2021 Vol. 36, No. 11
Display Method:
2021, 36(11): 1255-1263.
doi: 10.19303/j.issn.1008-0384.2021.11.001
Abstract:
Objective Expression patterns of 10 ZmbZIPs in Zea mays under stresses were analyzed for further understanding of the biological functions of bZIP associated with the plant development and stress responses. Method Expressions of the ZmbZIPs under imposed stresses of 200 mmol·L−1 NaCl, 20% PEG6000, 4℃, and nitrogen deficiency were studied. Result The evolutionary analysis divided the 10 ZmbZIP genes with a conserved domain consisting of a basic region and a leucine zipper into 5 subgroups. These genes expressed differently in different tissues indicating their diverse roles in the development of a maize plant. And they showed significantly differentiated expression patterns under the simulated salt, drought, low temperature, and nitrogen deficiency stresses reflecting their diverse and important roles played in the stress signaling pathways. Conclusion Differentiations on the expression patterns of 10 ZmbZIPs in different tissues and under different stresses as demonstrated in this study revealed diversity in biological functions of the genes in maize.
2021, 36(11): 1264-1271.
doi: 10.19303/j.issn.1008-0384.2021.11.002
Abstract:
Objective Tuber quality of Dioscorea persimilis at different times of harvesting were compared. Method Tubers from a local Ninghua variety of D. persimilis were collected in 9 batches from October 20 to May 5 in the following year. Quality indicators including drying rate, protein, starch, amino acid, soluble sugar, sucrose, crude polysaccharide, allantoin, and total phenol of the tubers were determined. Multiple comparison and correlation analysis were performed on the data for analysis. Result On October 20 when biomass accumulation in tubers is normally near completion in a year, the contents of soluble sugar, sucrose, and crude polysaccharide reached their high levels, that were up to 5.69%, 5.29%, and 2.73%, respectively. The harvested tubers at the time generally taste better, but the total phenol content tends to be high, which make them more suitable for fresh consumption. Whereas, the tubers harvested around December 5 as the stems and leaves largely withered and those picked from March 15, at which time the tuber dormancy had terminated, till April 10, when germination already began, had a drying rate of 33.84%-35.50% along with the contents of starch, protein, allantoin, total amino acids, essential amino acids, and flavor amino acids up to 73.14%-78.12%, 6.33%-6.51%, 3.95-4.29 mg·g−1, 48.5-50.8 mg·g−1, 15.0-15.5 mg·g−1, and 18.9-20.2 mg·g−1, respectively. The polysaccharides in the tubers harvested between March 15 and April 10 were more than 2.92%. The compositional change led to a more desirable eating quality of the tubers harvested during those two periods. In addition, the change also reduced the rate of tuber breakage at and after harvest. In contrast, tube harvesting on around November 10 and from the end of December to the following March would result in an increase on the drying rate to above 36% making the tubers break more easily after picking that rendered them fit only for further processing. In between April 10 and May 5, when new shoots started to appear, nutritional quality and appearance became less desirable, and the total phenol content rose to a high level on the tubers, the planting of following crop was disrupted and tuber-harvesting was deemed improper. Conclusion Depending upon market demand for fresh consumption or need for further processing, D. persimilis tubers could be harvested from the time the biomass accumulation was completed till the beginning of new shoot germination. However, when tuber yield, breakage, post-harvest browning, appearance, nutritional quality, and new crop planting of D. persimilis are taken into consideration, the optimum harvest time would fall in the periods between when the stems and leaves wither on the plants and as the tuber dormancy ends before new shoots start to emerge in the following year.
2021, 36(11): 1272-1279.
doi: 10.19303/j.issn.1008-0384.2021.11.003
Abstract:
Objective In order to compare the estimation model effect of SPAD of rape leaves based on hyperspectral parameters. Method Models of partial least squares regression (PLSR), back propagation neural network (BPNN), support vector regression (SVR), and deep neural network (DNN) based on the spectral parameters selected from the correlation analysis between the spectral reflectance parameters and SPAD data were constructed and compared for the estimation of chlorophyll SPAD of rape leaves. Result The SPADs and the original spectra in the blue wave of 425-495 nm and red wave of 665-680 nm of the leaves had a weak positive correlation. However, significantly inverse correlations between the SPADs and the green-yellow band of 510-650 nm and between that and the red edge band of 690-735nm were observed. The negative correlation coefficient between SDb and SDy was as high as −0.98, while the positive correlation coefficient between CARI and MCARI, CI and NDVI705 0.99. The 3 sets of SDb and SDy, CARI and MCARI, and CI and NDVI705 had significant linear correlations with the leaf SPAD. They could be somewhat interchangeable rendering them potential for accuracy improvement. The DNN model had an R2 of 0.93 and an RPD of 3.92 indicating a high predictability of the two models. They were followed by SVR, while PLSR and BPNN models being similar. Conclusion There were different degrees of correlation between the SPADs and the spectral parameters of rape leaves. The non-linear prediction model based on machine learning showed higher stability and predictability than the others, and the deep learning algorithm more effective in estimating SPAD of rape leaves.
