10 June 2021, Volume 35 Issue 6
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1253-1262. https://doi.org/10.11869/j.issn.100-8551.2021.06.1253BBX is a kind of important transcription factors which belongs to zinc finger proteins in plants. BBX regulate the expression of some genes involved in abiotic stress, and improve the resistance of plants to adversity stress. In order to explore the expression pattern of LaBBX gene responds to low temperature stress in Lepidium apetalum seedlings and analyse its codon bias. Based on the previous analysis of Lepidium apetalum transcriptone database BBX CDS sequence was cloned. The cDNA of this gene was 733 bp in length, encoding 242 amino acids, and was named as LaBBX. LaBBX contained two B-box zinc finger protein domains, its protein molecular weight was about 61.66 kDa and the theoretical isoelectric point was 5.09, with no signal peptide segments and no transmembrane region. The qRT-PCR analysis showed that LaBBX gene was rapidly and significantly up-regulated when seedlings of Lepidium apetalum were under low temperature stress, after 6 hours stress, the expression of LaBBX was 21 times as the control, and retained high level expression within 24 hours. The results suggest that LaBBX play an important role in regulating the resistance of low temperature stress in Lepidium apetalum seedling. Analysis of codon usage bias of the Lepidium apetalum LaBBX gene showed that: The ENc, CAI, and GC content of LaBBX were respectively 55.453%, 0.244%, and 46.78%, indicating that the codon bias level of LaBBX in Lepidium apetalum was low and biased toward the synonymous codons with A or T. According to the RSCU value, 8 codons showed hign-frequency. The CDS sequence and RSCU cluster analysis showed that the preference of LaBBX gene was closest to that of Brassicaceae burnett in dicotyledonous plants. Many factors play an important role in shaping codon usage bias of the Lepidium apetalum LaBBX gene such as mutation and selective pressure. The yeast expression system was found to be most suitable for heterologous expressing LaBBX gene, and Arabidopsis thaliana is the most ideal genetic transformation receptor of the LaBBX gene. This study provides important information for further studies on the heterologous expression and the function of the LaBBX gene in Lepidium apetalum.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1263-1272. https://doi.org/10.11869/j.issn.100-8551.2021.06.1263To screen the cold tolerance identification indexes, construct a new comprehensive evaluation system for cold tolerance and excavate the cold-tolerant germplasm resources in high oleic acid peanut. In this study, the cold tolerance of 56 high oleic acid germplasms was comprehensively evaluated by membership function method, principal component factor analysis, correlation analysis and cluster analysis, and meanwhile the cold-tolerant germplasm resources were selected. The results showed that the 11 identification indexes of cold tolerance were summed up as germination factor, germination time factor and cotyledon fresh weight factor according to the contribution rate. The germination index and cold tolerance index could be considered as the optimal identification indexes for the cold tolerance of high oleic peanut during germination. However, the cold tolerance of high oleic peanut germplasm resources at germination stage was affected by multiple indexes. The D value of comprehensive evaluation on cold tolerance of high oleic acid peanut at germination stage ranged from 0.080 to 0.754, with an average value of 0.497, suggesting that there was great variation in cold tolerance of different high oleic acid peanut varieties at germination stage. Furthermore, 56 high oleic acid peanut germplasm resources were divided into 5 cold tolerance grades at germination stage, including 1 material with stronger cold tolerance, 20 materials with medium cold tolerance, 29 general materials with poor cold tolerance, 5 materials with bad cold tolerance and 1 material with cold sensitivity. These cold-tolerant germplasms can be used as materials for breeding and research on cold tolerance mechanism of high oleic acid peanut. What’s more, this study also provides a theoretical reference for ascertaining the cold tolerance of high oleic acid peanut germplasm resources.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1273-1280. https://doi.org/10.11869/j.issn.100-8551.2021.06.1273In order to explore the regulation effect of NAC gene on carotenoid accumulation, this study cloned PpNAC19 gene from peach. Sequence analysis showed that the open reading frame sequence of PpNAC19 (XP_007223324.1) was 867 bp in length, encoding 288 amino acids with a NAM domain. The predicted molecular weight of the protein was 33.2 kDa, and the average hydrophobic coefficient was-0.719, which was a hydrophilic protein. Subcellular localization predicted that PpNAC19 protein was localized in the nucleus. Amino acid sequence alignment and cluster analysis showed that PpNAC19 had a close relationship with Prunus dulcis (VVA20514.1). The results of qRT-PCR revealed that PpNAC19 was expressed in different organs of peach, and the expression was the highest in hard-core fruit. During the whole fruit ripening process, the carotenoid content in yellow fleshed peach was obviously higher than that in white fleshed peach. The expression of PpNAC19 gene was higher in yellow fleshed peach, while the expression of carotenoid degradation gene PpCCD4 in yellow fleshed peach is significantly lower than that in white fleshed peach. The results of double luciferase test showed that PpNAC19 could transcriptionally inhibit the activity of PpCCD4 promoter. This experiment provides a theoretical basis for further research on the function of PpNAC19 gene in the carotenoid metabolism of peach fruits.