Identity and properties of bacteria inhabiting seeds of selected broadleaf weed species

Seeds of five weed species were examined for the presence of seedborne bacteria. A total of 459 isolates were obtained from 1,740 seeds. The bacteria were identified and examined for distribution among seed viability classes, antifungal activity, and potential phytopathogenicity. Weed seeds varied for the prevalence of bacteria and in the types of bacteria associated with each plant species. Antifungal activity exhibited by 80% of the bacteria may limit seed deterioration by potential fungal seed pathogens. Some of the seedborne bacteria (15%) were potentially phytopathogenic. It is suggested that the complex nature of the weed seed-bacteria associations may be an obstacle to the development of biotic agents for manipulating weed seed activity in soil.