2021, 36(11): 1280-1287.
doi: 10.19303/j.issn.1008-0384.2021.11.004
Abstract:
Objective Roles of iron (Fe), manganese (Mg), boron (B), and molybdenum (Mo) played in the seed germination and seedling physiological activities of Polygala tenuifolia were studied. Methods P. tenuifolia seeds were soaked in solutions containing the trace elements in 5 concentration gradients. Seed germination was evaluated according to the germination rate, germination index, and seedling vigor index. Measurements on root length, fresh weight, and contents of proline, soluble total sugar, superoxide dismutase (SOD), peroxidase (POD), and superoxide dismutase (POD) of the seedlings were also obtained for the analysis. Result The Fe treatments of 0-40 mg·L−1 increased the indices except proline content with statistically significant differences. But beyond that level the indices declined rapidly. Under the Mg treatments in the range of 0-150 mg·L−1, all indices excluding proline content increased to levels higher than those of control except for catalase activity. As did with Fe, when the Mg concentration became higher, the indices declined. The proline content increased in the seeds being treated with either Fe or Mg within the concentration ranges tested. The seed germination rate and index as well as the seedling vigor index, root length, and fresh weight increased with increasing B concentration from 0 to 1.5 mg·L−1 with a peak observed at 1.0 mg·L−1, which was higher than that of control. At 1.5 mg B·L−1, the contents of proline and total soluble sugar and the activities of SOD, POD, and CAT reached their maximal levels, which, beside proline, were higher than those of control. In the concentrations of 0-40 mg·L−1, Mo induced increases on the indices higher than those of control, but not on proline content and SOD activity. At higher concentrations, Mo caused declines on the indices. Conclusion The selected trace elements could promote the germination of P. tenuifolia seeds at low concentrations but inhibit it at high concentration. The treatments of 40 mg Fe·L−1, 150 mg·L−1 Mg, 1.0-1.5 mg·L−1 B, or 40 mg·L−1 Mo appeared best for the seed germination as well as seedling growth.
2021, 36(11): 1288-1294.
doi: 10.19303/j.issn.1008-0384.2021.11.005
Abstract:
Objective Methods suitable for embryo rescue in the interspecific hybridization between Brassica campestris and B. albograbra were investigated. Method The interspecific crossing was carried out using B. campestris L. as female parent and B. albograbra L. H. Bailey as male parent. An embryo rescue culture for the hybridization was conducted with 8 different media at 6 sampling times followed subsequently by 4 proliferation media and 9 rooting media. Result The embryo genesis rate at 26.32% of ERM4 medium consisting of MS, 0.5mg 6-BA·L−1, 0.5mg NAA·L−1, 1.0mg KT·L−1, and 1.0g AC·L−1 was the highest among all. The samples collected 12d after pollination had the best rate of 26.32%, DM1 (i.e., MS+ 0.9mg 6-BA·L−1+0.1mg NAA·L−1) the greatest proliferation coefficient of 5.37, and RM4-2 (i.e., 1/2MS+ 0.5mg IBA·L−1) the top rate of 37.21% and average 8.33d on rooting. Conclusion The optimum conditions for the embryo rescue in the interspecific hybridization between B. campestris L. and B. albograbra L. H. Bailey included sampling at 12d after pollination and following by culture on ERM4 medium for embryo induction, on DM1 for ovule proliferation, and on RM4-2 for seedling rooting.
