Research on the species causing Botryosphaeria dieback disease in the Eastern Mediterranean Region vineyards, their prevalence and management of the disease using endophytic fungi

Botryosphaeria dieback pathogens can cause severe economic losses in viticulture. Currently, there is no effective control method against these diseases. However, some microorganisms, known as endophytes, live in plants without any adverse effect, and they can be used as potential biological control agents against plant diseases. This study aimed to determine the species and prevalence of Botryosphaeriaceae in vineyards in the Eastern Mediterranean Region, to examine grapevines for endophytic and pathogenic fungi, to investigate the antagonistic potential of endophytic fungi under both laboratory and field conditions, and to determine their potential to reduce disease severity by treating them to the plant with different methods. A total of 100 vineyard areas were examined in September-October 2021. Symptoms associated with grapevine trunk diseases were observed in 72 of the 100 vineyards examined; Disease prevalence was 72%, and the mean disease incidence was 1.1%. A total of 42 fungi from 8 different species (Diplodia seriata, Diplodia olivarum, Neofusicoccum parvum, Neoscytalidium dimidiatum, Lasiodiplodia brasiliensis, Botryosphaeria dothidea, Neofusicoccum australe and Dothiorella omnivora) belonging to the Botryosphaeriaceae family were obtained. Pathogenicity test were carried out on dormant grapevines variety Cardinal. The activity of endophytes was evaluated with dual culture tests. The wound protection performances of potential endophytic fungi, Penicillium fructuariae-cellae, Penicillium canescens, Aspergillus flavipes, Aspergillus allahabadii and Trichoderma brevicompactum were investigated against D.seriata, D.olivarum, N.parvum, N.dimidiatum, L.brasiliensis, B.dothidea, N.australe and D.omnivora under greenhouse conditions. In wound protection experiments, effects of T. brevicompactum ranged from 79% to 81.9% against N.parvum, the most virulent pathogen, additionally, P. fructuariae-cellae and P. canescens were found to have 78.8% and 78.4% wound protection efficacy against N. parvum, respectively. T. brevicompactum showed efficacy rates of 69.6% and 71.8% against N. parvum and L. brasiliensis, respectively, in field trials. This study indicates that alternative promising endophytic fungal species could be used for the biocontrol of Botryosphaeria dieback in grapevine.