soil  metagenome
The sampling site is in Xinmin City, Liaoning Province.In August 2024, three poplar trees with similar growth were randomly selected from each plot. First, an iron shovel was used to remove the surface covering, followed by a soil knife to carefully excavate the upper layer of soil around the base of the trunk. The growth orientation of the root system was monitored, and the fibrous roots were identified along the lateral branches of the roots. Branches were pruned, and the fibrous roots were carefully removed while retaining soil adhering to them. Soil was retained approximately 4 mm away from the root surface, and the rhizosphere soil was collected using the shake-off method. The fibrous roots and rhizosphere soil from poplar trees in each plot were recorded as one replicate each. A total number of 12 root samples and 12 rhizosphere soil samples were collected across four varieties.