2021, 36(11): 1295-1301.
doi: 10.19303/j.issn.1008-0384.2021.11.006
Abstract:
Objective Effects of different calcium fertilizers and application methods on the fruit quality of Kyoho grape were studied to provide guidelines for the production and cultivation. Method Four-year-old Kyoho grape vines were cultivated in a rain shelter facility to observe the results under treatments of varied calcium fertilizers and applications. Two different calcium fertilizers, 1 500 x sugar alcohol calcium and 800 x calcium nitrate, were used to either spray on the leaves and/or fruit ears or combine the spraying with rhizosphere irrigation. Grape peel color, calcium contents in different parts, and soluble solid, total sugar, and total acid contents, as well as firmness of the fruits were monitored. Result The fertilizing method affected both the peel color change and pulp quality as well as the calcium content in different parts of the grapes. When the leaves and fruit ears were sprayed and accompanied by rhizosphere irrigation with the sugar alcohol calcium fertilizer, the pericarp color was intensified. The contents of total phenols, anthocyanins, covalently bound pectin, and ion-bound pectin of the grapes also increased to become significantly higher than those of control. The calcium contents in peel and pulp were 1.36 and 1.73 times of control, respectively; the flesh firmness 19.28% higher than that of control; and the soluble solid mass fraction 5.71% higher than that of control. Conclusion The calcium fertilizations improved both internal and external quality of Kyoho grapes. By combining the foliar-and-ear spraying with rhizosphere irrigation using the 1,500x sugar alcohol calcium fertilizer, significant improvements on the fresh fruit quality could be realized.
2021, 36(11): 1302-1314.
doi: 10.19303/j.issn.1008-0384.2021.11.007
Abstract:
Objective Effects of magnesium on the growth, development, and metabolism of Citrullus lanatus were studied to determine the appropriate nutrient supply for the melon cultivation. Method At the concentrations of 0, 24, 48, 96, and 192 mg·L−1 on magnesium in sand culture, the growth characteristics (i.e., leaf and root morphology, chlorophyll fluorescence, and biomass accumulation), fruit quality (i.e., vitamin C, soluble solids, soluble protein, and soluble sugar), and physiological responses (i.e., osmoregulation, membrane damage, and antioxidases) of various C. lanatus varieties were compared. Result In the range of 24-96 mg·L−1, the application of magnesium reduced the vulnerability of leaf membrane to damages, increased the contents of antioxidant glutathione (GSH) and ascorbic acid (AsA) as well as the activities of photosystemⅡ (PSII), peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and monodehydroascorbate reductase (DHAR), while decreased the contents of malondialdehyde (MDA) and proline (Pro), and reduced the cell membrane permeability of the leaves. The addition also promoted the AsA-GSH cycle, photosynthesis, and the biomass accumulations on vitamin C, soluble solids, soluble protein, and soluble sugar. Among the treatments, the 48 mg·L−1 magnesium addition in the culture substrate rendered the most significant improvements on the growth and development of C. lanatus. Whereas, either a deficiency (at 0 mg·L−1) or an excess (e.g., at 192 mg·L−1) on the nutrient ill-affected the membrane lipid peroxidation and shortened the plant roots. Furthermore, the chlorophyll fluorescence declined as indicated by the lower oxygen evolution complex (OEC), quantum yield for electron transport (φEo), and receptor library capacity (Sm), the density of reaction centers (RC/CSo) decreased, the light energy absorption per unit reaction center (ABS/RC) lowered, and the dissipative (DI0/RC), capture (TR0/RC), and QA reduction rate (Mo) increased. Thus, either deprivation or over-supply of magnesium could significantly disrupt the normal photosynthetic function inhibiting the growth of C. lanatus. Conclusion Particularly in deficiency, but also in excess, magnesium in soil could diminish the PSII activity and retard the growth of C. lanatus. Appropriate application of the nutrient, such as at 48 mg·L−1 concentration in soil, could effectively improve the physiological activity, stabilize the structure and function of PSII, strengthen the leaf photosynthesis to result in healthy growth and high quality fruit production of C. lanatus.
