New Ascomycetes Associated with Grapevine Dieback in Algeria

This study was conducted during spring 2012 to detect the causal organism (s) responsible for a new grapevine dieback disease in Algeria. Samples of grapevine wood were collected from 10 grapevine fields located in two regions (Medea and Tipaza). Several fungi were isolated from the margin between healthy and diseased tissues. Botryosphaeria spp, were identified based on the morphological characteristics of the culture and confirmed by Beta tubulin (ß-tubulin) region. The sequences submitted to the GenBank (NCBI) under accession numbers (KC960991)( HQ660477)( AY236931), revealed 99-100% homology. Other fungal species Entoleuca mammata and Rosellinia merrilli. were also isolated at low frequency. Inoculation In vitro of grapevine plantlets, with the two Botryosphaeriaceae species, produced smallest necrosis after five-week incubation; Botryosphaeria obtsusa (Diplodia seriata) were virulent compared with B. dothidea. The species tested were re-isolated from necrosis symptoms on infected plantlets .