10 July 2020, Volume 34 Issue 7
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1369-1377. https://doi.org/10.11869/j.issn.100-8551.2020.07.1369
In order to develop superior peanut germplasms, the effect of ethyl methane sulfonate (EMS) mutagenesis on dry seeds of Zhenzhuhong 1 was studied based on soaking method. The results showed that with semi-lethal rate as the selection criterion, the appropriate mutagenesis condition was 0.8% EMS treatment for 10 hours. Nine superior M5 mutants were developed, four mutants showed high yield, good quality and superior comprehensive characters. Compared with Zhenzhuhong 1 (CK), their dry pod yields increased by 10.93% ~ 26.78%, and their shelling percentages were also higher. The oleic acid content of You Zhenzhuhong 1 2Ⅱ/19 was 56.68%, 8.44 percentage points more than CK; and the ratio of oleic acid to linoleic acid (O/L) was 1.92, 0.57 more than CK. The linoleic acid content of You Zhenzhuhong 1 2Ⅲ/8 was 39.05%, 3.28 percentage points more than CK. The crude fat content of You Zhenzhuhong 1 2Ⅲ/10 was 54.52%, 1.50 percentage points more than CK. The oleic acid content of You Zhenzhuhong 1 3Ⅰ/8 was 53.70%, 5.46 percentage points more than CK; and its O/L was 1.71, 0.36 more than CK. Analysis of inter-simple sequence repeat (ISSR) markers revealed that there were significant molecular differences between the nine superior M4 mutants and Zhenzhuhong 1, and there were also significant molecular differences among these mutants. This study has created superior germplasms for peanut genetic improvement and functional gene research, providing a reference for peanut breeding by EMS mutation.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1378-1386. https://doi.org/10.11869/j.issn.100-8551.2020.07.1378In the early study, a rice short-root mutant ksr8 (Oryza sativa kasalath short root 8) was isolated from an ethylmethane sulfonate (EMS)-mutagenized rice library of indica Kasalath. Phenotype characterization, genetic analysis, gene mapping and cloning, complementation analysis and exogenous application of arginine were conducted to clarify the molecular mechanism of ksr8 root development. Phenotyping analysis showed that the elongation of primary, lateral and adventitious roots and plant height were all inhibited in ksr8 compared with the wild type Kasalath. At the maturation stage, the tiller number, the panicle length and the number of grains per panicle of ksr8 were also reduced. Acetocarmine staining and resin semi-thin sectioning analysis revealed defects in the meristematic cell division activity and cell elongation in the elongation region of the root tip of ksr8. Results of genetic analyses showed that the mutant phenotype was controlled by a recessive nuclear gene, which was mapped to a 106 kb region between markers InDel3 and RM3280 on chromosome 3. One root related gene OsASL1 (LOC_Os03g19280) was found in the region, which encodes an argininosuccinate lyase catalyzing the last step of the arginine biosynthesis pathway. Sequencing analysis confirmed a point mutation (G653 to A) in the CDS sequence of OsASL1, resulting in an amino acid substitution (Arg 218 to Lys). Transgenic complementation analysis confirmed that the mutation in OsASL1 was responsible for the phenotype of ksr8. Further analysis showed that the root defects of ksr8 can be restored by exogenous application of arginine. Our results confirmed that the ksr8 gene was a new allele of OsASL1 and further clarified the important role of OsASL1 in root development of rice, providing genetic resources and theoretical basis for further exploration of the molecular mechanism of rice root development.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1387-1396. https://doi.org/10.11869/j.issn.100-8551.2020.07.1387Calcineurin B-like proteins (CBLs) interacting protein kinases (CIPKs) act as a class of serine/threonine protein kinases, which play critical roles in response to abiotic stress signaling in plants. Based on our previous RNA-seq data that Vitis amurensis responded to cold stress, seven CIPK members were observed to be involved in the early injury and perception phase of the CBL-CIPK signaling pathway, among which VaCIPK18 was significantly up-regulated. To further investigate the function of the kinase in cold stress, VaCIPK18 was cloned by homologous cloning. The ORF of VaCIPK18 was 1320 bp in length, encoding 439 amino acids. Based on the bioinformatics analysis of VaCIPK18 protein, the peptides rich in epitopes in the extracellular domain were obtained, and the C-terminal regulatory domain (230-439 aa) was constructed into the prokaryotic expression vector pET28a-SUMO. The recombinant expression vector was further transformed into E. coli Rosetta strain, and the inclusion body protein of 42 kDa was expressed under the condition of 0.8 mmol·L-1 IPTG and induction at 37℃ for 4 h. The recombinant protein was used as an antigen to immunize white rabbits, and an anti-VaCIPK18 polyclonal antibody was obtained with high titer-specificity. Western blotting indicated that the antibody specifically binds to grape endogenous CIPK18, and the band was coincided with the 50 kDa position as expected. The results showed that the protein expression level of CIPK18 in grape leaves responding to cold stress was consistent with that at normal temperature condition, but there were possible phosphorylation and ubiquitination under both conditions. The current study provides a basis for further investigations of protein localization, expression, and function of VaCIPK18.