2021, 36(11): 1315-1322.
doi: 10.19303/j.issn.1008-0384.2021.11.008
Abstract:
Objective Transcriptomes of different guava cultivars were obtained for comparison. Methods Transcriptome sequencing by Illumina Hwaseq 2 500 was conducted on 8-9 mature fruit pulp from 8 varieties of Psidium guajava Linn, namely Red Heart (HX), Rainbow (CH), Purplish Red (ZH), Crystal (SJ), Shuzhen (XZ), Colored-leaf B (CYB), Colored-leaf (CY), and Purple Star (ZX). Results By comparing to the database, 126979 Unigenes of an average length of 766 bp with a N50 of 1654 bp and a N90 of 267 bp were identified. There were 27274 genes co-expressed in the 8 cultivars. The PCA and differential gene expression cluster analyses showed that the differences on the function expressions between the genes of SJ and CYB was less than those between ZH and other cultivars. SJ and CYB were clustered in a category and HX, CH, XZ, CY, and ZX in a different category, while ZH significantly differentiated from the other cultivars. Conclusion The substantial amount of transcription data secured from this study could be useful for the classification as well as the expression and identification of functional genes of guava germplasms.
2021, 36(11): 1323-1329.
doi: 10.19303/j.issn.1008-0384.2021.11.009
Abstract:
Objective Response of Impatiens uliginosa to copper ions on the floral color with respect of the physiological and biochemical properties of the petals was investigated. Method Under treatments of varied Cu2+ concentrations (i.e., 0, 5, 10, 15, and 20 mg·L−1) in culture medium, the chromaticity, pH of cell fluid, pigments, and basal metabolites of flower petals of the I. uliginosa at full blooming stage were determined. The correlations among Cu2+, physiological and biochemical indices, and flower color were analyzed. Result (1) The contents of anthocyanins, flavonoids, and soluble sugars in petals decreased significantly in comparison to control as the Cu2+ concentration increased (P<0.05). (2) Soluble protein increased significantly over control with increasing Cu2+ at P<0.05. (3) In the range of 0-15 mg·L−1, Cu2+ exerted no significant effect in the contents of carotenoids and proline. (4) There were extremely significant correlations among the color values, anthocyanins, flavonoids, soluble sugar, proline, and soluble protein of petals on the plants treated by Cu2+ at different concentrations. (5) The stepwise regression analysis showed that the flower chromaticity a* and b* were mainly affected by anthocyanins, soluble sugar and proline. Conclusion Anthocyanin appeared to directly govern the color of I. uliginosa flowers. Cu2+ seemed to affect the petal color through regulating anthocyanin biosynthesis inI. uliginosa.
2021, 36(11): 1330-1336.
doi: 10.19303/j.issn.1008-0384.2021.11.010
Abstract:
Objective A high-efficiency, real-time, inline assay using near infrared spectroscopy to determine the moisture content in coconut meat was developed. Method The near infrared (NIR) spectra of 360 mature copra specimens came from varied germplasms were scanned by a grating diffuse NIR instrument made in China (S400 NIR Spectrophotometer for Quality of Agricultural Products). The collected data were separated by half into modeling and test sets. The quantitative partial least squares analysis was applied for the model construction with data pretreatments, such as first derivative, second derivative, scatter correction, zero-centered, and range normalization. Result The developed models achieved optimal performance. The root mean square error of calibration (SEC) and that of prediction (SEP) on the models were 0.7605 and 0.8378, respectively, while the correlation coefficients on the modeling and test sets 0.9963 and 0.9960, respectively. Conclusion The newly developed method for the determination of copra moisture content was capable of instantly and precisely delivering the measurement. It could be employed for real-time detection on a coconut processing line for quality assurance and yield prediction. Moreover, similar approach could conceivably be used to develop protein, fat, and carbohydrate determinations for copra as well.
2021, 36(11): 1337-1343.
doi: 10.19303/j.issn.1008-0384.2021.11.011
Abstract:
Objective Drug resistance and rpoB Method Brain, heart, and liver tissues were aseptically collected from the dead Muscovy ducks that were infected by the disease for isolation, identification, and drug resistance of the pathogen. The genomic DNA of the isolated strains were extracted and the 16S rDNA gene specific primers used for PCR identification. The disk method was applied to test the drug sensitivity of the isolates. The rifampicin resisting region in the rpoB Result Forty-nine strains of R. anatipestifer were isolated to show a broad-spectrum resistance to 11 to 21 kinds of drug, such as, aminoglycosides, macrolides, compound sulfamethoxazole, polymyxin B and rifampicin. But they were highly sensitive to tetracyclines, β-lactams, and florfenicol. In the rpoB Conclusion It appeared that tetracyclines, β-Lactams, and florfenicol could be the first choice for preventing and treating duck infectious serositis. The single point amino acid mutation location of R494K in the region that determines the rifampicin-resistance could harbor the key to unlocking the mechanisms of the drug resistance of R. anatipestifer.
