Abstract:

 In order to screen out the biocontrol bacteria with growth-promoting effect, soil samples were collected from Hebei, Shandong and other places, and the growth-promoting strains with high-yield IAA ability were isolated and screened, and the potential growth-promoting strains with growth-promoting ability were identified based on morphological characteristics, physiological and biochemical indexes and multi-gene phylogenetic tree analysis, and the growth-promoting effects of growth-promoting strains on cucumber seed germination and cucumber seedlings in pot experiments and field experiments were determined. The results showed that one bacterium, Arthrobacter pascens S17, which had a significant growth-promoting effect on cucumber seedlings, was isolated and identified. Arthrobacter pascens S17 could synthesize IAA in large quantities in DF⁺ medium, and the highest IAA content was 128.54 μg/mL. The growth rate of cucumber seedling plant height and leaf area of cucumber seedlings reached 35.99% and 26.90% by root irrigation treatment with Arthrobacter pascens S17, and the physiological indexes of cucumber seedlings were significantly higher than those of the control. Arthrobacter pascens S17 has a significant effect on cucumber growth, and has a certain development and application prospect.

Key words:

Arthrobacter pascens, indentification, growth-promoting, seed treatment, field trials