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Seasonal (temporal) variations can influence the δ13C, δ2H, δ18O, and δ15N values and nutrient composition of organic (ORG), green (GRE), and conventional (CON) vegetables with a short growth cycle. Stable isotope ratio mass spectrometry (IRMS) and near-infrared spectroscopy (NIRS) combined with the partial least squares-discriminant analysis (PLS-DA) method were used to investigate seasonal effects on the identification of ORG, GRE, and CON Brassica chinensis L. samples (BCs). The results showed that δ15N values had significant differences among the three cultivation methods and that δ13C, δ2H, and δ18O values were significantly higher in winter and spring and lower in summer. The NIR spectra were relatively clustered across seasons. Neither IRMS-PLS-DA nor NIRS-PLS-DA could effectively identify all BC cultivation methods due to seasonal effects, while IRMS-NIRS-PLS-DA combined with Norris smoothing and derivative pretreatment had better predictive abilities, with an 89.80% accuracy for ORG and BCs, 88.89% for ORG and GRE BCs, and 75.00% for GRE and CON BCs. The IRMS-NIRS-PLS-DA provided an effective and robust method to identify BC cultivation methods, integrating multi-seasonal differences. [ABSTRACT FROM AUTHOR]

Chromate [Cr(VI)] is a highly toxic heavy metal element, representing one of the most prevalent sources of wastewater contamination. It poses a significant threat to human health and food safety. Therefore, effective treatment before discharging wastewater is of paramount importance. In this study, termite nests (Coptotermes formosanus and Odontotermes formosanus), as natural biomass materials, were used to adsorb Cr(VI) ions in wastewater as a strategy to reduce environmental pollution and minimize poisoning by Cr. Structural and morphological characterizations were performed using scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. Batch adsorption experiments were conducted to evaluate the influence of termite nest dosage, coexisting ions, and pH. To gain further insight, detailed studies on adsorption kinetics, adsorption isotherms, and adsorption thermodynamics were undertaken. The results indicate that under acidic pH conditions, both termite nests exhibit the highest adsorption capacity for Cr(VI), with an optimal adsorbent dosage of 10 g/L. The maximum adsorption capacities of C. formosanus nest and O. formosanus nest for Cr(VI) were found to be 48.52 mg/g and 35.99 mg/g, respectively. Thermodynamic studies confirmed the spontaneous and endothermic nature of the adsorption process. In the rapeseed cultivation experiment, the growth status of Brassica chinensis L. post-adsorption treatment wasmarkedly improved compared to the untreated group. Additionally, the concentration of Cr(VI) in the plants was significantly reduced. This demonstrates both the inhibitory effect of Cr(VI) on the growth of oilseed rape and the effectiveness of water remediation techniques. In addition, both types of termite nests can be effectively reused by 0.1 mol/L HCl. To the best of our knowledge, this is the first report of adsorption removal of Cr(VI) by C. formosanus nest and O. formosanus nest. Compared to traditional natural biomass adsorbents, termite nests exhibit a relatively higher adsorption capacity for Cr(VI). The results of this study demonstrate that subterranean termite nests can efficiently remove Cr(VI) from wastewater, offering the potential for a cost-effective and reusable bioremediation agent with the advantages of ease of operation. [ABSTRACT FROM AUTHOR]

In order to evaluate the ability of microorganism in the rhizosphere of Brassica chinensis L. to decompose the organic phosphorus> the taxonomic status of its dominant phosphate-solubilizing bacteria was clarified, and the culture conditions were further optimized, thus to provide the basis for the development of microbial fertilizers. The organic phosphorus-decomposing bacteria in the rhizosphere of Brassica chinensis L. were screened by using the Mengjinna organic phosphorus plate method, and the phosphate-solubilizing ability of the strains was analyzed through the molybdenum antimony resistance colorimetric method. Then, the colonial morphology of the dominant phosphate-solubilizing bacteria was further observed. And the phylogenetic tree was constructed through the homology comparison of 16S DNA sequence and nearest neighbor method to determine the taxonomic status of the dominant strain FG5. Last, the optimum culture conditions of strain FG5 were further explored by using the single factor and orthogonal experiments. The results showed that.: three strains of organic phosphate-solubilizing bacteria were isolated and screened from the rhizosphere of Brassica chinensis L., among which the strain FG5 had the best phosphate-solubilizing effect. After the inoculation with strain FG5 and culture for 3 days, the mass concentration of free phosphorus in the medium was as high as 165. 20 ug • mL_1. The colony of FG5 was circular with a dry surface and slight protrusions, and the edges were wavy off white. The homology comparison results of the 16S DNA sequence indicated that the strain FG5 was Bacillus tequilensis. The results of single factor and orthogonal experiments showed that the optimum culture conditions for the strain FG5 were as follows: mannitol as carbon source, urea as nitrogen source, culture temperature of 27°C, rotational speed of 180 r • min-1, inoculation amount of 1.5% (V/V). Under this condition, the phosphate-solubilizing ability of FG5 reached 307. 25 ug • mL-1, which was 85. 99% higher than that before the optimization of culture conditions. The strain FG5 had a strong ability to decompose the organic phosphorus and had good potential for the application of microbial fertilizers. [ABSTRACT FROM AUTHOR]

