10 June 2020, Volume 34 Issue 6
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1129-1137. https://doi.org/10.11869/j.issn.100-8551.2020.06.1129Rice yield depends on size and coordination of the sink and source-related traits. To study effect of pyramiding of different sink-source genes on yield and its related traits, near-isogenic lines of four cloned sink-source genes including NAL1LT, GNP1TQ, Ghd7MH63 and Ghd89311 in different genetic backgrounds were used as materials to develop F2 populations for pyramiding different genes, and homozygous single and two-gene pyramiding individuals were selected by marker-assisted selection using their respective linkage markers for further evaluation of yield and its related traits in F3 lines. The results showed that individuals with NAL1 LT + Ghd7 MH63, NAL1 LT + Ghd89311 and Ghd7 MH63+ Ghd89311 had significant yield-increased effect with 26.45%, 45.47% and 48.03% higher than their respective high-value parents, suggesting the three types of pyramiding had synergistic effect on sink-, source- and yield-related traits in their progenies. Oppositely, another three pyramiding types of NAL1LT + GNP1TQ, GNP1TQ + Ghd7 MH63 and GNP1 TQ + Ghd89311 had no significant effects on yield, some yield-related traits increased but other decreased or maintained the same levels as parents. For pyramiding breeding of complicated quantitative traits, we think it should firstly, study pyramiding effect of different genes on yield traits to ascertain pyramiding effectiveness among them, which will give us twofold results with half the effort in breeding. Our results will provide a theoretical basis of molecular pyramiding improvement of rice sink and source traits.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1138-1143. https://doi.org/10.11869/j.issn.100-8551.2020.06.1138
To prevent and control Rice black-streaked dwarf virus (RBSDV) disease effectively, we reared a mass of small brown planthopper(Laodelphax striatellus, SBPH) with RBSDV-infected rice plants in the laboratory, then selected and analyzed the sensitivity of 20 local rice varieties in Zhejiang province to RBSDV infection by observing symptoms, measuring plant height and counting incidence after artificial inoculation assay. The results showed that the expression of RBSDV RNA decreased dramatically in indica rice, such as Shenliangyou 5814 and Y-liangyou 302, compared with that in japonica rice. Moreover, the expression of OsMYC2 and OsNPR1 in RBSDV-infected indica rice were significantly up-regulated than that in mocked indica plants. These results indicated that the resistance of the indica rice to RBSDV infection might be partly due to activate the jasmonic acid and salicylic acid pathway. Together, these results provided a new strategy for screening rice varieties resistance to RBSDV.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1144-1151. https://doi.org/10.11869/j.issn.100-8551.2020.06.1144MYB transcription factors play an important regulation role in the salt stress-responsive of plant. In order to characterize the biological function of a MYB transcription factor, RcWER-like, its'expression profile in diverse tissues under salt, hormone, and salt combined with hormore treatment were analyzed by real-time PCR. In this study, a MYB transcription factor gene of rose, RcWER-like was cloned from R. chinensis Old Blush based on the transcriptome and genome data. Bioinformatic analysis showed that the total length of RcWER-like gene was 882 bp, and the ORF of RcWER-like was 669 bp, which encode 223 amino acids. Multi-alignment of RcWER-like with other MYB type proteins revealed that RcWER-like had two conserved domains in the N-terminal. Phylogenic tree analysis showed that RcWER-like was clustered with PpWER-like in Prunus persica, PmWER-like in Prunus mume and MdWER-like in Malus domestica, and belonged to the R2R3-MYB type transcription factor. Real-time PCR results showed that the expression level of RcWER-like was significantly increased at 24 h under salt stress, and the SA and MeJA treatments could also induce the expression of RcWER-like. In addition, under salt stress, RcWER-like was significantly up-regulated by SA and MeJA, which was higher than that under salt stress and exogenous hormone treatment. Meanwhile, there were significant differences in the expression patterns of RcWER-like in different tissues at different time points under the treatment of salt and hormone. These evidences implied that the R2R3-MYB transcription factor RcWER-like in Rosa chinensis Old Blush could response to SA and MeJA, and might play an important role in response to salt stress. The results will provide candidate gene resources and theoretical basis for salt tolerance molecular breeding of rose.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1152-1162. https://doi.org/10.11869/j.issn.100-8551.2020.06.1152Growth-regulating factors play important roles in plant growth and development as well as plant tolerance to abiotic stress. To investigate the characteristics of GRFs gene family and their evolutionary relationship, GRFs gene family in Brachypodium distachyon were identified and analyzed using bioinformatics method. The results showed that Brachypodium distachyon contained 12 GRF genes. The length of protein sequence ranged letween 238 and 577 aa. The sequence alignment analysis showed that GRF genes have two conserved domains: QLQ and WRC, and a wide range of conservative motif. All the GRF genes were found to be distributed unevenly in the five chromosomes with the maximum in bd03. Based on phylogenetic relationship in Brachypodium distachyon, four pairs of orthologous genes were revealed. RT-qPCR analysis found that expression level of all the GRF genes were higher in actively growing tissues than in senescent tissue and root, and most GRF genes were induced by exogenous hormones, especially GA3, suggesting that most of GRF genes were involed in the meristem function and organ formation. The results of this study could provide a theoretical foundation for the protein function analysis of the GRFs family in Brachypodium distachyon.