Research Progress on the Growth-Promoting Effect of Plant Biostimulants on Crops

A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant biostimulants(PBs)in production can reduce the application of traditional pesticides and chemical fertilizers and improvethe quality and yield of crops,which is conducive to the sustainable development of agriculture.An in-depthunderstanding of the mechanism and effect of various PBs is very important for how to apply PBs reasonablyand effectively in the practice of crop production.This paper summarizes the main classification of PBs;Thegrowth promotion mechanism of PBs was analyzed from four aspects:improving soil physical and chemical properties,enhancing crop nutrient absorption capacity,photosynthesis capacity,and abiotic stress tolerance;At thesame time,the effects of PBs application on seed germination,seedling vigor,crop yield,and quality were summarized;Finally,how to continue to explore and study the use and mechanism of PBs in the future is analyzedand prospected,to better guide the application of PBs in crop production in the future.

Ecology and social system of northern gibbons living in cold seasonal forests

Gibbons in China represent the northernmost margin of present day gibbon species distribution （around N25°）. Compared to tropical habitats, northern gibbon habitats are characterized by low temperatures and remarkable seasonal variation in fruit abundance How gibbons adapt to their cold and seasonal habitats and what ecological factors affect their sociality are key questions for understanding their ecology and social system evolution, the elucidation of which will contribute to the conservation of these special populations/species. According to preliminary short-term studies, northern gibbons consume more leaves and use larger home ranges than tropical gibbons. Interestingly, some Nomascus groups consist of more than one adult female. However, these preliminary results are not well understood or incorporated into current socio-ecological theories regarding gibbon species. To better understand northern gibbons, our team has systematically studied three habituated groups of Nomascus concolor, three groups of N. nasutus, and two habituated groups of Hoolock tianxing since 2002. In this paper, we stress the challenges facing gibbons living in northern habitats and summarize their behavioral adaptations to their harsh environments. We also describe the northern gibbon social system and discuss the potential relationships between their ecology and sociality. Finally, we highlight future research questions related to northern gibbons in China.

A continuing 30-year decline in water quality of Jiaojiang Estuary, China

A quantitative description of a long-term series of aquatic environmental factors and their spatial distributions was generated using measured data from the Jiaojiang Estuary from 1982 to 2011. The aquatic environmental factors included suspended matter, salinity, and nutrients. Based on these factors, the aquatic ecosystem health in the Jiaojiang Estuary over the last 30 years was analyzed. The results indicated that the suspended matter concentration in the estuary was mainly affected by the amounts of suspended sediment and solid waste, with the value fluctuating over a long period, and the range of high concentration expanded continually; the salinity was mainly affected by precipitation and surface water resources, showing an overall decreasing trend, and the region with low salinity moved seaward and toward the reclamation areas; and the nutritional status, mainly affected by discharge of industrial wastewater and domestic sewage, was satisfactory in the 1980s and 1990s, but the status became severe in recent years. Reclamation had a great influence on these three factors： high reclamation strength led to a significant increase in the suspended matter concentration and a deterioration of the nutritional status, and the reclamation rate was negatively related with the salinity in the estuary. There was a significant positive correlation between the health status of the aquatic ecosystem and salinity, with a correlation coefficient of 0.93. The correlation coefficient between the health status and nutritional status was -0.71, while the correlation between the suspended matter concentration and health status was not as significant as that of the other two factors. The dynamics of the aquatic environment could be divided into four stages： sustainable health from the 1980s to the 1990s, continued deterioration from 2000 to 2003, improvement from 2004 to 2005, and secondary deterioration from 2006 to 2011. The Jiaojiang Estuary is faced with imminent environmental pressure at present.