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1397-1408. https://doi.org/10.11869/j.issn.100-8551.2020.07.1397To understand the alkaline-responsive mechanism of P. triloba under short-term alkaline stress, we performed next-generation sequencing using Illumina HiSeq 2500 platform to identify alkaline stress-related DEGs (differentially expressed genes) in P. triloba. Approximately 53.0 million high-quality clean reads were generated from 59.6 million raw reads, and a total of 124,786 unigenes were obtained after de novo assembly of P. triloba transcriptome data. Among which 8 948 unigenes were identified as alkaline stress-responsive DEGs. Gene Ontology (GO) enrichment analysis based on these DEGs suggested that 28 genes may play important roles in the early alkaline stress response. Additionally, analysis of DEGs with the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that pathways DEGs were involved in were significantly different among different time of treatment. The consistency between the quantitative real-time PCR (RT-qPCR) results and the RNA-Seq data of seven alkaline responsive genes confirmed the reliability of the RNA-Seq results. Our study was the first investigation into the transcriptome of P. triloba responding to alkaline stress. The research contributes to the genomic resources available for P. triloba, as well as it deepens our understanding of alkaline tolerance mechanisms in P. triloba. It will also provide new insights into our understanding of alkaline acclimation mechanisms in Chinese plum (Prunus salicina) trees.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1409-1420. https://doi.org/10.11869/j.issn.100-8551.2020.07.1409In order to further elucidate the important function of SBP gene family in foxtail millet, NCBI blast and HMMER search were used to identify the SBP genes in foxtail genome, and to analyze the physicochemical properties and phylogenetic tree of SBP family in foxtail millet. The expression SBP gene family in foxtail millet treated with PEG and ABA were detected by real-time fluorescence quantitative PCR (RT-qPCR). The results showed that 19 members of SBP gene family were identified from the whole genome of foxtail millet and they encoded proteins with 199-1 118 aa, which distributed across 9 chromosomes. The results of phylogenetic tree showed that the SBP protein could be divided into 2 categories. The first category was classified into 6 sub-categories, and the second category only contained one SBP proteins. The numbers of exons were variable, ranged from 2-11, and all of the SBP proteins were hydrophilic protein. The results of subcellular localization prediction showed that the members of the gene family were located mainly in the nucleus except SBP7. Cluster analysis showed that foxtail millet SBP was closely related to monocotyledonous sorghum and rice than to cotyledonous Arabidopsis thaliana. Upstream promoter region analysis founded a large number of cis-acting elements closely related to hormones, drough, light, pathogenic factors and stress condition. The results of RT-qPCR showed that the relative expression of SBP gene was up-regulated under PEG and ABA treatment, and the expression quantity of SBP in leaf was higher than that in stem. The expression quantity of SBP under PEG was significantly higher than ABA treatment. The expression levels of SiSBP13 in leaves and stems after 4 hours of PEG stress were 180 and 15 times as that before treatment. After 4 hours of ABA induction, the expression of SiSBP13 in stems was up to 8 times that before stress. After 24 hours of induction, the expression of SiSBP13 in leaves was 28 times higher than that before stress. This study laid an important foundation for further analysis of the specific functions of SBP genes at different development stages in foxtail millet.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1421-1431. https://doi.org/10.11869/j.issn.100-8551.2020.07.1421In order to investigate the changes in gene expression levels of juvenile H. kuda under high and low temperature stress, the transcriptome sequencing of the juvenile’s liver was performed using the PE150 sequencing strategy based on the Illumina platform. Sequencing data of control group, high temperature stress group and low temperature stress group were assembled totally 22 513 single gene clusters (Unigene) were obtained, with an N50 of 2 223 bp and an average length of 1 122.71 bp. Compared with the control, 14 009 differentially-expressed genes were obtained in the high temperature group, of which 5 443 genes were up-regulated and 8 416 genes were down-regulated. Compared with the control, 20 030 differentially-expressed genes were also obtained in the low temperature group (14 016 genes were up-regulated and 6 014 genes were down-regulated). Enriched by KEGG database, the differentially-expressed genes under high/low temperature stress both caused significant changes in the antioxidant pathway-related genes (HSP70, HSP90, SOD, etc.) in juvenile H. kuda. In addition, The high temperature stress also caused significant changes in the expression of immune system-related genes (PIK3R, AKT, IL-10, TLR, etc.) and apoptosis-related genes (CYCS, CASP9, CASP3, etc.), while the low temperature stress caused significant changes of genes related to DNA damage repair (MSH, DDB2, XRCC2, RAD52, OGG1, PMS2, etc.), fatty acid metabolism (StARD7, APOA4, CYP51, Fadsd6, etc.) and cell apoptosis (P21, P53, BAX, etc.). Thirteen differentially-expressed genes such as IL-10, HSP70 and stearoyl-CoA desaturase were selected to validate the results, and the results of RT-qPCR were almost consistent with those of RNA sequencing. This work can lay a preliminary foundation for further research on the regulation mechanism of temperature stress in H. kuda, and help to prevent extreme temperature damage to the culture of H. kuda.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1432-1439. https://doi.org/10.11869/j.issn.100-8551.2020.07.1432The objective of this research is to investigate the effects of acetosalicylic acid (ASA) on cell growth, fucoxanthin accumulation and expression levels of genes related to the biosynthesis of fucoxanthin in the model diatom Phaeodactylum tricornutum. Growth rate, fucoxanthin content and gene expression were detected by spectrophotometer, high performance liquid chromatography (HPLC) and real-time PCR respectively. The results indicated that fucoxanthin content were closely associated with the concentrations of ASA. ASA at a certain concentration suppressed proliferation of algae cells. With the concentration of ASA iuncreased, the content of fucxanthin was first increased and then declined. Notably, the content of fucoxanthin in Phaeodactylum tricornutum treated with 10 mg·L-1 ASA was the highest (1.78 g·kg-1DW), which was 1.9 times as much as that in control groups. The expression of genes (including PSY, PSD, ZDS, CRTISO, LCYB and ZEP) that encoding pivotal enzymes associated with the fucoxanthin biosynthesis were increased following ASA treatment. In particularly, the transcripts of detected genes were significantly up-regulated under 10 mg·L-1 ASA treatment when compared with the control (P<0.01). Principal component analysis (PCA) indicated these six genes were positively correlated with fucoxanthin accumulation, therein ZEP exhibited the highest contribution. In general, proper concentrations of ASA induced the expression of genes responsible for fucoxanthin biosynthesis and increased the production of fucoxanthin. The present study provides a theoretic basis for molecular mechanism of fucoxanthin biosynthesis in Phaeodactylum tricornutum.