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1281-1290. https://doi.org/10.11869/j.issn.100-8551.2021.06.1281Mitogen-activated protein kinase (MAPK) cascades play essential roles in plant response to biotic and abiotic stresses. In order to study the function of MAPKKK genes during tea postharvest processing, the full length cDNA of three MAPKKK genes were cloned from tea cultivar ‘Fudingdabaicha’cultivar, and named as CsMAPKKK18, CsMAPKKK18-like and CsMAPKKK-NPK1, respectively. Bioinformatic analyses showed that the coding sequence of CsMAPKKK18, CsMAPKKK18-like and CsMAPKKK-NPK1 are 1 005 bp, 1 209 bp and 1 077 bp in length, and encode 334, 402 and 358 amino acids putatively located on the vacuole, mitochondria and nucleus respectively. Conserve domain analysis showed that three CsMAPKKK belonged to MEKK family with conservative region of G(T/S)PX(W/Y/F)MAPEV. Phylogenetic tree analysis showed that CsMAPKKK18 and CsMAPKKK18-like have the closest relationship to homologies in Solanum lycopersicum and Capsicum annuum while MAPKKK-NPK1 corresponding to Ricinus communis and Vitis vinifera. qRT-PCR analysis showed that the CsMAPKKK genes were highly expressed in roots. In the processing of white tea withering, CsMAPKKKs were up-regulated significantly, and particularly the expression level of CsMAPKKK18 raised up to 65-fold. In the green-making procedure of Oolong tea, the transcription level of CsMAPKKK18 increased to 26-fold. CsMAPKKK18-like was significantly up-regulated at the third tumbling procedure and down-regulated at the solar withering, second tumbling and before fixation procedures. CsMAPKKK-NPK1 was dramatically down-regulated at the solar withering procedure and up-regulated at the first, second and third tumbling procedures. These results demonstrated that CsMAPKKKs might be involved to the withering processing of white tea and green-making procedures of oolong tea, and provided a foundation for further studies on the quality formation mechanism of tea processing.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1291-1299. https://doi.org/10.11869/j.issn.100-8551.2021.06.1291Haidao 86 is a rice variety, which originally grew on coastal beaches and showed high resistance to alkali stress. In this paper, the difference in nitrogen metabolism of Haidao 86 and an alkali sensitive variety Zhenshan 97 under alkali stress was studied to find out the physiological and molecular bases for the high alkali resistance of Haidao 86. The rice seedlings were treated with salt solution at pH 9.0, then the contents of nitrogen-containing substances, the activity of nitrogen assimilation enzymes and the expressions of related genes were examined. The results displayed that alkali stress caused less decreases in contents of NO3- and soluble protein in Haidao 86 than those in Zhenshan 97, but induced higher accumulation of NH4+in Zhenshan 97. For Haidao 86 under alkali stress, the NR activity in roots as well as GS activities in roots and leaves showed no significant difference, the NR activity in leaves as well as GOGAT activities in roots decreased, while the GOGAT activity in leaves increased when compared with those under control. The activities of NR, GS and GOGAT in Zhenshan 97 all decreased significantly under alkali stress, and the extent of reduction was greater than those of Haidao 86. Alkali stress had no significant effect on the activity of glutamate dehydrogenases (GDH) in Haidao 86, but induced a significant increase in that of Zhenshan 97. Analysis of relative transcript levels of nitrogen metabolism genes using qRT-PCR displayed, that, under alkali stress, the expression pattern of NR and GDH genes in Haidao 86 and Zhenshan 97 were consistent with the change of enzyme activities, while the expression of NADH-GOGAT genes were different from the change of enzyme activities, the expression of OsNADH-GOGAT1 and NADH-GOGAT2 was significantly increased, the transcript levels of NR and GOGAT genes in Haidao 86 were higher than those in Zhenshan 97, on the contrary, transcript levels of GDH genes in Haidao 86 were lower than those in Zhenshan 97. Summarily, the high alkali stress resistance of Haidao 86 is related to its stable activities of enzymes in nitrogen metabolism, the results provide an important theoretical basis for further understanding the mechanism of salt tolerance of rice and breeding salt tolerant rice varieties.