10 November 2020, Volume 34 Issue 11
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2377-2385. https://doi.org/10.11869/j.issn.100-8551.2020.11.2377KNOX gene family is a unique transcription factor in plant growth and development, which plays an important role in plant morphogenesis. In order to study the characteristics of sorghum KNOX gene family and the expression pattern of SbKNOX22. Bioinformatics and qRT-PCR were respectively used to identify KNOX gene family and detect the gene expression level in this study. The results showed that 23 KNOX genes (SbKNOX1-SbKNOX23) were identified in sorghum. Subcellular localization analysis suggested that all the members were located in the nucleus. The length of amino acid sequence was between 184~802 aa, and the molecular weight was between 20.23~86.14 kDa, as well as the theoretical isoelectric point was between 4.76~7.28. The proteins of the KNOX gene family were all hydrophilic proteins, distributed on 8 chromosomes of sorghum. According to the phylogenetic analysis, sorghum KNOX gene family can be divided into Class Ⅰ and Class Ⅱ subfamilies. Gene structure analysis showed that the numbers of exons and introns in Class Ⅱ members were various. Besides, the Homeobox KN domain was the most conservative among all 5 Motifs. qRT-PCR analysis demonstrated that SbKNOX22 was mainly expressed in sorghum leaves. After salicylic acid treatment, the expression level of SbKNOX22 was induced and reached the peak at 6 h. PEG6000 and mannitol could decrease the expression of SbKNOX22 after 0.5 h, whereas, the SbKNOX22 expression was enhanced after NaCl treatment and reached the peak at 9 h. This study provides a basis for further exploring the role of KNOX family in regulating sorghum growth and development, signal transduction and plant hormone regulation.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2386-2396. https://doi.org/10.11869/j.issn.100-8551.2020.11.2386Corn leaf aphid (Rhopalosiphum maidis Fitch) is one of the most predominant insect pests in maize fields and causes significant loss of the crop worldwide. The use of insect-resistant germplasms is a very effective and economical way to control this insect pest. In order to develop resistant hybrids for aphid control, it is necessary to identify and screen resistant germplasms, determine genetic pattern of resistance, and explore resistant genes. In the present study, newly collected maize germplasms for corn leaf aphid resistance have been evaluated; the aphid-resistance loci from maize inbred line 32t33 have been identified by employing a combination of bulked segregant analysis and high-throughput sequencing technology. The results showed that 5 out of 98 maize germplasms were highly resistant to corn leaf aphid. The resistance from the inbred line 32t33 is subject to polygenic control and exhibited quantitative genetic characteristics. Two genomic regions on chromosomes 3 and 5 were identified to be associated with corn leaf aphid resistance, with sizes of 19.66 Mb and 6.34 Mb, respectively. Furtherly, five candidate genes associated with the aphid resistance have been initially predicted. The results of this study could help to enrich aphid-resistance maize resources, better understand the maize aphid-resistance mechanism and develop new hybrids with corn leaf aphid resistance.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2397-2406. https://doi.org/10.11869/j.issn.100-8551.2020.11.2397In order to study the genetic diversity of edible cassava in Guangxi, coefficient of variation, genetic diversity index, cluster analysis, polymorphism analysis and genetic similarity coefficient of 48 edible cassava materials were analyzed. The results showed that the average phenotypic variation coefficient of 48 accessions was 37.9%, coefficient of variation of angle of branching was the highest (86.7%); the average genetic diversity index was 0.807 and the largest diversity index character was color of root cortex (1.842). Genetic diversity was analyzed using 13 SSR molecular markers and the results showed that 118 bands were identified.Among them, 106 bands were polymorphic with of polymorphic rate of 86.23%; UPGMA clustering analysis showed that the genetic similarity coefficient among those materials ranged from 0.415 to 1.000. The phenotypic clustering and molecular clustering were inconsistent. No association was found between taxonomy and geographical origin, but there was some correlation with plant type traits. When the genetic similarity coefficient was 0.62, the materials could be clustered into two groups, the first group had irregular geographical distribution, and materials of the second group were mostly distributed in southern Guangxi. The results indicated that the genetic diversity of local edible cassava resources in Guangxi has a certain richness, which can lay a foundation for the creation of excellent edible cassava germplasm resources and the breeding of new varieties.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2407-2415. https://doi.org/10.11869/j.issn.100-8551.2020.11.2407In order to understand the inheritance of sugar-related traits in pumpkin fruit, two high generation of inbred lines with significant difference in sugar content and composition, the guangdong local high line (CMO-97) and Thailand line (CMO - E), were used as the parents to build F2 segregation population in this study. Based on the high-throughput sequencing and parental genome resequencing results, molecular markers linked to the sugar-related trait of the pumpkin were developed. The markers located in the original location mapping region of sucrose and glucose ratio (qs/g19-a) on the genetic map was encrypted. The key genes controlling sweetness of pumpkin were predicted and molecular markers closely linked to fruit sugar content were screened. The results showed that 9 pairs of InDel markers and 6 pairs of KASP markers were polymorphic among the 50 pairs of InDel markers and 12 pairs of KASP markers. The encrypted linkage group 19 contained 6 KASP markers, 9 InDel markers and 112 SNP markers. The qs/g19-a localization region was narrowed from 968.7 to 356.3 kb. Compared with the reference genome information, we found that there were 56 genes in the narrowed localization region, among which there were 4 candidate genes related to sugar content. The results of this study provide reference and molecular marker resources for breeding studies on pumpkin sugar content.