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Aphis gossypii Glover and Acyrthosiphon gossypii Mordvilko (Hemiptera: Aphididae) are important pests of cotton (Gossypium hirsutum L.) in Xinjiang, China, that reduce yield and lint quality. We studied competition between the two aphid species in laboratory arenas to better understand population change and competitive advantage between the two and to provide a theoretical basis for the observed population outbreak of aphids in cotton fields. To study intraspecific competition, densities of 5, 10, and 15 aphids per 5-cm-diameter leaf disc were established in individual 6-cm-diameter arenas. Equal numbers of each species were placed on leaf discs in the arenas to establish densities of 3, 5, and 10 aphids of each species per leaf disc to assess interspecific competition. In intraspecific competition assays, the mean generation time (T) and the net reproductive rate (Ro) of both species decreased as aphid density increased, while the intrinsic rate of increase (r) and finite rate of increase (λ) of Acy. gossypii increased as density increased. In interspecific competition assays, population growth of A. gossypii was higher than with Acy. gossypii at the same density, while the mean generation time of A. gossypii was less than with Acy. gossypii. The net reproductive rate, intrinsic rate of increase, and finite rate of increase were higher in A. gossypii than in Acy. gossypii. Density is a key factor affecting competition between A. gossypii and Acy. gossypii. The higher the density, the more intense the interspecific competition, with interspecific competitiveness of A. gossypii stronger than that of Acy. gossypii.

Accurate tropospheric delays from Numerical Weather Models (NWM) are an important input to space geodetic techniques, especially for precise real‐time Global Navigation Satellite Systems, which are indispensable to earthquake and tsunami early warning systems as well as weather forecasting. The NWM‐based tropospheric delays are currently provided either site‐specific with a limited spatial coverage, or on two‐dimensional grids close to the Earth surface, which cannot be used for high altitudes. We introduce a new method of representing NWM‐derived tropospheric zenith hydrostatic and wet delays. A large volume of NWM‐derived data is parameterized with surface values and additional two or three coefficients for their vertical scaling to heights up to 14 km. A precision of 1–2 mm is achieved for reconstructing delays to the NWM‐determined delays at any altitudes. The method can efficiently deliver NWM‐derived tropospheric delays to a broader community of space geodetic techniques., Plain Language Summary: Precise positioning with microwave‐based space geodetic techniques, such as Global Navigation Satellite Systems (GNSS), requires accurate modeling of the atmospheric refraction. Numerical Weather Models (NWM) can provide tropospheric delays with an accuracy of 1–2 cm in zenith direction and are therefore useful for improving the data analysis. However, due to the large data volume to handle, NWM‐based products are typically provided only for selected sites, or on a global grid referring to a specific height. We provide an efficient method to represent the vertical profile of tropospheric delay from the Earth surface up to 14 km altitude with a precision of 1–2 mm. The method is used to preserve the precision of NWM‐derived tropospheric delays at the altitudes using three to four coefficients per geographic location (longitude, latitude) at the ground. This paves the way of applying the NWM‐based accurate tropospheric delays in space geodetic data analysis, especially for global augmentations of real‐time GNSS, which play a critical role in the rapid characterization and early warning of geohazards such as earthquake and tsunami, as well as kinematic platforms of high altitudes., Key Points: New method for precise modeling of the zenith hydrostatic and wet delays from the Earth surface up to an altitude of 14 km. Tropospheric delay vertical modeling precision of better than 3 mm is achieved on a global scale. The method provides numerical weather model‐derived precise tropospheric augmentation correction for real‐time space geodetic techniques., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, China Scholarship Council CSC, Helmholtz OCPC Program, https://cds.climate.copernicus.eu/cdsapp

Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), Sugarcane streak mosaic virus (SCSMV), Sugarcane yellow leaf virus (SCYLV), and Sugarcane bacilliform virus (SCBV) are the major viruses infecting sugarcane worldwide. This study proposed a multiplex reverse transcription–polymerase chain reaction (RT–PCR) assay for the simultaneous detection and identification of these sugarcane viruses. Results showed that five primer pairs amplified their respective target viruses, indicating the assay specificity. The sensitivity of the assay was similar to or 10–100-folds lower than that of singleplex RT–PCR for detecting SCMV or the four other viruses, respectively. When detecting the five viruses in field sugarcane samples, the detection results of multiplex RT–PCR were approximately identical to those of singleplex RT–PCR, thereby indicating the relative reliability of the former. The proposed multiplex RT–PCR can simultaneously detect SCMV, SrMV, SCSMV, SCYLV, and SCBV in sugarcane, making it a suitable, efficient, and practical detection method for sugarcane viruses.

Sugarcane is an important sugar and energy crop worldwide. It utilises highly efficient C4 photosynthesis and accumulates sucrose in its culms. The sucrose content in sugarcane culms is a quantitative trait controlled by multiple genes. The regulatory mechanism underlying the maximum sucrose level in sugarcane culms remains unclear. We used transcriptome sequences to identify the potential regulatory genes involved in sucrose accumulation in Saccarum officinarum L. cv. Badila. The sucrose accumulating internodes at the elongation and mature growth stage and the immature internodes with low sucrose content at the mature stage were used for RNA sequencing. The obtained differentially expressed genes (DEGs) related to sucrose accumulation were analysed. Results showed that the transcripts encoding invertase (beta-fructofuranosidase, EC: 3.2.1.26) which catalyses sucrose hydrolysis and 6-phosphofructokinase (PFK, EC: 2.7.1.11), a key glycolysis regulatory enzyme, were downregulated in the high sucrose accumulation internodes. The transcripts encoding key enzymes for ABA, gibberellin and ethylene synthesis were also downregulated during sucrose accumulation. Furthermore, regulated protein kinase, transcription factor and sugar transporter genes were also obtained. This research can clarify the molecular regulation network of sucrose accumulation in sugarcane.

Hexokinase (HXK) catalyses hexose phosphorylation and senses glucose signalling to control carbon partition in plants. In sugarcane, HXK is involved in regulating source/sink carbon balance. However, the characteristics of sugarcane HXK genes remain unclear. This study revealed that the full-length cDNA sequence of the HXK gene ShHXK8 cloned from sugarcane mature leaves contains a 1560 bp open reading frame and encodes a putative protein of 519 amino acids. Amongst HXKs from monocot and dicot subjected to phylogenetic analysis, ShHXK8 was clustered into a monocot-specific group with OsHXK7, SbHXK8 and ZmHXK1. Gene expression analysis in Saccharum spp. hybrid ROC22 plants showed that ShHXK8 was expressed in leaves and stalks and expressed highly in mature leaves and young internodes. The difference in the expression of ShHXK8 was compared in high-sugar-content (HSC) and low-sugar-content (LSC) Saccharum officinarum plants. The expression of ShHXK8 in the leaves and internodes 3–24 of HSC plants was lower than that of LSC plants. The expression of ShHXK8 in the internodes 1–2 of HSC plants was higher than that of LSC plants. ShHXK8–GFP fusion was located in the cytosol by transiently expressing the corresponding vectors in rice mesophyll protoplasts. ShHXK8 might function as a cytoplasmic hexokinase involved in hexose metabolism in sugarcane mature leaves and young internodes.

In this paper, based on the high speed schlieren technology, the test observation platform of long gap discharge process and channel insulation recovery process was set up. The synchronization strategy was put forward too. Based on the applied voltage, discharge current and video image were recorded synchronously, discharge channel and electrode contact point of the spherical shock wave and cylindrical shock wave along the discharge channel were discovered after the long air gap breakdown. Statistics obtained the curve of cylindrical shock wave propagation speed and radius of the shock wave, and the influence law of the applying different voltage type on shock wave velocity.