Seasonal (temporal) variations can influence the δ13C, δ2H, δ18O, and δ15N values and nutrient composition of organic (ORG), green (GRE), and conventional (CON) vegetables with a short growth cycle. Stable isotope ratio mass spectrometry (IRMS) and near-infrared spectroscopy (NIRS) combined with the partial least squares-discriminant analysis (PLS-DA) method were used to investigate seasonal effects on the identification of ORG, GRE, and CON Brassica chinensis L. samples (BCs). The results showed that δ15N values had significant differences among the three cultivation methods and that δ13C, δ2H, and δ18O values were significantly higher in winter and spring and lower in summer. The NIR spectra were relatively clustered across seasons. Neither IRMS-PLS-DA nor NIRS-PLS-DA could effectively identify all BC cultivation methods due to seasonal effects, while IRMS-NIRS-PLS-DA combined with Norris smoothing and derivative pretreatment had better predictive abilities, with an 89.80% accuracy for ORG and BCs, 88.89% for ORG and GRE BCs, and 75.00% for GRE and CON BCs. The IRMS-NIRS-PLS-DA provided an effective and robust method to identify BC cultivation methods, integrating multi-seasonal differences.

[Objective]To screen the most suitable organic carbon fertilizer for the growth of Brassica chinensis L. . [Method]Brassica chinensis L. was used as the study material to explore the effects of different organic carbon fertilizers (brown sugar, sucrose, humic acid) on the yield and quality. [Result]The results showed that treatments of different kinds of organic carbon fertilizer could promote the yield increase of Brassica chinensis L., and the treatment of humic acid had the most significant effect with the yield increased by 21. 83%. The contents of soluble sugar, soluble protein and VC were the highest in humic acid treatment, and the contents of chlorophyll and carotene were increased. There were no significant differences in soluble solids and dry weight among the treatments. [Conclusion]The application of humic acid can improve the yield and quality of Brassica chinensis L. . [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

PLDxL copolymers were synthesized from physically stable rigid poly(l‐lactic acid) (PLLA) and a few different molecular weights of polydimethylsiloxane (PDMS) to increase the O2 and CO2 permeabilities of PLLA films and make them acceptable for packaging highly respirable products. The effect of PDMS on the morphology, mechanical properties, and gas permeability of PLDxL was investigated. Copolymers showed approximately 10 times the fracture strain and 1.7 times the CO2 and O2 permeabilities of neat PLLA. Additionally, PLDxL maintained an increased CO2/O2 perm‐selectivity consistent between 5 and 40°C. Passive modified atmosphere packaging of Brassica chinensis L was developed to assess the membrane's impact on headspace gas inside the package. The results showed that poly(amide)/poly(ethylene) packaging with 48 cm2 PLD1.8L membrane as a breathing window can provide 50 g B. chinensis L. with a healthy atmosphere of 3%–8% O2 and 5%–8% CO2 between 6 and 22 days. Vegetables packaged in PLD1.8L had the lower respiration rate, lower nitrite contents, and less proliferation of microorganisms. Moreover, a suitable atmosphere kept vegetables with higher ascorbic acid and a good appearance after more than 2 weeks of storage at 5°C. Practical Application: The permeability of the PLLA‐based membrane can be adjusted for the breathable window membrane of sealed fresh products. In the future, several types of film could be developed to match the respiratory and metabolic characteristics of different kinds of products. Such PLLA‐based specialized membranes can refine the fresh‐keeping function and be more attractive to the customer. [ABSTRACT FROM AUTHOR]