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2416-2424. https://doi.org/10.11869/j.issn.100-8551.2020.11.2416VQ family genes are kind of plant-specific genes, which encoding VQ motif-containing proteins that can interact with WRKY protein to regulate downstream genes and play crucial roles in the development and various stress responses in plants. In the present study, 26 VQ family genes were identified from the genome of melon by bioinformatics approach, which were randomly and unevenly distributed on 11 chromosomes. Phylogenetic analysis indicated that melon VQ proteins could be classified into seven groups, VQ in different group can play different biological function in different pathway. Gene structure analysis showed that melon VQ genes only have one exon, indicating the gene was highly conserved. Gene expression patterns analysis showed that one VQ family gene was constitutively expressed in almost all tissues and 23 VQ family genes expressed only in specific tissue. Six VQ family genes were regulated by powdery mildew infection, indicating these genes play important roles in resisting to powdery mildew disease in melon.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2425-2434. https://doi.org/10.11869/j.issn.100-8551.2020.11.2425To explore the main pathogens and its’ growth characteristics of postharvest soft rot of kiwifruit, In September 2017, 100 fruit samples with soft rot symptoms were collected at the kiwifruit base in Fenghuang County, Hunan Province. The flesh between the diseased and the good were taken out to isolate and purify the pathogens. Then the morphologies of strains were observed, and molecular biological of pathogens were identified. At the same time, the effects of media, carbon source, nitrogen source, temperature, and pH value on the growth of pathogenic bacteria were analyzed. The results showed that, the strains were identified as Botryosphaeria dothidea and Diaporthe phaseolorum. The growth rates of the two strains were faster in PSA, YPGA, PDA and SDA media. The growth rates of Botryosphaeria dothidea and Diaporthe phaseolorum were 16.1 to 18.6 mm·d-1 and 13.9 to 16.5 mm·d-1, and the mycelial density was also very dense. The growth of pathogenic bacteria was better when starch, sucrose and maltose were used as carbon sources, the growth rates of Botryosphaeria dothidea and Diaporthe phaseolorum were 15.9 to 17.7 mm·d-1 and 12.4 to 16.4 mm·d-1. Yeast powder, peptone and glycine used as nitrogen sources were more suitable for the growth of Botryosphaeria dothidea and Diaporthe phaseolorum. The growth rates of Botryosphaeria dothidea and Diaporthe phaseolorum were about 11.0 mm·d-1 and 9.5 mm·d-1, However, the growth rate is only 7% higher than that with CA medium. Besides, the optimum pH value for Botryosphaeria dothidea and Diaporthe phaseolorum are 5 to 7, the optimum temperature are between 25℃ and 30℃, and the lethal temperature is about 85℃. The results of this study provide a reference for the identification of kiwifruit soft rot pathogens and the green control of soft rot diseases during kiwifruit storage.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2435-2443. https://doi.org/10.11869/j.issn.100-8551.2020.11.2435
To investigate the growth, physiological and biochemical responses of different genotypes of Betula luminifera under low nitrogen stress, we conducted a split-plot experiment using seedlings of three genotypes: G49-3, G50-1, and U3. There B. luminifera plants were grown in Hoagland nutrient solution under control (CK, 15 mmol·L-1 $NO_{3}^{-}$) and low nitrogen (LN, 0.03 mmol·L-1 $NO_{3}^{-}$) treatments. After 21 days of LN treatment, the chlorophyll content, plant height, shoot dry weight, shoot N content, and N content were significantly reduced in all three B. luminifera genotypes, with the greatest decrease in G49-3 and the lowest decrease in G50-1. Root-shoot ratio, total root length, total root surface area, and root average diameter were higher under LN treatment. Peroxidase (POD), superoxide (SOD), and nitrate reductase (NR) levels were lower in leaves with LN treatment; G50-1 was the genotype with the least influences. Quantitative reverse-transcription polymerase chain reaction (RT-qPCR), revealed that NRT1.1 and NRT1.2 were down-regulated in both leaves and roots of all three genotypes under LN. In contrast, NRT2.1 was up-regulated in roots, suggesting that NRT2.1 plays a major role in nitrate transfer in B. luminifera roots under LN stress. Comprehensive membership function analysis showed that the average value of G50-1 (0.73) was higher than those of U3 (0.44) and G49-3 (0.34), indicating that among these genotypes, G50-1 is the most tolerant to LN stress and G49-3 the most sensitive. These results reveal the physiological mechanism of B. luminifera adapting to low nitrogen environment. It also suggest that it is feasible to select and breed improved varieties of B. luminifera with high LN tolerance and N efficiency using traditional genetic improvement strategies.