Julio Javier Díez Casero

Fungi isolated from diseased nursery seedlings in Spain

Fungal endophytes in container-grown seedlings in forest nurseries located in the North Plateau of Spain have been studied. Influences of nursery, season (spring and autumn), host genus and plant part on those fungal assemblages have been also evaluated. Four nurseries were sampled in spring and three in autumn. Analysed material consisted of stems, roots and rhizosphere from five host species, Quercus ilex, Q. pyrenaica, Pinus pinea, P. nigra and P. sylvestris. A total of 581 isolates corresponding to 13 taxa were found in this study. Fusarium moniliforme, F. oxysporum and Trichoderma viride were the most frequently isolated fungi. Number of fungal species per observation differed significantly among the sampled parts. Multivariate Correspondence Analysis allowed the discrimination of samples in five groups based on nursery, season, host genus and plant part. Isolation frequencies of F. moniliforme and F. oxysporum were higher in the roots and in spring, whereas those of T. viride were higher in the rhizosphere and in autumn. A relationship was observed between presence of T. viride and absence of Fusarium spp. in forest nurseries. T. viride, could serve as a biological control agent against Fusarium spp. in forest nurseries.