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1300-1306. https://doi.org/10.11869/j.issn.100-8551.2021.06.1300In order to explore the role of ethylene and the response to ethylene signal of narcissus bulbs during bulb swelling phase, the ethylene amount and NtERFs genes expression in scales and inner buds of narcissus bulbs were detected. The relationships among bulb development, ethylene content and the expression of NtERFs genes were discussed. The results showed that the weight of bulb continually increased from March to May, which indicated that this period was swelling phase of bulbs. Ethylene amount released from scales increased sharply in mid-May. The ethylene released from inner bud was significantly higher than that from scales, and the peak appeared in late April. These results suggest that the ethylene released from inner bud has a bearing on bulb expansion and can induce the releasing of ethylene from scales. The ethylene from scales could lead to leaf chlorosis. The expression profiles of NtERF1, NtERF4 and NtERF118 were consistent with the ethylene releasing pattern of scales, those 3 genes may be involved in ethylene signaling in scales, and NtERF1 could be a key response factor. NtERF2, NtERF3, NtERF4 and NtERF26 might participate in ethylene signaling response in inner bud, and NtERF2 gene was a primary ethylene response factor of inner bud, in addition, the NtERF2 gene from scales could involve in the signaling response to the ethylene released from inner bud. Hence, these results implied the feedback regulation among vegetative growth, ethylene releasing and NtERFs expression in narcissus bulbs. The results of this study provided a basis for further study on the role of ethylene and its signal transduction in the vegetative growth of narcissus bulbs.
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Establishment of Magnetic Nanoparticles-Mediated Genetic Transformation System in Capsicum annuum L.Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1307-1312. https://doi.org/10.11869/j.issn.100-8551.2021.06.1307In order to provide a controlled, broad-spectrum and high efficiency method of genetic transformation for gene editing of pepper. Using B2 as the experimental material, magnetic nanoparticles (magnic nanoparticles, MNPs) and vector plasmid pCas9-TPC were added to the pollen medium, the pollen was introduced into the magnetic field at room temperature for 30 min under the action of the MagnetoFACTOR plate 24. The pollen carrying the CRISPR/Cas9 vector was artificially pollinated and the seeds were harvested after the fruit matured. The transformation was detected by the resistance marker of herbicide resistant (ammonium phosphine) carried on the vector plasmid DNA; the DNA and RNA of T0 generation and DNA of T2 generation plants were extracted, and the primer of CRISPR/Cas9 was designed for PCR amplification. The presence or absence of CRISPR/Cas9 vector in T0 and T2 generation plants was detected. The integration of T0 generation plants with southern hybridization detection gene editing vector and cayenne genome was observed. The results showed that the average conversion efficiency was about 63.70%, T0 generation plants DNA and RNA and DNA of T2 generation, CRISPR/Cas9 vectors were amplified by PCR. 8 positive plants were randomly selected for southern hybridization, and 1-3 bands were randomly present. The results show that the nano-magnetic granule-mediated pollen transformation method can establish a high-efficiency gene editing and transformation system on pepper, and provide a better tool for the genetic breeding of pepper.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1313-1321. https://doi.org/10.11869/j.issn.100-8551.2021.06.1313To improve the expression efficiency of thymosin, fusion tags were designed to perform recombinant expression of thymosin α1 and β4 (Tα1, Tβ4) in vitro. The liquid chromatograph-mass spectrometer (LC/MS) method was used to confirm the complete molecular weight of fusion proteins with different expression vectors, and expression of different expression vectors was detected by reversed-phase ultra-high performance liquid chromatography. The results showed that two tags A18-KEKE and DKL6K could efficiently express Tα1 and Tβ4. The LC/MS analysis showed that the over-expression bands of all tested samples contained the target peptides with the fusion tag A18-KEKE. The expression of thymosin was as high as 73-123 mg ·OD-1·L-1. In addition, A18-KEKE and DKL6K could effectively promote the expression of glucagon-like peptide-1 (GLP-1), glucagon-like peptide-2 (GLP-2), parathyroid hormone (PTH 1- 34) and glucose-dependent insulinotropic polypeptide (GIP), confirming that the broad-spectrum applicability of these two fusion tags. In this study, we successfully screened two tags that can be used for the recombinant expression of different thymosin family polypeptides in E. coli, and the high expression levels of the fusion proteins indicates their prospects in industrial application prospect.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1322-1328. https://doi.org/10.11869/j.issn.100-8551.2021.06.1322In order to effectively screen the biocontrol bacteria that had a good control effect to bacterial wilt disease (Ralstonia pseudosolanacearum), in this paper, quorum-sensing quenching gene aiiA was amplifed and control effects in greenhouse were tested. The taxonomic status was clarified by traditional bacteriological and molecular biological identification methods. The results showed that 12 biocontrol strains containing aiiA gene were obtained from 253 test strains, and the strain B15 that had a good control effect to tobacco bacterial wilt was screened out by further control test in greenhouse. The disease occurrence was delayed for 2 days, and the control effect was 68.33% in 14 days after inoculation with strain B15. On NA plate the colony of the strain B15 was round, white, and the surface was shiny and rough. The bacterial cell was rod-shaped and gram-positive. The salinity tolerance of the bacteria was 7%. According to the results of physiological and biochemical assay, 16S rDNA and gyrB gene sequence analysis, the strain B15 was identified as Bacillus cereus. The strain B15(B. cereus)with quorum quenching-sensing gene aiiA might provide a new biocontrol bacterial strain against R. pseudosolanacearum.