Crocus Corm Scars : Guess what it is ?!

[Croquin]

For 2 years now, healthy crocus corms without any sign of injury showed, after some short period of drying, depressed areas on their living surface (living tissues below the protective envelopes) - as displayed on the two pictures below.



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I had previous contacts with professionals who suggested that the living tissues of the corm could have been crushed by stones or tools while digging them out of the ground, and that the observed trace was simply a scar.
Indeed, it appears to be a scar, but its origin remains mysterious.

This year, we have been very carreful with the digging procedure and I am 100% sure that crushing cannot be the cause for these marks.
As visible on the picture, the shape is regular and comes with a systematic signature, always following the node limits.
It would be random if it was a crushing scar or a gnaw scar.

The tissue simply appears to have dried from within just below the surface, its surface appearance slightly changes, and the corm remains healthy for months until planting.
The mark pops up within days on previously unmarked healthy corms and does not expand further.
It does not seem to be contagious, and marked corms grow well.
 
I would very much appreciate any feedback of the croconut community, suggestion, brainstorming.
Has anyone of you already observed this and enquired about it ?

Is it physiological, a disease, a virus ?

[Lesley Cox]

Certainly different from anything I've seen and I can't think of any possible solution or reason for it. The lower picture looks like something maybe a surgeon might encounter!

[Croquin]

This is difficult a challenge, I know.
Mindboggling to me, but you croconut forumists have greater expertise and I hope we can find some clues together.

I also understand that it might be difficult though, due to lack of observations.
Let's imagine that this phenomenon is not uncommon, it will only be seen if you remove the protecting envelopes : who does this ?
(well, I did on random samples to double check the health of the corms, and that's how I discovered it).

May I suggest that, if nobody has ever seen that previously, you try to denude a sample of your crocus corms this summer, make regular observations, and eventually report ?
Peeling off the protective envelopes (dead tissues) can be easily done without harming the plant.
The corms will just need to be manipulated more carrefully, but they grow perfectly well.

[daveyp1970]

They look like rodent teeth marks.

[Croquin]

yes, a little on the first picture, but not on the second picture.
I assure you they are not, the depression is very regular on its sides.