Fungal endophytic communities in healthy and declining Quercus robur L. and Q. cerris L. trees in Northern Italy.

The composition and the role of endophytic fungal communities of broad-leaved trees in connection with health status of the host still have several points to clarify. An investigation was performed in a plain oak forest located in north-western Italy with groups of trees showing decline by oak puzzle disease. Healthy-looking and declining English oak (Quer-cus robur) and Turkey oak (Q. cerris) were tested to assess possible variations of composi-tion of their endophytic communities related to health status. Samples collected in spring (buds) and in autumn (leaves, annual shoots and twigs) were surface-sterilized; fragments were removed and placed on PDA for isolation of fungi. Correspondence analysis showed a marked difference between twig assemblages and those ones of herbaceous tissues, due to the low frequency of Tubakia dryina in twigs, whereas this fungus is the most frequent in buds, leaves and shoots (over 40% in some cases). T. dryina was more frequently isolated from leaves of declining oaks and from buds of healthy oaks; Monochaetia monochaeta showed a preference for healthy trees, especially in leaves and buds. No important differ-ence was noted between communities of the two tested oak species.