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1329-1339. https://doi.org/10.11869/j.issn.100-8551.2021.06.1329CRISPR/Cas9 is a genome directed editing technique mediated by small guide RNA. Since 2005, the technology has been developed rapidly and was widely used in biology, medicine and crop genetics and breeding. Compared with meganucleases, zinc finger nucleases (ZFNs) and transcription-like activator effector nucleases (TALENs), CRISPR/Cas9 technology has unsurpassed advantages and has become the most important gene editing technology at present due to its simple operation and high editing efficiency. This paper systematically described the origin, development and the characteristics of CRISPR/Cas9 gene editing, summarized the application of this technology in crop gene editing and other aspects. The purpose of this paper is to provide reference for crop germplasms innovation, gene mining and breeding.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1340-1346. https://doi.org/10.11869/j.issn.100-8551.2021.06.1340Effects of red light irradiation on nutritional quality of post-harvest radish sprouts were investigated. Harvested radish sprouts were treated with red light for 8 h, then stored at 4°C. Samples were collected at 0, 1, 2 and 3 d after treatment for quantification of glucosinolates and antioxidants (chlorophylls and anthocyanins), as well as the antioxidant capacity. The results showed that red light treatment increased the contents of total aliphatic glucosinolates (glucoraphasatin etc.) and indolic glucosinolates (4-methoxy glucobrassicin etc.) by 9.5% and 20.6% respectively, notably postponed the decrease of glucoraphasatin, one anticancer component, during storage. In addition, increased contents of chlorophylls and anthocyanins, as well as the antioxidant capacity (at early stage of storage period) were observed in red light treated sprouts. These results provide a theoretical basis for the application of light treatment in maintaining nutritive value of radish sprouts during post-harvest storage.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1347-1355. https://doi.org/10.11869/j.issn.100-8551.2021.06.1347In order to investigate the effects of three pretreatments(blanching, freeze-thaw and ultrasonic treatment) on the volatile components of broccoli stem and leaf juice, the headspace solid-phase microextraction-gas chromatography mass spectrometry was used to determine these volatile components in the juice produced from broccoli stem and leaf treated with different pretreatments. Results showed that the main odorous components of broccoli stem and leaf juice were hexanal, heptaldehyde, nonanal, (E)-2-hexenal, (E, E)-2,4-heptadienal, and 1-pentanol, 1-octanol, 1-hexanol, (E)-3-hexen-1-ol, methyl mercaptan, 2-ethylthiophene, methyl thiocyanate, dimethyl disulfide, β-lonone, and 6-methyl-5-hepten-2-one. Blanching and freeze-thaw treatment could effectively reduce both the types and contents of volatile components in broccoli stem and leaf juice than ultrasonic treatment. Compared to the control group that had not been pretreated, methyl mercaptan and dimethyl disulfide were determined in the broccoli stem and leaf juice treated with blanching, the aldehydes content was lower and the esters content was increased. Besides, the sulphide content of blanching group was lower than that of freeze-thaw treated group. This study provided a techique basis for the development of fruit and vegetable juices.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1356-1366. https://doi.org/10.11869/j.issn.100-8551.2021.06.1356Peanut protein’s application in acidic beverage is limited due to its reduced solubility and flocculation under acidic conditions. In this study, a combination of high-pressure homogenization and neutral proteolysis was used to improve the solubility of peanut protein at pH 4.0. The effect of different concentrations of modified protein addition on the stability of juice were analyzed according to the Turbiscan backscattering coefficient value and Turbiscan instability index (TSI). The optimal process obtained by response surface analysis was: homogeneous pressure 79.74 MPa, ratio of material to liquid 7.23%, enzyme addition amount 517 U·g-1, and enzymatic hydrolysis time 48.20 min. The nitrogen solubility index (NSI) of modified peanut protein at pH 4.0 increased from 4.04% to 37.49%. The modified peanut protein was added to orange juice at pH 3.88, and the stability index TSI of fruit juice with 3% and 4% modified protein addition was 1.95 and 2.23, respectively, which was significantly better than those with 5% protein added samples (TSI 3.29). These results showed that high-pressure homogenization and neutral proteolysis compound modification could significantly improve the solubility of peanut protein at pH 4.0, and the modified protein had good stability in acidic beverages, which provided a reference for the application of plant protein in acid beverages.