Identification and molecular characterization of endophytic fungi in grape cultivars grown under ecological conditions of Tokat province

Endophytes live in intra/intercellular tissues of taller plants and these microorganisms do not cause any symptoms in the host plant. Endophytic microorganisms have different functions playing important roles in development, growth, tolerance and adaptation of plants to stresses, diseases and pests in the nature. In this thesis, it was aimed to examine the endophytic fungal flora in dormant cuttings of different grape varieties, to characterize them morphologically and molecularly, to perform pathogenicity tests on the detected endophytic fungi and to determine their antagonistic effects against the factors that cause some grapevine stem diseases. Standard table grape cultivars (18 each) grown in Tokat province, local grape cultivars (12), clones of Narince grape cultivar (21) and some grafted and ungrafted American grapevine rootstocks were used as the plant material of the study. As a result of isolation from the samples taken from the internal tissues of dormant cuttings, DNA extraction, PCR, gel electrophoresis processes and gene sequencing processes, classical and molecular diagnoses, 23 endophytic fungi (Acremonium aegyptiacum, A. fusidioides, A. hyalinum, A. sclerotigenum, Alternata alternata, Alt. infectoria, Aspergillus ochraceus, A. piperis, Athelia bombacina, Aureobasidium pullulans, Cerrena unicolor, Cladosporium cladosporioides, Epicoccum nigrum, Fusarium avenaceum, Neosetophoma clematidis, Neosetophoma italica, Oidiodendron cerealis, Paraconiothyrium fuckelii, Penicillium commune, Phoma tropica, Pseudogymnoascus pannorum and Sarocladium strictum) were identified in dormant materials. In pathogenicity tests, these species did not cause any lesions on grapevine saplings. In addition, 7 pathogenic fungi species (Botryosphaeria dothidea, Cadophora luteo-olivacea, Cytospora sp., Cytospora salicacearum, Diatrype stigma, Neonectria ramularia and Truncatella angustata) were identified in this study. The lesion lengths of virulent fungi varied between 6 - 65 mm. The most virulent fungus (65 mm) was encountered in Botryosphaeria dothidea. Among the endophytic species, Acremonium aegyptiacum, Epicoccum nigrum, Fusarium avenaceum, Neosetophoma clematidis and Pseudogymnoascus pannorum exhibited a high antagonistic effect against pathogenic Botryosphaeria dothidea, Diatrype stigma, Cadophora luteo-olivacea, Cytospora salicacearum and Truncatelle angustata. It was concluded that identified endophytic fungi might have an important biocontrol potential against pathogens associated with grapevine stem diseases.