EDITORIAL
From its educational farm, located in Boisset in the Haute-Loire, the former presenter Fanny Agostini honors each day, in the morning of Europe 1, food and agriculture in France. Sunday, it evokes the truffle, a "black gold" threatened with extinction by global warming.
"The truffle, this delectable mushroom that is worth its weight in gold (more than 1,000 euros per kilo) has always been at the origin of many speculations about its development." Peter Mayle, writer, has even described the world of truffles "more secret than the organization of the General Information".
The truffle is however consumed since the beginning of the 16th century, when François 1st introduced it to the court, thus making it possible to demystify its image. Indeed, this mushroom, which was born underground as a result of storms, has been banned from consumption for several centuries, because associated with the work of the devil ... It will however be necessary to wait until the beginning of the 21st century to start piercing the huge mystery around this mushroom.
The invisible link that connects the truffle to its tree
It is François le Tacon and his INRA team who will understand for the first time the fundamental symbiotic relationship that unites truffles with their host tree (mainly oaks, beeches, hazelnuts or lime trees). A surprising idea comes to mind: since trees use carbon dioxide (CO2) during photosynthesis, it is sufficient to mark this gas with an isotope (carbon 13) and study its progress in the biosphere. To the astonishment, marked CO2 was discovered in the neighboring truffles. It remained only to discover this invisible link that connects these rare mushrooms to their mother tree.
The luck struck in the Oise, when a speleologist, on a field mission to study bats, discovered strange black balls that lined the floor of the gallery in which he was progressing. Amazed by this discovery, he brought samples of his find back to the surface, which he presented to mycologists. Their result was without appeal: it was truffles of Burgundy in formation!
It is thanks to this unexpected discovery that François the Tacon had for the first time the possibility to study the formation of these mushrooms and put his finger on the umbilical cord of the truffles; because yes, it is indeed a filament invisible to the naked eye that acts as an intermediary with the tree and provides the nutrients necessary for the growth of truffle embryos.
Male champion and female mushroom
More troubling still, the truffles are sexed, it means that there are male mushrooms and female mushrooms. At the foot of a tree, it is usually truffles of the same sex which are born, and their filaments must come into contact with those of a truffle belonging to the other sex to give birth to little truffles, a little like at home. Human being !
Unfortunately, this surprising mushroom so popular becomes increasingly rare ... At the dawn of the 19th century, France produced 700 tons of truffles a year, while today truffle producers rarely exceed 50 tons ... The fault climate change, among others, which increases the frequency of intense heat events and soil drought; an example that illustrates how everything is linked in Nature.
In a future shaken by climate change, we must maneuver with an overall vision to hope to preserve the details that prove to be essential to the functioning of the world. "