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2444-2451. https://doi.org/10.11869/j.issn.100-8551.2020.11.2444In order to establish a high-effective regeneration system for Swertia davidii, induction of callus and axillary buds were conducted using stem tips with leaves, stem with buds and leaves to explore the effects of different hormones on plant regeneration based on a single factor experiment, a complete combination test and a L9(34) orthogonal experiment. The results indicated that leaves were the most suitable materials for indirect organogenesis among three kinds of explants of S. davidii. The callus could be induced at the notch after culturing for 7 days and numerous adventitious shoots were differentiated after culturing for 30 days on the MS medium containing 6-BA 2.0 mg·L-1 and KT 1.5 mg·L-1. The multiplication coefficient of these shoots cultured on the same medium reached to 8.75. Stem with buds were suitable for direct organogenesis. Axillary buds began to grow after 7 days on the MS medium supplementing 6-BA 2.0 mg·L-1 and NAA 1.0 mg·L-1; the coefficient of axillary buds formation was 4.06. The optimal medium for rooting was found to be MS medium containing NAA 0.05 mg·L-1. The rooting rate was 100% when cultured up to 30 days with whole plant regeneration. After acclimatization training, the survival rate of plantlets was more than 90% after transplanting into the field. Indirect organogenesis had a higher efficiency than that of direct organogenesis. Our present study provides a high-effective regeneration system for S. davidii from callus to adventitious shoot. The protocol constructed provides technical support for protecting the wild resource and seedling breeding, and also offers afoundation for the further genetic transformation.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2452-2459. https://doi.org/10.11869/j.issn.100-8551.2020.11.2452In order to study the microbial diversity in the rhizosphere soil and bulb of saffron in Chongming, the microbial community composition was analyzed using Illumina MiSeq high-throughput sequencing technology. The results showed that the bacteria and fungi were similar at the phylum level in the rhizosphere soil and saffron bulbs, but the microbial abundance and diversity in rhizosphere soil was significantly higher than that in the bulbs. However, the microbial diversity of rhizosphere soil was significantly higher than that of bulbs at genus and species levels. At the species level, the rhizosphere soil or bulb has its own unique bacteria or fungi, and has a relatively high abundance. The pathogenic endophytic fungi Phialophora and Cadophora were also detected in Chongming saffron bulbs. Therefore, it is speculated that saffron disease is also closely related to its endophytic bacteria and fungi in addition to the soil flora. This study has tentatively elaborated community structure and diversity of microorganisms in rhizosphere soil and bulbs, and provided theoretical basis for further screening suitable sterilization agent for Chongming saffron cultivation soil and bulbs.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2460-2469. https://doi.org/10.11869/j.issn.100-8551.2020.11.2460The adventitious roots of Valeriana officinalis could synthesize secondary metabolites stably, and tissue culture techniques have quick reproduce and large reproductive coefficient. In order to product efficiently the active ingredients of Valeriana officinalis. The effects of pH value, carbon source type, sugar concentration, salt concentration, total N concentration and total P concentration on the suspension culture have been analyzed: The optimal suspension culture condition was gained for adventitious root. The growth curve has been constructed. Meanwhile the content of valepotriate, acevalepotriate, and valerenic acid in normal adventitious roots were contrasted, browning adventitious roots and aseptic seedling roots. The results showed that the ideal suspension culture condition of adventitious roots was twice major element concentration, 48.46 mmol·L-1 total N concentration, 1.5 mmol·L-1 total P concentration in RCM medium, and 40 g·L-1 sucrose, 0.5 mg·L-1 NAA, pH 5.7, cultured at 25±2℃, 100 r·min-1 in dark then harvested the adventitious roots after 28 days inoculation. It was also found that in this condition the content of valepotriate, acevalepotriater, and valerenic acid were respectively 7.222 mg·g-1, 0.355 mg·g-1, and 4.016 mg·g-1, the content of the components in browning root significantly decreased. The content of the components in the aseptic seedling roots was the least. It also provided reference for the adventitious roots induction and the active ingredients production of V. officinalis.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2470-2476. https://doi.org/10.11869/j.issn.100-8551.2020.11.2470In order to improve the drying quality of kiwifruit slices, shorten the drying time and reduce the energy consumption, the kiwifruit slice was dried by air impingement drying. The effects of constant and alternating temperatures on the drying characteristics and quality of kiwifruit slices were studied. The results showed that both the drying process of constant and alternating temperature air-impingement drying of kiwifruit slice occurred in the falling rate period. Air temperature affected the drying characteristics of kiwifruit slices. There was no significant difference in sugar content between the alternating temperature drying and constant temperature at 40℃. The difference in titratable acid content between the alternating temperature drying and the constant temperature of 70℃ was not obvious. The resilience and the Vitamin C preservation rate of the alternating temperature drying (70→40℃) were higher, and its ΔE value was between constant temperature drying at 50 and 70℃. The unit energy consumption of the 70→40℃ drying method was significantly lower than that of the 40→70℃ drying method. In summary, the kiwifruit slices processed by the 70→40℃ cooling drying method had the best integrated quality. The research provided a technical basis for the application of alternating temperature air-impingement drying technology in kiwifruit slices.