Gremmeniella abietina in North-western Spain: Distribution and Associated Mycoflora

Abstract

Gremmeniella abietina, in its conidial state (Brunchorstia pinea), was recently reported in Palencia (north-west Spain) on Pinus halepensis in 1999. For that reason, the main aim of the present study was to determine the distribution of G. abietina in areas next to that where it was first recorded in order to evaluate there the current spread of the pathogen. Fungal mycoflora occurring in trees showing symptoms of G. abietina was also recorded with the goal of discussing the possible role it plays in the disease expression observed in the field. The isolation method consisted of finding fruitbodies on plant tissues after incubating them in wet and warm conditions. G. abietina was found in five out of a total of 40 stands that were examined. Furthermore, in another 25 stands, trees showing symptoms similar to those caused by G. abietina were also recorded. In addition to that, another 22 fungal species were isolated from plant fragments. Thyriopsis halepensis, Sclerophoma pythiophila and Cenangium ferruginosum were frequently isolated from injured plant fragments and were recovered from many stands (up to 70% of the total stands). These fungal species could play a role in the disease symptoms expression observed in the field, which were initially attributed exclusively to G. abietina. Lophodermium pinastri, Naemacyclus niveus and Pestalotia stevensonii, previously reported to be secondary pathogens on pine, were also occasionally recovered.