Community Compositions of Phytoplankton and Eukaryotes during the Mixing Periods of a Drinking Water Reservoir: Dynamics and Interactions

Niu

2020

Agronomy

Alternate drip irrigation (ADI) is a useful irrigation method for water conservation and the regulation of soil quality; however, knowledge about the underlying mechanism of soil-root-bacterium interactions is limited. To determine the mechanism by which ADI transforms soil nutrients and thereby promotes plant growth and to provide a basis for the reasonable selection of drip irrigation methodology, the present study investigated the effects of ADI on the composition and potential function of the bacterial community in tomato rhizosphere soils under greenhouse conditions and analyzed the soil-root-bacterium interactions under ADI. The results revealed that, compared with the soils of the plots treated with surface drip irrigation with plastic film mulching (DI-PFM), the soils of the plots treated with ADI presented an optimized bacterial community structure and optimized soil nitrogen (N) and phosphorus (P) metabolism. The soil available N contents under ADI with lower irrigation limits of 50%, 60%, and 70% of field capacity (A50, A60, and A70 treatments, respectively) were 1.48, 2.19, and 1.91 times greater than those under DI-PFM, respectively; similarly, the soil available P contents were 1.49, 1.65, and 2.91 times greater; the total phosphorus (TP) contents in the tomato roots were 1.06, 1.94, and 1.59 times greater, respectively; and the TP contents in the tomato plants were 1.03, 1.75, and 2.84 times greater, respectively. In addition, the total nitrogen (TN) contents in the tomato roots under ADI with lower irrigation limits of 60% and 70% of field capacity were 1.07 and 1.14 times greater than those under DI-PFM, and the TN contents in the tomato stems were 1.21 and 1.12 times greater than those under DI-PFM. However, compared with DI-PFM, ADI improved tomato yields by 24.23% under only 70% of field capacity. Therefore, ADI significantly enhanced soil-root interactions and stimulated the activation of soil N and P, but only a proper low soil moisture content (SMC) led to significantly increased tomato yields.

Section: High-throughput Analysis Of the Soil Bacterial Communitymentioning

confidence: 99%

Nitrogen and Phosphorus Absorption and Yield of Tomato Increased by Regulating the Bacterial Community under Greenhouse Conditions via the Alternate Drip Irrigation Method

Niu

2020

Agronomy

“…The RDP Classifier algorithm (http://rdp.cme.msu. edu/) containing the Silva (SSU123) 16S rRNA database was applied to annotate each OUT sequence with a 70% confidence threshold (Yan et al 2020).…”

Section: Methodsmentioning

confidence: 99%

Characteristics and Diversity of Endophytic Bacteria in Endangered Chinese Herb Glehnia littoralis Based on Illumina Sequencing

Huo

Polish Journal of Microbiology

Zhang

et al. 2020

Glehnia littoralis is an endangered medicinal plant growing in the coastal ecological environment and plays an important role in coastal ecosystems. The endophytes in the plant have a significant role in promoting plant growth and enhancing plant stress resistance. However, the endophytic bacterial structure associated with halophyte G. littoralis is still not revealed. In this project, the construction and diversity of endophytic bacterial consortium associated with different tissues of G. littoralis were illustrated with high throughput sequencing of the V3-V4 region of the bacterial 16S rRNA. The results resolved that the diversity and richness of endophytic bacteria were significantly higher in root than in leaf and stem. The operational taxonomic units (OTU) analysis demonstrated that the Actinobacteria and Proteobacteria were dominant in all the samples at the phylum level, and Pseudomonas, Bacillus, Rhizobium were the dominant genera. Our results unraveled that the bacterial communities differed among different tissues of G. littoralis. Endophytic bacterial communities in leaf and stem shared more similarity than that in the root. Furthermore, the difference of bacteria community and structure among different tissues were also detected by principal coordinate analysis. Taken altogether, we can conclude that the bacterial communities of different tissues are unique, which could facilitate understanding the diversity of endophytic bacteria in G. littoralis.

“…The other data processing was based on the methodological flowchart (Supplementary Figure S1). Rarefaction curves and alpha diversity indices (Ace), bacterial community diversity (Shannon index) and coverage were calculated using MOTHUR (http://www.mothur.org) [16]. The Venn diagrams and abundance-rank curves were created by using R Software (version 3.2.3, R core team, Vienna, Austria) [17].…”

Section: Data Processingmentioning

confidence: 99%

Responses of Bacterial Community, Root-Soil Interaction and Tomato Yield to Different Practices in Subsurface Drip Irrigation

Niu

2020

Sustainability

The objective of this study was to reveal the regulatory mechanisms underlying the soil bacterial community of subsurface drip irrigation (SDI). The effect of different buried depths of drip tape (0, 10, 20, 30 cm) on the soil bacterial community in a tomato root-zone was investigated using high-throughput technology. Furthermore, the mutual effects of root growth, tomato yield and soil bacterial community were also analyzed to explore the response of root-soil interaction to the buried depth of drip tape. The results indicated that SDI (i.e., 10, 20 and 30 cm buried depths of drip tape) changed the soil bacterial community structure compared to surface drip irrigation (a 0 cm buried depth of drip tape). SDI with a 10 cm buried depth of drip tape significantly reduced the relative abundances of Proteobacteria, Chloroflexi, Gemmatimonadetes, Acidobacteria, Firmicutes and Planctomycetes, but significantly increased the relative abundances of Actinobacteria, Candidate_division_TM7 and Bacteroidetes. SDI of 20 and 30 cm buried depth significantly decreased the relative abundances of Roteobacteri, Actinobacteria and Planctomycetes, however, increased the relative abundances of Chloroflexi, Gemmatimonadetes, Acidobacteria, Firmicutes, Candidate_division_TM7 and especially some trace bacteria (for example Nitrospirae). Furthermore, under 20 cm or 30 cm of buried depth, the abundances of nitrogen metabolism and phosphonate and phosphinate metabolism based on the PICRUSt (Reconstruction of Unobserved States) method were significantly improved as well as soil porosity and root forks at 0-10 cm. These changes strengthened root-soil interaction and improved tomato yield per plant by 22.47% and 19.38% under 20 cm and 30 cm of buried depth, respectively, compared to surface drip irrigation. Therefore, the responses of bacterial community and root-soil interaction to drip tape buried depth of 20 cm and 30 cm are proven to be beneficial for the increasing of tomato production.