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2477-2483. https://doi.org/10.11869/j.issn.100-8551.2020.11.2477To prepare monoclonal antibodies against soybean agglutinin (SBA) with high affinity. BALB/c mice were immunized with 50 μg of protein of SBA in 200 μL emulsion, and the antiserum titer and sensitivity were identified by indirect ELISA and indirect competitive ELISA respectively. The mouse with higher serum titer and sensitivity was selected for cell fusing. The hybridoma cell strain secreted monoclonal antibody (mAb) against SBA was selected by limited dilution subcloning. The SBA mAb was prepared by inducing ascites in vivo and the immunological characteristics of which were identified. The results indicated that the NO.1 mouse has the highest serum titer and sensitivity, the IC50 was 574.1 μg·L-1. The NO.1 mouse was selected for cell fusing, and one hybridoma cell strains 5B4E10 were screened. The titer of mAb produced by 5B4E10 was above 1∶409 600, IC50was 82.04 μg·L-1, the subtype was IgG1, the affinity constant Ka was 1.83×109L·mol-1. Furthermore, there was no cross reaction between the prepared mAb and glycinin, β-conglycinin, other anti-nutrient factors. In conclusion, the result of this study would provide an antibody basis for the immunological detection method of SBA in soybean and its products.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2484-2491. https://doi.org/10.11869/j.issn.100-8551.2020.11.2484In order to improve the quality of low-salted pickled vegetables, this study analyzed the microstructure, texture, flavor and sensory evaluation of pickled cucumbers, and studied the effect of different treatments (low-salt pickles, low-salt pickles of composite pickles, and high-salt pickles) on the quality of pickled cucumbers. The results showed that the texture and flavor quality of high-salted pickled cucumber and composite low-salt pickled cucumber were better than low-salt pickled cucumber. Among them, the hardness of high-salted pickled cucumber was slightly higher than that of composite pickled cucumber, slight difference between total amino acid and total organic acid was observed; the hardness of composite pickled cucumber was 271 g higher than that of low-salted pickled cucumber; the total amount of amino acids and organic acids was 35.3 and 55.1 mg·100 g-1 higher than that of low-salted pickled cucumber samples, respectively. The texture, flavor and sensory quality of the composite pickled cucumber were similar to the traditional high-salt pickled cucumber, which were superior to the low-salt pickled cucumber. This study provides data support to effectively solve the problem of low salt pickling and the quality of cucumber.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2492-2498. https://doi.org/10.11869/j.issn.100-8551.2020.11.2492To study the physical and chemical properties of oat protein and make better use of oat protein resources, oat protein was extracted from oat by alkaline extraction and acid precipitation. The effects of different pH and temperature on the solubility, ζ-potential and particle size distribution of oat protein were analyzed. The results showed that around pH 5.0, oat protein had the lowest surface charge, larger particle size, and lower solubility and emulsification. When the pH value was far away from the isoelectric point, the surface charge of oat protein increased, particle size gradually decreased and the solubility and emulsification increased. As the temperature increases (55-95℃), oat protein was dissociative, particle size was smaller. As the solubility of oat protein increased, the stability was improved. When increasing the temperature to 121 and 130℃, oat protein precipitated to form larger particle size of aggregate. However, solubility and stability were significantly reduced.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2499-2506. https://doi.org/10.11869/j.issn.100-8551.2020.11.2499In order to increase the utilization rate of follicles, chicken follicles were used as raw materials in this study, and then yolk oil was extracted by solvent extraction from lecithin and cholesterol removed follicle residue. The effects of extraction temperature, time, solid-liquid ratio and ethanol concentration were studied by single factor and orthogonal test. Extracted yolk oil was oxidized and the volatile flavor compounds were analyzed by gas chromatography-ion mobility spectroscopy (GC-IMS). The results showed that the optimum extraction conditions were temperature 75℃, time 55 min, solid-liquid ratio 1∶10, ethanol concentration 95%. Volatile flavor compounds were identified, including alcohols (4 kinds), aldehydes (3 kinds), esters (2 kinds), ketones (2 kinds), and 1furan. 3-Methylbutanal was the characteristic flavor compound in oxidized solkoil. The results provide new ideas for the development, utilization and increasing the added value of by-products for laying hens.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2507-2518. https://doi.org/10.11869/j.issn.100-8551.2020.11.2507In order to develop and utilize the functional compound of limonin in lemon seeds, the optimal system of limonin extraction by ionic liquids aqueous two-phase separation (ILs-ATP) system was studied in the present study; meanwhile, the extraction process of the optimal ILs-ATPS were optimized by response surface methodology. The results exhibited that the highest extraction yields of limonin from lemon seeds were obtained in the ILs-ATPS of 1.5 mol·L-1 [TMG][Cl]/1.35 mol·L-1 NaH2PO4among all ILs-ATP systems, with the extraction rate of 97.59%. Response surface optimization results showed that the highest yields of limonin was achieved with 59.40% ethanol and liquid to material ratio of 18.08∶1 for extracting of 90.74 min in 74.22 ℃. The difference between the predicted maximum extraction yield of limonin (12.126 mg·g-1 FW) and the content in verification test (12.381 mg·g-1 FW) was not significant following a one-way ANOVA, indicating that the predicted model possessed high predictability and accuracy. In addition, the extracted limonin compound could effectively scavenge reactive oxygen radicals and inhibit the peroxidation of unsaturated fatty acid, contributing to a strong antioxidant activity. These results provided the theoretical foundation for the exploitation and practical application of lemon (Citrus limon) source.