10 March 2021, Volume 35 Issue 3
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 509-517. https://doi.org/10.11869/j.issn.100-8551.2021.03.0509In order to speed up the breeding process of Louisiana iris, hybridization and 60Co-γ radiation mutagenesis were carried out on five Louisiana iris varieties. Based on the EST-SSR markers of I.brevicaulis and I.fulva, 14 pairs of SSR markers were selected for genetic diversity analysis on Louisiana iris varieties, their hybrid offspring and mutagenic materials. The results showed that there was little genetic difference between the offspring of five Louisiana iris varieties and their maternal plants. However, after irradiation with 60Co-γ, great genetic differences from their parents were observed rays for five Louisiana iris cultivars. The survival rate of tissue culture plants was significantly negatively correlated with the dose of 60Co-γ mutagenesis. And the survival rates of different varieties under treatments of 2.5, 5, 10, 20 and 40 Gy were 20.77%~24.99%, 13.33%~17.89%, 10.11%~15.71%, 3.33~10.14% and 1.11%~2.77% respectively. The phenotypic traits of the mutagenic materials could be observed via tissue culture rapid propagation system. In this study, in vitro culture combined with 60Co-γ radiation mutation breeding was carried out for the first time on Louisiana iris, and 10 pairs of SSR markers were screened for identifying Louisiana iris varieties, hybrid offspring and mutagenic materials were screened. The research provide theoretical basis for Louisiana iris hybrid breeding, radiation mutation breeding and SSR-based germplasm identification.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 518-525. https://doi.org/10.11869/j.issn.100-8551.2021.03.0518The premature senescence of functional leaves at the late growth stage has become an important constraint factor for yield and quality improvement of hybrid rice. In order to investigate its physiological characteristics, two rice genotypes, the functional leaves premature senescence mutant (ospls2) and its wild type (Zhehui 7954), were used to compare the differences in the chlorophyll content, chlorophyll fluorescence, reactive oxygen species, antioxidant protective enzyme system, and soluble sugar content in the top three functional leaves during the late growth stage. The results showed that the total chlorophyll content, chlorophyll a/b and PSⅡ maximum photochemical efficiency (Fv/Fm) in ospls2 mutant decreased significantly with the senescence of the functional leaves during late growing stage, and were notably lower than those in the wild type. However, the Fluorescence (F0) had an opposite trend. Compared with the wild type, ospls2 mutant exhibited dramatically lower activities of SOD, CAT and APX in the functional leaves, and these enzymes were decreased significantly with the process of leaf senescence. Furthermore, the decreasing of CAT activity occurred later than APX, indicating that the early and late increase in the content of H2O2was mainly due to the decreased activity of APX and CAT, respectively. In addition, POD may play a role in catalyzing ROS production, and not as antioxidant enzymes. The results will provide an insight into the breeding of the early-senescence-resistant rice at the late growth stage.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 526-534. https://doi.org/10.11869/j.issn.100-8551.2021.03.0526
In order to create compact waxy corn germplasms, Zheng58 (a compact common maize inbred line) and Tong759 (a expanded waxy maize line) were used as donor and recurrent parent, respectively. The favorable alleles of major QTL (qLA5) for leaf angle were transferred by backcross with seletion for leaf angle combined marker-assisted selection and 29 plants for BC2F2 were created. Through the background selection of 48 markers and the comprehensive identification of 18 traits such as plant type, stress resistance, yield and quality under high density, 4 new waxy germplasms with compact plant type, high yield, strong stress resistance and good quality were screened out. The average genomic content of the recurrent parent in 4 new germplasms increased from 78.48% to 88.67%, which can be used as parent materials for compact waxy maize breeding. The results of this study provide theoretical references for the improvement of waxy maize germplasms by using common maize and the breeding of new compact and high quality fresh eating waxy maize varieties.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 535-548. https://doi.org/10.11869/j.issn.100-8551.2021.03.0535Cucumber green mottle mosaic virus (CGMMV) is a quarantine disease that affects watermelon production. To investigate the CGMMV-associated defense response in watermelon at proteomic level, we sampled watermelon leaves before and post CGMMV inoculation and employed isobaric tag for relative and absolute quantification (iTRAQ) technology to identify the differentially expressed proteins (DEPs), and KEGG analysis was carried out for these DEPs. The protein-protein interaction (PPI) networks were constructed using Cytoscape software and RT-qPCR analysis were carried out for determining the expression patterns of proteins in response to CGMMV stress. In total, we quantified 61 proteins