Biological Control of Damping-Off of Alfalfa Seedlings with Bacillus cereus UW85.

摘要: We explored the potential of biological control alfalfa (Medicago sativa L.) seedling damping-off caused by Phytophthora megasperma f. sp. medicaginis screening root-associated bacteria for disease suppression activity in a laboratory bioassay. A total 700 bacterial strains were isolated from roots field-grown plants using Trypticase soy agar. simple, rapid assay was developed to screen ability reduce mortality Iroquois seedlings that inoculated with P. zoospores. Two-day-old planted culture tubes containing moist vermiculite, and each tube different culture. Sufficient zoospores added result 100% seedlings. Of isolates tested, only 1, which identified as Bacillus cereus designated UW85, reduced 0% initial two secondary screens. Both fully sporulated cultures predominantly released spores sterile filtrates these UW85 effective protecting damping-off; vegetative cells or endospores inside parent cell had low biocontrol activity. Cultures grown semidefined media significantly greater activities than complex tryptic medium. In small-scale trial field infested medicaginis, coating seeds increased emergence alfalfa. The results suggest may have agent damping-off, thus providing an alternative current strategies.