Abstract:

In order to clarify the herbicidal activity and crop safety of the weed pathogenic strain GD-0221, weed pathogenic strain GD-0221 was isolated from the root of diseased Glycyrrhiza uralensis by tissue isolation method. The taxonomic status of this strain was determined by morphological and molecular identification. The pathogenicity of the strain to the isolated leaves of five broadleaf weeds was determined by cake inoculation in vitro. The broth inoculation method was used to determine the pathogenicity to the five broadleaf weeds and the safety of the main crops in Qinghai in vivo. The strain was identified as Fusarium oxysporum by morphological and DNA sequence analysis, and it was pathogenic to five broadleaf weeds Elsholtzia densa, Chenopodium album, Malva verticillata, Polygonum lapathifolium and Polygonum aviculare. In vivo inoculation test result showed that pathogenicity rate of weeds was 33.33%-100.00%, it had the most prominent pathogenic effect on Elsholtzia densa. In terms of crop safety, the strain was safe to Hordeum vulgare, Triticum aestivum, but not safe to Brassica campestr, Vicia faba and Pisum sativum. Strain GD-0221 had the potential to be developed as a microbial herbicide against broadleaf weeds in gramineous crops.

Key words: Fusarium oxysporum, herbicidal activity, crop safety, microbial herbicide