BACTERIAL DISEASE OF BIRCH FOREST IN KAZAKHSTAN

Abstract

Introduction. Forest stand degradation has been evidenced recently, caused by the worsening of environmental situation. The plantations are weakened by various diseases, particularly by bacterial diseases, being the most dangerous ones. The work is aimed at the examination of birch plantations in Kazakhstan in order to detect bacterial diseases, their symptoms, expression and pathogenic agents. Object of research – inhomogeneous and homogeneous birch stands in the northern and eastern parts of Kazakhstan. Research methods included evaluation of birch stand condition on the sampling units, laboratory-based genetic identification of phytopathogenic microorganisms which comprised the following stages: detecting total DNA, amplification of the fragments of bacterial and fungal locus by polymerase chain reaction (PCR), sequence analysis. Electrophoretic analysis was carried out using genetic analyzer ABI PRISM 310 (Applied Biosystems, USA); the amplicones were purified using Gene JETPCR Purification Kit (Fermentas, Lithuania). Results. Based on the results of research the bulk of the infected trees found in the North Kazakhstan and the Akmola Region are aged between 40 and 60 and the number of infected trees varies within 48-69 %. The degree of contamination in most species is weak and medium. The number of infected trees aged 30-35 is significantly lower and amounting to about 31 %. In most cases the degree of contamination is weak. Bacterial disease is focused mainly in topographic low areas. The key symptom of bacterial disease in birch plantations of Kazakhstan is the appearance of scarcely noticeable swellings, which gradually increase in size and discharge into rough-edge wounds. Crown thinning and change of the foliage colour are the consequent symptoms. In the samples of infected timber taken from the North of Kazakstan we detected dominating pathogenic bacterium Pseudomonas sp. (~70 %), in the East - saprophitic bacterium Propionobacterium sp. (≈90 %). Traditional pathogenic agent of bacterial dropsy Erwinia multivora Scz.-Parf. was not revealed in either of the samples.