[Illumina Miseq sequencing-based fungal community of rhizosphere soils along root orders of poplar plantation].

The study on microbial community composition in rhizosphere soils surrounding different order roots is of great significance for understanding the interactions between roots and microbes. Using Illumina Miseq sequencing technology, this study analyzed the differences of fungal community structure in bulk soils and rhizosphere soils surrounding different root orders of poplar (Populus × euramericana 'Neva') tree. The microbial species annotation showed that 128, 124, 130 and 101 fungal genera were classified in the rhizosphere soils around 1-2 order roots (R1), 3 order roots (R2), 4-5 order roots (R3) and in the bulk soils (NR), respectively.

[Ionic homeostasis of Populus ×euramericanna 'Neva' influenced by irrigation with magne-tized brackish water.].

The research aimed to study the characteristic of ionic homeostasis of annual seedlings of Populus ×euramericanna under irrigation with non-magnetized and magnetized 0 or 4.0 g·L NaCl solution for 30 days in the growing season. The ion contents of K, Na, Ca and Mg in the lea-ves and roots were measured by atomic absorption spectrophotometry (AAS).

[Seasonal dynamics of quantitative and morphological traits of poplar fine roots and their differences between successive rotation plantations].

Based on the fine root samples of the first and second generations of poplar (Populus x euramericana ' Neva'), this study examined the response of quantitative and morphological traits of fine roots of different orders and the difference between generations. The results showed that, the quantitative traits of fine roots, such as root length, root surface area and root biomass, presented obvious seasonal variation, and the fine root traits had obvious difference among root orders. The quantitative traits of lower-order fine roots showed significant seasonal difference, and the fine root biomass increased in the growing season and then decreased significantly.

[Characteristics of phosphate-solubilizing microbial community in the soil of poplar plantations under successive-planting and rotation.].

The metagenome sequencing was used to compare the difference of six soil samples, the rhizosphere soil of the first and the second rotation poplar plantations (RSP1, RSP2), the bulk soil of the first and the second rotation poplar plantations (BSP1, BSP2), the soil of rotated peanut field (RPS) and the abandoned land soil (ALS) after poplar clear cutting, in phosphate-solubili-zing microbial community and abundance of phosphatase gene (PG) in a poplar plantation. The results showed that microorganisms from nine genera were related to phosphorus cycle with Bacillus and Pseudomonas being the dominant. The abundance of PSMs was highest in ALS, followed by RPS, RSP2 and BSP2, RSP1 and BSP1, respectively.

[Effects of exogenous phenolic acid on soil nutrient availability and enzyme activities in a poplar plantation].

By using ion exchange resin membrane as a plant root simulator, this paper studied the variations of soil nutrient availability and enzyme activities in a poplar plantation after applying phenolic acid. The exogenous phenolic acid had significant effects on the soil nutrient availability and enzyme activities, and the effects were concentration- and time dependent. With increasing phenolic acid concentration, the extraction mass of soil NH4+ -N and NO3- -N decreased significantly.