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1440-1446. https://doi.org/10.11869/j.issn.100-8551.2020.07.1440Epibrassinolide (EBL) has been shown to play an important role in plant growth and stress resistance. In this study, the callus of Zoysia matrella (L.) Merr. was treated by salt stress with different NaCl concentrations, and different concentrations of EBL were added under the salt stress. The influences of EBL on callus growth and plant regeneration, the activites of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) of the callus and the leaves from the regenerated plantlets were measured and analyzed. The results showed that when the salt concentrations were equal or greater than 0.6%, the growth of callus was inhibited and the callus regeneration was inhibited when the salt concentrations were equal or greather than 0.4%. The effect of adding 0.05 mg·L-1EBL was the most significant in improving the salt tolerance of callus, while 0.02 mg·L-1EBL was the most significant to improve the salt tolerance of callus regeneration. When the NaCl concentration was 0.6%, the growth rate of diameter increased by 51.74%, as well as the fresh weight increased by 49.73% of callus under the treatment of 0.05 mg·L-1EBL.When the NaCl concentration was 0.4%, the amount of plantlets increased by 38.14% and the roots with lengths equal or greater than 5 mm increased by 20.12% of regeneration under the treatment with 0.02 mg·L-1EBL. In this study, plants of Zoysia matrella with stronger salt tolerance were obtained through experiments, which indicates that the addition of EBL in vitro can effectively alleviate salt stress and promote the growth and regeneration of Zoysia matrella callus. The results of this study also provide a basis for the wider application of Zoysia matrella in saline-alkali land improvement.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1447-1455. https://doi.org/10.11869/j.issn.100-8551.2020.07.1447
To investigate the effects of Trichoderma harzianum M-33 strain applied together with wheat straw on biological control of potato black scurf and potato rhizosphere soil microbiota, the antagonism of T. harzianum M-33 against Rhizoctonia solani was surveyed by dual culture and scanning electron microscope. Then, the biological control of T. harzianum M-33 strain applied together with wheat straw against potato black scurf was studied by pot experiments, and its effect on rhizosphere soil micr-ecosystem of potato was further analyzed by dilution-plate method and high-throughput sequencing technology. The results showed that the spatial competition and hyperparasitism were the main antagonistic mechanism of T. harzianum M-33 against R. solani, the emergence rate of the treatment was 100%, and the disease control effect was 70.26%, significantly higher than that of CK. The plant height, stem diameter and branch numbers of potato treated with the treatment were 43 cm, 0.82 cm and 3.89, respectively, and all the three parameters were significantly higher than that of CK. The numbers of rhizosphere soil fungi in the treatment were significantly reduced by 29.54% compared with CK, while the numbers of rhizosphere soil bacteria, actinomycetes and Trichoderma genus in the treatment were significantly increased by 75.36%, 60.58% and 1407.27% respectively compared with CK. T. harzianum M-33 applied together with wheat straw had great impacts on fungal community diversity and community structure composition of fungi, but small impacts on bacteria. The treatment promoted the accumulation of beneficial microbes in potato rhizosphere soil. The present study provided a theoretical basis for the efficient utilization of Trichoderma and biological control of potato black scurf.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1456-1463. https://doi.org/10.11869/j.issn.100-8551.2020.07.1456To explore the main pathogenic fungi and their prevention and control during the cultivation of Ganoderma lucidum, the pathogenic strains were firstly isolated and purified from G. lucidum growing wood and fruiting body that were infected by pathogenic fungi, and then identified by morphological and rDNA-ITS sequence analysis. The biological characteristics of the isolated strains were further studied. Moreover, the inhibition effect of allyl isothiocyanate on the mycelial growth of the isolated strains was tested. The results showed that four pathogenic fungi were isolated and strain OTA was Aspergillus flavus; OTC was Trichoderma sp.; OTB and OTD were Penicillium infrabuccalum. The four pathogenic fungi grew well in PDA media; the suitable temperature was 25 to 30℃; the optimum carbon source was xylose, glucose, fructose and sucrose for OTA, OTB, OTC and OTD. The optimum nitrogen source was beef extract for OTA, urea for OTB, NaNO3 for OTC and peptone for OTD, respectively. Strains OTB, OTC and OTD grew well in acid condition while the growth of OTA was not affected significantly by pH. Allyl isothiocyanate had good inhibition effect on OTA, OTB, OTC and OTD, and the inhibition rate all exceeded 97% at the dosage of 20 μL·L-1. Allyl isothiocyanate could be used as a fumigant in the cultivation process of G. lucidum. The work provides theoretical basis for the prevention and control of pathogenic fungi during the cultivation of G. lucidum.