Chemical Fractionation Of Cu And Zn And Their Impacts On Microbial Properties In Slightly Contaminated Soils

Chemical fractionation of Cu and Zn in bulk soil and its effects on soil microbial properties were determined in Cu and Zn contaminated soils (Cu: 35.57~46.37 mg·kg-1, Zn: 74.33~127.20 mg·kg-1) sampled from an agricultural field in outskirts of Zibo, China during the month of September, 2011. A sequential extraction technique (SET) was used for metals chemical fractionation analysis in soils and a correlation analysis was applied to determinate the effects of metal on soil microbial properties. Chemical speciation showed that Cu and Zn were mostly present in the residual fraction and their concentrations in the most labile fraction (acid soluble fraction) were the lowest in the investigated soils. However, the correlation analysis indicated that the labile forms of Cu/Zn, such as its acid soluble, reducible or oxidizable fractions, were usually significantly negatively correlated with the tested microbial activities at 0.05 or 0.01 probability levels. These results indicate that the metal labile fractions could exert an inhibitory effect on the soil microbial parameters even in the minor contaminated soils. Int. J. Agril. Res. Innov. & Tech. 3 (1): 20-25, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.1604

Assessment of Five Chilling Tolerance Traits and GWAS Mapping in Rice Using the USDA Mini-Core Collection

Rice (Oryza sativa L.) is often exposed to cool temperatures during spring planting in temperate climates. A better understanding of genetic pathways regulating chilling tolerance will enable breeders to develop varieties with improved tolerance during germination and young seedling stages. To dissect chilling tolerance, five assays were developed; one assay for the germination stage, one assay for the germination and seedling stage, and three for the seedling stage. Based on these assays, five chilling tolerance indices were calculated and assessed using 202 O. sativa accessions from the Rice Mini-Core (RMC) collection. Significant differences between RMC accessions made the five indices suitable for genome-wide association study (GWAS) based quantitative trait loci (QTL) mapping. For young seedling stage indices, japonica and indica subspecies clustered into chilling tolerant and chilling sensitive accessions, respectively, while both subspecies had similar low temperature germinability distributions. Indica subspecies were shown to have chilling acclimation potential. GWAS mapping uncovered 48 QTL at 39 chromosome regions distributed across all 12 rice chromosomes. Interestingly, there was no overlap between the germination and seedling stage QTL. Also, 18 QTL and 32 QTL were in regions discovered in previously reported bi-parental and GWAS based QTL mapping studies, respectively. Two novel low temperature seedling survivability (LTSS)–QTL, qLTSS3-4 and qLTSS4-1, were not in a previously reported QTL region. QTL with strong effect alleles identified in this study will be useful for marker assisted breeding efforts to improve chilling tolerance in rice cultivars and enhance gene discovery for chilling tolerance

An AT-hook gene is required for palea formation and floral organ number control in rice

AbstractGrasses have highly specialized flowers and their outer floral organ identity remains unclear. In this study, we identified and characterized rice mutants that specifically disrupted the development of palea, one of the outer whorl floral organs. The depressed palea1 (dp1) mutants show a primary defect in the main structure of palea, implying that palea is a fusion between the main structure and marginal tissues on both sides. The sterile lemma at the palea side is occasionally elongated in dp1 mutants. In addition, we found a floral organ number increase in dp1 mutants at low penetration. Both the sterile lemma elongation and the floral organ number increase phenotype are enhanced by the mutation of an independent gene SMALL DEGENERATIVE PALEA1 (SDP1), whose single mutation causes reduced palea size. E function and presumable A function floral homeotic genes were found suppressed in the dp1–2 mutant. We identified the DP1 gene by map-based cloning and found it encodes a nuclear-localized AT-hook DNA binding protein, suggesting a grass-specific role of chromatin architecture modification in flower development. The DP1 enhancer SDP1 was also positional cloned, and was found identical to the recently reported RETARDED PALEA1 (REP1) gene encoding a TCP family transcription factor. We further found that SDP1/REP1 is downstreamly regulated by DP1