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1163-1177. https://doi.org/10.11869/j.issn.100-8551.2020.06.1163In order to explore the functional gene information of transcriptome in bottle gourd, the transcriptome of Fuzhou bottle gourd was sequenced by high-throughput non-parametric sequencing technology and 664 252 268 reads fragments were obtained. The reads gave 87 518 Unigenes with the total length of 91 405 320 bp, and 76.03% of Unigenes were concentrated in 1-1 000 bp. The results of functional annotations showed that 55 725 Unigenes were annotated in Nr database, among which 26 354 Unigenes were annotated in cucurbitaceae, accounting for 47.29% of the total Unigenes. GO database annotated 18 278 Unigenes, which closely related to molecular function, cell structure function and biological process function with 55 subgroups. 41 635 Unigenes were annotated in COG database, which were divided into information storage and processing, cell process and signal transmission, metabolism and non-characteristic genes with a total of 25 functional groups and the number of genes involved in amino acid transport and metabolism was the largest. There are 24 770 Unigenes annotated in the KEGG database, involving 220 KEGG metabolic pathways. SSR locus retrieval results showed that there were 11 029 SSR loci in 8 617 Unigenes containing SSR sequences, with a frequency of 9.846%. The results of this study would lay a foundation for the further development of metabolic pathways and SSR molecular markers in bottle gourd.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1178-1186. https://doi.org/10.11869/j.issn.100-8551.2020.06.1178In order to explore the epigenetic mechanism of tolerance acquisition of the invasive plant Flaveria bidentis under heavy metal cadmium (Cd) stress, a pot experiment was conducted to simulate different concentrations of Cd contaminated habitats. Methylation sensitive amplification polymorphism (MSAP) technique was used to analyze the genomic DNA methylation variation characteristics of plant leaves under different Cd stress[0(CK)、2(Cd-1)、4(Cd-2)and 8(Cd-3) mg·kg-1]. The results showed that 726 methylation bands were amplified by 15 pairs of primers, and the percentage of primer polymorphism was 84.75%. With the increase of Cd stress concentration, the proportion of fully methylation and total methylation in leaves of Flaveria bidentis showed a gradual increase trend. The Cd-1, Cd-2 and Cd-3 was 1.51, 1.59 and 2.11 times the fully methylation level of the CK, respectively. Total methylation level of Cd-1, Cd-2 and Cd-3 increased by 39.28, 53.30 and 63.97 percentage point compared with the CK, respectively. The results of methylation analysis of Flaveria bidentis with different treatments showed that both remethylation and demethylation occured under Cd stress, but remethylation was the main transformative mode. Correlation analysis results showed that the levels of DNA fully methylation and total methylation levels were negatively correlated with phenotypic plasticity of growth and above-ground tolerance indexes, while positively correlated with antioxidant enzyme activity, Cd contents of different tissues, accumulation and transfer coefficient. The results of this study provide a new perspective for the prevention and control of invasive plant Flaveria bidentis from the aspect of epigenetics.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1187-1195. https://doi.org/10.11869/j.issn.100-8551.2020.06.1187In order to explore the function of mitogen-activated protein kinase (DsMAPK) in Dunaliella salina, the interacting proteins with MAPK in D.salina were screened by immunoprecipitation-mass spectrometry. The pGS-21a-MAPK plasmid was transfected into E. coli BL21 to express MAPK and prepare polyclonal antibodies. D. salina cells at logarithmic growth stage were treated with salt stress, then the total protein of D. salina was extracted and tested by SDS-PAGE and Western blotting. Using endogenous target protein as bait, total proteins of cell and MAPK’s antibody were co-incubated. The immunoprecipitation compound purified by protein A/G agarose beads were detected by mass spectrometry. The results showed that the prepared polyclonal antibody has good specificity and 165 specific differential proteins were screened out. Through GO and KEGG analysis, we found that these differentially expressed proteins are mainly involved in metabolism, genetic information transmission, signal transduction and other biological processes. Protein interaction network analysis revealed that 4 different proteins interact directly with MAPK. The results provide new information for further study on the molecular mechanism of D.salina responding to salt stress.