10 April 2022, Volume 36 Issue 4
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 681-688. https://doi.org/10.11869/j.issn.100-8551.2022.04.0681
In order to study the effect of high energy carbon ion on maize, two maize inbred lines Chang 7-2 and PH6WC were treated with high energy carbon ion. The seedling emergence rate, plant height, ear position and other phenotypes of modern plants were analyzed, and the grain characters after harvest were determined. The results showed that high energy carbon ion treatment had different effects on different maize materials, and the sensitivity of different characters to high energy carbon ion was varied. The emergence rate of two maize inbred lines decreased significantly after high energy carbon ion irradiation, and the survival rate was very low under high dose irradiation. The plant height of Chang 7-2 and PH6WC decreased significantly under 40~100 Gy irradiation, the ear height of PH6WC decreased significantly under 100 Gy irradiation, the ear height of Chang 7-2 decreased significantly under 60~100 Gy irradiation, the leaf angle of Chang 7-2 increased under 80~100 Gy irradiation, the leaf length of chang7-2 decreased significantly under 40~100 Gy irradiation, the leaf length and width of PH6WC decreased significantly under 100 Gy irradiation, and the leaf width of Chang 7-2 increased significantly under 80~100 Gy irradiation. In addition, tassel branch number of Chang 7-2 increased significantly under 20 Gy irradation, but decreased significantly at 100 Gy irradation. For the grain characters, the grain thickness increased significantly and the grain length decreased, but the 100 grain weight increased significantly. Therefore, 40~60 Gy is the most suitable mutagenic dose for Chang 7-2, while 60~80 Gy is the most suitable dose for PH6WC. The results of this study can provide a certain basis for high energy carbon ion mutation dose of maize seeds.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 689-697. https://doi.org/10.11869/j.issn.100-8551.2022.04.0689
A rice male sterility mutant dtp1(defective tapetum and pollen 1) was obtained by irradiation of Songxiangzaojing seeds with 60Co-γ irradiation. In order to study the mechanism of sterility and clone the target gene the morphological observation, cytological analysis and gene mapping were carried out. The results showed that the dtp1 mutant had normal vegetative growth, but its anthers were thin and pale yellow, showing non-pollen-type male sterile. Paraffin section analysis showed that the dtp1 mutant could undergo normal meiosis, but the tapetum was slightly stained with irregular microspore at microspore development stage. In the later stage, the tapetum was abnormally enlarged and the microspore could not form pollen grains. Genetic analysis showed that dtp1 was controlled by a single recessive nuclear gene. By map-based cloning, the DTP1 gene was located between SYrbC7-2680809 and SYrbC7-2832575 on chromosome 7 with a physical distance of 151.7 kb containing 14 open reading frames. This study laid a foundation for further cloning and functional analysis of DTP1 gene.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 698-705. https://doi.org/10.11869/j.issn.100-8551.2022.04.0698
Soft and aromatic rice Diantun502 is a main variety for the production of special high-quality rice in Yunnan, which productivity has been severely degraded due to large-scale cultivation for more than 30 years. If there is no control of pests and diseases for the variety, the incidence of rice blast will be 100%, and the yield will be decreased by 41.9%. For the sustainable development of the industry, it is very important to conduct rejuvenation of the rice. In this study, its rejuvenation was carried out using the methods of single panicle selection, plants comparison and lines evaluation, which focused on several crucial and typical characters including rice blast resistance, fragrant and soft characters. The results showed that three lines were selected in 26 700 plants of the variety population with about 0.01% of the selection rate. In comparison with the original variety Diantun502, the selected lines had similar phenotype and taste quality, but their yield and rice blast resistance were increased by 41.1% and 58.3%, respectively. The production captivity of rejuvenation Diantun502 population, which was generated by blending propagation of the lines, was improved obviously. The results would be provided technology and experience references for soft and aromatic inbred rejuvenation in Yunnan.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 706-715. https://doi.org/10.11869/j.issn.100-8551.2022.04.0706