Biochar is widely used in agriculture to efficiently solve the problem of sludge. In this study, sludge-based biochar (referred to as BC1, BC2, and BC3) was prepared by mixing sludge with FeCl3, Na2SiO3, and Ca (H2PO4)2, respectively. Then, it was mixed with fresh soil to plant Brassica chinensis L. The analysis of the effects of the three biochar types showed that all of them were beneficial to the growth of Brassica chinensis L. We added the biochar to the soil and found that the concentration of heavy metals did not exceed the recommended threshold. Additionally, the aboveground part of Brassica chinensis L. met the standard requirement for food safety (GB 2761–2017). Notably, BC3 stood out with the best effect on the growth of Brassica chinensis L. and resulted in the improvement of the physical and chemical properties of soil such as ammonium nitrogen, available phosphorus, and available potassium (BC3 was followed by BC2 and BC1). BC3 could efficiently inhibit the migration of heavy metals, thereby reducing the overall heavy metal pollution level and ameliorating the soil nutrients. BC3 could increase the organic carbon by 258.92%, available phosphorus by 234.45%, and available potassium by 37.12% compared with the CK group. The THQ and TTHQ estimates of Brassica chinensis L. were lower than one, indicating that the health risk of heavy metal intake was not prominent. Additionally, the application of the proposed biochar could reduce the form of F1 (acid extracted state) and increase the form of F4 (residue state) in soil. Overall, we conclude that the application of the proposed biochar can promote the root absorption of heavy metals and inhibit the migration of heavy metals. [ABSTRACT FROM AUTHOR]

【Objective】The study was conducted to explore the remediation effects of biochars derived from mulberry and cinnamon branches on cadmium(Cd) pollution in water and soil environments, with a view to providing a theoretical basis for the resource utilization of woody agroforestry wastes and the remediation of Cd-contaminated environment.【Method】Both mulberry and cinnamon branches were slowly pyrolyzed under 400℃ for 2 h. The obtained biochars were tested for their isothermal adsorption of Cd, and then added into the Cd contaminated soil grown with Brassica chinensis L. in a pot experiment.【Result】Adsorption of Cd b y either mulberry biochar (MB400) or cinnamon biochar (CB400) could be fitted by Langmuir isothermal equation, and the maximum adsorption capacities (Q0) were 4 305.61 mg/kg and 442.77 mg/kg, respectively. It was obvious that MB400 had much higher capacity for adsorption of Cd than that of CB400 treatment, which may be attributed to its higher values in pH, ash and CEC and available phosphorus(AP). Furthermore, MB400 addition significantly reduced the content of available cadmium(AvCd) while it showed little effect under CB400 treatment. The dry matter of B. chinensis L. was remarkably enhanced by adding both biochars. The bioconcentration factor(BCF) of Cd decreased from 5.95 in the control to 4.29 (MB400) and 4.85 (CB400).【Conclusion】Both biochars had high adsorption capacity for Cd, and could inactivate Cd availability and thereafter inhibited Cd accumulation in cabbage tissue. MB400 showed better effect than CB400.