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1196-1204. https://doi.org/10.11869/j.issn.100-8551.2020.06.1196To investigate the molecular mechanism of Bacillus methylotrophicus WM7 respond to low temperature stress, gene transcription profiles of strain WM7 grown at 30℃ and 15℃ were compared by transcriptome analysis. Some differentially expressed genes were verified by RT-qPCR. The results showed that a total of 2029 differentially expressed genes were found, of which 1519 were up-regulated and 510 were down-regulated. GO and KEGG analysis revealed that 1199 genes were categorized into cell component, molecular functions and biological process function groups and 683 genes were annotated in 225 metabolism pathways. These genes were significantly enriched in pentose phosphate pathway, purine and amino acid synthesis pathway. The significantly up-regulated genes at 15℃ were related to fatty acid metabolism, ABC transporters, transcriptional regulators, signal transduction, carbon and nitrogen metabolism, etc. In addition, a large number of differential expressed genes of unknown function were identified, and some of these genes were showed to be over 50-fold up-or down-regulated expression. This study facilitate to elucidate the molecular mechanism of strain WM7 respond to low temperature by gene expression research, which laid the foundation and provide the gene information for fully revealing the low temperature growth mechanism of strain WM7.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1205-1212. https://doi.org/10.11869/j.issn.100-8551.2020.06.1205The flap endonuclease 1 (FEN1) is a member of the structure-specific 5' nuclease superfamily, known for participating in Okazaki fragment maturation, DNA recombination, apoptotic DNA fragmentation and long-fragment base excision repair (LP-BER). FEN1 plays its role in various metabolic pathways to maintain genome stability in different species. Abnormal expression of FEN1 in vivo can lead to disorders in many biological processes, such as increased mutation rate of autoimmune deficiency, unstable microsatellite sequence, DNA degradation and so on, resulting in serious damage to the organisms. Therefore, the expression of FEN1 in vivo must be regulated strictly, accurately and promptly. Recent studies have shown that post-translational modification of FEN1 plays an important role in regulating its activity, cellular localization and functional stability. In this paper, the research progress on the regulation of FEN1 post-translational modification was summarized, showing the regulation and influence of post-translational modification of FEN1 on its function, providing a basis for further study on the procedural regulation of FEN1.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1213-1220. https://doi.org/10.11869/j.issn.100-8551.2020.06.1213In order to explore the feasibility of pre-harvest oxalic acid treatment in postharvest preservation of broccoli, broccoli was sprayed with 20 mmol·L-1 oxalic acid aqueous solution 5 days before harvest (pure water spraying as control), and the harvest broccoli heads was stored for 15 days at 2℃ followed by 20℃ for 4 days. During storage time, physiological and quality parameters were periodically determined. The results indicated that pre-harvest application of oxalic acid on broccoli significantly inhibited the ethylene production and respiration rate(P<0.05), delayed the increase of weight loss, restrained the L* value increase and H value decrease and maintained the appearance color, and delayed the decline of vitamin C, chlorophyll content and firmness. Overall, pre-harvest treatment of oxalic acid significantly increased the storage quality of broccoli head, which provided the theoretical foundation of oxalic acid application on broccoli storage.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1221-1229. https://doi.org/10.11869/j.issn.100-8551.2020.06.1221The paper aimed to reveal the antifungal activity and possible mechanism of plant essential oil on dominant pathogens of postharvest sweet cherries. Hongdeng, the main varietiy in Taian, Shandong Province, was chosen as the raw material, traditional morphological identification method combined ITS analysis was performed to separate dominant pathogens from rotten sweet cherries, and antifungal activity of clove essential oil on three pathogenic fungal strains was assessed by in vitro fumigation and contact. The results showed that these strains were identified as Botrytis cinerea, Alternaria alternate and Colletotrichum gloeosporioides. Clove oil at certain concentrations exhibited obvious antifungal effects by inhibiting mycelial growth and spore germination of the three strains, and fumigation was better than contact. For B. cinerea, A. alternate and C. gloeosporioides, the minimal inhibitory concentrations (MIC) of clove oil in air phase were 120, 100 and 100 μL·L-1 in vitro testing, respectively. Moreover, the possible mechanisms of fumgitoxic action were related to the hydrophobicity of essential oils which enabled them to disrupt membrane structure of microorganism, and lead to loss of cell contents. In conclusion, clove essential oil was proved to be a promising candidate as effective antifungal agent for postharvest decay of sweet cherries.