Cellulose synthase (CesA) is the key enzyme involved in cellulose synthesis. To explore the molecular characteristics, expression pattern of CesA and its regulated relationship in moso bamboo (Phyllostachys edulis), bioinformatics methods were used to systematically analyze the members of CesA gene family in this study. Based on the RNA-seq data and qPCR technology, the expression pattern of CesA in moso bamboo tissues was analyzed, and yeast one hybrid technology was used to verify the regulatory effect of transcription factor MYB on CesA. The results showed that a total of 21 CesAs (PeCesA1~PeCesA21) were identified in moso bamboo, which contained 8~14 introns. Collinearity analysis showed that 19 PeCesAs had fragment duplication, but the Ka/Ks values were less than 1.0. The length of proteins encoded by PeCesAs was 904~1 093 aa, with molecular weight of 101.10~123.63 kDa, and the theoretical isoelectric point ranged from 5.95~8.60. The prediction of subcellular localization showed that all PeCesAs were located in the plasma membrane. Conserved motif analysis demonstrated that PeCesAs had 20 conserved motifs, containing the characteristic motifs of D, D, D and QxxRW in CesA family. Phylogenetic genetic analysis showed that 52 members of the CesA family from four species including moso bamboo were clustered in seven branches. RNA-Seq data analysis showed that the expression levels of five PeCesAs (PeCesA1/5/10/11/17) were significantly different in roots, and the middle and base parts of shoots with different heights. Moreover, PeMYB35 and PeMYB37 had a strong co-expression relationship with PeCesA1/5/10/11/17. The qPCR results further confirmed that PeMYB35 and PeCesA1/5/10/11/17 had similar expression trends with the increase of shoot height. In addition, all the promoter sequences of PeCesA1/5/10/11/17 contain the MYB binding site GAMYB. The results of yeast one hybrid confirmed that PeMYB35 could bind the GAMYB in PeCesA1 promoter, suggesting that it might further regulate the expression of PeCesA1. The results provided a reference for further study on the mechanism cellulose biosynthesis in moso bamboo.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 716-727. https://doi.org/10.11869/j.issn.100-8551.2022.04.0716
MAP65-3 is a key regulation factor in plant cytokinesis, to explore the function of OsMAP65-3 gene in rice, by CRISPR/Cas9 system, both OsMAP65-3 genes, OsMAP65-3.1 and OsMAP65-3.2, were edited in this study. Two different target sites were selected for each gene, and the target sites of both genes were placed on the same vector.Then two double-gene-editing vectors, CSMAP65-3A and CSMAP65-3B were obtained. Seventeen CSMAP65-3A transformed plants and 20 CSMAP65-3B plants were generated by agrobacterium-mediated genetic transformation, and 16 and 20 positive plants were identified by PCR, respectively. Sequencing analysis of the OsMAP65-3s in the T0 generation plants showed that OsMAP65-3s were edited. Two sites in OsMAP65-3.1 were edited by 17.5% and 9.38%, respectively; while two sites in OsMAP65-3.2 by 15.62% and 45%; osmap65-3.2, osmap65-3.2/OsMAP65-3.1(+/-) and OsMAP65-3.2(+/-)/OsMAP65-3.1(+/-) materials were obtained in T0 generation. This study lays a solid foundation for further creation of OsMAP65-3s mutants, gene function research and elucidation of the molecular mechanism of cytoplasmic division in rice.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 728-737. https://doi.org/10.11869/j.issn.100-8551.2022.04.0728
The phosphodiesterase PDE specifically catalyzes the hydrolysis of the 3'-cyclic phosphate bond of cAMP/cGMP 3', 5'-cyclic phosphate, adjust the intracellular cAMP level, and then regulate the growth and development of pathogenic fungi. However, the specific regulatory mechanism of PDE genes in Alternaria alternata needs further investigation. The PDEL and PDEH of A. alternata were cloned by reverse transcription-polymerase chain reaction (RT-PCR). Bioinformatics of AaPDEL and AaPDEH genes and their encoded proteins were analyzed through online tools such as TMHMM, ProtScale and SOPMA. Quantitative real-time PCR (qRT-PCR) was used to analyze the expression characteristics of PDEL and PDEH during infection structural differentiation of A. alternata. PDEL and PDEH of A. alternata were cloned and assigned as AaPDEL and AaPDEH, respectively. The length of coding sequence(CDS) was 3 132 bp and 2 886 bp, encoding 1 043 and 961 amino acids, respectively. Bioinformatics analysis showed that both AaPDEL and AaPDEH were unstable hydrophilic proteins without signal peptide and transmembrane structure, and both had multiple phosphorylation sites, which were located on mitochondria and nucleus, respectively. AaPDEL and AaPDEH have class Ⅱ and I conserved catalytic domains, respectively. The results of phylogenetic analysis showed that AaPDEL and AaPDEH were closely related to wheat brown spot (Pyrenophora tritici-repentis) and tomato petiole (Stemphylium lycopersici), and the homology was as high as 79.25% and 88.80%, respectively. qRT-PCR analysis showed that expression levels of AaPDEL and AaPDEH were significantly upregulated at appressorium formation stage (6 h) on hydrophobic surface, which were 1.19 and 1.97-fold higher than that at the initial germination stage (2 h). These results indicate that AaPDEL and AaPDEH play important regulatory roles in infection structure differentiation of A. alternata.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 738-744. https://doi.org/10.11869/j.issn.100-8551.2022.04.0738