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1464-1469. https://doi.org/10.11869/j.issn.100-8551.2020.07.1464In order to investigate the degradation of acephate by irradiation. Parameters affecting the electron beam degradation process of acephate solution and added acephate in corn grit were analyzed through single factor experiments with irradiation dose, initial concentration, pH, KMnO4 dosage considered. The results showed that the degradation rate of acephate went up with the increase of irradiation dose, decreased with the increase of the initial concentration of acephate at the same irradiation dose, and reached the maximum when the dose increased to 9 kGy. The degradation rates of acephate with initial concentrations of 25, 50, 100, and 150 mg·L-1 were 95.76%, 94.32%, 90.40%, and 65.60%, respectively, whereas the degradation rate in corn grit was 44.05%.In addition, when the pH value of the solution was neutral, the irradiation degradation effect of acephate was better than that at acidity. There was a significant effect of KMnO4 on the irradiation degradation rate of acephate solution. When the concentration of KMnO4 was 8×10-4 mol·L-1, the degradation rate of 100 mg·L-1 acephate was 94.10% after 7 kGy dose irradiation. In this study, the results could provide a scientific basis in the degradation of organophosphorus pesticides by electron beam irradiation.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1470-1479. https://doi.org/10.11869/j.issn.100-8551.2020.07.1470In order to investigate the effects of γ-aminobutyric acid (GABA) on sucrose metabolism of peach fruit under low temperature storage the Hujingmilu peach fruit were treated with 5 mmol·L-1 exogenous GABA and 100 μmol·L-1 GABA-T inhibitor (VGB). The juice yield, GABA content, soluble sugar content, sucrose metabolism intermediates and sucrose metabolism related enzyme genes were analyzed. The results showed that exogenous GABA treatment and GABA combined VGB treatment could effectively inhibit chilling injury of peach fruit during cold storage by increasing the contents of endogenous GABA and sucrose. Exogenous GABA treatment also inhibited the expression of PpSUS5, a sucrose-degrading enzyme gene, and slowed down the reduction of sucrose in peach fruit, thus improving the resistance ability of fruit to cold damage. In addition, exogenous GABA combined VGB treatment enhanced the expression of sucrose synthase-related genes PpSPS1, PpSPP1 and PpSUS3, maintained the high levels of sucrose contents and inhibited the occurrence of chilling injury. The results provided theoretical basis for postharvest storage and preservation of peach fruit.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1480-1490. https://doi.org/10.11869/j.issn.100-8551.2020.07.1480In order to obtain a special yeast strain that can quickly brew high-quality peach wines, the spontaneous fermented mash of the peaches was used as the raw material. Preliminary screening of strains by TTC chromogenic method and Durham tube method was conducted. Third-stage re-screening of strains through analysis of alcohol tolerance, fermentation speed and wine production capacity, flavor and sensory of fermentation liquor were also carried out, and Saccharomyces cerevisiae PY01 with high quality and efficiency was obtain. Response surface optimization was used to optimize the brewing process, in which, the initial pH value, main fermentation temperature and yeast inoculation amount were chosen as the influencing factors, and the alcohol content as the response value. The results showed that the optimum fermentation parameters for PY01 strain fermented peach wines were determined as follows, the initial pH 3.9, the fermentation temperature 26℃ and the yeast inoculum 6.2%. Under the optimized process conditions, alcohol yield of the peach fermented wines was 12.78% vol, the total sugar content was 6.17 g·L-1. This is a semi-dry peach fermented wine with a pure flavor and a mellow taste. This study provided references for strain selection and processing optimization for industrial production of the peach wines.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1491-1496. https://doi.org/10.11869/j.issn.100-8551.2020.07.1491To clarify the influence of different harvesting time on the quality of royal jelly, royal jelly collected from April to September were used to compare content of major royal jelly proteins (MRJPs), total soluble protein and polyphenol and to analyze the relevant between antioxidant activity and MRJPs. The results showed that there were significant differences among MRJPs (P<0.05), and the content of royal jelly harvested in June was the lowest. Content of water soluble protein and total phenol exhibited no significant differences (P>0.05), and the correlation coefficients of free radical scavenging ability and MRJP1, MRJP3 were 0.828 and 0.847 respectively; the correlation coefficients of total antioxidant capacity and MRJP1, MRJP3 were 0.680 and 0.743 respectively. There was positive correlation between the antioxidant activity of royal jelly and its major royal jelly proteins, but no significant correlation was observed between the antioxidant and content of polyphenols. This indicates the free radical scavenging ability and total antioxidant capacity of royal jelly exhibited by several antioxidants. The research provides references for the study of antioxidant activity of royal jelly.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1497-1506. https://doi.org/10.11869/j.issn.100-8551.2020.07.1497In order to evaluate the flavor of Mucor-type Douchi, HS-SPME/GC-MS combined with electronic nose and tongue was used to study the fermentation process. HS-SPME/GC-MS method was used to detect volatile flavor components of Mucor-type Douchi in different fermentation periods. 