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1367-1375. https://doi.org/10.11869/j.issn.100-8551.2021.06.1367To study the mathematical relationship between the dielectric properties(DP) of kiwifruit and its main qualities. The DP, nutrient composition, color difference and texture of hayward kiwifruit in different storage periods were tested. The characteristic frequency points of quality indicators (Vc, soluble solid, ΔE, hardness, cohesiveness and springiness) were selected out by successive projections algorithm(SPA) and genetic algorithm in combination with partial least squares(GA-PLS). The prediction models of kiwi fruit were established based on the dielectric parameters at the characteristic frequency points. The results showed that the optimal models of Vc content and ΔE value was SPA-NN, hardness, soluble solids content, cohesiveness and elasticity was GA-PLS-NN. The determined coefficients of the models were 0.971, 0.934, 0.922, 0.984, 0.908 and 0.954, respectively. There was no significant difference between the predicted value and the measured value(P>0.05) for each quality indicator. The dielectric detection technology combined with SPA and GA-PLS can reflect the characteristic quality of kiwifruit, and the research lays a foundation for the non-destructive detection of kiwifruit property.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1376-1384. https://doi.org/10.11869/j.issn.100-8551.2021.06.1376In order to optimize the extraction process of polyphenols from lotus seed peel waste (LSPW) by acidic ethanol solution (acetic acid + ethanol + water), and investigate the potential application of the polyphenols extract (PEL) as a natural antioxidant in food, a response surface methodology was used to optimize the extraction process of polyphenols from LSPW, and the antioxidant activities of PEL were also investigated in vitro. The results showed that the optimum extraction process was as follows: ethanol concentration 41%, liquid to solid ratio 59 mL·g-1, acetic acid addition amount 1.56 mL·100mL-1, extraction temperature 70℃, and extraction time 20 min. Under these conditions, the yield of polyphenols from LSPW was 9.65%, and polyphenols content in the extract was 24.03%. PEL had strong ability to scavenge DPPH free radical (IC50=0.032 mg·mL-1) and reduce Fe3+ (eq.=268.64 mg AAE·g-1), and its capacity to inhibit lipid oxidation was equivalent to 37.12%, 39.20% (FTC method) and 72.92%, 67.60% (TBA method) of that of tert-butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA), respectively. This study could provide a theoretical basis for the development and utilization of polyphenols from LSPW as well as the potential natural antioxidant of PEL in foods.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1385-1393. https://doi.org/10.11869/j.issn.100-8551.2021.06.1385In order to improve the nutritional value of rice noodles. In this study, the pea flour of different particle size were added to rice noodles, and the effects of addition ratio (0%, 7.5%, 15%, 30%) on silty properties of rice noodles and the cooking, texture and sensory properties of rice noodles were analyzed. The results showed that pea flour can increase the protein content in rice noodles, and the protein content of rice noodles with 30% pea flour content is 1.73 times of the original. The pea flour reduced the peak viscosity, final viscosity and setback of rice flour, which improve the stability of the cold paste of the rice noodles, during aging of the rice noodles. With the increase of pea flour content, the hardness and cooking loss of rice noodles increased gradually, while the sensory score decreased. The particle size of pea flour showed an impact on the quality of rice noodles. With the same dosage, the cooking loss of rice noodles with 200 mesh pea flour was reduced by 9.08%-20.73% compared with that with 80 mesh pea flour; the total sensory evaluation score was increased by 1.35%-10.43%. In summary, it is possible to obtain rice noodles with good quality that 30% pea flour addition and reducing the particle size of the pea flour shall be considered. The results of this study might be useful for the development of nutritional and healthy rice noodles.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1394-1401. https://doi.org/10.11869/j.issn.100-8551.2021.06.1394In order to study the ingredients of Yunnan tobacco essential oil and the extraction tecnology of nicotine and neophytadiene, the typical flue-cured tobacco leaves in Yunnan were used as raw materials to extract nicotine and neophytadiene by CO2 supercritical fliud extraction(CO2-SFE), ultrasonic assisted extraction, Soxhlet reflux extraction and solvent extraction. The composition and content in the extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). The extraction rates and the relative contents of nicotine and neophytadiene in the obtained extracts were compared with different extraction methods and solvents, and the suitable extraction methods for nicotine and neophytadiene in Yunnan flue-cured tobacco leaves were determined. The results showed that the yields of tobacco essential oil from high to low by the four processes were soxhlet extraction, solvent extraction, ultrasound-assisted extraction and CO2-SFE with ethanol as extractant. Nicotine, neophytadiene, n-hexadecanoic acid (Z, Z), 9,12,15-octadecatrienoic acid, 1,5,9-trimethyl-12-(1-methyl ethyl) -4,8,13-cyclotetratriene-1,3-diol and vitamin E were the main components in all the extracts obtained under different extraction processes. The total relative contents of nicotine and neophytadiene were as follows: soxhlet extraction(75.58%, 2.85%) > CO2-SFE(35.01%, 26.80%) > ultrasound-assisted extraction(32.28%, 28.24%) > solvent extraction(9.56%, 45.20%). The results of this study provide a theoretical basis for the study on the ingredients in Yunnan smoke oil, as well as nicotine and neophytadiene.