Sugarcane streak mosaic virus (SCSMV, genus Poacevirus) causes sugarcane mosaic disease and leads to considerable economic losses. However, current methods for SCSMV diagnosis are limited. In this study, a novel isothermal assay was established on the basis of reverse transcription–recombinase polymerase amplification (RT-RPA) and evaluated in terms of its ability to detect SCSMV. The established RT-RPA assay with high specificity and reliability was 100-fold more sensitive than the RT-polymerase chain reaction. The evaluation of the temperature limit revealed that the assay had a flexible reaction temperature (26–46 °C), thereby indicating that the reaction mixture can be incubated with simple heating equipment, ambient temperature, or even human body heat. Time limit assessment results revealed that SCSMV can be detected in 5 min at 38 °C and in 20 min at 26 °C, thereby suggesting that the assay was rapid for SCSMV detection. Overall, the RT-RPA assay was specific, sensitive, reliable, and rapid for SCSMV detection, with a flexible and easily reachable reaction temperature. Thus, it can be an ideal method for SCSMV detection in sugarcane.

Sugarcane yellow leaf virus (SCYLV, genus Polerovirus) is a harmful agent that causes sugarcane yellow leaf disease. Current methods for SCYLV detection present some limitations. In this study, a novel isothermal amplification assay, namely reverse transcription-recombinase polymerase amplification (RT-RPA), was developed to promote SCYLV detection for disease management. The assay was evaluated in terms of specificity, sensitivity, reliability, temperature limit, and time limit. The developed RT-RPA assay was highly specific and non-cross-reactive with Potato leafroll virus, which is a type of species in Polerovirus. This assay can also detect at least 103-fold diluted cDNA from a SCYLV-infected sugarcane leaf, and its sensitivity is tenfold lower than that of RT-polymerase chain reaction (PCR). The reliability of the proposed assay was examined by detecting field sugarcane samples via RT-RPA and RT-PCR assays. The RT-RPA assay showed the same results as those of RT-PCR assay, indicating that the former was highly reliable for SCYLV detection. Analysis of the temperature and time limits revealed a wide operating temperature range from 27 to 45 °C, which was easily reached, and a rapid assay duration of 20 min. In summary, the developed RT-RPA assay was rapid, specific, and reliable with acceptable sensitivity and easily reachable operating temperature and thus could be a promising tool for SCYLV diagnosis in sugarcane.

Stone fruits have a single-core, and the core volume is large, located in the center of the fruit. In the process of transmission and reflection spectroscopic detection, the influence of fruit core on light cannot be ignored when light passes through flesh. Analyzing the difference in optical characteristics between stone fruits and citrus fruits tissues can provide a theoretical basis for the design of a reasonable optical detection device. It is of great significance for the optical detection of fruit quality. In this paper, a self-developed near-infrared diffuse reflection optical fibre probe with multi-point emission and multi-point reception is used to collect the diffuse reflection spectra of peach and navel orange, and compare the spectral characteristics of the two fruits. The spectral energy of peach is about twice as strong as the spectral energy of navel orange between 600 nm and 900 nm. Preprocess the spectral data with preprocessing methods to reduce the influence of noise and stray light. Compare the partial least squares (PLS) regression models of peach and navel orange. Experiments show that the results of using the baseline correction preprocessing method are all the best. The prediction correlation coefficient (Rp) of the peach is better than that of the navel orange and the root mean square error of the prediction (RMSEP) is also lower. The Rp of peach reached 0.92, and RMSEP was 0.32°Brix. It turned out that after light enters the fruit tissues, part of the light will be reflected out of the fruit when it encounters the core of the fruit. Therefore, in the diffuse reflection detection mode, stone fruits can receive more light and the spectral energy will be stronger than that of citrus fruits.

The smart substation plays an important role in the smart grid. This paper expounds the ideas of centralized protection and control unit (CPC) in smart substation, and analyzes the situation in the engineering applications.

