The presence of pathogenic bacteria Pseudomonas syringae in cereals in Lithuania

Abstract

Pseudomonas syringae pathovars cause bacterial diseases of cereals in nearly all temperate and subtropical cerealgrowing regions. As being of low importance compared to fungal diseases, P. syringae has not been studied in cereal crops in Lithuania. However, leaf blights and glume discolorations, uncharacteristic of fungal diseases, were found relatively frequently in the fields. Therefore, the study aimed to identify the occurrence of P. syringae in cereals grown in Lithuania. In this study, cereal crops were tested for the presence of plant pathogen P. syringae. In total, 452 symptomatic plant samples of winter wheat, winter triticale, spring wheat and spring barley were collected in 2013-2015. Symptoms of leaf blight and basal glume blotch on grain were more frequently detected in spring and winter wheat crops than in winter triticale and spring barley. Symptomatic leaves and grain yielded 113 P. syringae strains (51 from leaves and 62 from grain), but only 13 strains (10 from wheat, 2 from triticale and 1 from barley) were pathogenic to host plants when tested by spray method (SM). These strains were isolated from grain (10 strains) and leaves (3 strains) of all sampled plant species originating from different districts of the country. Based on 16S rRNA gene sequence analysis, leaf injection method (LIM) and origin of pathogenic strain, it can be assumed that P. syringae pv. atrofaciens is the dominat causal agent of bacterial diseases of cereals, particularly basal glume blotch of wheat.