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2519-2525. https://doi.org/10.11869/j.issn.100-8551.2020.11.2519In order to analyze the monoglyceride compositions of Asterias rollestoni gonad, the derivative methods and chromatographic conditions of monoglycerides were optimized, and the fragmentation rules and mass spectrometry characteristics of monoglyceride derivatives were analyzed and monoglyceride compositions in Asterias rollestoni gonad were also detected in this paper. The results indicated that trimethylsilylation had ideal derivative effects on monoglycerides, and the ideal chromatographic separation effects of monoglyceride derivatives were obtained by the weak-polar glass capillary column (HP-5MS, 30 m × 0.25 mm × 0.25 μm). Moreover, the characteristic ions of 1-monoglyceride derivatives were m/z 73, m/z 205, [M-103]+ (base-peak ion) and [M-15]+, while 2-monoglyceride derivatives were m/z 73 (base-peak ion), m/z 129, m/z 218, [M+H-162]+ and [M-15]+. Gas chromatographic retention time of monoglyceride derivatives displayed certain regularitys, and 2-monoglyceride derivatives were eluted earlier than 1-monoglyceride derivatives. Additionally, eight monoglycerides were identified from Asterias rollestoni gonad, which were mainly consisted of 1-monopalmitin (1-C16:0-MG) and 1-monostearin (1-C18:0-MG), while the contents of 2-monoglycerides were relatively low. This research provides theoretical references for derivatization, chromatographic analysis and mass spectrometric identification of monoglycerides.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2526-2532. https://doi.org/10.11869/j.issn.100-8551.2020.11.2526In order to establish a rapid analysis method for perchlorate in wines with simple pretreatment, accurate quantification and high sensitivity, wine samples were extracted with acidified methanol solution, purified by WAX solid phase extraction column, filtered by hydrophilic polypropylene membrane (GHP), separated by Phenyl-Hexyl column, electrospray ion source in multiple reaction monitoring and detection in negative ion mode to determine perchlorate in wine. The results showed that the detection time was 12 min, the detection limit and limit of quantitation were 0.15 μg·L-1 and 0.5 μg·L-1, respectively. The recoveries at spikes of 1, 2, 5, 10 and 20 μg·L-1 ranged from 94.5% to 105% with the relative standard deviation (RSD) less than 3.17%. The establishment of this method can provide some technical support for the testing of wine producers and relevant regulatory authorities.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2533-2540. https://doi.org/10.11869/j.issn.100-8551.2020.11.2533In order to compare the content proportion of rebaudioside D (RD) and rebaudioside A (RA) in different varieties of Stevia Rebaudiana Bertoni, the optimized high performance liquid chromatography methods were established by selecting suitable stationary phase in C18, HSS T3 and Amide chromatographic column. The results showed that the selectivity of HSS T3 column to stevia glycosides was better, which could separate RA, ST, rebaudioside F (RF), rebaudioside C (RC), rubusoside (RBS), rebaudioside B (RB) and steviolbioside (SB) at the same time. The HPLC method employed was an isocratic mobile phase consisted of mixture of acetonitrile and sodium phosphate buffer (0.01%) with a ratio of 32.68(v∶v) at a flow rate of 1.0 mL·min-1 and with 10 μL injections, and the detection wavelength was set at 210 nm and the column temperature at 40℃. Amide column showed the best separation ability for RD, the HPLC method employed was an isocratic mobile phase consisted of a 76:24 (v:v) mixture of acetonitrile and water at a flow rate of 0.8 mL·min-1 and with 10 μL injections, the detection wavelength was set at 210 nm and the column temperature at 40℃. The HPLC results showed that the content proportion of RA and RD in 12 strains of Stevia Rebaudiana Bertoni was different. The content and proportion of RD in No. 2 were high, suggesting that this strain could be used as raw material to produce high content of RD. The content of stevia glycosides mainly RA in No 3, 5, 7 and 11 was higher, suggesting that these strains were rich in RA and high yield of steviol glycosides. The proportions of RA+RD in No. 1 and 8 were high, suggesting that steviol glycosides were of better sweetness quality in these raw materials. The HPLC methods established in this study could provide reference for the analysis of RD and RA in Stevia Rebaudiana Bertoni, and the results can provide reference and guidance for the selection of suitable Stevia rebaudiana Bertoni varieties in practical applications.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2541-2550. https://doi.org/10.11869/j.issn.100-8551.2020.11.2541In order to investigate the dynamic changes of fungal community composition and diversity in the process of edible betelnut processing, the fungal rRNA gene ITS1 region was sequenced by Illumina Miseq high-throughput sequencing technology, the results showed that fungi could be assigned to 9 phyla, 31 classes, 84 orders, 164 families, 226 genera, and 520 OTUs using 24 betelnut samples, the dominant fungi include Aspergillus, Cladosporium, Candida, Lecanicillium, Simplicillium, Penicillium, Tuber, Cyberlindnera, Rhodotorula, Cutaneotrichosporon, unidentified Saccharomycetales_fam_Incertae_sedis, unidentified Saccharomycetales and unidentified Malasseziales, Aspergillus was the dominant fungi with a relative abundance of 66.70% to 97.67%, the other dominant fungi showed great differences in different process of edible betelnut processing. The diversity analysis showed that the community structure were more similar in soaked betelnut without soda, washed betelnut, roasted betelnut and added bittern betelnut, the community structure were more different in soaked betelnut with soda, brightened betelnut, cored betelnut and finished product betelnut. The results showed that there was no significant difference in fungal richness but significant difference in fungal diversity during processing processes of betelnut, and the community structure were varied in finished product betelnut. This study provides theoretical support for the research and development of anti-mildew technology for edible betelnut.