Bacillus pumilus - a new phytopathogen of Scots pine­­

Abstract

Large bleeding lesions on stem and branches of pine trees, wet black spots and depressed cancer wounds of different sizes at the base of knots, dying off the bark around knots and sapwood exposure over a large area, wilting, yellowing and shedding of needles on the individual branches and whole crown may indicate the presence of pathogenic bacteria. Monitoring the health of pine plantations in Lviv and Minsk regions showed the spread of diseases that can be caused by bacteria. In order to identify the pathogenic bacteria associated with pine vascular diseases, we collected needles, bark and sapwood from symptomatic trees. Ten potential pathogenic isolates were prepared from diseased tissues. All isolates were found pathogenic and identified as Gram-positive, rod-shaped and spore-forming. The isolates were identified as Bacillus pumilus, based on morphological and biochemical characteristics, and also on 16S rRNA gene sequence analysis. Pathogenicity studies of different B. pumilus isolates revealed that they have a potential to cause the soft rot disease in pine seedlings and symptoms of wetwood disorder in young Scots pine trees.

Keywords

• pinus sylvestris
• bacteriosis
• phytopathogenic bacteria
• soft rot