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1230-1236. https://doi.org/10.11869/j.issn.100-8551.2020.06.1230In this work, experiments were explored to prepare the cross-linked enzyme aggregates (CLEAs) of β-glucosidase from black plum seeds and evaluate their stability. After determination of the optimal preparation parameters, including the optimum precipitation agent, volume ratio of precipitant to enzyme liquid and glutaraldehyde concentration, then the shape and surface morphology of the CLEAs were examined using scanning electron microscopy. Moreover, the salidroside synthesis catalyzed by CLEAs was chosen as a model reaction to investigate the thermal and operational stabilities. The optimum precipitation agent, volume ratio of precipitant to enzyme liquid, glutaraldehyde concentration and crossing-linking time were found to be 95% ethanol, 1:3 (v:v), 30 mmol·L-1 and 1.0 h, under which the activity recovery of CLEAs recorded 91.4%. Compared to free enzyme, the surface morphology of CLEAs displayed a very high specific surface area, abundant pores and dense channels. Experimental data of the thermal stability indicated that CLEAs retained 75.1% of their original activity after incubation for 2.0 h at 60℃, which was 6.1 times high than that of the free enzyme. For the operational stability, 73.5% of the initial activity of CLEAs was still maintained after eight successive cycles of reuse. This study proves CLEAs of β-glucosidase from black plum seeds exhibited good activity, thermal stability and operational stability, which was advantageous to the synthesis of the glycosides.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1237-1247. https://doi.org/10.11869/j.issn.100-8551.2020.06.1237In order to monitor the changes of the lipomic profile in the white shrimp during air frying process and the effects of different air frying temperatures (140, 170, 200℃, 10 min) on the lipid composition of the muscle tissue of the white shrimp were investigated by iKnife-REIMS technique, principal component analysis (PCA) and orthogonal partial least-square discriminant analysis (OPLS-DA). After statistical analysis and lipid identification, 10 fatty acid molecular species and 31 phospholipid molecular species were found. Linoleic acid (m/z 279,21.88%)、EPA (m/z 301,16.59%) and DHA (m/z 327,15.14%) were the most abundant fatty acid ions, while[PE 36:1-H]- (m/z 744,20.16%) and [PE 38:5-H]-/[PC O-36:5-H]- (m/z 764,15.92%) were the major phospholipid ions. With the increase of the air frying temperature, the relative contents of saturated fatty acids and PA increased, while the contents of unsaturated fatty acids, PE, PC and PI decreased. Six potential markers (m/z 277,m/z 770,m/z 810,m/z 818,m/z 844 and m/z 836) were identified by shared and unique structure-plot (SUS-plot), which could be used for real-time identification of different fried samples. After method validation, the sensitivity and precision of iKnife-REIMS method could meet the requirements of high-throughput lipidomics profiling of white shrimp during air-frying process. This study provides new detection technique for the study of lipidomic changes in food processing.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1248-1256. https://doi.org/10.11869/j.issn.100-8551.2020.06.1248
In order to investigate the in?uence of salt on the quality of chicken soup and volatile flavor substances, the hybrid F1 of Wuding chicken and Digao chicken was used as the research object. The chicken soup was stewed with material-water a ratio of 1:3 for 2 h. Headspace solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to detect the effects of different salt additions on volatile flavors in chicken soup. The results showed that the flavor component of chicken soup increased with the increase of salt addition. Among them, the volatile flavor substances with relative high content in chicken soup were mainly aldehydes and alcohols. The aldehydes were mainly heptaldehyde, hexanal, trans-2-furaldehyde, furfural, 2-heptenal, N-octanal, trans-2-nonenal and alcohols were mainly n-octanol and heptanol. The results of sensory evaluation showed that when the amount of salt addition was 2.0%, the sensory score of chicken soup was the highest, and the composition of volatile flavor substances was rich. Therefore, when the ratio of material to water was 1:3, stewed for 2 h, and the amount of salt addition was 2.0%, the quality and consumption of chicken soup was the best. The results would provide research methods and scientific basis for the research and quality of volatile components of chicken soup products.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1257-1265. https://doi.org/10.11869/j.issn.100-8551.2020.06.1257In order to improve the edible nutritional value of freshwater shrimps, the nutrient composition, fatty acids and mineral composition of muscles and shrimp yolk fetched from the wild and cultured freshwater shrimps under different process (fresh, steaming, boiling) were quantified by national standards. The results showed that the carbohydrate content of wild shrimps was significantly higher than that of farmed shrimps (P<0.05), while the crude fat content in wild shrimps’ yolk (96±4 mg·g-1) was lower than that of cultured shrimps significantly (135±3 mg·g-1). Fatty acids were mainly stored in shrimp yolk, especially monounsaturated fatty acids (MUFA). Shrimp muscle and yolk were rich in calcium (Ca), strontium (Sr) and other mineral elements. Harmful mercury (Hg) and cadmium (Cd) were stored in shrimp yolk, but they were all below the national standard limit. The content of crude ash and carbohydrate in the muscles increased significantly after steaming and boiling, but the water content decreased significantly. Compared with steaming, boiling process resulted in more significant decrease in fatty acids and minerals. The comprehensive comparison showed that the content of protein and fatty acids in the muscles of cultured shrimps were not different significantly with wild shrimps. But the fat content of shrimp yolk in farmed freshwater shrimps was more abundant, and shrimp yolk’s ability to enrich heavy metal was weaker, so the cultured shrimps were safer than the wild. In the cooking methods, steaming remained more nutrients than boiling. This study provided a theoretical basis for the reasonable consumption and food safety of freshwater shrimp.