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2551-2560. https://doi.org/10.11869/j.issn.100-8551.2020.11.2551In order to study effect of water and nitrogen regulation on nitrogen absorption and utilization of drip-irrigated grape in arid areas, a field experiment was carried out in this study with Xinjiang fresh grape (Vitis vinifera cv. Frey) as the experimental material and 15N tracer technique. Two irrigation levels (4 950 and 5 400 m3·hm-2, respectively, marked as W1 and W2) and three nitrogen application levels (177, 235 and 292 kg·hm-2, respectively, marked as F1, F2 and F3) were set in the experiment. The results showed that there were significant differences in total nitrogen content and 15N abundance among the treatments (P<0.01), and enrichment occurred in 0~20 cm soil layer. The nitrogen uptake capacity of each organ significantly increased with the increase of water and nitrogen input (P<0.01). The biomass of root, stem and leaf organs increased significantly with the increase of nitrogen uptake (P<0.01). F3 treatment was not conducive to the accumulation of biomass in fruit organs. The amount of fertilizer nitrogen absorbed by fruit trees gradually increased with the increase of water and nitrogen input, which was significantly affected by the regulation of water and nitrogen (P<0.01), and the amount of soil nitrogen absorbed by fruit trees was greater than that of fertilizer nitrogen. The 15N-labeled nitrogen use efficiency and partial productivity of W2F1 were the highest, which were 38.36% and 114.20 kg·kg-1, respectively. The yield of W2F2 was the highest, which was 20 253 kg·hm-2, but it was not significantly different from that of W2F1. Too much water and nitrogen input would cause excessive growth of stem and leaf, and was not conducive to improving the 15N-labeled nitrogen use efficiency. In summary, W2F1 is a feasible water and nitrogen operation model with both economic and ecological effects. The results of this study provide a reference for the high yield and high efficiency planting of drip irrigation grape in arid area.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2561-2568. https://doi.org/10.11869/j.issn.100-8551.2020.11.2561To explore effect of different vegetation restoration types on soil organic carbon turnover in degraded red soil, δ13C of vegetation and soil organic carbon were analyzed in the natural restoration grassland, Pinus massoniana forest and Schima superba forest. The results showed that C4 plants were dominated in the natural restoration grassland, while C3 plant mainly occurred in the Pinus massoniana and Schima superba forest. The δ13C increase of soil organic carbon from litter to soil was beyond the normal range from current research in both stands, indicating that sources of soil organic carbon were the mixture of the pasture and the currently restored forest. Soil organic carbon from the surface soil was lower than that from the original grass carbon. The δ13C of soil organic carbon increased with the depth in both stands. The decomposition rate of soil organic carbon in the Schima superba forest was lower than that of soil in the Pinus massoniana forest, but the retention time of SOC was the opposite in two forests. Although the proportion of soil organic carbon from new carbon in the Pinus massoniana forest was higher than that in Schima superba forest, the soil organic carbon decomposes more solwly in muhe forests. In the long run, the carbon sequestration process of Pinus massoniana and Schima superba soils needs more reasonable evaluation. This study provides a theoretical basis for the selection of tree species for vegetation restoration and enriches the research for soil organic carbon of vegetation restoration in degenerated red soil regions.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2569-2577. https://doi.org/10.11869/j.issn.100-8551.2020.11.2569High yield and high nitrogen (N) efficiency maize breeding is one of the strategies to increase crop yield and simultaneously reduce fertilizer input. In the present study, 11 commercial maize varieties were used to study kernel yield and ear characteristics at two locations (Jianyang and Zhongjiang) with LN, MN and HN nitrogen (0,150 and 300 kg N·hm-2) rates in the Southwest China. ANOVA and correlation analysis were used to analyze all these yield component data. Nitrogen efficiency of maize cultivars were grouped according to genotype × nitrogen response interaction, in order to analyze yield increase potential and related yield components.We found that, grain yield was significantly affected by the interaction among genotype (G), nitrogen (N), and location (L). The ear diameter and 100-kernel weight were significantly influenced by interaction between genotype and N.There were differences in nitrogen efficiency genotype among 11 experimental maize varieties. Based on the average yields achieved with high or low N application, the tested varieties were classified into four types: Efficient-efficient, high-N efficient, low-N efficient and nonefficient-nonefficient under neither low nor high N inputs. High-yielding and N-efficient varieties (efficient-efficient and high-N efficient) was 45.5% of the total cultivar numbers used. efficient-efficient and high-N efficient varieties could potentially increase maize yield by 6.74~7.54% or 9.88~13.45% under either high or low N rates. And efficient-efficient and high-N efficient varieties showed different potential of reducing N input under different locations. Under HN rates, N input could be reduced more than 19.18% in high-yielding and N-efficient varieties. Percentage yield increase had a significant positive correlation between ear diameter and 100-kernel weight. Zhenghong 311, Chuandan189 and Miandan1256 showed a high-yielding and N-efficient potential at both locations.These results indicated that selecting and cultivating maize varieties with high-yielding and N-efficient potentials or low-N efficient feature on soils with different fertility can increase yield and reduce N input in the Central Sichuan Basin. This study provides some advice for the breeding of high yield and high N-efficiency maize varieties.