Grapevine fanleaf degeneration disease (GFDD) in vineyards in the Odesa region, diagnosis, prospects for its recovery by heat treatment

Goal. Grapevine fanleaf virus (GFLV) is one of the main causes of grapevine fanleaf degeneration disease (GFDD) and is present in almost all areas where grapevine (Vitis spp.) is cultivated. In this work, we ascertained the presence and spread of GFLV in different commercial vineyards in Odesa region, to identify the causative agent, to study the possibility of its treatment by the method of water heat treatment and the influence of its different temperature regimes on the physiological parameters of the plant. Methods. Field — examination of industrial plantations for the presence of symptoms of grapevine short node. Molecular biological method of polymerase chain reaction (PCR) in real time — identification of grapevine fanleaf virus. Research was conducted in accordance with DSTU 8562:2015. The identification of grape short knot virus was carried out in laboratory conditions on the equipment for the PCR laboratory, which undergoes annual calibration. Results. As a result of the phytosanitary survey of industrial grape plantations in the Odesa region, grape bushes of various varieties with symptoms of short knot were found. With the help of real-time PCR, grape short knot virus was identified. The reaction conditions are selected and recommended. The effect of thermotherapy as a means of improving the health of plants affected by grapevine shortknot virus was studied. The influence of different modes of heat therapy of grape vines and seedlings on the physiological indicators of Vitis vinifera L. material during its preparation for grafting: callus formation, cell germination was studied. Conclusions. As a result of the conducted phytosanitary survey of vineyards in the Odesa region, grape bushes with symptoms of short knot were found, which amounted to 20%. The PCR method for the identification of grape short knot virus in real time with hybridization-fluorescence detection has been improved. It was established that among all the grape varieties studied, the technical variety Cabernet Sauvignon was the most susceptible to viral infection. It has been proven that with the help of the method of thermotherapy, it is possible to heal grape vines and seedlings that have been affected by the short knot virus of grapes. The optimal mode (50°С with exposure of 30 min.) was selected for water thermotherapy of grape vines, which did not affect their physiological parameters.