Inoculated Truffle Trees: How Black Truffle Mycorrhiza Works

Inoculated truffle trees are host trees whose roots have been colonised in the nursery by the black truffle fungus, Tuber melanosporum.

Without that inoculation, a tree is only a tree. With it, the roots and the fungus form a partnership that can produce truffle for decades.

This page explains what that partnership is and how to check that a plant really has it.

The symbiosis, in a grower’s words

The fungus and the plant live in symbiosis: each provides food to the other. That is the whole mechanism, and the grower adds the part that matters for a plantation: if the plant lacks food, it will not give any to the fungus.

A truffle harvest is therefore a consequence of a healthy tree. Anything that weakens the tree, from poor soil to pests, reaches the fungus a step later.

Why a weak tree stops giving truffle

The grower gives an everyday example: leaf galls. The insect eats some of the leaf, the tree has less surface for photosynthesis, it makes less food for itself, and so there is less for the fungus.

How a nursery proves the inoculation

Around 43 nurseries in Spain produce inoculated black truffle plants. The grower we work with has visited them and works with two, and his advice is to look at the controls, not the pots.

The sector’s quality checks are a root-by-root inspection under the microscope that counts the share of root tips colonised by Tuber melanosporum, a species check by PCR to rule out contaminating truffles, and a batch guarantee backed by an independent laboratory. A colonisation rate of 20 to 25 per cent is cited in product sheets as a correct index.

• Microscope check of root tips, batch by batch.
• PCR verification of the species, against Tuber brumale, Tuber indicum and Tuber aestivum.

Ordering inoculated truffle trees

The density the grower plants at is 300 trees per hectare, so the surface fixes the number of plants.

Tell us the surface and the country. Live plants are subject to plant-health rules that differ by destination, so where they can be sent is confirmed at the time of ordering, and the price comes with the quotation.

Related pages:

• Truffle Trees for Black Truffle (Tuber Melanosporum)
• Truffle Trees for Sale: Black Truffle Plants from Spain
• Truffle Seedlings for a Black Truffle Plantation
• How to Grow Black Truffles
• Tuber Melanosporum: the Black Truffle