ABSTRACT
Although the effects of fertilization and microbiota on plant growth have been widely studied, our understanding of the chemical fertilizers to alter soil chemical and microbiological properties in woody plants is still limited. The aim of the present study is to investigate the impact of long-term application of chemical fertilizers on chemical and microbiological properties of root-associated soils of walnut trees. The results show that soil organic matter (OM), pHkcl, total nitrogen (TN), nitrate-nitrogen (NO3-), and total phosphorus (TP) contents were significantly higher in non-fertilized soil than after chemical fertilization. The long-term fertilization led to excessive ammonium-nitrogen (NH4+) and available phosphorus (AP) residues in the cultivated soil, among which NH4+ resulted in soil acidification and changes in bacterial community structure, while AP reduced fungal diversity. The naturally grown walnut trees led to an enrichment in beneficial bacteria such as Burkholderia, Nitrospira, Pseudomonas, and Candidatus_Solibacter, as well as fungi, including Trichoderma, Lophiostoma, Phomopsis, Ilyonectria, Purpureocillium, Cylindrocladiella, Hyalorbilia, Chaetomium, and Trichoglossum. The presence of these bacterial and fungal genera that have been associated with nutrient mobilization and plant growth was likely related to the higher soil OM, TN, NO3-, and TP contents in the non-fertilized plots. These findings highlight that reduced chemical fertilizers and organic cultivation with beneficial microbiota could be used to improve economic efficiency and benefit the environment in sustainable agriculture.
ABSTRACT
Paradox is one of the most important rootstock resources in USA and China walnut industry. In this study, we characterized the complete chloroplast genome of Paradox (Juglans major × J. regia) based on next generation sequencing. The circular complete chloroplast genome was 160,324 bp in length, containing a large single-copy (LSC) region of 89,852 bp, and a small single-copy (SSC) region of 18,410 bp. These two regions were separated by a pair of inverted repeat regions (IRa and IRb) of 26,031 bp each. A total of 131 functional genes were encoded, consisted of 87 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. The overall GC content of the chloroplast genome was 36.1% and the GC contents of the LSC, SSC, and IR regions were 33.7, 29.9, and 42.6%, respectively. The phylogenetic analysis by Neighbor-Joining showed that Paradox was relatively closely related to J. major compared to other species of Juglans genus. This complete chloroplast genome will provide valuable insight into evolution, molecular breeding, and phylogenetic analysis of Juglans species.
ABSTRACT
Catalpa speciosa (Warder) Engelm. is a precious Catalpa tree widely used as a large ornamental shade tree. In this study, the complete chloroplast genome was assembled from Illumina sequencing data. The completed plastome was 158,239 bp in length, including a large single copy (LSC) region of 85,036 bp, a small single copy (SSC) region of 12,639 bp, and a pair of inverted repeat (IR) regions of 30,282 bp. The overall GC content of the genome was 38.09%, and the corresponding values of the LSC, SSC and IR regions were 36.44%, 33.57%, and 41.35%, respectively. A total of 129 genes were annotated, including 83 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis was carried out based on complete plastome sequences of C. speciose and 11 other species from Bignoniaceae family. The newly characterized complete chloroplast genome will provide essential data for further studies of C. speciosa.
ABSTRACT
A Au-Ag-Au multi-segmental hybrid structure has been synthesized by using an electrodeposition method based on an anodic aluminum oxide (AAO) membrane. The third-order optical nonlinearities, second harmonic generation (SHG) and photoluminescence (PL) properties containing ultrafast supercontinuum generation and plasmon mediated thermal emission have been investigated. Significant optical enhancements have been obtained near surface plasmon resonance wavelength in all the abovementioned nonlinear processes. Comparative studies between the Au-Ag-Au multi-segmental hybrid structure and the corresponding single-component Au and Ag hybrid structures demonstrate that the Au-Ag-Au multi-segmental hybrid structure has much larger optical nonlinearities than its counterparts. These results demonstrate that the Au-Ag-Au hybrid structure is a promising candidate for applications in plasmonic devices and enhancement substrates.
ABSTRACT
An optical technique is proposed for the accurate calibration of pulsed high magnetic fields utilizing the magnetic field dependent photoluminescence (PL) properties in an Er(3+):YVO(4) single crystal at 80 K. Bright green PL emissions are excited by a 487.5 nm laser line and can be enhanced greatly by a magnetic field at certain field values (B(c)). Since the B(c)'s under 10 T are extremely stable for a given sample at a certain temperature, and the FWHM of the enhancement peaks are less than 0.9 T, an Er(3+):YVO(4) single crystal is proven to be a good candidate for pulsed high magnetic field calibration. The detailed processes and numerous advantages of the technique are presented in this work.