2021, 36(11): 1344-1350.
doi: 10.19303/j.issn.1008-0384.2021.11.012
Abstract:
Objective The gene related to an important neuroendocrine receptor of NPFF (neuropeptide FF), NPFFR2 (Neuropeptide FF receptor 2), that participates in the regulation of corticotropin-releasing hormone (CRT) and anxiety-like behaviors was analyzed for study on the stress response of Minxinan black rabbit. Method NPFFR2 was cloned, sequenced, and analyzed. Result Two transcript variants of NPFFR2 from Minxinan black rabbits were cloned to show the contents of 1 815 bp and 1 824 bp nucleic acid sequences. They had same sequences in 5′-UTR and coding region but multiple mutations in 3′-UTR. The predicted mRNA secondary structure displayed multiple mutations in the 3′-UTR which could cause changes on the structure as well as the function of NPFFR2. The phylogenetic analysis indicated the NPFFR2 from the rabbit was most closely related to that from Homo sapiens. According to the predicted protein structure and subcellular location, NPFFR2 protein belonged to the G protein-coupled receptors family and had 414 amino acids and 7 transmembrane α-helixes. Conclusion Two transcript variants of NPFFR2 from Minxinan black rabbits were cloned. The structures and functions of the transcripts and translated proteins were predicted by bioinformatics obtained. The results would be helpful for further study on the functions of NPFFR2 of Minxinan black rabbit.
2021, 36(11): 1351-1358.
doi: 10.19303/j.issn.1008-0384.2021.11.013
Abstract:
Objective Effects of feeding hybrid pennisetum forage supplemented with rumen-protected methionine (RPMet) on the growth and nutrient digestion and metabolism of Fuqing goat were studied. Method Thirty 4-month-old, 11.88±1.48 kg Fuqing goats from a same batch of estrus synchronization were randomly divided into 5 groups of 6 goats in each group. The feeding experiment including basic diet (CK) and an addition of RPMet at 2.5 g·d−1 (Group Ⅰ), 5.0 g·d−1 (Group Ⅱ), 7.5 g·d−1 (Group Ⅲ), or 10 g·d−1 (Group Ⅳ) started after a pre-testing period of 15 d to last for 60 d. In the middle of the feeding period, 3 goats were randomly selected from each group to determine the apparent nutrient digestion and nitrogen metabolism of the animals. Result (1) No significant differences in DMI, IBW, and FBW were found among all groups (P＞0.05). The total weight gain and ADG of Group Ⅰ and Group Ⅱ were significantly higher than those of control (P＜0.05), but not on those of Group Ⅲ and Group Ⅳ (P＞0.05). (2) The apparent digestions of DM, OM, GE, NDF, ADF, and CP by the goats in Group Ⅱ were the highest. Those of GE, CP, and ADF were significantly higher in Group Ⅱ than in other groups (P＜0.05), those of DM and OM significantly higher than in Group Ⅲ and Group Ⅳ or control (P＜0.05), and that of NDF significantly higher than in Group Ⅲ and Group Ⅳ (P＜0.05). (3) The nitrogen intake of the goats in the control group was significantly lower than that of the treatment groups (P＜0.05). The urine and fecal nitrogen in goats of Group Ⅰ and Group Ⅱ were not significantly different from those of control (P＞0.05), but significantly higher than those of other test groups (P＜0.05). Group Ⅰ and Group Ⅱ animals also had significantly higher nitrogen deposition and deposition rate than those of other groups (P＜0.05). The biological value of nitrogen of the goats in Group Ⅰ was the highest and significantly higher than that in Group Ⅲ, Group Ⅳ, and control (P＜0.05), while Group Ⅳ was significantly lower than control (P＜0.05). Conclusion The supplementation of RPMet at a rate of 2.5～5.0 g·d−1 in the hybrid pennisetum forage benefited nutrient digestion and utilization of the Fuqing goats which promoted fattening before slaughtering.