Epithiospecifier plays an important role in the regulation of glucosinolate metabolism, and it catalyzes isothiocyanates into epithionitriles and nitriles. In this study, our aim is to isolate an epithiospecifier gene from broccoli and clarify its sequence characteristics as well as its expression pattern challenged by Xanthomonas campestris pv. campestris (Xcc). Results showed that the full genomic DNA of BoiEPS was 1 270 bp in length, harboring a 238 bp intron. The length of its complete coding sequence was 1 032 bp, encoding 343 amino acids, and the deduced protein contained two Kelch domains. Phylogenetic analysis indicated that BioEPS was grouped with EPSs from Brassica rapa and B. napus into the same clade, however, EPSs from other cruciferous plants were found to be clustered in different clades. Quantitative real-time PCR results revealed that the expression of BoiEPS was induced by Xcc, and the highest expression level was observed at 24 h. Over-expression of BoiEPS in broccoli significantly enhanced its resistance to Xcc, and the expression of pathogenesis-related gene BoPR1 increased significantly. Results of our present study provided an insight into exploring the mechanism involved in black rot disease resistance in broccoli.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 745-753. https://doi.org/10.11869/j.issn.100-8551.2022.04.0745
In order to evaluate the effects of electron beam irradiation sterilization on the quality of Chinese medicinal materials Lonicerae flos. The sterilization effect, the content of the index components chlorogenic acid, antioxidant activity and fingerprint of Lonicerae flos and its extract were evaluated when they were irradiated by electron beam with the absorbed doses of 0, 2.8, 6.3, 9.5, 18.8 kGy. The results showed that electron beam irradiation could effectively reduce the number of total aerobic bacteria count, total yeast and mold count in Lonicerae flos and its extract, and the survival decreased obviously with the increase of absorbed dose. The content of chlorogenic acid and the scavenging rate of 1,1-diphenyl-2-picrylhydrazyl(DPPH·) were not significantly affected by electron beam irradiation, and there was no obvious linear correlation with the absorbed dose (P>0.05). When the absorbed dose was increased to 18.8 kGy, the electron beam irradiation showed no significant effect on the unirradiated samples (P>0.05). The similarity of fingerprints of Lonicerae flos and its extracts treated with different absorbed doses of electron beam irradiation was 1. Cluster analysis showed that the electron beam irradiation did not make significant difference in their fingerprints. Therefore, electron beam irradiation sterilization would not significantly affect the quality of Lonicerae flos and its extract. This study can provide a reference for the scientifically application of electron beam irradiation technology in the storage of Lonicerae flos.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 754-765. https://doi.org/10.11869/j.issn.100-8551.2022.04.0754
In order to produce high-quality Southern steamed bread, the range of raw material characteristics of wheat flour for high-quality southern-style steamed bread was determined. In this study, 20 kinds of wheat flour were used as raw materials to prepare southern-style steamed bread. The effects of physicochemical properties, gelatinization properties, tensile properties and farinographic properties of wheat flour on the quality of southern-style steamed bread were investigated. The correlation indexes of wheat flour affecting the comprehensive quality of Southern steamed bread were selected by stepwise back analysis, and the range of correlation indexes of wheat flour suitable for processing Southern steamed bread was obtained by cluster analysis.The results showed that ash content, falling value, peak viscosity, forming time, stabilizing time, weakening value, elongation, stretching area, stretching ratio and maximum stretching ratio of wheat flour were significantly correlated with the comprehensive quality score of southern-style steamed bread (P< 0.05). The key indexes affecting the comprehensive quality of southern-style steamed bread were elongation, formation time and peak viscosity. The reference key indexes of wheat flour suitable for processing southern-style steamed bread were: elongation 126.00 to 158.00 mm, forming time 1.70 to 5.00 min, and peak viscosity 1 027.00 to 1 326.00 Pa·s. The establishment of wheat flour raw material selection model and the determination of key index range can predict the quality of Southern steamed bread. A basis for the selection of Southern steamed bread raw materials was provided, and further improved the comprehensive quality of Southern steamed bread.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 766-776. https://doi.org/10.11869/j.issn.100-8551.2022.04.0766