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1266-1271. https://doi.org/10.11869/j.issn.100-8551.2020.06.1266In order to explore the specific content of bioactive ingredients in the broccoli leaves. Broccoli leaves were selected as the research material to analyze the bioactive ingredients contained. The contents of sulforaphane, total phenolics, total flavonoids, total proteins in broccoli leaves were 92.5 μg·g-1 (dry weight), 3.15 mg·g-1 (dry weight), 2.48 mg·g-1 (dry weight) and 89.38 mg·g-1 (dry weight). Ribulose-1,5-diphosphate carboxylase/oxygenase (Rubisco) occupied most of the proteins in broccoli leaves. This study clarified the specific contents of four bioactive components in broccoli leaves, which provided some data support for the further utilization of broccoli waste.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1272-1280. https://doi.org/10.11869/j.issn.100-8551.2020.06.1272Food allergy is one of the serious food safety problems threatening human health. Food irradiation can reduce the allergenicity of food allergens and is a potential physical desensitization technology. In this review, the characteristics, principle and development history of irradiation desensitization technology were introduced, and the research progresses on reducing the allergenicity of animal foods(e.g. milk, eggs, shrimp and fish) and plant foods (peanut, soybean, wheat and nuts) by irradiation were summarized. In addition, the reducing effects and impact factors of irradiation on food allergens were analyzed, and the future research direction of irradiation desensitization technology was discussed. The purpose is to provide reference for the research and application of reducing the allergenicity of food allergens by irradiation technology.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1281-1293. https://doi.org/10.11869/j.issn.100-8551.2020.06.1281In order to explore the reasonable amount of nitrogen in wheat,in different regions, Beijing and Shijiazhuang, two strong gluten wheat Gaoyou 2018 and Shiluan 02-1 were as experimental materials and we set three nitrogen uptake rates that are 75 kg·hm-2, 105 kg·hm-2 and 135 kg·hm-2. The effects of topdressing nitrogen on photosynthetic characteristics and yield of flag leaves of wheat was studied through field experiments to provide reference for high-yield and high-efficiency cultivation of wheat. In the range of 75~135 kg·hm-2 nitrogen application, increasing the amount of nitrogen application could significantly increase the net photosynthetic rate of flag leaves of wheat at flowering stage, increase stomatal conductance and decrease the concentration of carbon dioxide in the intercellular space. With the increase of the number of flowering days, the net photosynthetic rate and stomatal conductance of flag leaf of Gaoyou 2018 decreased faster than Shiluan 02-1, but the intercellular CO2 concentration increased. With the increase of nitrogen application rate, the content of chlorophyll increased with the increase of nitrogen application rate. At 14 days after flowering, C2 and C3 increased by 6.01% and 13.81%, respectively, relative to C1 treatment. The grain yield, biomass yield and harvest index of two gluten- resistant wheat increased with the increase of N application rate, the average increase was 6.235%, 3.11% and 3.015% respectively. But they differed due to different varieties. Comparing the two strong gluten cultivars selected in this study, the Beijing pilot is more conducive to the display of the photosynthetic performance potential of the flag leaves than the Shijiazhuang pilot, but the Shijiazhuang environment is more suitable for the growth of the tested cultivars and can give fuller play to its production potential. The photosynthetic indexes and chlorophyll content were the highest when the nitrogen topdressing amount was 135 kg·hm-2 (excluding the net photosynthetic rate of the flag leaf), and the maximum yield was obtained for both varieties. However, the yield difference between 105 kg·hm-2(C2)and 135 kg·hm-2(C3)was not significant, the suitable topdressing amount of nitrogen for strong gluten wheat Gaoyou 2018 and Shiluan 02-1 is 105 kg·hm-2. The results of this study can provide theoretical and technical references for high-quality and efficient production of strong gluten wheat in different ecological regions.