Pathogenic characteristics of isolates of Bipolaris and Exserohilum species from weeds

摘要

The pathogenic characteristics of 10 isolates of Bipolaris species and two isolates of Exserohilum species, isolated from the leaves of six weed species of the family Poaceae (Tab. 1) have been studied. Weeds (Cynodon dactylon, Panicum crux galli, Setaria glauca, Setaria verticillata, Setaria viridis and Sorghum halepenae) with expressed symptoms of leaf spots were collected in maize crop at Zemun Polje. Pathogenicity of isolates was tested by artificial inoculation of hosts, sorghum and maize, inthe control environmental chamber. Leaf, stalk and ear of maize plants were also inoculated in the field. Obtained results indicated that all studied isolates of Bipolaris and Exserohilum species expressed pathogenicity to their hosts which they had beenisolated from. Four out of seven tested isolates of Bipolaris species were pathogenic to sorghum, whereas nine out often studied isolates of this genus were pathogenic to sorghum and maize in the control environmental chamber, on one hand. On the otherhand, in the field, four isolates of Bipolaris species showed pathogenicity to maize leaves, five to stalks and eight to ears. Two isolates of Exserohilum species revealed pathogenicity to maize leaves and non-pathogenicity to maize ears, but one isolatewas pathogenic to maize stalks.