Assessment of potential application of Canada thistle [Cirsium arvense (L.) Scop.] pathogens in biological control of this weed.

摘要

The aim of the study was to identify pathogenic fungi isolated from Cirsium arvense and the assessment of their pathogenicity to Canada thistle. Plant material was collected from natural stands of C. arvense located on vast meadows of the Warta River valley. Pathogens were isolated from leaves, stems and rhizomes and transferred onto PDA medium. Pathogenicity of these fungi was assessed under greenhouse conditions. Disease symptoms were often observed on C. arvense plants growing in analyzed habitats. Fungi isolated most commonly from infected plants belonged to the following genera: Fusarium, Alternaria, Sclerotinia and Penicillium. In the greenhouse experiment it was found that analyzed fungal isolates differed in their pathogenicity. The results of performed research indicated that some of these fungi (genera Fusarium and Sclerotinia) might be considered as a suitable agents for biological control of C. arvense. Moreover, symptoms of rust Puccinia punctiformis were observed on plants growing in the greenhouse.