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1294-1301. https://doi.org/10.11869/j.issn.100-8551.2020.06.1294To better understand the physiological mechanism behind the phenomenon of decreased photosynthetic rate when foxtail millet seedlings are treated with Sigma Broad, different concentrations (0, 7.5, 15.0, 30.0, 60.0 mg·L-1) of 3.6% Sigma Broad were sprayed at the five-leaf stage of Zhangzagu 5 and Jingu 21, and gas exchange parameters, photosynthetic key enzyme activities and soluble matter content were determined and analyzed after 7 days later. The results showed that the net photosynthetic rate (Pn), ETR, the activities of phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPDK), NADP-malate dehydrogenase (NADP-MDH), were reduced with the increasing of Sigma Broad at 15 mg·L-1. The NAD-malic enzyme (NAD-ME), Ribulose-1, 5-bisphosphate carboxylase oxygenase (Rubisco) activities and soluble substances content increased first and then decreased with the increased concentration of Sigma Broad in the two varieties, and the maximum values of NAD-ME, reducing sugar, sucrose and soluble protein were all appeared at the treatment of 15 mg·L-1 for both varieties. In summary, Sigma Broad making the obvious damages to the net photosynthetic rate in leaves of foxtail millet is partially due to that the activities of PSⅡ photochemical, PEPC, NADP-MDH, and PPDK were reduced, and the activities of Rubisco and NAD-ME and the metabolism of sugar were affected.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1302-1310. https://doi.org/10.11869/j.issn.100-8551.2020.06.1302In order to further explore the higher density of maize in Hexi Oasis Irrigation Area, whether high yield can be obtained under the condition of water and nitrogen reduction, the photosynthetic potential, dry matter accumulation, grain yield and yield composition of maize during growth period were determined. The field experiment designed traditional irrigation (W1) and growth period reduction 20% irrigation (W2), high nitrogen application (450 kg·hm-2, N1), reduction of 30% nitrogen application (300 kg·hm-2, N2) and three planting density of 75,000 plants·hm-2 (D1), 97,500 plants·hm-2 (D2) and 120,000 plants·hm-2 (D3). The results indicated that no significant difference was found in the photosynthetic potential of W2N2 and W1N1 corn in the late growth stage. Under the W2N2 treatments, the photosynthetic potential of D2 increased by 8.7% compared with D1 during the whole growth period of the maize. There was no significant difference between D2 and D3. The dry matter accumulation of W2N2 was eventually equal to W1N1 at a low amount of water and nitrogen conditions. The dry matter accumulation of D2 increased by 21.1% compared with D1 during the whole growth period of maize and no significant difference was found between D2 and D3. The grain yield of W2N2D2 was the same with that of W1N1D2. The dry matter accumulation of D2 increased by 9.0%~33.7% compared to that of D1 treatment. Irrigation and nitrogen applications had no significant effect on the grain number per ear and 1000-grain weight of maize. Under the same water and nitrogen conditions, the grain number of D3 corn compared with D1 decreased by 5.9%~26.1%, and the 1000-grain weight of corn decreased by 9.2%~12.3%. In conclusion, W2N2D2 still maintained a large photosynthetic potential of maize under reduced irrigation and nitrogen application at the later stage of growth, which provides material guarantee for the formation of corn yield, thus obtaining high yield. Therefore, maize planting with plant density of 97,500 plants per hm-2 in a condition of reduced 20% irrigation and 30% nitrogen application can be recommended as a technical reference.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1311-1319. https://doi.org/10.11869/j.issn.100-8551.2020.06.1311In order to select suitable walnut species, we should make appropriate trees and explore the physiological mechanism of response to moisture changes.Through the artificial precipitation environment (-50%, -25%, CK, +25%, +50%), this study used the potted seedlings method were adopted to study leaf relative water content (RWC), water saturation deficit (WSD), soluble sugar (SS),soluble protein (SP), proline (Pro), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), chlorophyll a and chlorophyll b, total chlorophyll, malondialdehyde (MDA) content, and the relationship between each index and the ability of walnut seedlings to adapt to water changes by grey correlation analysis. The results showed that the simulated rainfall caused the RWC, chlorophyll a, chlorophyll b and total chlorophyll content to gradually increase with the increase of precipitation amount; the contents of WSD, SS, SP, Pro, MDA, SOD, POD and CAT gradually decreased with the increase of precipitation amount,and the degree of change in the response of different varieties was different; the results of grey correlation analysis showed that correlation between physiological indexes and water fitness of walnut seedlings followed the order of SOD > MDA > chlorophyll b > SP > chlorophyll a >POD > RWC > WSD > Pro > SS > CAT. The correlation degree of SOD was greater than 0.70; the correlation degree between MDA and chlorophyll b were above 0.65. When the precipitation amount was +50%, compared with the precipitation amount of +25%, the RWC and WSD of Xiangling did not change that much, the chlorophyll a, chlorophyll b and total chlorophyll decreased, and the MDA content increased. When the precipitation amount was -50%,the activity of SOD and POD in Xiangling were lower than the precipitation amount was -25%. Combined with the results of this study, it is suggested that in the future planting of walnuts, Xiangling is not suitable for growing in relatively arid and humid regions,Liaohe1 has strong adaptability in different rainfall conditions, followed by Qingxiang. The research provided a theretical relerence for rational planting and water management in walnut production.