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1402-1409. https://doi.org/10.11869/j.issn.100-8551.2021.06.1402In order to further rationally develop and utilize the salmon skin, the objective of this study was to characterize the antioxidant activities and functional properties of salmon skin which was hydrolyzed by Neutrase, Alcalase, Flavourzyme and Protamex of hydrolysis. The results showed that Alcalase salmon skin hydrolysate exhibited the highest hydrolysis degree (20.18%) and TCA-soluble nitrogen yield (40.14%),contained up to 99.97% small molecular mass polypeptide and had better antioxidant activity than did other groups (P<0.05). Also, Alcalase hydrolysate had the highest solubility (87.21%) and water holding capacity (26.92%). The highest oil holding capacity (4.67%) and emulsifying activity index (14.69%) were detected for Neutrase hydrolysate. However, the highest emulsion stability index was found for Flavourzyme hydrolysate (P<0.05). In conclusion, Alcalase is the optimal protease for the preparation of salmon skin antioxidative hydrolysate. This study provided data support and theoretical foundation for the high value utilization of salmon skin by-products.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1410-1419. https://doi.org/10.11869/j.issn.100-8551.2021.06.1410To explore the effect of non-Saccharomyces in red koji on the flavor components of rice wine, the yeasts were firstly isolated and purified from red koji and identified by molecular biological technology. Afterwards, the isolated non-Saccharomyces strains were respectively combined with Monascus purpureus to brew rice wine by pure fermentation, and the flavor components such as organic acids, amino acids and volatile compounds in the brewed wines were analyzed. The results showed that four non-Saccharomyces were isolated and strain CKS-2 is Wickerhamomyces sp.; CKS-3 is Meyerozyma guilliermondii; CKS-4 is Rhodotorula mucilaginosa; CKS-7 is Torulaspora delbrueckii. Among the four non-Saccharomyces strains, CKS-7 has a good ability to produce alcohol and malic acid. The contents of serine, histidine, tryptophan and leucine in the wine fermented by CKS-7 are higher than those fermented by other non-Saccharomyces, and CKS-7 is a good strain to synthesize 2-phenylethanol, isoamyl alcohol and ethyl palmitate. CKS-7 can improve the quality of red koji rice wine and is a potential non-Saccharomyces which can be used in red koji rice wine brewing.
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Influence Factors Analysis of Soil Trace Elements in Xunwu County Based on the Geographical DetectorJournal of Nuclear Agricultural Sciences. 2021, 35(6): 1420-1432. https://doi.org/10.11869/j.issn.100-8551.2021.06.1420Based on the data of the 572 soil samples collected from the surface layer (0 ~ 20 cm) in Xunwu County in 2018, descriptive statistical analysis, correlation analysis, geostatistical analysis and geographic detectors were applied to analyze spatial differentiation of soil B, Se, Mn and Cu in distribution and its influencing factors in Xunwu County, Ganzhou city, Jiangxi province. According to the “Specification of land quality geochemical assessment”, there was no deficiency or excess of soil total Se, but the contents of soil total B, Mn and Cu in the soil were slightly deficient or deficient; Semi-variogram function analysis showed that the soil B, Se, Mn and Cu of the nugget effect were 11.82%, 35.27%, 49.75% and 17.46%, which showed the soil B and Cu had strong spatial variation, while the soil Se and Mn had moderate spatial variation. Geographical detectors analysis showed that the contents of heavy metal element As, elevation, subclass, soil genus and parent material had significant impacts on the spatial variability of four soil trace elements(P<0.05), therein the contents of heavy metal element As and soil genus were the main factors affecting the four trace elements in Xunwu County; the contents of heavy metal element As, land use type, vegetation coverage, vegetation type, soil genus, parent material and other soil-forming factors had non-linear interaction with slope, aspect and other terrain factors. The results can provide theoretical support for the regulation of soil trace elements in Xunwu County.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1433-1439. https://doi.org/10.11869/j.issn.100-8551.2021.06.1433In order to evaluate the enrichment and remediation capacity of castor on heavy metal cadmium (Cd) in polluted farmland, five castor varieties were selected for field trials. The agronomic characteristics, yield,Cd enrichment and translocation capacity, remediation capacity in Cd contaminated soil were investigated. The results showed that the five varieties of castor grew well in Cd-polluted farmland. The plant height, stem diameter and seed yield per plant of Dianbi2 were 440.78 cm,5.04 cm and 338.85 g, respectively, which were significantly higher than other varieties. The Cd content, Cd accumulation in roots, stems, leaves, and fruits, and enrichment coefficients were significantly different among five castor varieties. The Cd content in roots, stems, and fruits of Jingzuobima1 were 1.40 mg·kg-1, 1.14 mg·kg-1 and 0.33 mg·kg-1, respectively, which were significantly higher than other varieties. In terms of remediation capacity, the Cd accumulation of Dianbi2 was 3.38 mg per plant, while the annual extraction rate was 5.34%, which was significantly higher than other varieties. Although Jingzuobima1 has the strongest enrichment capacity, its Cd accumulation and annual extraction efficiency are the lowest due to its smallest biomass. This study shows that castor has a strong enrichment capacity to accumulate heavy metal Cd in soil and can be used to remediate the Cd-polluted soil in Gejiu, Yunnan province, and planting Dianbi2 can result in a better remediation effect. This study provides a theoretical basis and reference for remediation of Cd polluted areas in Yunnan.