68 volatile compounds were identified within 11 samples, including 18 esters, 7 aldehydes, 3 acids, 26 alcohols, 4 ketones, and 10 others. Volatile flavor components increased from 15 kinds of pre-fermentation to 31 kinds of later period of fermentation (35-42 days), while the content increased from 1.69 μg·g-1 of pre-fermentation to 44.20 μg·g-1 of fermentation end point, showing an increasing trend. While and it was not stable until late fermentation stage., which was consistent with the results of electronic nose. The results of electronic tongue analysis showed that after 35 days of fermentation, the astringency, bitterness and bitter aftertaste of the finished product decreased to an appropriate level, and the value of delicacy and richness was higher. The volatile flavor components were rich in variety, high in content, rich in flavor, good in richness, good in taste and flavor. Therefore, the combination of HS-SPME/GC-MS and electronic sensory technology is feasible to distinguish the quality of Mucor-type Douchi, which can provide a theoretical basis for the optimization of production conditions.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1507-1517. https://doi.org/10.11869/j.issn.100-8551.2020.07.1507In order to enrich the zearalenone detoxification strain bank, a zearalenone-degrading strain NS2 was obtained and screened from food samples collected in 7 cities, such as Shaoyang City, Hunan Province, which was identified as Bacillus amyloliquefaciens by 16s rDNA. The detection results of ZEN content before and after degration by high performance liquid chromatography showed that the degradation rate of the 5 mg·L-1 ZEN standard was as high as 96.0% and the solid fermentation was 72 h. The degradation rate of the strain on the 2.5 mg·L-1 ZEN standard in corn flour was as high as 88.2%. The ZEN degradation products treated by the bacteria were detected by high performance liquid chromatography and quadrupole time of flight mass spectrometry. No toxic effects of α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) were detected. an analog of estrogen ZEN. In addition, NS2 can inhibit the growth of pathogenic microorganisms Escherichia coli and Salmonella typhimurium by producing secondary metabolites with antibacterial action, according to antibacterial acticity test and xylanase, cellulase, proteuse activity test. These results indicate that Bacillus amyloliquefaciens NS2 can degrade ZEN efficiently, which has potential application prospects and lays a material foundation for the development and application of ZEN detoxification products.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1518-1524. https://doi.org/10.11869/j.issn.100-8551.2020.07.1518The enzymatic properties of cutinase from Botrytis cinerea and its effect on the plant cuticle were investigated.The cutinase fermentation broth was obtained by cutin induction, and the supernatant was separated to obtain cutinase. The effects of temperature, pH value, metal ions and organic solvent on the activity of cutinase was investigated using spectrophotometry. The effect of crude cutinase on grape’s cuticle was studied by scanning electron microscopy. Results showed that the optimum reaction temperature of cutinase was 35℃, the optimum pH value was 7.5, using high stability can be maintained under this situation. Na+, Mg2+, Ca2+ can promote the activity of cutinase, while Zn2+, Cu2+and Fe3+ inhibited its activity; methanol, acetone and isopropanol promoted the enzyme activity, but ethanol, acetonitrile and chloroform showed the opposite effect; the crude cutinase caused a significant degradation of grapes’ cuticle. This result provides a theoretical basis for the control of postharvest diseases of fruits and vegetables.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1525-1533. https://doi.org/10.11869/j.issn.100-8551.2020.07.1525Freshness is an important indicator for judging the quality of aquatic products. Traditional methods for detecting freshness of aquatic products are cumbersome, time-consuming and laborious, thus establishing a fast and convenient detection method has important practical significance and academic value. Biosensors have been widely studied and applied to the detection of freshness of aquatic products in recent years due to their advantages of fastness, specificity and sensitivity. Based on a brief description of traditional and new freshness detection methods, this paper reviews the application and research progress of biosensors in the detection of aquatic products freshness, especially the latest developments in the enzyme immobilization carriers and nanosensors. This paper also outlines the current problems and trends in biosensor technology for the detection of freshness of aquatic products. The purpose of this paper is to provide a reference for the subsequent research of this kind of biosensor.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1534-1542. https://doi.org/10.11869/j.issn.100-8551.2020.07.1534In order to explore the application mode of nitrogen fertilizer for high-quality cultivation of rice in cold regions, japonica rice cultivars Kenjing 7 and Kenjing 8 were used as experimental materials. Through two years of field experiments (year 2017-2018), four methods of nitrogen fertilizer application were set up: conventional fertilization (T1, 150 kg·hm-2 N, base fertilizer:tiller fertilizer:spike fertilizer=6:3:1), nitrogen fertilizer postpone 1 (T2, 150 kg·hm-2 N, base fertilizer:tiller fertilizer:spike fertilizer=4:3:3), nitrogen reduction based on T2 (T3, 135 kg·hm-2 N, base fertilizer:tiller fertilizer:spike fertilizer=4:3:3) and nitrogen fertilizer postpone 2 (T4, 150 kg·hm-2 N, base fertilizer:tiller fertilizer:spike fertilizer=5:3:2). T1 was used as the control to study the effects of nitrogen application on phytic acid, protein and mineral elements of rice grains in cold regions. The results showed that the effect of nitrogen fertilizer and variety on phytic acid content of rice grain was significant or extremely significant.Compared with T1, the content of phytic acid in T2, T3 and T4 decreased by 31.92%, 48.94% and 21.28%, respectively. T2, T3 and T4 increased the contents of albumin, globulin, glutenin and protein in grains, especially T2 treatment, with an average increase by 0.14, 0.01, 0.45 and 0.60 percent, respectively. The content of gliadin decreased in T2 and T3 treatment, and increased slightly in T4 treatment, but there was no significant difference with T1. T2 and T3 increased the contents of Cu, Mn, Fe, Ca, K, Zn in rice, especially T2; Under T4 treatment, the content of each mineral element has no obvious regularity. By analyzing the correlation between phytic acid content and protein, eight mineral elements content in rice under nitrogen fertilizer management, it was found that phytic acid content was negatively correlated with protein, albumin, globulin, glutenin and Cu, Mn, Fe, Zn, Ca, Mg and K, especially, it has a significant negative correlation with globulin, Zn and Ca content. In conclusion, the balanced distribution of nitrogen fertilizer can reduce the content of phytic acid in rice, increase the content of protein and mineral elements, and effectively improve the protein components, so as to improve the nutritional quality of rice. The results of this study provide a theoretical basis for the nitrogen management of high quality rice cultivation in cold regions.