The compositions and physicochemical properties of starches from 15 different Zhongshu series potato cultivars were evaluated. The optical microscope and scanning electron microscope results showed a wide range of particle size distribution of potato starch granules and different morphologies of potato starches. The small granules of potato starches were ellipsoidal, the large ones were oval, elongated or irregular. The result showed that physicochemical properties were varied form different potato starches. The solubility and swelling degree of different potato starches were ranged from 25.92%~28.74% and 4.90~6.26 g·g-1, respectively. The onset temperature (To), peak maximum temperature (Tp), conclusion temperature (Tc) and gelatinization enthalpy(ΔH) were 61.44~65.55℃、64.49~68.69℃, 67.87~72.54℃, 7.21~13.49 J·g-1, respectively. The peak viscosity, setback and consistence were 2 499.3~3 220.4 BU, 514.0~2 218.4 and 401.0~884.1 BU, respectively. Correlation analysis results showed that phosphorus content was positively correlated with peak and trough viscosity and negatively correlated with solubility. The average particle size D[4,3] was positively correlated with the short-range order parameters 1 045/1 022 cm-1 and 1 022/995 cm-1, respectively. To was negatively correlated with peak viscosity. The gelatinization temperature was negatively correlated with peak viscosity and break value, and positively correlated with and trough viscosity, final viscosity and consistence, respectively. The results of this study can provide a scientific basis for promoting the application of Zhongshu series potato starch in food processing.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 777-787. https://doi.org/10.11869/j.issn.100-8551.2022.04.0777
To improve the quality of spent-hen breast meat, the effects of tumbling curing and ultrasonic combined tumbling-assisted curing on water holding capacity (WHC), tenderness and volatile flavor components of chicken breast meat were investigated. In this study, based on the differences of marinade absorption rate and meat quality (cooking loss, centrifugal loss, shear force) of chicken breast meat under different curing processes, the reasons for meat quality change were analyzed by the technology of low-field nuclear magnetic resonance (NMR), tissue section and headspace solid phase microextraction gas phase mass spectrometry (HS-SPME-GC-MS). The results showed that both tumbling curing and ultrasonic combined tumbling-assisted curing accelerated the curing rate, improved the WHC and tenderness of chicken meat. The reason might be that the mechanical action of tumbling and ultrasonic which promotes the migration and uniform distribution of water and destroys the muscle fiber structure, and ultrasonic and rolling have a synergistic effect. In addition, tumbling curing, ultrasound-assisted tumbling curing had effects on the types and contents of volatile flavor components of chicken breast meat. The results of this study will provide a theoretical basis for improving meat quality and developing meat products with low phosphate content.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 788-794. https://doi.org/10.11869/j.issn.100-8551.2022.04.0788
Glycerol-3-phosphate, as a synthetic precursor of osmotic regulator floridoside, participates in the algal stress defenses. To understand the stress resistance mechanism of Pyropia haitanensis, ultra performance liquid chromatography coupled with mass spectrometry was used to analyze the fluctuance of glycerol-3-phosphate in P. haitanensis under abiotic stress (temperature, salinity and drought). The results showed that the content of glycerol-3-phosphate changed rapidly after 1 h of temperature stress. As the temperature was higher than 23℃, the content of glycerol-3-phosphate was proportional to the stress temperature, but decreased when the temperature was lower than 12℃. The content of glycerol-3-phosphate increased rapidly under salinity stress, and the change rate under high salinity stress was significantly higher than that under low salinity stress. The content of glycerol-3-phosphate increased slightly (1.19 times) after 1h drought stress and then showed a downward trend as the drought time continued to 12 h. After abiotic stress, the contents of glycerol-3-phosphate tended to the control level in the recovery cultural condition. Hence, glycerol-3-phosphate could respond to environmental stress, which possibly explain the stress resistance mechanism of P. haitanensis.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 795-803. https://doi.org/10.11869/j.issn.100-8551.2022.04.0795
