Spatial distribution of dark septate endophytes in a confined forest plot

Abstract

In the present study we investigated the abundance and spatial distribution of dark septate root endophytes (DSE) in a 3×3 m plot in a spruce stand (Picea abies). A total of 144 DSE isolates were obtained by means of a hierarchical sampling design. Most roots were colonised, as DSE were isolated from 81.7% of root segments. ISSR–PCR fingerprinting was used to identify 21 unique ISSR types. Dominant types were isolated from adjacent points that covered an area of up to 6.8 m² of the study plot, and ISSR types were intermingled extensively. Frequency of isolation of the different ISSR types was uneven with two dominant types that accounted for 38% and 28% of all DSE isolates, respectively. Seven DSE strains representing six different ISSR types were identified as Phialocephala fortinii based on the morphology of fertile conidiophores and/or ITS 1 and 2 sequence comparisons.