Proximity association in polygynous western black crested gibbons(Nomascus concolor jingdongensis):network structure and seasonality

We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network analysis.The spatial proximity changed seasonally and was affected by temperature and rainfall.Preferred proximity association was not distributed randomly among individuals.Kinship was one explanation for the social structure,as offspring preferred to maintain close proximity with their mothers.The proximity of infants to mothers decreased with age,and independent offspring had lower proximity to mothers than dependent ones.We found that the adult male had different proximity relationships with two different adult females.The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group.Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences.Temperature influenced group proximity association,with individual proximity increasing in the cold months and decreasing in the hot months.Group proximity decreased in months with higher anthropogenic disturbance.

Proximity association in polygynous western black crested gibbons (Nomascus concolor jingdongensis): network structure and seasonality

We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally and was affected by temperature and rainfall. Preferred proximity association was not distributed randomly among individuals. Kinship was one explanation for the social structure, as offspring preferred to maintain close proximity with their mothers. The proximity of infants to mothers decreased with age, and independent offspring had lower proximity to mothers than dependent ones. We found that the adult male had different proximity relationships with two different adult females. The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group. Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences. Temperature influenced group proximity association, with individual proximity increasing in the cold months and decreasing in the hot months. Group proximity decreased in months with higher anthropogenic disturbance.

Microbial Communities in Water during Red Tides along the Coast of China-A Case Study of Prorocentrum Donghaiense Red Tide in the East China Sea

Red tides are a major public hazard in the global oceans.The coast of the East China Sea is the sea area where red tide disasters are the most frequent and serious in China.In order to accurately grasp the occurrence of red tides in the coastal waters of the East China Sea,and to understand the microbial communities in the waters during the occurrence of red tides in the East China Sea,a special survey of red tides in the coastal waters of Zhejiang,China was carried out in June 2018.The results showed that nutrient concentrations of N and P were generally high in this area,DIN concentrations in most areas exceeded the permitted limit of Chinese seawater quality grade I.There were significant differences in dissolved oxygen,pH,COD,chlorophyll and phytoplankton abundance of red tides.During the investigation,red tides were found in the waters near the Yushan Islands.The content of chlorophyll a was 42.12mg/m3,the cell abundance of phytoplankton was 8.16×108/L,and the abundance of Prorocentrum edulis accounted for 98.5%.The Illumina MiSeq sequencing platform was used for 16s high-throughput sequencing of water microorganisms,and a total of 16 bacteria were identified.Proteobacteria is the first dominant phylum,followed by Cyanobacteria and Bacteroides.Some differences in bacterial community compositions between HAB and the nearby seawater were observed.The predominant bacteria in the red tide occurrence area were Proteobacteria,comprising 46.1%of the relative abundance;while the predominant bacteria in the nearby sea area,comprising 42.0%of the relative abundance.

Occurrence and distribution of antibiotic resistance genes in the sediments of the East China Sea bays

The coastal area of the East China Sea has experienced rapid urbanization and industrialization in China since 1980 s, resulting in severe pollution of its environments.Antibiotic resistance genes(ARGs) are regarded as a kind of emerging pollutant with potential high risk. The sediment samples were collected from Hangzhou Bay(HB),Xiangshan Bay(XB), and Taizhou Bay(TB) to investigate the spatial occurrence and distribution of 27 ARGs and class I integron–integrase gene(intI1) in the coastal area of the East China Sea. The PCR results showed the frequent presence of 11 ARGs and intI1 in the sediments of the three bays. The qPCR results further showed that sulfonamide resistance was the most prevalent ARG type and antibiotic target replacement and protection were the most important resistance mechanisms in the sediments. Regarding the subtype of ARGs, sulI, tetW, and dfrA13 were the most abundant ARGs, in which sulI was higher in TB(based on both the absolute and relative abundances) and dfrA13 was higher in HB(based on the relative abundances). The network analysis revealed that intI1 had significant correlations with tetC, sulI, sulII, and blaPSE-1. Oil was the key connected factor, which had positive connections with sulI, sulII, and blaPSE-1. In addition, the joint effect of heavy metals and nutrients & organic pollutants might be crucial for the fate of ARGs in the coastal sediments.

