Help needed: disease identification

Yves Bertheau bertheau at solair.inapg.inra.fr
Sat May 25 04:33:43 EST 1996


@rsvs.ulaval.ca wrote:
> 
> Unidentified Arabidopsis disease
> 
> Information search...
> 
> I seek help to identify and find a cure to a disease destroying some
> of our Arabidopsis plants. This disease attacks plants grown in soil
> in growth chambers. Up to now, attempts to identify this pathogen were
> inconclusive.
> 
> The first symptom detected is a senescence of the basal leaves. This
> senescence later spreads upward along all (or sometimes only one) of
> the stems. A premature wilting of higher stems and inflorences is also
> often observed, associated with a hook-like bending at a dried stem
> segment.
> 

Did you made observations of brown color into the vascular system?

> The disease is presumed to be spreading vascularly. It does not appear
> to be transmitted through seeds since a normal amount of disease is
> noted among individuals originating from seeds collected on affected
> plants. Furthermore, our seeds are routinely sterilized and germinated
> in vitro. It seems also unlikely to be related to a nutrient

I do not work with Arabidopsis but the efficiency of sterilization is 
highly dependent on the surface of the seeds and of the chemicals
 duration... used. Moreover, some diseases are transmitted by seeds
(some fungi, bacteria and viruses). In these cases the sterilization is
is inefficient...

> deficiency or an air-borne pathogen since it is often noted that only
> one or a few plants per container are affected, even when several
> plants touch each other.

But did this disease extend from an initial point?
With most of the vascular diseases, the symptoms develop on a plant
then extend to the surrounding ones (if the time of plant culture
is long enough...)
Otherwise insects (flying or not...) are also good vectors

> 
> We have experienced in the past a few, sporadic, occurrences of this
> disease. The number of plants affected has, however, recently
> increased severely. I would be very grateful for insights from anyone
> facing a similar problem and/or having successfully identified and
> defeated this pathogen. Thank you for your attention.

I do not know this disease, but the symptoms you described are quite 
similar to those of other vascular fungal disease. Test this hypothesis
by using a systemic fungicide e.g. Alumine Phosethyl (in France
the trade name is "Alliet" from Rhone Poulenc) but maybe could you find
other ones.

> 
> Martine Jean
> Université Laval
> e-mail: mjean at biota.rsvs.ulaval.ca


Did you send also your message to sci.bio.phytopathology?

Maybe are there some phytopathologists they know this disease...

Hoping it will help you...

-- 
Yves Bertheau, INRA INA P-G, Pathologie Vegetale, 16 rue Claude Bernard,
75231 PARIS cedex 05, FRANCE, Tel +33 (1) 44.08.16.98  or 44.08.17.04
Fax: +33 (1) 44.08.17.00 or 16.31, Internet:
bertheau at inapv.inapg.inra.fr
http://inapv.inapg.inra.fr/Welcome.html



More information about the Arab-gen mailing list