Abstract:

The aim is to provide excellent strain resources and technical support for plant-microbial joint remediation. The cadmium-tolerant strain WYN5 was selected as the test material to determine the growth promotion ability of the strain in vitro. The strain was identified by physiological and biochemical tests combined with morphology and phylogenetic analysis. In the hydroponic experiment, inoculated strain WYN5 could promote the increase of plant height, root length, dry weight of root, stem and leaf when the cadmium concentration was 0-10 mg/L. WYN5 treatments increased by 26.2%-28.0%, 15.0%-50.7%, 12.5%-66.7% and 10.5%-20.8%, respectively. Cadmium content in roots, stems and leaves of all treatments also showed an increasing trend. Compared with the control, cadmium concentration in roots of WYN5 treatment was increased by 25.1%-128.7%, and reached a significant level (P < 0.05). Cadmium concentration in stems and leaves was increased by 40.8%-64.9%. Inoculated strain WYN5 can promote the enrichment of cadmium in ryegrass and promote the transfer of cadmium from roots to stems and leaves, which has certain application potential in the remediation of cadmium-contaminated soil by plant-microorganism combination.

Key words: cadmium-tolerant strain, ryegrass, growth promotion, hydroponic experiment, cadmium-contaminated soil