As a functional probiotic, Bacillus subtilis can promote crop growth and improve nutrient utilization by various mechanisms, so it has been made into bioorganic fertilizer as a replacement for chemical fertilizer. However, the effects of B. subtilis bioorganic fertilizer application on the yield and quality of commercial crops of Brassica chinensis L., the soil physicochemical properties and the microflora have not been clarified. In this study, pot experiments were conducted using Brassica chinensis L. plants with four fertilization treatments: control without fertilization (CK), chemical fertilizer (CF), organic fertilizer (OF), and bioorganic fertilizer containing B. subtilis (BF). After 30 days of pot experiment, the results showed that BF efficiently improved plant height and biomass (1.20- and 1.93-fold, respectively); as well as significantly increasing soil available potassium and pH value. Using high-throughput sequencing, we examined the bacterial and fungal communities in the soil, and found that their diversity was remarkablely reduced in the BF treatment compared to CK group. A principal coordinate analysis also showed a clear separation of bacterial and fungal communities in the BF and CK groups. After application of B. subtilis bioorganic fertilizer, some beneficial bacteria (such as Bacillus and Ammoniphilus) and fungi (Trichoderma and Mortierella) were enriched. A network analysis indicated that bacteria were the dominant soil microbes and the presence of B. subtilis stimulated the colonization of beneficial microbial communities. In addition, predictive functional profiling demonstrated that the application of bioorganic fertilizer enhanced the function of mineral element metabolism and absorption and increased the relative abundance of saprotrophs. Overall, the application of bioorganic fertilizer effectively changed the soil microflora, improved the soil available potassium and pH value, and boosted the yield of Brassica chinensis L. This work has valuable implications for promoting the safe planting of facility vegetables and the sustainable development of green agriculture. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND Water is critical to the production of crops, especially when faced with seasonal drought or freshwater scarcity. We compared the effect of negative pressure irrigation (NPI) on water use efficiency (WUE), nutrient uptake, yield and quality of Brassica chinensis L. using a greenhouse plot experiment. Three different water supply pressures (−5, −10 and −15 kPa), and a conventional irrigation (CK) treatment, were arranged in a randomized design with three replications. RESULTS: Our results suggest that plant height, leaf area, number of leaves and ratio of root to shoot were significantly correlated with water supply pressure. Specifically, our results show that B. chinensis L. yield was increased 50% with NPI versus CK. Water supply pressure had a significant effect on N and P nutrient uptake and no significant effect on K. The average concentration of vitamin C was greatest with −5 kPa treatment and consecutively declined. According to our results, NPI can save up to 36.8% of water used and improve WUE by 61.3% during growth of B. chinensis L. Our results suggest that the optimum irrigation management strategy is −5 kPa treatment. CONCLUSION: NPI versus CK can provide more stable irrigation water and retain soil moisture during plant growth, resulting in an increased WUE and yield with suitable water supply pressure. While our results suggest that NPI can enhance B. chinensis L. yield and perhaps also quality, future research should explore the mechanism of NPI in relation to yield and water use efficiency. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study the effects of metal-based nanoparticles on the germination and growth of vegetable seeds, an experiment was conducted in July 2017 to explore the effects of different zinc oxide nanoparticles（ZnO NPs）and zinc sulfate（ZnSO4）treatments（0, 50, 100, 200, 500, 700, and 1 000 mg·L-1）on germination performance and seedling growth of Raphanus sativus L. and Brassica chinensis L.. Results showed no significant difference in the germination rate between the two vegetable crops under different ZnO NPs and ZnSO4 treatments（P>0.05）when compared with the control; while the biomass of both vegetables was inhibited. ZnO NPs and ZnSO4 inhibited the root length of both vegetables more than their shoot length. The inhibition rate of ZnO NPs on root elongation of both vegetables was greater than that of ZnSO4, while it increased with an increase in treatment concentration, reaching up to 98% at 1 000 mg L-1. However, ZnSO4 inhibited shoot growth of both vegetables much more than ZnO NPs. The results revealed that although ZnO NPs and ZnSO4 had no significant effect on the germination of both vegetables, they both inhibited the root length and shoot length to some extent. [ABSTRACT FROM AUTHOR]

【Objective】In order to study the optimal NPK ratio for Brassica chinensis L..【Methods】Part of “3414” fertilizer effect strategy was used to design Brassica chinensis L. fertilization experiment. Combined with the changes of soil nutrient composition,the biomass and soil nutrient content of Brassica chinensis L. were compared under different treatments. 【Results】The fresh weight and NPK content of Brassica chinensis L. Using N2P2K2 fertilization strategy were significantly higher than other treatments. This strategy was highly beneficial to maintain the soil nutrition structure and prevent soil alkalization. It was determined that the N2P2K2 fertilization strategy was better.【Conclusion】 On this basis,the optimal fertilization strategy for Brassica chinensis L. was revised to be 2.373∶2∶2 by curve fitting of nitrogen fertilizer effect on the P2K2 level. Using the optimal NPK ratio,the fresh weight and NPK content of Brassica chinensis L. were close to the maximum point,making the return the highest. [ABSTRACT FROM AUTHOR]

