Characterization of phomopsis isolates causing phomopsis dieback of grapevine and their sensitivity against some fungicides and hot water treatments

In this study the Phomopsis isolates obtained from the Aegean Region were identified with classical and molecular methods and their sensitivity was tested against hot water treatments and some fungicides in in vitro. At the end of the classical and molecular test (PCR, gene sequencing and phylogenetic analysis) results, all the isolates were found to be Diaporthe ampelina (Syn. Phomopsis viticola). Four isolates (CUZF70, CUZF78, CUZF97 ve CUZF140) were grouped as 'G' type and the rest (19) were groupped as 'W' types isolates. All the isolates were determined to have different virulence levels (with 6.5-20.3 mm lesion lengths) in pathogenicity test. Three (CUZF 70, CUZF78, CUZF97) of the six isolates involved in hot water treatments lost their viability at 48°C-45 min. and the other ones lost at 48°C-30 min (CUZF62, CUZF101, CUZF144) respectively. The fungicides (cyprodinil + fludioxonil, tebuconazole and fludioxonil) used in the study were found to be the most effective ones inhibiting colony growth of the isolates. Particularly, cyprodinil+fludioxonil inhibited mycelial growth of some isolates upto 89.5% efficacy at 1 ppm concentration. From this thesis study, some basic fungicide and hot water treatments data were obtained to reduce Phomopsis infections for grapevine nurseries to use in their rootling production.