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1440-1450. https://doi.org/10.11869/j.issn.100-8551.2021.06.1440To explore the effects of different biochar types and biochar application methods on the tobacco-growing soil, a field experiment was conducted in the red soil areas in Yanyuan country, Sichuan province. The effects of different biochar types (i.e., maize straw biochar (YM), rape straw biochar (YC)) and biochar application methods (i.e., band application, hole application, band application combined with hole application) on the changes of soil organic carbon fractions and enzyme activities during the growth of tobacco were studied. Results showed that biochar types and application methods significantly affected the soil total organic carbon (TOC) contents. Compared with control (no biochar addition), biochar application increased the soil TOC contents by 6.9%~39.7%, especially for the rape straw biochar applied in the hole. The application of biochar increased the contents of soil labile organic carbon fractions (LOC, the sum of dissolved organic carbon (DOC), microbial biomass carbon (MBC) and readily oxidizable carbon (ROC)) and particulate organic carbon (POC). The average contents of LOC in soil amended with were significantly higher than those with YM, but the opposite result was found for POC. Additionally, biochar types and application methods significantly influenced the contents of soil LOC fractions. Soil DOC contents in YM and YC increased by 25.3%~36.4% and 33.3%~51.3% relative to the control, respectively (P<0.05). The highest contents of MBC, ROC and POC at the vigorous stage were obtained in the YC treated soil via the hole application method, which increased by 34.6%, 28.9% and 38.3% compared with the control, respectively. Soil sucrase and protease activities were significantly influenced by biochar types and biochar application methods. Compared with the control, higher activity of soil sucrase was observed in the YC treated soil, especially for the hole application, which increased by 24.1%~30.6%. YM application increased the soil urease and peroxidase activities in the squaring and maturity stages, and the promotion degrees were better than YC. Overall, biochar applications increased the contents of soil organic carbon fractions and sucrase activities. Biochar derived from rape straw and applied in the hole could better increase soil LOC fractions and surcase activity than others in this study. These results provide a conservation technique in tobacco growing soil and a scientific basis and practicing guidance for the application of biochar.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1451-1456. https://doi.org/10.11869/j.issn.100-8551.2021.06.1451In order to explore the effect of biochar combined with nitrogen fertilizer on millet growth and soil, this research studied the effects of biochar(C0, 0 g·kg-1, C1, 20 g·kg-1, C2, 40 g·kg-1) combined with nitrogen fertilizer (N0, 0 g·kg-1, N1, 0.133 g·kg-1, N2, 0.266 g·kg-1) on soil nutrients, root millet morphology, photosynthesis, dry matter accumulation, etc., using Jingu 21 as a test material, a pot experiment to completely randomized design. The results showed that both biochar and nitrogen fertilizer significantly increased the soil nutrient content, and C2N2 processing has the largest increase. Compared with C0N0, the alkali hydrolyzed N content increased by 61.03%. Biochar has a significant promotion on Millet photosynthesis, root morphology, and dry matter accumulation. Under the same biochar level, the low nitrogen fertilizer will promote millet photosynthesis, root morphology, and dry matter accumulation, while the high nitrogen fertilizer will inhibit them. Compared with C0N0, C2N1 has the best effect in which the above-ground dry weight increases the most, with an increase by 129.24%. it summary, it can be seen that biochar and an appropriate amount of nitrogen fertilizer can improve soil nutrient status and promote dry matter accumulation in the above ground. Under the conditions in this experiment, C2N1 is the optimum combination, so the combination of biochar and appropriate amount of nitrogen fertilizer can promote millet growth, which can provide a certain theoretical basis for the yield increase of millet while reducing fertilizer usage.