The time-area fishing closure impacts on fish stock; Qiantang River before and after a four-month fishing closure

Fishing closures, commonly used to manage fisheries’ catch, involve temporarily closing a body of water to particular fishing gears to control fishing effort and protect feeding and spawning areas. In recent years in Qiantang River of China, with the socio-economic development, protection of fish stock has become increasingly urgent. The year 2019 was the first year that Qiantang River was included in the unified fishing ban system for the south of Yangtze River basin. Here, fish captures and hydroacoustic surveys were carried out in the research area of Qiantang River in order to present comparative descriptions of the dominant fish species, the temporal changes of fish size, density, biomass, and distribution affected by the four-month fishing closure in 2019. The results showed that Pseudobrama simoni (Bleeker, 1864) was the most dominant species both before and after the closure by using the traditional capture method. The mean target strength (TS) of overall fish after closure was –50.28 ± 0.19 dB, which was lower than that before, resulting in a significantly shorter derived mean length (13.42 ± 0.74 cm). The mean fish density and calculated biomass after closure were both significantly higher than that before it. More than 50% of fish species were distributed in the water of 5–20 m depth after the closure, which likely occurred in water deeper than 20 m before. Meanwhile, fewer outliers were found in different depth categories after closure. It is concluded that the four-month closure in 2019 had a positive effect on fish size, density, and biomass, leading to protection of pelagic fishes and a more even distribution of fish

CHEMICAL FRACTIONATION OF CU AND ZN AND THEIR IMPACTS ON MICROBIAL PROPERTIES IN SLIGHTLY CONTAMINATED SOILS

Chemical fractionation of Cu and Zn in bulk soil and its effects on soil microbial properties were determined in Cu and Zn contaminated soils (Cu: 35.57~46.37 mg·kg-1 , Zn: 74.33~127.20 mg·kg-1) sampled from an agricultural field in outskirts of Zibo, China during the month of September, 2011. A sequential extraction technique (SET) was used for metals chemical fractionation analysis in soils and a correlation analysis was applied to determinate the effects of metal on soil microbial properties. Chemical speciation showed that Cu and Zn were mostly present in the residual fraction and their concentrations in the most labile fraction (acid soluble fraction) were the lowest in the investigated soils. However, the correlation analysis indicated that the labile forms of Cu/Zn, such as its acid soluble, reducible or oxidizable fractions, were usually significantly negatively correlated with the tested microbial activities at 0.05 or 0.01 probability levels. These results indicate that the metal labile fractions could exert an inhibitory effect on the soil microbial parameters even in the minor contaminated soils

Characteristics and Changing Trend of Water Pollution in North Plain of Shang Yu

The plain river network area is strongly influenced by human activities, with flat terrain, weak hydrodynamics and poor water quality. Previous studies have mostly focused on water quality categories, lacking an overall study of the pollution characteristics of water bodies and their changing trends. In order to comprehensively grasp the water pollution situation of the river network in the northern Yu Plain, this study scientifically analysed the water quality characteristics of the river network in the northern Yu Plain and its correlation with rainfall through regression analysis and MK mutation test based on the long series of water quality and rainfall data of the Dongjin River and Unity River in the northern Yu Plain from 2017-2021. The results show that the correlation between water quality and rainfall in the river network of the northern Yu Plain is not significant, reflecting that the pollution in the watershed is still controlled by point sources, but there is a trend for the Unity River to change to non-point source control; the CODMn, NH3-N and TP of the Dongjin River and Unity River all show a high positive correlation, and the correlation of the Dongjin River is higher than that of the Unity River; the MK mutation test shows that there is no significant mutation point in the Dongjin River in the last five years, and the Unity River has no significant mutation point in the last five years. The MK mutation test shows that there is no significant mutation point in Dongjin River in the past 5 years, and there is a sudden change in water quality in Unity River from 2017 to 2018, and the water quality indexes show a decreasing trend in general, but remain stable in recent years. The study aims to academically reveal the dominant factors, pollutant characteristics and water quality trends of pollutants in rivers in the northern Yu Plain, and to propose scientific references for the pollution prevention and control of other plain river networks