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1320-1326. https://doi.org/10.11869/j.issn.100-8551.2020.06.1320In order to establish a irrigation system for the standardized cultivation of perilla [Perilla frutescens (L.) Britt], effects of drought stress (mild drought, moderate drought and severe drought) on the growth and quality of perilla was studied by using the seedling as the material and the normal water supply as the control (CK). The results showed that the mild and the moderate drought stress significantly increased malondialdehyde (MDA) content and relative electrical conductance (REC) of perilla leaves, and it maintained antioxidant enzyme activity, proline, soluble sugar and soluble protein content at a high level. The treatment of severe drought stress also significantly increased the MDA content and the REC of perilla leaves, but its antioxidant enzyme activity, proline, soluble sugar and soluble protein content were significantly lower than CK. With the prolongation of stress treatment time, under the condition of serve drought, the MDA content and REC of the leaves increased gradually, while the antioxidant enzymes activities, proline, soluble sugar and soluble protein were decreased. With the increase of drought stress, the biomass of the upper part of the perilla significantly decreased, and the total volatile oil content in the leaves increased first and then decreased. The result indicated that the drought stress treatment was not conducive to the growth of perilla, but proper drought stress treatment can promote the synthesis of volatile oil in perilla leaves, thus significantly improve the medicinal quality of perilla leaves. The study provided a theoretical basis for cultivation of perilla.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1327-1336. https://doi.org/10.11869/j.issn.100-8551.2020.06.1327By simulating the way of rain-fog leaching under natural conditions, a laboratory experiment was conducted to investigate the allelopathic effect of growth, physiology and biochemistry of I. indigotica exposed to leaf litter extracts of Camellia sinensis (LLEC) (CK: 0 mg·mL-1,T1: 6.25 mg·mL-1, T2: 12.5mg·mL-1, T3: 25 mg·mL-1, T4: 50 mg·mL-1). The changes of growth, antioxidant enzyme activity, gene expression, cell membrane damage rate, malondialdehyde, hydrogen peroxide, osmotic regulators and secondary metabolites were measured. The results showed a dose-dependent effect, namely promoting effect at low concentration and suppressing effect at high concentration on the growth of Ⅰ. indigotica. Compared to CK, the growth of Ⅰ. indigotica was enhanced by T1 treatment. However, it was not conducive to its growth when the concentration of LLEC exceeded the tolerance threshold of Ⅰ. indigotica. With increasing the concentration of LLEC, the content of soluble sugar and soluble protein increased first and then decreased, but proline content continued to increase. There were no significant differences between the malondialdehyde content, the cell membrane damage rate and hydrogen peroxide content and CK by T1 treatment. These indicators increased significantly under T3 and T4 treatments. The activities and gene expressions of antioxidant enzymes were affected to different degrees by LLEC. The activity of peroxidase and ascorbate peroxidase by T1 treatment, the activity of catalase by T2 treatment were the highest, but the activities of four antioxidant enzymes by T4 treatment were significantly lower than those of CK. A significant positive correlation was found between the activities of peroxidase and related gene expression level, but the correlation between enzyme activities and related gene expression levels of superoxide dismutase,catalase and ascorbate peroxidase were not significant. Remarkable difference was observed in the accumulation of secondary metabolites in Ⅰ. indigotica under different concentrations of LLEC. The contents of indigo and indirubin were the highest under T1 treatment, and the contents of total flavonoids were the highest under T4 treatment. In conclusion, low concentration of LLEC could promote the growth and accumulation of indigo and indirubin of Ⅰ. indigotica, while high concentration of LLEC could promote the accumulation of total flavonoids. The research provides a theoretical reference for intercropping model of C. sinensis and Ⅰ. indigotica in the young tea field.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1337-1349. https://doi.org/10.11869/j.issn.100-8551.2020.06.1337In order to investigate curing characteristics of upper tobacco leaves, the difference of water loss rate, yellowing and browning characteristics, chlorophyll relative content (SPAD), color values, polyphenol oxidase (PPO) activity and chemical composition content of the different maturity leaves of K326, Bi’na1, Zunyan6, Guiyan1, Guiyan4 and Honghuadajinyuan (Hongda) were studied during curing or during drawer testing. The results showed that Bi’na1 had smaller water loss rates while Hongda and Guiyan1 had larger water loss rates; Bi’na1 and K326 had shorter yellowing time while Hongda had a longer yellowing time during curing and drawer testing. The average PPO activity of Bi’na1 was less than 0.4 U and