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2578-2586. https://doi.org/10.11869/j.issn.100-8551.2020.11.2578This study investigated the performance of spent mushroom substrate (SMS) as a bulking agent to alleviate gaseous emissions and optimize product maturity in co-composting of chicken manure and tobacco wastes. SMS were mixed completely into composting piles for 35 days at three addition ratios (i.e. 0%, 5%, and 10% of total wet weight of raw composting materials). Results showed that the composting temperature for all treatments could maintain at above 55℃ for more than 8 days, which conforms to the Chinese Hygienic Standards for Non-hazardous Disposal of Night Soil. Although adding 5% or 10% SMS to composting piles could effectively improve the compost maturity and exert no toxic effects on crop growth, all treatments failed to meet the maturity standard. Moreover, compared with the control treatment, treatments with 5% SMS addition reduced the TOC and TN losses by 2.39 and 8.9 percent, respectively. By contrast, TOC loss was enhanced by 0.27 percent while TN loss was reduced by 11.89 percent when the SMS addition was increased by 10%. Results obtained from this study suggested that SMS as a bulking agent at a suitable addition proportion could efficiently improve composting performance in terms of gaseous emissions and maturity in chicken manure and tobacco wastes co-composting. It provides important reference value for the utilization of agricultural organic wastes in composting and the reduction of agricultural pollution gas emission.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2587-2594. https://doi.org/10.11869/j.issn.100-8551.2020.11.2587In order to explore the effects of combined foliar application of amino acids with boric acid on Lactuca sativa L, a pot experiment was conducted using Lactuca sativa L as material. Glutamic acid, alanine and aspartic acid were chosen and foliar sprayed in 3 concentrations(5, 10, 20 mmol·L-1) mixed with 1% boric acid, 11 treatments in total, including spraying 1% boric acid alone and water sprayed as controls. We measured the growth indicators, quality indicators and boron content after the harvest. The results show that: Spaying boric acid alone had no significant effect on the biomass of Lactuca sativa L while all the three kinds of low concentration amino acid spraying together with boric acid could significantly increase the yield, among them, mixed spraying of alanine and boric acid increased the biomass of Lactuca sativa L by 9.4% in average. Compared with the control, the combined spaying of amino acids with boric acid could significantly increase the total protein content of Lactuca sativa L leaves, while reducing nitrate accumulation, thereby improving the quality; Compared with spraying boric acid alone, appropriate concentration of amino acids spraying together with boric acid could significantly increase the accumulation of nitrogen and potassium of Lactuca sativa L, besides, spaying glutamic acid and aspartic acid respectively mixed with boric acid could also significantly increased the accumulation of phosphorus in Lactuca sativa L; Compared with spraying boric acid alone, the combined spaying of amino acids with boric acid effectively increased the above ground boron content of Lactuca sativa L, among them, mixed spraying of alanine and boric acid not only increased the aboveground boron content of Lactuca sativa L by 41.0%, but also increased the underground boron content of Lactuca sativa L by 15.6%. Besides, no matter the aboveground part or underground part of Lactuca sativa L, there was a significant positive linear relationship between the concentration of sprayed alanine and the boron content. The application effect of alanine and boron mixed spraying was better than the other two amino acids, so alanine acid can be considered adding to boron fertilizer as a synergist. This study provides a theoretical basis for developing new type buron fertilizer.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2595-2606. https://doi.org/10.11869/j.issn.100-8551.2020.11.2595In order to explore the effects of seedling raising methods and seeding amount combined with transplanting machines on the quality, yield and population quality of machine transplanting rice, hybrid indica rice Fyou498 was used as test material and a three-factor random block test was used to set up two seedling raising methods: seedling raising by nutrient soil and slime seedling raising; 3 seeding amount: 65, 85 and 105g / plate; 2 types of rice transplanting machines: 4 rows of walk-on rice transplanters and 6 rows of riding high-speed rice transplanters, to study the effects of the combination of seeding raising and transplanting machines on the yield and population quality of mechanically transplanted. The results showed that the method of raising seedlings, the amount of seed and the transplanting machines had a significant effect on the yield of mechanically transplanted rice, and the interaction effect was significant. The uniformity, machine uniformity, and dry matter accumulation of seedlings in nutrient soil had increased by 2.39% ~ 3.22%, 0.26% ~ 2.66%, 0.88% ~ 24.50% compared to thin mud seedlings. It was 1.30% ~ 4.76%, 0.24% ~ 12.70%. With the increase of the seeding amount, the uniformity of the seedlings gradually decreased, the uniformity of machine cutting, the uniformity of heading, the dry matter weight of population, the leaf area index (LAI), and the yield all increased first and then decreased. The 6-row ride-on high-speed rice transplanter had higher uniformity than the 4-row walk-on rice transplanter. In addition, the uniformity of heading, dry matter weight of population, group growth rate, and efficient LAI at the earing stage increased realizing an increase in output of 3.59%~5.6%, and economic benefits increased by 7.5%. In summary, on the basis of nutrient soil seedling cultivation, the seeding amount is 85 g per plate, and the supporting 6-row ride-on high-speed rice transplanter can improve the uniformity of the machine-transplanting group, optimize the group quality, and achieve the simultaneous improvement of high yield and efficiency. The results of this study provide theoretical guidance and practical basis for machine-planted rice production.