[Evaluation of isolation and field effect of ginseng disease resistance and growth-promoting bacteria].

ABSTRACT

This study was aimed to isolate the strains with both disease resistance and growth-promoting, and clarify the field application effects of the strain for laying the further application foundation. The strains with good antagonistic effect were isolated from the 298 strains in Panax ginseng and the soil by plate confrontation method. The nitrogen fixation potential was verified by Ashby medium. The Salkowski method was used to determine the ability of producing IAA. Silicate medium screening and flame spectrophotometry was used to determine the ability of dissolving potassium. CAS method was applied to detect the ability of producing siderophores to determine its growth characteristics. The morphological, physiological and biochemical and 16S rRNA sequences were used to identify the species. The method of root irrigation was used to determine the effects of its disease control and growth-promoting on ginseng. A strain TY15 with broad spectrum of antimicrobial effect, nitrogen fixation, potassium-dissolving and the capacity of producing IAA and siderophores was obtained by screening. And the strain TY15 was identified as Pantoea agglomerans. The control effect of TY15 on the disease of ginseng in the field was 68.02%, which was equivalent to 68.94% of 30 billion per gram of beneficial microecological bacterium agent. The fresh weight of P. ginseng treated with TY15 strain was increased by 22.73% compared with the control group treated with water. And finally a strain TY15 with good application prospects was obtained.