Low-temperature oxidative dehydrogenation of propane over NiV mixed oxides derived from LDH precursors

A series of NiV mixed metal oxide (MMO) catalysts were derived from the NiV layered double hydroxides (LDHs) synthesized by the constant pH coprecipitation method. The synthesis parameters, (i) Ni/V molar ratio and (ii) calcination temperature (Tp), were controlled. The MMO catalysts were characterized by physicochemical characterization techniques and then tested for the oxidative dehydrogenation of propane (ODHP). The results showed that the calcination temperature affected the crystalline phase formation and grain size of NiO, as well as the activated temperature of propane, and the addition of V greatly regulated the activity and quantity of the surface oxygen species and improved the propylene selectivity. 4NiV-500 catalyst (Ni/V = 4, Tp = 500 °C) exhibited the best catalytic performance at low temperature (250 °C) with an initial propylene selectivity of about 70%. Therefore, it is an effective method to obtain NiV MMO catalysts with excellent low-temperature activity for ODHP, using LDHs as the precursors while controlling the appropriate amount of V and calcination temperature simultaneously

Length-to-weight and length-to-length relations of 15 freshwater fish species (Actinopterygii: Cypriniformes) from the Oujiang River, China

Length-to-weight and length-to-length relations were estimated for 15 freshwater fishes belonging to the order Cypriniformes from Yuxi power station to Kaitan reservoir dam trunk stream of the Oujiang River, Zhejiang Province, China. The following species were studied: Distoechodon tumirostris Peters, 1881, Xenocypris davidi Bleeker, 1871, Plagiognathops microlepis (Bleeker, 1871), Hemibarbus labeo (Pallas, 1776), Hemibarbus maculatus Bleeker, 1871, Chanodichthys erythropterus (Basilewsky, 1855), Culter alburnus Basilewsky, 1855, Chanodichthys dabryi (Bleeker, 1871), Opsariichthys bidens Günther, 1873, Zacco platypus (Temminck et Schlegel, 1846), Sinibrama macrops (Günther, 1868), Hemiculter leucisculus (Basilewsky, 1855), Pseudohemiculter hainanensis (Boulenger, 1900), Rhodeus sinensis Günther, 1868, and Squalidus argentatus (Sauvage et Dabry de Thiersant, 1874). The determination coefficients r2 of LWRs were all over 0.96, and the 15 values of parameter b were consistent with the predicted range of 2.5–3.5. The total length-to-standard length relations were also calculated with r2 ≥ 0.97. Our study provides new information on LWR for 1 species and LLRs for 8 species, as well as new maximum total length recorded for 4 species (i.e., Distoechodon tumirostris, Opsariichthys bidens, Pseudohemiculter hainanensis, and Rhodeus sinensis) in FishBase. This study is expected to provide a useful baseline for further studies of population parameters to improve management decisions on the Oujiang River

Model research and open sea tests of 100 kW wave energy convertor Sharp Eagle Wanshan

To find an efficient and economic way to convert wave energy, a one-base multi-buoy offshore floating wave energy converter Sharp Eagle Wanshan is designed, consisting of four absorbing buoys, one semi submersible barge, and other components. The working principle of the device is described in this paper. An experiment of a 1:13.78 model machine was carried out to test the hydrodynamic performance of the device and make an initial evaluation for the design The influence of wave period, wave height, work load and wave direction was tested. After construction, two-stage open sea tests have been finished in the waters near Wanshan Islands from November 2015 to June 2016. The device showed great power generation capacity with total generated output of 30530.57 kWh, and largest daily generation of 1847.09 kWh. During the open sea tests, the energy conversion efficiency was measured, and results show that capture width ratio of Wanshan remains higher than 20% in the wave period between 4 and 6.5 s and wave height range of 0.6-1.8 m. After operating in a wide range of conditions, including a tropical storm on May 27, amounts of tests data, experiences and lessons have been obtained and will be summed up and presented in the paper. (C) 2017 Elsevier Ltd. All rights reserved