Mycorrhizal fungi and N-Fixation

truffler1635 at truffler1635 at
Thu May 25 12:11:37 EST 2000

In article <20000523105426.19147.00000779 at>,
  permacltur at (Permacltur) wrote:
> I gather that the nodules were cut open because I inquired about the interior
> color and got an answer -- yellow.  We have  had a response from a worker in
> India who is going to try to replicate the results.   I have also received a
> suggestion that some tomatoes form tubers, which is interesting all by itself.
> The person who reported the results said that each of her tomato plants was of
> a different variety, reducing in my view the significance that those more
> distant from the beans did not have root swellings.  I think we are going to
> have to let this one ride unless we get some results from the folks in India.
> The more information I have, the less likely it seems that we can conclude
> anything from this report.
> Dan Hemenway
> Barking Frogs Permaculture Center
> Sparr FL USA
> ---------
> 	<<Subject: Re: Mycorrhizal fungi and N-Fixation
> From: bobharames at aol.comnojunk  (BobHarAmes)
> Date: Mon, May 22, 2000 2:39 AM
> Message-id: <20000522010903.02133.00000618 at>
> I've worked on rhizobia, N2-fixation, N-transfer by VAM from soil to the host,
> and also with tomato but never have seen nodules on tomato except nematodes.  I
> suspect they may have actually observed root knot nematode on tomato and
> confused it with rhizobia.  Were x-sections made of the tissue or rhizobium
> cultured from surface disinfected nodules?  I'm skeptical also.  Dr. Bob Ames.
I regret the lateness of this reply, but my original reply was eaten
when DejaNews went through its most recent "upgrade."

I wouldn't discount the rhizobia (Rhizobium?) on tomato plants. I have
seen similar structures on my tomato plants here in Oregon when I pull
them up after the first frost to compost them.

The difference may be the availability of mycorrhizae in soils. The west
coast has thousands of species of mycorrhizae available. A study of 4
truffle species (hypogeous sporocarps, not necessarily Tuber sps) of
four commonly collected truffles identified that all four were
associated with nitrogen-fixing bacteria. These sporocarps were: Tuber
gibbosum, Barssia oregonensis, Rhizopogon vinicolor and Hymenogaster

To inoculate seedlings with N-fixing bacteria, find a plant producing
some (try bean, pea or or legumes at first), pull the plant up, wash the
roots, blend them in a food processor or blender, add lots of water,
then apply to the plants you wish to inoculate.

BTW, the prairie lupine was the first plant to colonize the newly
barren/sterilized soil of Mt. St. Helens after the eruption. Undoubtedly
part of its ability to colonize this inhospitable landscape was the
association of Rhizobium bacteria and N-fixation.

Daniel B. Wheeler

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