Multiple insecticides’ residues after the mixed application of several neonicotinoids cause combined pollution and bring new challenges to food safety and pest control during agricultural production. In this study, three neonicotinoid insecticides, namely imidacloprid (IMI), acetamiprid (ACE), and thiamethoxam (TMX), were mixed and evenly sprayed on Brassica chinensis L. in the field. Then, the insecticides’ residues were dynamically monitored to determine the differences in their rates of dissipation and final residues after 10 days. The results showed that the dissipation kinetics of neonicotinoids still conformed to the first-order kinetic model for binary or ternary application of neonicotinoid mixtures, with all determination coefficients (R2) being above 0.9 and the dissipation half-life (DT50) being 2.87–6.74 d. For treatment groups with five times the recommended dosages (IMI 300 g·hm−2, ACE 900 g·hm−2, and TMX 600 g·hm−2), mixed insecticides had a slower dissipation rate, and the DT50 values of mixtures were longer than those of single insecticides. Moreover, the final insecticide residues with mixed application were higher than those of single compounds at 10 d after spraying. Thus, mixed applications of neonicotinoids may increase food safety risks as they increase the final insecticide residues in Brassica chinensis L., and care should therefore be taken when considering the combined use of such compounds.

Sucrose is crucial for plant growth, but research about the effect of sucrose on the uptake of different nitrogen (N) and the metabolism of glycine is lacking. The uptake of glycine by pakchoi, when it was in a mixture of glycine, nitrate, and ammonium or acted as the single N source under different sucrose levels were detected in a sterilized environment. The optimal sucrose level for pakchoi growth varied with N supply; it was 6 μM in the single N source of glycine, while it was 15 μM in the mixture. The N contribution of glycine increased under the optimal sucrose, while the N contribution of ammonium decreased. The effect of exogenously supplied sucrose on the uptake and metabolism of glycine is dependent on the N supply. With the single N source, the metabolism of glycine to serine in roots rather than uptake was the limiting step under a high sucrose level (300 μM). In the mixed nitrogen, active uptake and the metabolism of glycine to serine are the limiting steps under high sucrose level. Externally supplied sucrose affects the absorption and metabolism of glycine by pakchoi greatly, and this effect varied with nitrogen supply. [ABSTRACT FROM AUTHOR]

The research took Trichoderma strain as tested strains which isolated from the rhizosphere of healthy and high yield pepper, M2 was classified and identified by combining morphological classification with molecular identification means(rDNA-ITS sequence analysis), whose effect on growth of Brassica chinensis L. was explored, in order to provide superior strains for bio-fertilizer development. After solid fermentation of Trichoderma M2, under the condition of the greenhouse, took some research on the growth promoting effect on Brassica chinensis L. of Trichoderma M2. The results showed that the strain M2 was identified as Trichoderma harzianum strain. M2 had obvious effects on promoting growth, the SPAD and edible leaf number of Brassica chinensis L. Adding of 5.0×109 cfu M2 had the best effect on increasing the biological yield. Compared with CK, fresh weight and dry weight was increased by 30.26%and 20.08%respectively. Followed by inoculation of 5.0×108 cfu M2, fresh weight and dry weight was increased by 18.33% and 12.46% respectively. Therefore, M2 showed evident promoting effect on Brassica chinensis L., and had potential application value. [ABSTRACT FROM AUTHOR]