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2607-2613. https://doi.org/10.11869/j.issn.100-8551.2020.11.2607In order to explore the relationship between anthocyanin accumulation and response to low temperature stress of foxtail millet, green and purple variety which was rich in anthocyanin were treated at low and normal(CK) temperature at seedling stage. We observed the pigments distribution in leaves and measured the photosynthesis, anthocyanin, relative chlorophyll, malondialdehyde(MDA), proline(Pro) and soluble sugar(SS) content. The results showed that under low temperature, anthocyanins were mainly distributed in mesophyll cells, upper and lower epidermis cells in purple leaves, but almost no anthocyanins were detected in green variety. Compared with green variety, anthocyanins content changed obviously in purple leaves. Additionally, the anthocyanin content of purple variety B13, B45 and B55 increased by 234%, 226% and 126%, respectively, after 12 days of low temperature induction compared with the control group. After the induction of low temperature, the net photosynthetic rate(Pn) and the chlorophyll content of purple variety were decreased, while the SS and Pro content was significantly increased, and the MDA content did not show regular changes. The correlation analysis showed that the anthocyanin content of purple variety was significantly negatively correlated with relative chlorophyll content and Pn, but significant positively correlated with Pro and SS content after 12 days of low temperature induction, while the relative chlorophyll content was positively correlated with Pn of purple variety. Thus, the anthocyanin in leaves of purple foxtail millet varieties can be induced by low temperature, and it can participate in response to low temperature stress together with Pro and SS in foxtail millet. The study provides a theoretical basis for exploring the cold resistance of purple leaf of foxtail millet and expanding the planting area.
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2614-2622. https://doi.org/10.11869/j.issn.100-8551.2020.11.2614In order to improve the utilization rate of photosynthetic active radiation (PAR) and shape the reasonable population structure of cotton population in the Yangtze River Basin, we set different planting densities (B1: May 13, B2: May 25) and sowing dates(M1: 7.5×104 plants·hm-2, M2: 9.0×104 plants·hm-2, M3: 10.0man4 plants·hm-2, M4: 12.0×104 plants·hm-2) to study the effects of different cultivation modes on the spatio-temporal distribution of cotton canopy PAR. The results showed that: in a certain period, the canopy with May 13 sowing date had a strong ability to intercept PAR, and there was a positive correlation between the PAR interception rate of canopy and plant density within a certain range at the same sowing date. At sowing date of B1, PAR interception rate of canopy increased at first and then decreased. PAR interception rate of B1M4 was higher during early growth period, but the PAR interception rate of B1M1 was higher during late growth period. At sowing date of B2, PAR interception rate of canopy increased gradually with cotton plant growth in certain period, and was the highest in B2M4. Therefore, the canopy of 12.0×104 plants·hm-2 plant density could intercept more PAR when the sowing date was May 25, while the sowing date was May 13, the canopy of 7.5 ×104plants·hm-2 plant density had more advantages for intercepting PAR than others during late growth period. This study provides technical support for the field production of cotton in the Yangtze River Basin, and also offers theoretical basis for breeding new cotton varieties and cultivating simplified。
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Journal of Nuclear Agricultural Sciences. 2020, 34(11): 2623-2627. https://doi.org/10.11869/j.issn.100-8551.2020.11.2623In order to determine the best harvest time of roselle, two varieties M3 and M5 were used as test materials. The sepal yield, procyanidins and tannins content of roselle were studied at different harvest time after flowering. The results showed that with the delay of harvesting time sepal weight, procyanidins and tannin content in M3 and M5 increased at the beginning and then decreased. The fresh fruit weight and fresh sepal weight of M3 reached the maximum of 12.82 g and 7.75 g, respectively, on 21 days after flowering, the maximum dry sepal weight was 0.98 g on 28 days after flowering. The maximum fresh fruit weight of M5 was 6.97 g on 21 d after flowering, and the maximum fresh sepal weight and dry sepal weight were 3.90 g and 0.47 g respectively on 28 days after flowering. For the purpose of harvesting calyx, the two germplasm suitable harvesting time is 21~28 d after flowering.The highest proanthocyanidins content of M3 was 2 180.00 mg·kg-1 at 35 days after flowering, the highest proanthocyanidins content of M5 was 573.50 mg·kg-1 at 21 days after flowering. The optimal harvesting time of M3 and M5 for proanthocyanidins are 35 days and 21 days after flowering, respectively. While the highest tannins content of M3 was 2.30 g·kg-1at 28~35 days after flowering. The highest tannins content of M5 was 1.38 g·kg-1 at 42 days after flowering. The optimal harvesting time of M3 and M5 for tannins were 28~35 days and 42 days after flowering, respectively. In conclusion, the optimum harvesting time of roselle should be one month (28~35 days)after flowering. This study provides a reference for reasonable harvest of roselle.
