BackgroundExploiting soil microorganisms in the rhizosphere of plants can significantly improve agricultural productivity; however, the mechanism by which microorganisms specifically affect agricultural productivity is poorly understood. To clarify this uncertainly, the rhizospheric microbial communities of super rice plants at various growth stages were analysed using 16S rRNA high-throughput gene sequencing; microbial communities were then related to soil properties and rice productivity.ResultsThe rhizospheric bacterial communities were characterized by the phyla Proteobacteria, Acidobacteria, Chloroflexi, and Verrucomicrobia during all stages of rice growth. Rice production differed by approximately 30% between high- and low-yield sites that had uniform fertilization regimes and climatic conditions, suggesting the key role of microbial communities. Mantel tests showed a strong correlation between soil conditions and rhizospheric bacterial communities, and microorganisms had different effects on crop yield. Among the four growing periods, the rhizospheric bacterial communities present during the heading stage showed a more significant correlation (p <  0.05) with crop yield, suggesting their potential in regulating crop production. The biological properties (i.e., microbes) reflected the situation of agricultural land better than the physicochemical characterics (i.e., nutrient elements), which provides theoretical support for agronomic production. Molecular ecological network (MEN) analysis suggested that differences in productivity were caused by the interaction between the soil characteristics and the bacterial communities.ConclusionsDuring the heading stage of rice cropping, the rhizospheric microbial community is vital for the resulting rice yield. According to network analysis, the cooperative relationship (i.e., positive interaction) between between microbes may contribute significantly to yield, and the biological properties (i.e., microbes) better reflected the real conditions of agricultural land than did the physicochemical characteristics (i.e., nutrient elements).Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1174-z) contains supplementary material, which is available to authorized users.

rGO was used for simultaneously anchoring AgNPs and Daptomycin to prepare rGO@Ag@Dap for anti-bacterium. The new nanomaterial showed strong Gram-positive bacteria killing ability in vitro and enhanced wound healing infected with S. aureus in vivo.

Repair of damaged areas in open-pit (opencast) coal mines has emerged as an important environmental concern. Our research investigated the mechanism by which different ecological restoration methods affected soil nematode communities in damaged areas of desert steppe coal mines. Using high-throughput sequencing technology, nematode community composition, diversity, and function were analyzed to determine the response of nematodes to different ecological restoration methods in damaged areas of coal mines. For slope rehabilitation, vegetation blanket restoration exhibited more favorable effects than those exhibited by vegetation bag restoration and natural restoration. For rehabilitation of the platform area under the slope, the diversity of soil nematodes and the soil fauna analysis under alien soil restoration conditions were performed and exhibited similar characteristics to those of the native vegetation. Findings based on Linear discriminant analysis Effect Size (LEfSe) multi-level discriminant analysis and determination of shared genera suggest that Paraphelenchus, Cervidellus, Panagrolaimus, Microdorylaimus, Cephalobus, and Ecumenicus may be the key genera of soil nematodes in the damaged ecosystem of open-pit coal mines in the desert steppe. We found that reasonable water and fertilizer management in slope restoration and under-slope platform area restoration may play a key role in the restoration of damaged ecosystems in open-pit coal mines. We comprehensively analyzed the response of soil nematode communities and their functions to different ecological restoration methods, and provided a reference for evaluating the quality of underground ecosystem restoration of damaged areas in abandoned desert steppe open-pit coal mines.

Ecological restoration of open-pit mine wasteland is critical to the sustainable development of the mining industry. Using high-throughput sequencing, we analyzed soil properties and nematode community structure and function to evaluate the impact of ecological package restoration on the quality of underground ecosystem reclamation in desert steppe open-pit mine wasteland. After 7 years of ecological package restoration at an open-pit quarry, two management methods (annual removal of dominant plant genera and annual reseeding of missing plants) achieved the expected outcomes of the restoration project (return to the conditions of the pre-disturbed ecosystem). Based on LEfSe multi-level discriminant analysis and shared genera analysis, we suggest that Oxydirus, Dorylaimus, Trichotylenchus, Plectus, Scutylenchus, Paratylenchus, Tylencholaimus, and Cephalobus may be the key soil nematode genera in the damaged open-pit quarry ecosystem. We also evaluated the soil health status of different ecological package restoration time periods (2 and 5 years) at an abandoned desert steppe open-pit iron mine by analysis of the soil properties and nematode communities. We suggest that ecological package restoration for 5 years achieved the expected restoration outcomes in the open-pit iron mine wasteland. Based on LEfSe analysis and shared genera analysis, we suggest that Acrobeles, Microdorylaimus, Cehalobus, Tripylina, and Ecumenicus may be the key soil nematode genera in the damaged open-pit iron mine ecosystem. Our findings provide a reference for evaluating the reclamation effect of ecological package restoration in open-pit mine areas.

The enhancement of rice production numbers can be achieved by using quality rice cultivars and fertilizers. The double rice cropping model has given rise to an important rice production system in southern China. Exploring the possibility of whether hybrid vigor could make a substantial contribution to early and late season rice production, and how the heterosis expression of hybrid rice functions under different levels of fertilizer application is of great significance. The objective of this study was to evaluate the grain yield and associated plant traits of popular hybrid and inbred rice varieties with large-scale promotion under conditions of customary (high) and combined (low) fertilization in the early and late seasons of 2017-18 in Changsha County, Hunan Province, China. We found that hybrid rice varieties displayed their respective advantages in the early and late rice seasons, but the advantages in their relative yield traits varied. The leading advantages of early season rice were effective panicle number per hill (EPN), 1000-grain weight (KGW), harvest index (HI), yield, and nitrogen use efficiency (NUE), whereas in late season rice, the foremost advantages were grain number per panicle (GNP), HI, yield, and NUE. The EPN was the prime advantage of early season hybrid rice with a short growth period, and the GNP was the main advantage of late season hybrid rice with a long growth period. Notably, the main yield advantage of hybrid rice was stronger under combined (low) fertilization than under customary (high) fertilization. Hence, high yield can be achieved by selecting the best hybrid rice varieties supported by combined fertilization (lower fertilizer use with higher efficiency).

Abstract Increasing rice production by using genetically improved rice cultivars and fertilizer application has been the main objective of rice farming. The double rice-cropping system has been an important rice production system in the middle and lower reaches of the Yangtze River in China since the 1950s. It is of great significance to determine whether hybrid vigor can make a substantial contribution to early- and late-season rice production, and how the heterosis expression of hybrid rice functions under different level of fertilization application. The objective of this study was to evaluate the grain yield and associated plant traits of popular hybrid and inbred rice varieties with large-scale promotion under conditions of customary (high) and combined (low) fertilization in the early and late seasons of 2017-18 in Changsha County, Hunan Province, central Southern China. We found that hybrid rice varieties displayed their respective advantages in the early- and late-rice seasons, but the advantages in their relative yield traits varied. The main advantages of early-season rice were effective panicle number per hill (EPN), 1000-grain weight (KGW), harvest index (HI), yield, and nitrogen use efficiency (NUE). Whereas in late-season rice, the major advantages were grain number per panicle (GNP), HI, yield, and NUE. The EPN was the main advantage of early-season hybrid rice with a short-growth period, and the GNP was the main advantage of late-season hybrid rice with a long-growth period. The main yield advantage of hybrid rice was stronger under combined (low) fertilization than under customary (high) fertilization. Hence, high yield can be achieved by selecting good hybrid rice varieties and by using combined fertilization (lower fertilizer use with higher efficiency). This work is contributive for rice growers, extension specialists, and fertilizer producers, as it provides data that can be used to maximize yields with reduced fertilizer and pesticide inputs.