To investigate the effects of nano-copper oxide (CuO NPs) on plant growth, physio-biochemical characteristics, and heavy metal content under cadmium stress, a hydroponics experiment was conducted on the effects of single and combined treatments of CuO NPs (0, 10, 20, and 50 mg·L -1 ) and Cd (0, 1, and 5 μmol·L -1 ) on the fresh weight, photosynthetic pigment content, MDA content, antioxidant enzyme activity (CAT, POD, SOD, and GR), and Cu and Cd contents in Brassica chinensis L. The results showed that under the single addition of CuO NPs, the fresh weight and activities of CAT, POD, and GR were inhibited as a whole. Photosynthetic pigment content and SOD activity increased first and then decreased with the increase in CuO NPs concentration, whereas MDA content in leaves and roots, and Cu content in subcells of B. chinensis L. increased with the increasing of CuO NPs. As compared with that in the control, CuO NPs promoted the growth of B. chinensis L., and the fresh weight increased by 8.70%-44.87% at 1 μmol·L -1 Cd. When the content of Cd was up to 5 μmol·L -1 , a low content (10 mg·L -1 ) of CuO NPs promoted the growth of B. chinensis L., whereas a high concentration (50 mg·L -1 ) showed an inhibitory effect. The addition of CuO NPs could increase photosynthetic pigment and MDA contents under different Cd stress, and MDA content in leaves and roots of B. chinensis L. increased by 4.34%-36.27% and 13.43%-131.04%, respectively, than that in the control groups. Under the same concentration of 1 μmol·L -1 Cd, the addition of CuO NPs decreased the activities of CAT and GR, whereas the activity of POD increased. When the content of Cd was up to 5 μmol·L -1 , CuO NPs increased the POD activity and inhibited the activity of SOD and GR. The activities of CAT and CAT in the leaves of B. chinensis L. initially showed an increasing and then decreasing trend. CuO NPs and Cd showed antagonistic effects, the maximum reduction of Cd content in leaves and roots of Brassica chinensis L. under 1 μmol·L -1 Cd treatment was 45.64% and 33.39%, and that under 5 μmol·L -1 Cd treatment was 18.25% and 25.35%, respectively. The content of Cu and Cd in subcellular organs of the plants decreased, but the proportion of soluble components increased. These results indicated that CuO NPs at low concentrations promoted plant growth under Cd stress and further inhibited the absorption of Cd but increased the oxidative damage to B. chinensis L.

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a functional probiotic, Bacillus subtilis can promote crop growth and improve nutrient utilization by various mechanisms, so it has been made into bioorganic fertilizer as a replacement for chemical fertilizer. However, the effects of B. subtilis bioorganic fertilizer application on the yield and quality of commercial crops of Brassica chinensis L., the soil physicochemical properties and the microflora have not been clarified. In this study, pot experiments were conducted using Brassica chinensis L. plants with four fertilization treatments: control without fertilization (CK), chemical fertilizer (CF), organic fertilizer (OF), and bioorganic fertilizer containing B. subtilis (BF). After 30 days of pot experiment, the results showed that BF efficiently improved plant height and biomass (1.20- and 1.93-fold, respectively); as well as significantly increasing soil available potassium and pH value. Using high-throughput sequencing, we examined the bacterial and fungal communities in the soil, and found that their diversity was remarkablely reduced in the BF treatment compared to CK group. A principal coordinate analysis also showed a clear separation of bacterial and fungal communities in the BF and CK groups. After application of B. subtilis bioorganic fertilizer, some beneficial bacteria (such as Bacillus and Ammoniphilus ) and fungi ( Trichoderma and Mortierella ) were enriched. A network analysis indicated that bacteria were the dominant soil microbes and the presence of B. subtilis stimulated the colonization of beneficial microbial communities. In addition, predictive functional profiling demonstrated that the application of bioorganic fertilizer enhanced the function of mineral element metabolism and absorption and increased the relative abundance of saprotrophs. Overall, the application of bioorganic fertilizer effectively changed the soil microflora, improved the soil available potassium and pH value, and boosted the yield of Brassica chinensis L. This work has valuable implications for promoting the safe planting of facility vegetables and the sustainable development of green agriculture., Competing Interests: Authors XH, PM and ZW are employed by Shenzhen Batian Ecological Engineering Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Cheng, Huo, Meng, Cai, Wang and Zhou.)

With the climate data inside and outside a plastic greenhouse as driving variables, and the greenhouse structure, insect-proof net material, and characteristic breadth and leaf area index of Brassica chinensis L. as parameters, a canopy transpiration model for greenhouse B. chinensis was established, based on Penmam-Monteith transpiration model. This established model was validated by the experimental data of independent samples in a single greenhouse. The results showed that in lower reaches of Yangtze River, the vent discharge coefficient (Cd) of greenhouse covered with 20-, 25-, and 28-mesh insect-proof nets was 0.771, 0.758 and 0.736, and the wind pressure coefficient (Cw) was 0.33, 0.37, and 0.39, respectively. The determination coefficient (R²) between the predicted and measured canopy transpiration rate for the sunny, cloudy, and overcast days in summer was 0.95, 0.91, and 0.94, root mean squared error (RMSE) was 0.018, 0.014, and 0.015 g · m-2 · s-1, and relative prediction error (RE) was 14.27%, 18.05%, and 15.80%, respectively, suggesting that this model could better predict the transpiration rate of B. chinensis in the plastic greenhouse covered with insect-proof nets in lower reaches of Yangtze River. [ABSTRACT FROM AUTHOR]