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1457-1465. https://doi.org/10.11869/j.issn.100-8551.2021.06.1457In order to clarify the effect of different cropping patterns on alleviating continuous cropping obstacles in broccoli continuous cropping fields, Illumina Miseq high-throughput sequencing technology was used in this study to analyze and compare the effects of three different treatments (paddy-upland rotation of rice and broccoli, drought rotation of pumpkin and broccoli, and continuous cropping of broccoli) on the bacterial community structure and diversity in the rhizosphere soil of broccoli in broccoli planting fields of coastal beach area in Taizhou Bay, Zhejiang Province. The results showed that 28 phyla, 92 classes, 167 orders, 301 families and 691 genera of soil bacteria were obtained from the rhizosphere soil of broccoli by the three cropping patterns in Taizhou estuary, Zhejiang province. Proteobacteria, Acidobacteria, Actinomycetes,Gemmatimonadetes, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae and Verrucomicrobia were the dominant phyla with high relative abundance of bacteria in broccoli rhizosphere soil in Taizhou estuary coastal beach. Paddy-upland rotation could improve the relative abundance of Proteobacteria, Acidobacteria and Chloroflexi, while decrease the relative abundance of Actinobacteria, Gemmatimonadetes, Bacteroidetes and Cyanobacteria in rhizosphere soil of broccoli. The diversity index and richness index were the highest in the paddy-upland rotation, followed by drought rotation samples, and the broccoli continuous cropping was the lowest. Therefore, compared with long-term continuous cropping of broccoli, both paddy-upland rotation and drought rotation could improve the bacterial community structure of broccoli rhizosphere soil in Taizhou estuary coastal beach. However, paddy-upland rotation had better effects on improving the abundance and the diversity index of beneficial bacteria in broccoli rhizosphere soil and improving the ecological environment of broccoli rhizosphere. The finding provides the theoretical and practical evidence for broccoli cultivation of high yield and excellent quality in this region.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1466-1475. https://doi.org/10.11869/j.issn.100-8551.2021.06.1466In order to explore the effect of exogenously 2, 4-epibrassinolide (EBR) on the salt tolerance of mulberry(Morus L.), a pot experiment was carried out with mulberry variety gui sang you 12 as the material. Different concentrations (0.01, 0.10, 1.00μmol·L-1) of exogenous EBR were applied to investigate the effects of exogenous EBR on quality, root characteristics, pigment content, reactive oxygen species (ROS) level, malondialdehyde (MDA) content, relative permeability of plasma membrane, antioxidant enzyme activity and osmotic regulator content of mulberry seedlings under 200 mmol·L-1 NaCl stress. The results showed that the shoot fresh mass and dry mass, root fresh and dry mass, taproot length, total root length, root surface area, root average diameter,total root volume and the content of chlorophyll and carotenoids of mulbery seedling were increased when 0.10 μmol·L-1EBR was applied under salt stress. The ability to produce hydroxyl (·OH) and superoxide radicals ($\text{O}_{2}^{\frac{{}}{\cdot }}$) in leaves and roots were decreased, as well as the content of hydrogen peroxide (H2O2). On the other hand, the activities of superoxide dismutase (SOD), peroxidase oxidase (POD) and catalase (CAT) were increased. Meanwhile, the contents of proline, soluble protein and soluble sugar increased, but relative permeability of plasma membrane and MDA content dropped down. Among them, the root fresh mass and root volume were 1.56 and 1.57 times of salt stress, and the CAT activity and soluble sugar content in leaves reached 1.57 and 1.68 times of salt stress, respectively. This study provides a reference for revealing the physiological regulation mechanism of the external application of EBR to enhance the salt tolerance of mulberry.
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Journal of Nuclear Agricultural Sciences. 2021, 35(6): 1476-1483. https://doi.org/10.11869/j.issn.100-8551.2021.06.1476In order to explore the responses of different tissues of quinoa seedlings to drought stress, a pot-planting study was conducted with different field capacity (100%, 50%, 25%) and different treatment times (0, 48, 96h). Then the anatomical structures were observed, and the proline content, the activities of pyrroline-5-carboxylate synthetase (P5CS), proline dehydrogenase (PDH), peroxidase (POD), superoxide dismutase (SOD) and the catalase (CAT) were analyzed in the root, stem, and leaf tissues of quinoa seedlings. The results showed that the quinoa root diameter and epidermal thickness increased as the field capacity decreased and the treatment time extended with a maximum increase of 9.1% and 64.9%, respectively. The values of various indicators of the stem tissue exhibited a gradual decrease with the medullary cavity diameter decreasing by a maximum of 55.6%. The values of various parameters of the leaf tissue also reached the minimum under 25% field capacity in 96h. The proline content and the P5CS enzyme activity in the three tissues displayed a gradually increasing trend. The accumulation of proline in the leaves was higher than that in the stems and roots. The PDH enzyme activity in the leaves and stems gradually decreased, whereas it increased gradually in the roots. The antioxidant enzyme activity in all three tissues were different in different treatments. The enzyme activity in the leaves and stems reached the highest at 50% field capacity in 96 h, and the activity of the three enzymes in the roots still maintained higher activity at 25% field capacity in 96 h. In short, quinoa seedlings can adapt to a certain degree of drought by thickening the roots under drought stress. The drought resistance is improved by increasing proline content, P5CS enzyme activity and antioxidant enzyme activity in the seedlings. The morphology and physiological responses of the roots under drought are different from those of the leaves and stems. This study provides some basic information for further investigation and utilization of the mechanism of quinoa's stress resistance.
