Tuber melanosporum spread within sub-optimal climatic zones is controlled by fruiting triggers and not mycorrhiza survival

Abstract

<p><em>Tuber melanosporum</em> is the most valuable of all cultivatable truffle species. Farming of this species spans every continent with the exception of Antarctica. <em>Tuber aestivum</em> (syn. <em>T. uncinatum</em>) and <em>Tuber brumale</em> are truffle species that have similar host plant preference and a similar affinity for calcareous soils as <em>T. melanosporum</em>, but occur over a broader geographic zone. The geographic limit of <em>T. melanosporum</em> is thought to be climatically dictated but it is not known whether this is due to an impact on mycorrhizal survival or climatically-derived fruiting triggers. Here, data is compiled from five cultivated research sites in the climatically sub-optimal conditions of the UK in order to address this question. Here we show:</p><p><em>(</em><strong><em>i</em></strong><em>)Tuber melanosporum</em> mycorrhiza can survive and grow in sub-optimal climatic conditions.</p><p>(<strong><em>ii</em></strong>)It is climatically-derived fruiting triggers and not ectomycorrhiza survival that dictate the climatic preferences and geographic spread of <em>T. melanosporum</em>.</p><p>(<strong><em>iii</em></strong>)Important climatic parameters for potential fruiting triggers are sunshine hours, summer rainfall and summer temperatures.</p><p> </p><p>The data presented here not only aid our understanding of the ecological parameters of <em>T. melanosporum</em> but also have a practical application for truffle cultivators in choosing suitable locations for a plantation.</p>