• Cd, Cr, Pb, and As contents in some sites exceeded the safe limit. • Cd and Cr concentrations in some pak choi were above the threshold. • Bioaccessibility of heavy metals/metalloid (As) was highly variable. • The human health risk in studied area is existing. The rapid development of greenhouse vegetable production (GVP) in densely populated areas may cause the heavy metal/metalloid accumulation in soil and pose a threat to human health. In this study, 180 pairs of topsoil and pak choi (Brassica chinensis L.) samples were collected from GVP fields in Xi'an city in Northwest China to analyze health risks of Cd, Cr, Pb, and As in soil and pak choi combining in vitro bioaccessibility investigation. The results showed that Cd and Cr were common pollutants in both soil and pak choi. In the soil–pak choi system, the indexes of non-carcinogenic and carcinogenic risk for adults and children were 1.53, 2.68, and 1.37 × 10−4, 8.14 × 10−5, respectively, thereby indicating the presence of heavy metal/metalloid health risks for both groups. Based on the results, procedures to mitigate heavy metal/metalloid contamination risks should be discussed more during the development of GVP in the largest city in Northwest China. [ABSTRACT FROM AUTHOR]

Brassica chinensis L. was chosen and exposed to different concentrations of Cd exposure to evaluate its Cd-accumulating capacity and its potential cellular defensive mechanisms. Cd accumulation in the shoots and roots of B. chinensis was up to 1348.3±461.8 and 3761.0±795.0 mg per killogram of dry weight, respectively, under 200 µmol/L of Cd exposure. Increasing Cd accumulation in the plant was accompanied by rapid accumulation of phytochelatins (PCs), and the sequestration of Cd by PCs provided a primary cellular mechanism for Cd detoxification and tolerance of B. chinensis. Furthermore, malondialdehyde formation, hydrogen peroxide content and antioxidative enzyme activities such as superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase were observed in the shoots of Cd-stressed B. chinensis. Increasing enzyme activities in response to concentrations of 5 to 50 µmol/L Cd showed an efficient defense against oxidative stress, suggesting that the antioxidative system was a secondary defensive mechanism. These resulted in reduced free Cd damage and enhanced Cd accumulation and tolerance. Glutathione plays a pivotal role in these two detoxification pathways. In general, these results suggested that PCs and the antioxidative system are synergistic in combatting Cd-induced oxidative stress and that they play important roles in Cd detoxification of B. chinensis, and also give a deep understanding of the natural defensive mechanisms in plants under heavy metal stress. [ABSTRACT FROM AUTHOR]

Abstract: Phytotoxicity of heavy metal is the primary concern in applying biosolids (sewage sludge) to agricultural land. This study evaluates the changes in chemical speciation of Zn in three tropical soils of Taiwan measured with sequential extraction over a one-year period. Biosolids were applied to the soils at application rates of 10, 50 and 100Mgha−1, and correlated diethylene triamine pentaacetic acid (DTPA) and sequential extraction as extract for prediction of Zn bioavailability to Chinese cabbage (Brassica chinensis L.). Experimental results indicated that the exchangeable (F1) and Fe–Mn oxide (F3) fractions in the sequential extractions increased with application rate of biosolids in the soils over time. Large amounts of Zn in the soils following the cessation of biosolids application were identified as soluble and were adsorbed by Fe–Mn oxides. The organically bound Zn, which is associated with readily decomposable carbon, is in limited amounts in the biosolid-treated soils. The DTPA-extractable concentrations of Zn in all biosolid-treated soils decreased over the time. A positive and significant correlation (r 2 =0.96) was found between the Zn concentrations extracted with DTPA and sum of F1 and carbonate-bound (F2) fractions in the sequential extractions. Additionally, the concentrations of Zn extracted with DTPA were strongly correlated with the concentrations of Zn in the shoots of Chinese cabbages, indicating that F1+F2 in the sequential extractions was reliable for predicting Zn bioavailability to Chinese cabbage in the biosolid-treated soils. [Copyright &y& Elsevier]

