonize containers). I'll likely notice it in about 75 of 100 repots. I haven't done a whole lot of reading on the subject, so my observations are pretty much my guide at this stage of my growing abilities. I have decided that the symbiotic arrangement, when present, is as much a benefit as in in situ situations, but I don't think it's worth aggressively pursuing in container culture. Just as I usually see it in a high percentage of plants in spring, I have never seen it in containers during the hot months. I'm guessing that the combination of high fertility, lots of water, and especially higher container soil temperatures inhibits its growth. It probably recolonizes the containers as growth slows in fall because watering is reduced, fertility levels are allowed to drop (due to reduced growth), and soil temperatures become more favorable.

    Since I do recognize the relationship as a beneficial one, when I repot and root-prune woody plants, I mix a small amount of the old roots I've trimmed into the new soil of the same plant as an inoculate."

    Al

  • andromonoecious
    Original Author
    18 years ago

    As for Lucy, I posted the above questions on this FORUM!! to stimulate an intellectual exchange regarding bonsai plant culture. Also, I will assure you that I will promptly post any personal exchanges I receive that I feel are important to the discussion OR pejorative, bossy, or otherwise offensive. If this does not suit you, I suggest you ignore my postings altogether.

  • lucy
    18 years ago

    Tapla, seeing as you don't know what I said in my e-mail, it's probably best if you don't comment on it. The point was that I felt the poster, being a 'real' scientist, might get more meaningful responses from the Botany forum, as his question was quite technical. He chose instead to berate me publicly, rather than thanking me for the tip, so if he's happy with the responses he gets here, that's his business, but mine was completely misinterpreted and certainly not appreciated (obviously), and I'm really sick of the whole thing. The reason I continued to post here in the past few mos. was because so many regulars had left for other forums after the site was sold, and I felt sorry for newbies, etc. who were getting no answers at all. I obviously should just have minded my own business.

  • andromonoecious
    Original Author
    18 years ago

    I would like to apologize to the various contributors to this forum, particularly to Lucy, for the rather rancorous exchanges that I seem to have fueled. All I really intended to do was to gain insight on an issue over which I have pondered for some time. And, indeed, I achieved my goal from the responses (thanks very much, Al and Gerald) garnered by my initial questions despite the somewhat indecorous nature of some postings. As a botanist, my specialty involves plant molecular systematics, breeding systems, and evolution, however, I humbly bow to the expertise of the contributors to this forum when it comes to the cultivation, care, and health of bonsai and container plants. I assure you that your input is greatly appreciated, assimilated, and utilized by myself and my students. Understanding physiological principles cannot substitute for practical experience when it comes to growing plants. So, I would be pleased if Lucy and I could start anew and I pledge to everyone that I will use decorum in all future exchanges.

  • lucy
    18 years ago

    Andro - that's so much nicer! I do hope you understand where I was coming from though, because the majority of people who post to the majority of these forums tend to be asking about how to water their ficuses, and while there are obviously others a lot more knowledgable out there (who may have just been lurking a lot..?), I've seen a lot of unanswered questions here lately, and it seemed a shame for yours to (possibly) have the same fate. I may not always be as sweet as some people would like, but ... will leave this one alone for now! Tapla - I'm sorry, you are definitely one of the ones who does know an awful lot and you just ended up on the wrong end of the fallout here. I will, however, try to be less arrogant (what I've been called) about things if I can help it, because what I know is a drop in the bucket compared to plenty of others.... it's just hard to be patient sometimes.

  • flash14756
    18 years ago

    Dude, awsome vocabulary! You must have a I.Q. of, like, 300. In regards to the fungi, just try it. While it may not help a plant too far on its way out, anything is possible. If you have the room and the facilities you could collect samples of soil from differant species of trees try growing cultures of the diferent soils. As to the potting soil idea, the only way you could get any mycorrhizals at all would be by buying un-pasturized soil mix, which could be dangerous(especialy for an ailing plant). If you could get your hands on naturaly collected organic material, check the label to see where it was collected from. I'm sure you realize that the reason you would do this is so that you can get soil from the same enviroment as your chosen tree. What species did you have in mind?

