DRYING OF THE OAK IN KALMYKHIA
LM YAKOVLEVA1, LV KABASHNAYA1, RI GVOZDYAK1, PB DEREVYANKIN2 and LE OGORODNIK3
1 Institute of Microbiology and Virology of the National Academy of Sciences, Zabolotny str. 1 54, 252143, Kyiv, Ukraine; 2 Laboratory of forestry Acad.Sci of Russia, 143030, Moscow, Russia; 3Kyiv Taras Shevchenko University, pr.Akademika Glushkova, 2112, 252000, Kyiv, Ukraine
Background and objectives
Results and conclussions
Necrotic injuries envelop bark and wood. Through bacteriological analysis of necrotic zones (by methods /1/) of bark and wood we isolated pathogenic bacteria, which were identified as Pseudomonas syringae pv.syringae and P. cichorii accoding to /2/. In addition we isolated the less aggressive bacterium Erwinia spp.. Artificial infection of shoots and stems of the oak was achieved by introducing the bacteria P. syringae pv. syringae and P. cichori into mechanical injuries to the bark and wood. In the first year it was noted necrosis of bark or sometimes callus. Under affected bark we noted that the wood was coloured reddish-brown, yellow-brown and greyish-brown. Sometimes we noted developing of opene cankers. For a period of five years this disease made progress and led to the drying of the infected shoots. At the inoculation by the isolated strains P. syringae pv. syringae and P. cichorii we didn't reveal any difference in the symptoms of disease.
Thus the reason of the drying of the oak plantations in Kalmykhia is bacterial disease, caused by P. syringae pv.syringae and P. cichorii infecting the initial mechanical injuries made in the bark by the insects.