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1543-1550. https://doi.org/10.11869/j.issn.100-8551.2020.07.1543To better understand the characteristics of sorghum for NaCl stress at different growth stage, a bred salt tolerant hybrid, Jiliang No.1, was selected, and plants at germination stage (GS), seedling stage (SS), early jointing stage (EJS), later jointing stage (LJS), booting stage (BS) and flowering stage (FS), were treated with tap water (CK) and 0.6% NaCl solution (T) for 28 days. Results showed that compared with CK, NaCl stress resulted in a significant impact on plant height (PH), stem diameter (SD), fresh weight of aerial parts (FS) and dry weight of root (RDW) at the GS, and relative salt-injury rate (RSR) was the largest in the six growth stages. Spike fresh weight (SFW) was significantly impacted by NaCl stress at the EJS and followed by the LJS and BS. Heading time (HT) was less influenced when plants were subjected to NaCl stress starting at the EJS, LJS and BS. Soil and plant analyzer development (SPAD) values were significantly decreased when NaCl stress starts at the GS, EJS, LJS and BS. Na+ contents in leaves and roots in the six growth stages were significantly increased under NaCl stress,whereas K+ contents in leaves were significantly higher under NaCl stress than CK except for the GS. K+ content in root under NaCl stress was significantly lower than CK, and K+/Na+ in leaves and roots were all significantly decreased under NaCl stress in the six growth stages. Therefore, NaCl stress starting at the GS had the greatest effect on morphogenesis of sorghum seedlings, and salt stress starting at the EJS had the most significant effect on the accumulation of SFW. It is better to take some measures to reduce the influence of salt stress to plant in production. To some extent, the present research illustrated the characteristics and physiology mechanism for NaCl tolerance of Jiliang No.1, which provides a theoretical guidance for formulating the scientific and effective cultivation measures of sorghum in saline and alkali land.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1551-1560. https://doi.org/10.11869/j.issn.100-8551.2020.07.1551To reveal the relationship between content of endogenous hormones total polyphenols and cold-resistance, winter turnip rape Longyou 7 (cold resistant) and Tianyou 4 (cold sensitive) were used as experimental material. Under low temperature in the field, leaves and roots of plants were sampled to analyze the contents of endogenous hormones (IAA, ZR, GA3 and ABA) and total polyphenols, respectively. The results showed that IAA contents and ratio of (IAA+ZR+GA3)/ABA in leaves and roots of these two cultivars, ABA and ZR contents in leaves, GA3 contents and ratio of IAA/ZR in roots increased at first, and then decreased with decreasing temperature; GA3 contents in leaves and ZR contents in roots in Longyou 7 decreased, which increased at first, and then decreased in roots of Tianyou 4. As the temperature continued to drop, ABA contents increased in of roots Longyou 7, but increased at first, and then decreased in roots of Tianyou 4; total polyphenols contents in leaves of these two cultivars and roots of Longyou 7 increased at first, then decreased, and increased at last, decreased at first, and then increased in roots of Tianyou 4. The correlation analysis showed that overwintering rate of winter turnip rape had negative correlation with contents of IAA and ZR as well as ratio of (IAA+ZR+GA3)/ABA in leaves under lower temperature, but had positive correlation with contents of ABA and total polyphends in roots. Compared with Longyou 7, contents of IAA, ZR, ABA, total polyphenols and ratio of (IAA+ZR+GA3)/ABA in leaves of Tianyou 4 were higher after November 17th (-4.75℃), but contents of ABA and total polyphenols in the roots were lower. In conclusion, the faster growth in over ground parts, the worse cold resistance, and contents of ABA and total polyphenols in roots play important roles in cold tolerance. This study provided the theoretical reference for effect of endogenous hormone and polyphenols on cold tolerance of winter turnip rape.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1561-1567. https://doi.org/10.11869/j.issn.100-8551.2020.07.1561To further understand the adaptability and feedback ability of Dendrobium officinale to nitrogen application, changes of total nitrogen, total phosphorus and their stoichiometric ratios and the contents of non-structural carbohydrates in stems of D. officinale under nitrogen addition were studied. The two-year-old seedlings were treated by different mass percentages of urea (0 (CK), 0.2%, 0.6%, 1.0% and 1.5%) and the stems of seedlings were collected on the 5th, 15th and 30th days after treatment. The results indicated that nitrogen application changed the content of total nitrogen and total phosphorus in stems to varying degrees. When the concentration of urea was 0~0.6%, the total nitrogen concentration in stems decreased significantly after 30 days treatment. With the increase of urea concentration, the total nitrogen concentration in stems increased significantly. The change range of total phosphorus in stems was not significant. After 30 days treatment, the application of low concentration urea (0.2%~0.6%) was propitious to promoting the absorption and accumulation of phosphorus. When urea concentration was 0.6%, the N:P ratio reached, 3.17 the lowest value. In addition, the chlorophyll content reached the highest value when the