OCCURRENCE OF ACREMONIUM ENDOPHYTES IN WILD POPULATIONS OF LOLIUM SPPIN EUROPEAN COUNTRIES AND A RELATIONSHIP BETWEEN LEVEL OF INFECTION AND CLIMATE IN FRANCE

Infection with endophytic fungi (Acremonium spp.) was detected in wild populations of Lolium spp. from 15 of 20 European countries. Of 523 p opulations examined, 38% contained no infection, 48% contained 1-50% i nfection and 14% contained 51-100% infection. Level of infection was s lightly but significantly associated with abundance of Lolium in the s ward. For data from France, significant correlations were obtained bet ween level of infection and five climate variables; the highest correl ations were with evapotranspiration (0.66, P < 0.001) and water supply deficit (-0.66, P < 0.001). A model established using multiple regres sion analysis and incorporating five climatic variables, accounted for 56% of total variation; water supply deficit alone accounted for 43%. These climatic variables were shown by geostatistical analysis to acc ount for a spatial structure in infection level. Groups of Lolium popu lations with a high level of infection were located mostly in Mediterr anean regions, where stress from summer drought is common.