2021, 36(11): 1359-1364.
doi: 10.19303/j.issn.1008-0384.2021.11.014
Abstract:
Objective Antisera of V1, V2, C1, and C4 proteins encoded by the invasive cotton leaf curl Multan virus (CLCuMuV) were prepared for quarantine at entry ports and study on the pathogenic mechanism of the virus. Method Using a prokaryotic expression technology and IPTG induction, V1, V2, C1, and C4 were expressed and the specificity analyzed by western blot. Separately, New Zealand white rabbits were immunized with V1, V2, and C1, while mice with C4 to prepare the antisera. Specificity of the antisera was subsequently verified by western blot. Result The target gene fragments of V1 (768 bp), V2 (363 bp), C1 (1 089 bp), and C4 Conclusion The antisera of CLCuMuV V1, V2, C1, and C4 were successfully prepared for quarantine inspection and study on the pathogenic mechanism of the invasive virus.
2021, 36(11): 1365-1372.
doi: 10.19303/j.issn.1008-0384.2021.11.015
Abstract:
Objective A nondestructive, effective method was developed based on the hyperspectral imaging technology for early diagnosis of the highly destructive wet bubble disease on Agaricus Bisporus caused by Mycogone perniciosa. Method Information on the full band (401-1046nm) visible/near-infrared hyperspectral images on 200 healthy and 200 infected A. bisporus specimens was collected. After a preprocess using Savitzky-Golay 1st order derivative, Savitzky-Golay smoothing, or multiple scattering correction (MSC) on the obtained information of the 360 full bands, accuracy of the methodology in separating the healthy from the infected samples was scrutinized by using the Random Forest (RF), Support Vector Machine (SVM), and Extreme Learning Machine (ELM) models. Result The 3 models yielded similar results and the MSC-SVM combination had the best detection effect with the identification accuracy on the test set increased from 85.02% to 92.21%, and on the prediction set, from 87.38% to 91.04%. Conclusion The MSC-SVM model appeared to significantly improve the identification accuracy using the full band. It provided a basis for the development of rapid, nondestructive diagnostic device on the devastating disease of A. bisporus at early stage which has been conventionally conducted by expert visual examination, PCR analysis on the internal transcribed spacer gene, or traditional Koch's postulation.
2021, 36(11): 1373-1379.
doi: 10.19303/j.issn.1008-0384.2021.11.016
Abstract:
Object Changes on soluble carbon and nitrogen in cow bed material during composting with the aid of various exogenous bacterial fermentation agents were studied. Method Contents of soluble nitrogen, i.e., ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3−-N), soluble organic nitrogen (SON), and soluble carbon, i.e., soluble total carbon (STC) and soluble organic carbon (SOC) in the cow bed material, which had been used at a cattle ranch for 3 years, that was added with different commercially available bacteria agents were measured during the fermentation to determine the optimal application of the agents. Results The addition of fermentation agents increased NH4+-N, SON, and SOC, but reduced NO3−-N. Among the 3 agents tested, Guolong Biological Bed Inoculants performed best on most evaluation criteria, and it was followed by Baifeng Livestock and Poultry Bao and Feng Li Jing. No consistent display in SOC by the agents was observed. NH4+-N and STC increased to peak in 20 d and declined afterward. NO3−-N and SON tended to increase continuously to reach a maximum in 50 d. The SOC content toped in 10 d and then on a decreasing trend as the fermentation progressed. Conclusion The application of bacteria agents could increase the available carbon and nitrogen in the compost. However, there was the risk of increasing ammonia volatilization. Hence, an agent specific for the fermentation of livestock and poultry excrement would be recommended to be added to the compost for the fermentation of cow bed material.
2021, 36(11): 1380-1386.
doi: 10.19303/j.issn.1008-0384.2021.11.017
Abstract:
Objective Water-soluble PEG400-modified ZnS:Cu quantum dots (QDs) were prepared by hydrothermal method in search for an applicable rapid detection method on diquat. Method The QDs were characterized by their quenching intensities using a fluorescence spectrophotometer, an FTIR, and a UV-Vis spectrophotometer. Effect of PEG400 on the ZnS:Cu QDs was examined to determine the optimal modification for the establishment of a methodology to rapidly detect the toxicity of diquat on microorganisms. The correlation between QD quenching intensity and diquat concentration was examined for the methodology development. Result Under appropriate reaction conditions at the diquat concentration in the range of 1.45×10−6−8.7×10−6mol·L−1, the fluorescence quenching degree of QDs had an excellent linear relationship with diquat concentration of a correlation coefficient of 0.999 9. The detection limit of the method was 2.071×10−7mol·L−1. Conclusion The obtained PEG400-modified ZnS:Cu QDs was considered adequate to be applied for rapid detection of diquat in support of further development of related analytical methodology.