fertilizer concentration was 0.2%. The polysaccharide content of D. officinale treated with 0.2% urea nitrogen fertilizer was the highest compared with other fertilizer concentrations. The soluble polysaccharide content decreased with the increase of nitrogen fertilizer concentration. The concentration of 0.2%~0.6% urea was beneficial to the accumulation of starch in the stems of seedlings. Similarly, the content of non-structural carbohydrates remained high levels. The change of N:P value in D. officinale was mainly determined by the change of N content. N content, chlorophyll content and N:P ratio could affect the accumulation of soluble polysaccharides, starch and non-structural carbohydrates. In conclusion, 0.2% urea application not only promoted carbon metabolism of D. officinale, and accumulated more carbohydrates with physiological activity, but also played an important role in improving the resistance of D.officinale to adverse stress environment.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1568-1577. https://doi.org/10.11869/j.issn.100-8551.2020.07.1568To clarify the application method of acidic soil amendment, a three-factor and two-level field experiment was conducted to study effects of amendment type, application time and application rate on pH of tobacco-planting soil and its effects on the economic properties, physical characteristics and chemical composition of flue-cured tobacco. The results showed as follows: (1) Application of acidic soil amendments significantly increased soil pH(increase soil pH 1.24~1.58 after transplanted 60 d and increase soil pH 0.39~0.54 after transplanted 120 d); (2) The application of low-dose lime is beneficial to the plant height and stem circumference growth of flue-cured tobacco before topping. The application of acidic soil amendment is of great benefit to the growth of flue-cured tobacco leaves before topping; (3) The application of amendments mainly affected the economic character and physical properties index of flue-cured tobacco, and the total nitrogen content of tobacco leaves. The amount of modifier have the greatest influence on the economic characters of flue-cured tobacco, furthermore, the type of modifier and the application time have the greatest influence on the physical characters of tobacco leaves, in addition, the amount of amendment have the greatest influence on the chemical composition; (4) The application of the amendment can enhance the proportion of the high-class leaf by 7.32% to 15.46%, the average price by 1.22% to 9.81%, the yield by 1.72% to 40.65%, and the output value by 2.74% to 42.67%, and the economic character index, tobacco physical property index and tobacco chemical composition availability index of flue-cured tobacco can be increased from 6.53% to 32.31%, 0.65% to 7.04%, and 0.36% to 13.87%, respectively. When acidity amendment is applied in production, the application of 1500 kg·hm-2 lime in the site preparation makes the greatest effects on the improvement of acidic soil. Furthermore, the application of 1500 kg·hm-2 acid soil amendment in the tobacco membrane uncovering and soil cultivation has a better effect on soil improvement. The results of this study provide scientific basis for the development of the application technology of acid soil modifiers in mountainous areas.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1578-1587. https://doi.org/10.11869/j.issn.100-8551.2020.07.1578To delay ripening time, reduce the fruit drop rate, and improve the fruit quality and benefit of bayberry, we set up an experiment by the covering measures with insect-proof net (net) only or net with white, blue, green, red and black rain-proof cloths (cloth) during the hard-core (June 9) and color-changing phases (June 23), to study effects of the above treatments on the development and fruit quality. The results showed that net with green or blue cloth were beneficial to reduce temperature and relative humidity, while net with red and black cloth were opposite. The photosynthetic rates and shoot elongations of all the treatments were significantly inhibited with the inhibited rate of photosynthetic efficiency 30.62%-66.74%, and that of net with green cloth was the highest in the color-changing stage. At the mature stage, the fruit drop rate without net and cloth was 100%; the drop rate of treatments covered by net only and net with black cloth during the hard-core and color-changing phases were 35.23%-70.49%, and that of the other treatments were 16.44%-19.9%. Among them, the treatment of net with green or blue cloth delayed the ripen time for the longest, reaching 5-9 days. From the comprehensive analysis of the total sugar content and vitamin C content, the quality of the fruit covered with net and blue cloth was the best, and the treatment with insect net and black cloth was the worst. The results will provide theoretical guidance for effectively utilizing different color rainproof cloth to carry out facility cultivation and delay the supply period of bayberry.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1588-1597. https://doi.org/10.11869/j.issn.100-8551.2020.07.1588To improve the potential of biochars removing nitrate through sorption, peanut shell biochars (BC) were prepared by pyrolysis at 600℃ and modified with FeCl3, MnCl2, MgCl2 solution (BC-Fe, BC-Mn, BC-Mg) by calcination at 300 ℃. The surface structure and adsorption properties of these modified biochars which were loaded the metal ions were detected by isothermal adsorption test, scanning electron microscope (SEM), Fourier transform infrared spectrometry (FTIR) and X-ray diffraction (XRD). The results showed that the modified biochars (BC-Fe, BC-Mn, BC-Mg) significantly increased specific surface area by 6.7~12.2 times, pore volume by 3.3~6.0 times, and significantly enhanced the adsorption capacity of nitrate nitrogen ($\text{NO}_{3}^{-}$-N) by 11.5%~17.1% in comparison with the BC control (P<0.05). The maximum adsorption capacities of BC-Fe, BC-Mn and BC-Mg to $\text{NO}_{3}^{-}$-N were 41.58, 39.04 and 39.58 mg·g-1, respectively, as well as the best mass ratios of iron, manganese, magnesium ions to carbon were 0.8, 0.2 and 0.2, respectively. Therefore, BC-Fe showed the