Abstract:

Abstract: Potted Populus tomentosa and Populus × beijingensis cuttings were used to study the effect of root coupling agents, which consisted of two ectomycorrhizal fungi, plant growth regulator and plant resistance inducer with uniform design, on the cuttings growth,biomass,root vigor,soil acid phosphatase activity and soil available P around root area. The results showed that the height, the ground stem diameter and the total dry mass of the treated Populus tomentosa and Populus × beijingensis cuttings were increased by 16.0%～35.0%，19.4%～38.9%，15.5%～86.4% and 12.5%～26.2%，1.6%～20.3%，33.6%～72.7%, respectively in compared with the control. The root vigor of the treated Populus tomentosa and Populus × beijingensis cuttings were 6.71%～33.64% and 1.49%～49.46% higher than those of the control, respectively. There was a close correlationship between root vigor and biomass of cuttings. The coupling agents greatly increased the soil phosphatase activity and the increase was 20.91%～36.35% and 13.39%～54.98% respectively in the treated Populus tomentosa and Populus × beijingensis the rhizosphere. The coupling agents also enhanced the transformation of available P from insoluble P minerals, and the soil available P enriched in the rhizosphere of treated Populus tomentosa and Populus × beijingensis cuttings respectively with 7.49%～25.67% and 17.85%～53.50%.

Key words: Key words: Populus, rhizosphere microenvironment, root vigor, acid phosphatase, soil available P