In order to screen out bacteria with excellent histamine-degrading ability, and investigate their application in fermented food, the histamine-degrading bacteria from traditional fermented mackerel(Scomber japonicus) were isolated and purified by MRS medium, VRBDA medium and 2216E agar medium. Their growth, enzyme production characteristics and biogenic amine degradation of fermented mackerel were determined. The results showed that the strain V-TB-2-5 had high histamine-degrading activity, which was identified asPseudomonas azotoformans by 16S rRNA gene sequence phylogenetic analysis and morphological characteristics. The strain exhibited good growth and enzyme activity at 20~40℃, pH5~8 and 0~3.5% sodium chloride in nutrient broth medium, and the optimum growth and enzyme production conditions were 30℃, pH 7 and 1.5% sodium chloride. The optimum conditions for enzyme activity were 30oC and pH 7. The addition of Mn2+, Mg2+ or K+ stimulated the histamine-degrading activity significantly. However, Fe3+ or EDTA exhibited different degrees of inhibitory activities. When artificially inoculated in fermented mackerel, the strain V-TB-2-5 showed significant histamine-degrading activity with degradation rate of 18.2%~40.7% compared to the control group. Meanwhile, spermidine in the inoculated group decreased significantly, while spermine in the inoculated group decreased on the contrary. This study provides a theoretical and practical basis for the control of histamine biodegradation by strain V-TB-2-5 during the processing and storage of aquatic products.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 804-811. https://doi.org/10.11869/j.issn.100-8551.2022.04.0804
To further comprehend the residue and metabolism of Dufulin in plants, the residual distribution characteristics and metabolite dynamics of [benzyl-14C]-Dufulin were applied to soybeans (Glycine max) by the14C tracing method. The results revealed that, after treatment, Dufulin mainly retained in treated leaves. The half-life of Dufulin parent in soybean leaves was 15.32 d, and the residual concentrations of metabolites increased over time; 20 days after treatment, the results proved that the residual concentration of Dufulin in leaves was 6.960 mg·kg-1, accounting for 53.443% of the total radioactivity. The residual concentrations of metabolites: M4, M3 and M1+M2 were 3.838, 2.431 and 1.464 mg·kg-1, respectively. At harvest, the residual contents in edible beans did not exceed 0.3% of the total radioactive residue, and its metabolites were identical to those in leaves. The relative contents of parent and M4 were 51.932% and 20.301%, and both of the residual concentrations exceeded 0.050 mg·kg-1 at harvest. This study provides significant metabolic data for objectively assessing the safety of Dufulin.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 812-819. https://doi.org/10.11869/j.issn.100-8551.2022.04.0812
In order to clarify the status of exchangeable calcium and magnesium in tobacco planting soil in Tongren city, Guizhou province, taking the exchangeable calcium and magnesium in tobacco planting soil of arable layer in Tongren in 2019 as the research object, the spatial variation characteristics and influencing factors of soil exchangeable calcium and magnesium were analyzed by multivariate statistics and geostatistics. The results showed that: The contents of exchangeable calcium and magnesium in tongren tobacco-planting soil were rich, with an average value of 1.72 and 0.27 g·kg-1, respectively. However, 19.31% of soil exchangeable calcium and 27.59% of soil exchangeable magnesium were still at low and very low levels. In tobacco-growing soil, the ratio of calcium to magnesium in the appropriate range was only 29.70%, and the imbalance of ratio of calcium to magnesium was serious. The spatial variation of exchangeable calcium and magnesium contents and their ratios in tobacco-growing soils in Tongren city is the result of the combined effect of structural factors and random factors. The content of exchangeable magnesium in soil showed a trend of increasing gradually from northwest to southeast. In general, the ratio of calcium to magnesium increased gradually from the middle to southeast and northwest, with the highest ratio of calcium to magnesium in the middle of Sinan, and the lowest ratio of calcium to magnesium in the south of Jiangkou and the south of Songtao. pH had the greatest influence on the spatial variability of exchangeable calcium and magnesium, which could independently explain 41.6% and 55.7% of their variables, respectively. The relationship between pH and exchangeable calcium and magnesium showed power function and cubic function, respectively. With the increase of pH, the contents of exchangeable calcium and magnesium in soil increased. In conclusion, the spatial distribution of tobacco-growing soil in Tongren, Guizhou province is not uniform and the difference is large, and the imbalance is serious. The influence of pH on the spatial variability of exchangable calcium and magnesium is the greatest, and it shows a very significant positive correlation. Therefore, spatial differences should be paid attention to when guiding calcium and magnesium fertilization in Tongren tobacco area. In order to achieve classification guidance to different types of areas, soil nutrients can be balanced by regulating the application amount of calcium and magnesium fertilizer or regulating soil pH value with calcium and magnesium amendments. This study provides a scientific basis for the management of calcium and magnesium nutrients in tobacco fields in Tongren city.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 820-828. https://doi.org/10.11869/j.issn.100-8551.2022.04.0820