As a key support for smart grids, the smart substation has formed a mature technical solutions after long-term development. In recent years, the internet of things technology has been applied in the whole aspects of power system transmission and distribution. Based on the extensive data collection and fusion, it has improved the state awareness, intelligent decision-making, and asset management capabilities of the power system. With the application of the internet of things technology, the development direction and technical architecture changes of smart substations are important topics that need to be considered at present. Based on the analysis of the current substation development route, this paper studies the applicability of electric power internet of things technology in smart substations, and proposes a smart substation technology solution that combines traditional technology routes and internet of things technologies, wishing to provide some reference for the research of smart substations. Chinese Library Classification Number: TM715

Genetically modified crops which had been commercial applied extensively majorly are the insect resistance and herbicide tolerance events. In this study, the Bt insecticidal gene Cry1Ab, the glyphosate-tolerant gene EPSPS, and the selection marker gene PMI were combined into a single transferred DNA fragment and introduced into sugarcane by Agrobacterium-mediated transformation. Thirty-three resistant plantlets were obtained after selection using a PMI/mannose selection system. Thirty of these resistant plantlets were PCR positive for the three target genes. Southern blot assay revealed that the copy number of the integrated fragment in the transformed plantlets varied from 1 to 7. ELISA analysis showed that 23 of the 33 resistant plantlets expressed Cry1Ab and EPSPS protein. Five single-copy and ELISA-positive transgenic lines were tested under laboratory and field conditions to determine their resistance to insects and herbicides, and also evaluated their agronomic characteristics and industrial traits. Results showed that larvae fed with fodder mixture containing stem tissues from single-copy transgenic lines were weak and small, moreover, pupation and eclosion were delayed significantly during voluntary feeding bioassays. None of transgenic sugarcane was destroyed by cane borer while more than 30% of wild type sugarcane was destroyed by cane borer. For herbicide resistance, the transgenic plantlets grew healthy even when treated with up to 0.5% roundup while wild type plantlets would die off when treated with 0.1% roundup. Thus demonstrate that these transgenic lines showed strong insect resistance and glyphosate tolerance under both laboratory and field conditions. But in the field most of the transgenic plants were shorter and more slender than non-transformed control plants. So they presented poor agronomic characteristics and industrial traits than non-transformed control plants. Thus, a considerable number of embryogenic calli should be infected to obtain transgenic lines with potential for commercial use.

Sucrose Metabolism and Regulation in Sugarcane Photo assimilates store in the form of sucrose in the stalks of sugarcane that provide 70% of world sugar. To meet the growing demand for sugar, it needs to increase the sugar yield. Sucrose accumulation is a complex physiological process controlled by network genes. This review summarized the development in the molecular regulation mechanism of sucrose accumulation in sugarcane. The molecular involving in source-sink communication, sucrose metabolism and storage were discussed. Although the sugar yield in sugarcane has not been increased by genetically modification, further researches to clarify the regulatory networks of sucrose accumulation will be helpful to breed high sugar content sugarcane.

In this paper, an alternating direction implicit (ADI) difference scheme for two-dimensional time-fractional wave equation of distributed-order with a nonlinear source term is presented. The unique solvability of the difference solution is discussed, and the unconditional stability and convergence order of the numerical scheme are analysed. Finally, numerical experiments are carried out to verify the effectiveness and accuracy of the algorithm., Comment: 25 pages, 3 figures

Based on high-speed and bidirectional communication network, smart grid can make the traditional power network reliable, economical and efficient operation with advanced sensing and measuring technology, modern control method and sophisticated decision support system. A kind of power information acquisition system (PIAS) is proposed. The power information can be collected, processed and stored by its data acquisition terminal, and then send to region server via ZigBee SZ02 according to server demands. PIAS can manage the power consumption information in specific region through local area network (LAN) and perform interaction with power company by using present public network. The testing and the calibration verify that the performance of data acquisition terminal is better than that of Watt-hour Meter with 0.2% accuracy.