Multiple insecticides' residues after the mixed application of several neonicotinoids cause combined pollution and bring new challenges to food safety and pest control during agricultural production. In this study, three neonicotinoid insecticides, namely imidacloprid (IMI), acetamiprid (ACE), and thiamethoxam (TMX), were mixed and evenly sprayed on Brassica chinensis L. in the field. Then, the insecticides' residues were dynamically monitored to determine the differences in their rates of dissipation and final residues after 10 days. The results showed that the dissipation kinetics of neonicotinoids still conformed to the first-order kinetic model for binary or ternary application of neonicotinoid mixtures, with all determination coefficients (R2) being above 0.9 and the dissipation half-life (DT50) being 2.87–6.74 d. For treatment groups with five times the recommended dosages (IMI 300 g·hm−2, ACE 900 g·hm−2, and TMX 600 g·hm−2), mixed insecticides had a slower dissipation rate, and the DT50 values of mixtures were longer than those of single insecticides. Moreover, the final insecticide residues with mixed application were higher than those of single compounds at 10 d after spraying. Thus, mixed applications of neonicotinoids may increase food safety risks as they increase the final insecticide residues in Brassica chinensis L., and care should therefore be taken when considering the combined use of such compounds. [ABSTRACT FROM AUTHOR]

This work focuses on the bioaccumulation and toxic effects of di-(2-ethylhexyl) phthalate (DEHP) in the leafy vegetable Shanghaiqing (SHQ) (Brassica chinensis L.). The accumulated DEHP amount in the edible part and roots of SHQ increased as the DEHP concentration in the soil increased. DEHP accumulation was higher in the roots than in the edible part of the plant. The root concentration factors and bioaccumulation factors for DEHP in SHQ were 0.13–2.49 and 0.03–2.00, respectively. The DEHP translocation factors were below 1.0, indicating that DEHP preferentially accumulated in plant roots. The DEHP risk index in the edible part of SHQ in relation to the human body and in terms of dietary exposure risk assessment was also below 1.0, indicating a low health risk. High DEHP concentrations caused 1) inhibition of SHQ growth, 2) an increase in SHQ chlorophyll and malondialdehyde contents and 3) a decrease in soluble sugar and vitamin contents. Low DEHP concentrations stimulated total superoxide dismutase, peroxidase and catalase activities, while high DEHP levels showed an inhibitory effect. DEHP presence in soil affected not only SHQ growth but also quality. Our results provide the data needed for the proper assessment of food safety and the ecological impact of DEHP contamination in agricultural soils. • DEHP could accumulate and had toxic effects on Brassica chinensis L. • The accumulation and toxic effects increased with DEHP concentration. • DEHP was disadvantageous to the edible quality of vegetables. • DEHP was not easy to be translocated from roots to edible parts. [ABSTRACT FROM AUTHOR]

• Lignin is an important Cd repository in SCW of Brassica chinensis L. • LAC genes are involved in the cultivar-dependent lignin functions. • Lignin side chain region participates in cultivar-dependent complexation with Cd. • Cd fixation in SCW involved in different Cd accumulation through detoxification. To investigate the effect of lignin in the cultivar-dependent Cd detoxification of Brassica chinensis L., Cd and lignin contents, lignin composition and laccase genes expressions in low-Cd-accumulating (LAJK) and high-Cd-accumulating (HAJS) cultivars grown under control (CK) and 25 μ M Cd-treatment were determined. The results showed that lignin combined about 14 % of total Cd in both LAJK and HAJS. LAC genes were more up-regulated in HAJS than in LAJK, indicating that the LAC genes were involved in the cultivar-dependent lignin functions. Higher β -aryl ether (A) proportion in the lignin side chain region in LAJK than in HAJS were observed, whereas resinol (B) and phenylcoumaran (C) constitute much higher proportions in HAJS than in LAJK. Chemical calculation to estimate Cd affinity associating with lignin side chain region displayed that i) β -aryl ether (A) exhibited major coupling with lignin aromatic region; ii) resinol (B) and phenylcoumaran (C) displayed major participation in complexation with Cd. We therefore conclude that Cd compartmentalization in the secondary cell wall (SCW) by coupling with lignin side chain region is responsible for Cd detoxification related to cultivar-dependent Cd accumulation of Brassica chinensis. This is the first study on lignin composition in relation to Cd retention mechanisms in SCW. [ABSTRACT FROM AUTHOR]