  • andromonoecious
    Original Author
    18 years ago

    Greetings, Flash, and thank you for responding to my inquiries. During a recent ecology lecture, a student posed a question regarding the importance of mycorrhizal fungi to container-grown plants with bonsai plantings of Pinus spp. given as an example. The simple nature of this question belies an underlying complexity that demands a multi-faceted response and is perhaps incapable of resolution. Allow me to briefly address three issues:

    First, one must address the mutualism-parasitism issue regarding mycorrhizal fungi and their hosts. While mycorrhizas are generally considered to be classical mutualisms, "this is not always the case and upon closer analysis, there appears to be a continuum of plant responses to mycorrhizal colonization ranging from positive to neutral to negative." (Johnson et al., 1997 Functioning of mycorrhizal associations along the mutualism-parasitism continuum, New Phytol. (1997), 135, 575-58). The authors continue "Resource limitation is a key component of cost:benefit analysis of mycorrhizal effects on plant fitness." and conclude "Carbon allocated to a fungus is only a cost if it could otherwise have been allocated to increase plant fitness, and resources gained through the activities of a fungal symbiont are only beneficial if those resources are in limiting supply." In my assessment, as nutrient availability should not be an issue in a well-managed bonsai or otherwise container-grown plant, the presence and importance of the mycorrhiza to these should be minimal at best and perhaps neutral or even a detriment to the host.

    Second, the plant/micorrhiza association of heterotrophic plants such as orchids and monotropoid micorrhizas are an exception in that carbon flows from the fungus to the plant and, thus, the plant is parasitizing the micorrhiza. Consequently, in the attempted resolution of the original question, it is important to address specific plants (as you inquired in your posting).

    Third, the ultimate goal of bonsai plantings is considerably different from those of other plantings (i.e. micromanaged size and shape versus maximized gains in biomass, flower and fruit production, etc.).

    Thus, in order to answer the original question posed by my student, the judicious maneuver is to ask those with expertise in growing bonsai plants. Your advice and input are most appreciated and will be absorbed by the inquisitive minds of perhaps 40 of the 80 students in my class (some will miss class, others will be asleep, and a few will still be struggling with the meaning of mutualism).

    In conclusion, thank you very much and, regarding my vocabulary etc., I apologize for my epistolary style and hope I donÂt sound pretentious. "Old habits die hard" (anon.).

    Best regards,

    Ron

  • flash14756
    18 years ago

    mutualism (n) A type of symbiosis in which each partner in the relationship gains somthing from the other.

    I have heard about the symbiotic relationship in orchid germination, but just how important is it?

  • andromonoecious
    Original Author
    18 years ago

    In a perfunctory review, it is apparent this subject has received considerable attention. The symbiosis, at least for some plant species, appears to be obligatory as the dust-like seeds carry little or no nutrients needed for germination. You might find a recent paper very interesting:

    M.I. Bidartondo and T.D. Burns, 2005. On the origins of extreme mycorrhizal specificity in the Monotropoideae (Ericaceae): performance trade-offs during seed germination and seedling development. Molecular Ecology (2005) 14, 1549Â1560

    The authors discuss "myco-heterotropic" plant species which in essence parasitize other plant species mediated by mycolrrhizal fungi. This is a fascinating paper and can be accessed at the posted URL.

    Ron

    Here is a link that might be useful: Bidartondo & Burns 2005

  • SamWoeIII
    11 years ago

    Some three years ago I attended a UK horticultural trade show and came across a new company selling Mycorrhizal products.
    To say, this company's setup & literature was amateurish was kind, in effect the attitude was- 'This is what we do, look us up on the internet!' Being a retired journalist who covered at times horticulture, this invitation was followed up. Both technically plus experimentally. Since then everything bar just 5% of my work uses mycorrhizals. New seeds, plantings are almost always innoculated with 'Fairy Dust'. Thats what this stuff is, its been part of, by nature for millions of years. Works well too, ofcourse initially we had a collection of plants & trees on our plot, so these were treated with satellite plantings.
    Also in time we researched & progressed with methods of application
    e.g. NO fertilzer applied to a new plantings that have treated - For THREE WEEKS.
    Whilst we've been almost 100% successful since starting using this friendly fungi. Roses, clematis, tomatoes & succulents -
    (these latter two species indoors) have been notable. Finally it is noted this thread started with bonsai conifers -
    Our Fraser Fir in the garden has been a highlight even though its location is not ideal.
    If readers do a search on the INTERNET, they can view lists of species 95% that are symbioatic.
    One final caution though, I always wear latex gloves when using chemicals or indeed this fungi.Mycorrhizals may have been around in the nature for millions of years, but in this concentrated form - caution when handling any 'new' to you compounds - is preferable.

  • brendan_of_bonsai
    11 years ago

    If they were obligate relationships, the plants would die with out them. Since Bonsaid has been around for hundreds of years, and people who keep their plants well don't see them die, we can safely assume that people seeing their plants live are not missing any obligate symbiotic organisms.

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