that of Guiyan1 was larger than 0.5 U during curing. As for chlorophyll relative content, Hongda had larger SPAD values, then were Zunyan6 and Guiyan1, and the last were Bi’na1, Guiyan4 and K326 during drawer testing. Hongda and Zunyan6 showed a relatively poor color values, and Guiyan1 showed a more serious browning. However, Bi’na1 had a lighter browning during drawer testing. Moreover, flue-cured tobacco leaves of Bi’na1, Guiyan4 and Zunyan6 had a relatively suitable chemical composition content. Following progressive improvement of tobacco leaves maturity levels, the yellowing time of fresh tobacco leaves was shortened and the activity of PPO increased during curing, the total content plant alkaloid and nitrogen decreased, and the content of water-soluble total sugar and reducing sugar increased. In addition, the yellowing time and browning time of tobacco leaves were shortened, the SPAD value was reduced, and the color showed better before the leaf became browning with the improvement of tobacco leaf maturity levels during drawer testing. Variety and maturity not only affected the leaf phenotype, but also had a significant impact on its intrinsic physiology. The curing characteristics of different flue-cured tobacco varieties were not only closely related to the chemical composition, but also the genotypes. As for drawer testing, SPAD value could be used as a phenotypic indicator for judging the easy curing portential, and the color parameters could be used as a phenotypic indicator for judging the easy and endurable curing portential. Taken together, K326, Bi’na1, Guiyan1 and Guiyan4 had a better easy curing portential, then was Zunyan6, and Hongda showed the worst performance. In addition, Bi’na1 had a better endurable curing portential, then were K326, Guiyan4, Hongda and Zunyan6, and Guiyan1 showed the worst performance. According to the difference of curing characteristics of different flue-cured tobacco varieties, we have put forward some specific measures for different tobacco varieties curing, which lay the theoretical foundation for different flue-cured tobacco varieties curing and the improvement of upper tobacco quality.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1350-1358. https://doi.org/10.11869/j.issn.100-8551.2020.06.1350In order to explore the effects of selenium-sulfur interaction on the physiology and sulforaphane metabolism of broccoli sprouts under high temperature stress, broccoli seeds were sprayed with ZnSO4 or Na2SeO3 alone or combined with ZnSO4 or Na2SeO3 or both under high temperature stress. The main physiological and biochemical indexes of broccoli sprouts during germination were analyzed and the changes of gene expression of key enzymes in sulforaphane metabolism were analyzed by fluorescence quantitative PCR. The results showed that the application of Na2SeO3 alone could significantly increase the sprouts length and the fresh weight per plant (P<0.05), and effectively alleviate the inhibition of high temperature and ZnSO4 on the growth and development of broccoli sprouts. During germination, compared with spraying ZnSO4 alone, the selenium content, total antioxidant capacity, glucosinolates content, mesonase activity, isothiocyanate content and sulforaphane content of broccoli sprouts sprayed with ZnSO4 and Na2SeO3 after high temperature were significantly increased (P<0.05). The content of sulforaphane was 39% higher than that of spraying ZnSO4 alone. The expressions of MYB28, UGT74B1 and ST5b in sprouts treated with high temperature combined with ZnSO4 and Na2SeO3 for 4 days were significantly up-regulated compared with the control, while BoHMT1 was significantly down-regulated (P<0.05). To sum up, broccoli sprouts treated with high temperature combined with selenium and sulfur is an effective way to enrich sulforaphane. The results of this study provide a theoretical basis and technical support for the production of functional sprouts rich in sulforaphane.
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Journal of Nuclear Agricultural Sciences. 2020, 34(6): 1359-1367. https://doi.org/10.11869/j.issn.100-8551.2020.06.1359Soil salinization caused by soil sodium accumulation is becoming more and more serious,which is one of the important factors restricting rice yield and quality. Sodium ion is the main ion causing salt stress injury in rice. Study on the mechanisms of sodium ion uptake and transport in rice plants and the physiological and molecular mechanisms of rice in response to salt stress is very helpful to the selection and breeding of salt-resistant varieties and to the comprehensive management and utilization of saline-alkali land. This paper summarized the induction of salt signals and the characteristics of salt absorption and transport in rice, analyzed the effects of salt on rice morphology growth and development, and discussed the physiological mechanism of osmotic regulation, nutrient regulation, antioxidant system regulation and hormone regulation induced by rice in order to alleviate salt damage. The molecular regulation mechanisms of ion balance, membrane protection system and photosynthetic system in rice through differential expression of stress-resistant proteins and stress expression of salt-tolerant related genes are also discussed in present study. Besides, this paper proposed the exogenous application methods to improve salt tolerance of rice as well as the esearch prospects of this field.