To clarify the combined effects of nitrogen application rate and transplanting density on the formation of rice yield and grain quality, a field experiment was conducted in the coastal saline-alkali intertidal zone using Oryza sativa L. cv. Huaidao No. 5. The experiment contained six nitrogen application rates: N0(0 kg·hm -2), N210(210 kg·hm-2), N255(255 kg·hm-2), N300(300 kg·hm-2), N345(345 kg·hm-2) and N390(390 kg·hm-2). And two transplanting densities: D1(334 000 holes·hm-2, 12 cm×25 cm) and D2(278 000 holes·hm-2, 12 cm×30 cm), the yield and quality of rice were determined. The results showed that, with the increase of nitrogen application rate, the number of panicles per unit area and the number of grains per panicle increased first and decreased subsequently, which peaked under N300 treatment, whereas, the seed setting rate and 1000-grain weight showed a decreasing trend. The number of panicles and 1000-grain weight under D1 treatment were higher than those under D2 treatment, while the number of grains per panicle and the seed setting rate showed the opposite trend. Among all treatments, rice grain yield displayed highest under N300D1 treatment, reaching 7 978.83 kg·hm-2. The increase of nitrogen application rate improved the processing quality and nutritional quality of rice grain, while reduced the appearance quality and cooking and eating quality. The increase in transplanting density improved the nutritional quality of rice, but reduced the processing quality, appearance quality and cooking and eating quality. A combination of 300 kg·hm-2 (nitrogen), and 334 000 holes·hm-2 (density) was recommended, for rice high yield and good quality in the coastal saline-alkali intertidal zone. The current research aimed to clarify the co-effects of nitrogen application rates and transplanting density on rice yield and quality under salt stress, which would provide a theoretical basis for the high-yield and high-quality cultivation in the coastal saline-alkali intertidal zone.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 829-837. https://doi.org/10.11869/j.issn.100-8551.2022.04.0829
In order to determine the effect of nitrogen forms and its ratios on the occurrence of Panax notoginseng root rot, a pot experiment was conducted to study five nitrogen form ratios (ammonium to nitrate in the ratio of 0∶100, 25∶75, 50∶50, 75∶25 and 100∶0, respectively) and effects of Fusarium oxysporum infection on the growth, active components and resistance indices of P. notoginseng. The results showed that different nitrogen forms had no significant effect on the biomass and saponin content of P. notoginseng. Ammonium nitrogen promoted the accumulation of soluble sugar. The contents of chlorophyll, soluble sugar and flavonoid of P. notoginseng were decreased with the infection of pathogen. The disease index and the activities of peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were increased as the ratio of ammonium nitrogen increased, which was accompanied by the accumulation of phenols and lignin. In conclusion, the results showed that low ammonium nitrate ratio (especially 25:75) was beneficial to the growth of P. notoginseng, and could reduce the disease index and the occurrence of root rot. This study provides a theoretical basis for the prevention and control of P. notoginseng root rot from the level of nitrogen application.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 838-844. https://doi.org/10.11869/j.issn.100-8551.2022.04.0838