Ubiquitous indoor vision navigation using a smart device

GPS-based technology has served the positioning and navigation industry for decades with outstanding reliability and accuracy.However,limitations for location-based services in indoor scenarios remain where GPS signal reception suffers from severe degradation or even outages.Wi-Fi-based positioning is currently the most popular indoor location solution,with an availability and time-to-first-fix that are significantly better than GPS.However,the achievable position accuracy is only at the level of tens of meters on average depending on database density and signal reception quality.In order to improve positioning accuracy and availability,motion sensors like accelerometers,gyros,and magnetic compasses are increasingly integrated into smart devices.However,their position solutions suffer from the effects of significant accumulative errors.In this paper,a vision-based indoor positioning method is developed to overcome the limitations above.The proposed vision-based system relies on a single camera,widely available on smart phones and tablets.The derivation of the absolute 3D position from 2D snapshots of a single camera requires the use of an external geo-reference database.In this research,a ubiquitous floor plan database has been used to provide accurate geodetic information.Unlike other popular geo-reference databases,the database used in this work can easily be generated with existing resources.The proposed system has been developed as an iOS App and was tested on iPad for various indoor scenarios.The results show that the performance of the proposed system is superior to Wi-Fi-based positioning systems.

Identifying human-induced influence on microbial community:A comparative study in the effluent-receiving areas in Hangzhou Bay

Microbial community structure is afiected by both natural processes and human activities.In coastal area,anthropegenetic activity can usually lead to the discharge of the effluent from wastewater treatment plant(WWTP)to sea,and thus the water quality chronically turns worse and marine ecosystem becomes unhealthy.Microorganisms play key roles in pollutants degradation and ecological restoration;however,there are few studies about how the WWTP effluent disposal influences coastal microbial communities.In this study,sediment samples were collected from two WWTP effluentreceiving areas(abbreviated as JX and SY)in Hangzhou Bay.First,based on the high-throughput sequencing of 16S rRNA gene,microbial community structure was analyzed.Secondly,several statistical analyses were conducted to reveal the microbial community characteristics in response to the effluent disposal.Using PCoA,the significant difference of in microbial community structure was determined between JX and SY;using RDA,water COD and temperature,and sediment available phosphate and ammonia nitrogen were identified as the key environmental factors for the community difference;using LDA effect size analysis,the most distinctive microbes were found and their correlations with environmental factors were investigated;and according to detrended beta-nearesttaxon-index,the sediment microbial communities were found to follow"niche theory".An interesting and important finding was that in SY that received more and toxic COD,many distinctive microbes were related to the groups that were capable of degrading toxic organic pollutants.This study provides a clear illustration of eco-environmental deterioration under the long-term human pressure from the view of microbial ecology.

Observation of intra-group and extra-group copulation and reproductive characters in free ranging groups of western black crested gibbon(Nomascus concolor jingdongensis)

Black crested gibbons(Nomascus concolor)are 1 of only 3 gibbon species that have been observed in long-term polygynous groups,but their mating behavior and reproductive characters have never been reported.Based on population monitoring over 7 years and direct observation for 26 months of the study groups in Wuliang Mountain,central Yunnan,we describe for the first time the copulation behavior and breeding pattern of free-ranging western black crested gibbons.The gestation period of black crested gibbons is estimated to be between 6 and 7 months.The average breeding interval is 3.5 years,with infant independence at approximately 2.5 years.We observed 2 intra-group copulations and 5 extra-group copulations.Copulations were initiated when a female gave a‘solicitation’gesture.When a male made any mating attempt,the female might refuse it.These results demonstrate direct female mate choice.Both male and female gibbons dispersed from their natal groups and sometimes replaced paired adults in other groups.We observed no evidence of infanticide during inter-group conflicts or after replacement of adults.Together with extra-group copulations,these phenomena indicate a flexible social organization and complex mating system.We also observed a male-biased sex ratio among offspring.More genetic work is necessary to describe the effects of inter-group copulation and the genetic diversity of this population.