highest adsorption capacity for nitrate adsorption process. Acid condition was shown to improve the adsorption of modified biochars to $\text{NO}_{3}^{-}$-N. Langmuir equation was better fitted to describe nitrate isothermal adsorption of the above modified biochars (R2=0.935~0.961), and the quasi-first-order kinetics equation could describe nitrate kinetic adsorption well (R2=0.971~0.980). With higher specific surface area, well-developed pore structure, modified biochars optimize physical adsorption capacities and then enhanced the adsorption performance of nitrate. It also suggested that the oxygen-containing functional groups and metal ions on the surface of modified biochars would react with $\text{NO}_{3}^{-}$ by forming hydrogen bonds or electrostatic action, thereby enhancing the adsorption capacity of $\text{NO}_{3}^{-}$-N. The results of this study can provide a theoretical basis for the preparation and optimization of biochars to adsorb nitrate.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1598-1605. https://doi.org/10.11869/j.issn.100-8551.2020.07.1598In order to provide indirect evaluation factors for high-yielding slash pine (Pinus elliottii) breeding, genetic correlations among growth traits, crown traits and resin yield (RY), and the control the RY, growth traits and crown traits were investigated in 112 families of slash pine (28 years old) experimental forests located in northern, southern and middle parts of Jiangxi province, China. The results showed that the RY positively correlated with the growth and crown traits (excluded HLC). The top four genetic correlation coefficients were DBH (0.93), CSA (0.83), CL (0.78) and CW (0.73). In the genetic path analysis, the direct and indirect effects of each trait on RY were different. The main factors influencing RY were DBH, HGT, CSA and CW, of which of R-square were 0.557, 0.507, 0.424 and 0.240, respectively. The linear regression equation between RY and growth and crown traits was y=-0.255+0.040 x(DBH)+0.004 x(HGT)+0.006 x(CSA)+0.036 x(CW)(F=955.907**, R2=0.559), and the estimated accuracy of the model is 99.64%. The results of this experiment clarified the relationship between the growth traits, crown traits and RY of slash pine, among which, the HGT, DBH, CW and CSA had a great influence on RY. The established multiple regression model of RY had a certain practical significance, and it could achieve the purpose of estimating the RY through the rapid determination of HGT, DBH, CW and CSA. Therefore, it provided a basis for scientific, accurate and efficient prediction of the RY of slash pine.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1606-1612. https://doi.org/10.11869/j.issn.100-8551.2020.07.1606To investigate the allelopathic effect of water and methanol extracts of five pine needles(Pinus tabulaeformis, Pinus armandi, Cedrus deodara, Pinus bungeana, and Pinus sylvestnis var)on Trifolium repens L. using a Petri dish bioassay, the effects of different concentrations of pine needle extracts on seed germination and seedlings growth of Trifolium repens L. was studied. The seed germination indicators(germination rate, germination energy, germination index, and vigor index)show that aqueous and methanol extracts have significant inhibition on the seed germination of Trifolium repens L., and the inhibition increased with the increase of aqueous and methanol extract concentrations. Results also show that Pine needle extracts induce a general inhibition of the seedlings growth of the Trifolium repens L., and they have significant greater inhibition on root length than on the shoot height, but have no significant inhibition on dry weight. The allelopathy degree of aqueous extracts on Trifolium repens L. is in the order of Pinus armandi > Cedrus deodara > Pinus sylvestnis var > Pinus bungeana > Pinus tabulaeformis, while the allelopathy degree of methanol extracts on Trifolium repens L. is Pinus tabulaeformis > Cedrus deodara > Pinus armandi > Pinus sylvestnis var > Pinus bungeana. Therefore, all the aqueous and methanol extracts of five pine needles have allelopathic effect on Trifolium repens L., and inhibit its normal growth. Trifolium repens L. is not suitable for the compound pattern of forest and grass under the pine forest. This will provide a theoretical basis for the selection of forage forest grass composite model.
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Journal of Nuclear Agricultural Sciences. 2020, 34(7): 1613-1619. https://doi.org/10.11869/j.issn.100-8551.2020.07.1613In order to study the effects of different patterns of straw returning practice on the decomposition mechanism of wheat straw on rain-fed croplands in northern China, two treatments of straw returning field with rotary tillage (SRT) and straw covering with no-tillage (SNT) were conducted using wheat straw in nylon mesh bag in the long-term positioning test area of conservation tillage in Linfen Shanxi Province from 2014 to 2015. We characterized the change of the decomposing rate, cellulose, hemicellulose, lignin, organic carbon, total nitrogen content, straw organic carbon mineralization rate and total nitrogen release rate of wheat straw under different tillage methods. The results suggest that the decomposing rate of wheat straw was 50% in SRT, 31% in SNT after 375 days of field decomposing. The average decomposing rates of cellulose, hemicellulose and lignin of wheat straw was 65%, 45% and 53% in SRT, and 56%, 30% and 39% in SNT, respectively. The salinization rate of straw organic carbon of wheat straw was 57% in SRT and 40% in SNT. The nitrogen release rate of wheat straw was 15% in SRT, and 36% in SNT. The straw returning field with rotary tillage accelerated the decomposition of straw and components of straw. Straw covering with no-tillage was beneficial to the release of nitrogen from straw resulting in reduced nitrogen fertilizer addition. The low mineralization rate of organic carbon of wheat straw in straw covering with no-tillage can reduce the rate of carbon cycle and thus increase the carbon sequestration capacity in wheat field. This study provides valuable information on the straw returning practice on rain-fed croplands in northern China.