To explore the effect of salt stress on tomato flavor quality, the changes of contents of sugar, organic acids, amino acids and aromatic substances in cherry tomato (Lycopersicon esculentum Mill. var. cerasiforme Alef) fruits under different soil salt contents [T1:0.05 g·kg-1(CK)、T2:1.5 g·kg-1、T3: 3 g·kg-1、T4:4.5 g·kg-1、T5:6 g·kg-1] were studied with Cherry No.5 as the experimental material. The result showed that fructose and glucose contents were higher in each treatment, accounting for 94.88%~95.97% of the total. Salt stress could promote the accumulation of carbohydrates in the fruits. The fructose content was the highest in T5, which increased by 18.34% compared with the control. The content of glucose was the highest in T3, with a significant increase of 29.06% compared with the control. The organic acids were mainly citric acid and malic acid in the fruit, accounting for 88.30%-91.60% of the total. The content of organic acids increased first and then decreased with the increase of salt. The contents of citric acid and malic acid were the highest in T3, which were significantly increased by 61.40% and 129.90% compared with the control, and the total organic acid content was 1.71 times that of the control. The amino acid content of cherry tomatoes was also affected by salt stress. The contents of glutamic acid and aspartic acid under salt stress were higher. And except for methionine, the contents of all amino acids at T3 were the highest. In conclusion, a total of 47 aromatic substances were detected in the fruits of all treatments, including 12 aldehydes, 5 ketones, 14 alcohols, and 3 esters. The types and relative contents of aromatic substances in tomato fruits increased under salt stress. The contents of 2-hexenal, geranyl acetone, 6,10-dimethyl and 2-isobutylthiazole were significantly different from those of the control, which were important aromatic substances affecting tomato flavor under salt stress. The findings of this study could provide data support for the improvement of cherry tomato flavor quality under salt stress.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 845-855. https://doi.org/10.11869/j.issn.100-8551.2022.04.0845
In order to alleviate the damage of cucumber (Cucumis sativus L.) seedlings under low temperature, a cold-sensitive cucumber genotype (cv. Zhongnong 106) was used in this study to investigate the effects of compound sodium nitrophenolate (CSN) on seeds germination and seedling growth of cucumber under low temperature via soaking seeds or root application to the substrate of CSN. The results showed that soaking seeds with appropriate concentration of CSN significantly improved the germination rate, germination index, vigor index, number of lateral roots and fresh weight of cucumber during low temperature, and the optimal concentration of CSN was 50 mg·L-1. Moreover, during the growth of cucumber seedling, addition of 100 mg·L-1 CSN in substrate could significantly improve the quality and seedling index of seedlings exposed to low temperature, and enhance cold tolerance by increasing the mineral elements absorption, chlorophyll content, net photosynthetic rate, soluble protein content, proline content, root activity, the activities of antioxidant enzyme (superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase), the contents of IAA and BR but reducing the content of hydrogen peroxide and malondialdehyde. This study provides a new method for cultivating strong cucumber seedlings and improving the cold tolerance of cucumber seedlings, and offers technical support for the application of CSN in the cultivation of protected vegetables.
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Journal of Nuclear Agricultural Sciences. 2022, 36(4): 856-863. https://doi.org/10.11869/j.issn.100-8551.2022.04.0856
To investigate the effect of Brassinolide on the degradation of avermectin and phoxim residues in celery. Celery was used as experimental material coupled with QuEChERS method and high performance liquid chromatography (HPLC) to research the natural degradation of avermectin and phoxim on celery and effect of Brassinolide on their degradation.The results showed that when 1.8% of avermectin EC was sprayed, the safe harvest time of celery was 21 days and the half-life for avermectin was 6.60 days. When 40% of phoxim EC was sprayed,the safe harvest time of celery was 14 days and the half-life of phoxim was 3.04 days.BR could effectively promote the degradation of avermectin and phoxim,and the degradation effect was better than natural degradation. Further more, 0.1 mg·L-1BR was the optimal spraying concentration, and 2 times was the optimal number of spraying. Under the optimal concentration of 0.1 mg·L-1 BR,the half-life of avermectin was 4.03 days, and the safe harvest time was 14 days, which was 7 days earlier than the natural degradation, under the optimal two times of BR treatment, the half-lifet was 2.11 days, and the safe harvest time was 7 days, which was 14 days earlier than the natural degradation. Under the optimal concentration of 0.1 mg·L-1BR,the half-life of phoxim was 1.83 days, and the safe harvest time was 7 days with 7 days earlier than the natural degradation;under the optimal two times of BR treatment,the half-lifet was 1.05 days,the safe harvest time was 7 days,which was 7 days earlier than the natural degradation.Under the best spraying conditions,the degradation effect of BR on phoxim was better than on avermectin. This study provides a scientific basis for the safety control of pesticide residues level in celery products, and offers a reference for the degradation of pesticide residues in vegetable products.