that differentially expressed in response to CGMMV stress. These differentially expressed proteins (DEPs) included ribosomal proteins, PSI and PSⅡ proteins, ATP synthase, NADH dehydrogenase, HSP22.8, eukaryotic translation initiation factor, sucrose synthase and ethylene response factor. They were involved in KEGG pathways of photosynthesis, biosynthesis of scondary metabolites, and plant hormone signal transduction. PPI analysis identified 13, 32 and 43 DEPs for 48 h_0 h, 25 d_0 h and 25 d_48 h that involved in the known PPI network under CGMMV stress. RT-qPCR analysis obtained the expression patterns of SUS4, RPL22, NAD7, PSBH, defensin-like protein 5, ATPF, LSP1 and HSP22.8 at different infection stages of CGMMV. These results identify the proteins’ responsive to CGMMV infection, and lay a foundation for revealing molecular mechanism of CGMMV resistance in watermelon.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 549-555. https://doi.org/10.11869/j.issn.100-8551.2021.03.0549Verticillium wilt caused by Verticillium dahliae is one of the major diseases that restrict cotton production in China, which seriously affects cotton yield and quality. To study the molecular mechanism of interaction between cotton and Verticillium dahliae, the construction of yeast two-hybrid (Y2H) cDNA library was performed to explore interacting protein of SCP7 in cotton. In this study, the total RNA of cotton roots infected by Verticillium dahliae was extracted from the national certification cotton Baimian1. The quality of the total RNA was detected, and then the RNA was treated with DNase Ⅰ. The double-stranded cDNA was synthesized by SMART technology and purified after digestion, then ligated to pGADT7 to construct a cotton cDNA library. VdSCP7 is a Verticillium dahliae effector located in the host cellular nucleus, which can stimulate the immune response and enhance the disease resistance of cotton. VdSCP7 gene was amplified by using Verticillium dahliae cDNA as template. The product was purified and then recombined into pGBKT7 to construct bait vector pGBKT7-SCP7. After digestion and sequencing, the bait vector pGBKT7-SCP7 was transformed into yeast AH109 to identify the toxicity of bait protein and detect the self-activating activity of bait vector. The results showed that a cotton cDNA library with a library capacity of 2×106 CFU was obtained, and the diversity of library fragment was good and the recombination rate was about 94%. The titer of the plasmid library was about 2.0×109 CFU mL-1, which reached the requirements for constructing yeast two-hybrid cDNA library. The enzyme digestion and sequencing results showed that the bait vector pGBKT7-SCP7 was successfully constructed and identified as no toxicity and self-activation. The results laid a the foundation for the screening of Verticillium wilt resistance genes in cotton and the analysis of the interaction mechanism between VdSCP7 and cotton.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 556-566. https://doi.org/10.11869/j.issn.100-8551.2021.03.0556To determine the heterosis and genetic effects of maize deep-seeding tolerance-related traits. 22 F1 hybrids and 22 parents with different deep-seeding tolerance were used as materials to analyze the heterosis, genetic effect, and combining ability of 13 deep-seeding tolerance-related traits by ADM (additive-dominance-maternal effect genetic model) under 3, 15, and 20 cm depths in this study. It was found that: with the increase of sowing depths, seeding emergence rate (RAT), seedling length (SDL), root length (RL), mesocotyl coarse (MESC), and root weight (RW) of parents and F1 were decreased, however, mesocotyl length (MESL), coleoptile length (COLL), mesocotyl and coleoptile total length (MESL+COLL), mesocotyl length: coleoptile length ratio (MESL/COLL), coleoptile coarse (COLC), seedling weight (SDW), mesocotyl weight (MESW), and coleoptile weight (COLW) were increased; The Pearson correlation and PCA (principal component analysis) showed that the synergies or antagonisms of among 13 traits formed the response mechanism of maize deep-seeding tolerance. The 13 traits displayed obviously, F1 heterosis index were 90.97%~175.64%; Except for MESL/COLL and COLW, other traits showed positive mid-parent and over-parent heterosis. Thus, to improve maize breeding efficiency, it is necessary to pay attention to the selection of main basic materials, namely high-parent, middle-parent, and female-parent, as well as the influence of heterosis should be considered. The additive genetic effect of MESL, COLL, MES+COLL, MESL/COLL, and RL were predominated, these traits could be modified in early generations by simple backcross or single cross recombination; Other traits displayed additive and dominance main effects, and interaction effects with environment, these traits could be modified at specific sowing depths to reflect their heterosis. The general and special combining abilities of parents and F1 in 13 traits had significant differences, 8802A male-parent with good comprehensive additive effect value was screened, H21×8802A progeny may have the potent to improve and develop some elite deep-seeding tolerant maize materials. The study would be helpful for maize deep-seeding tolerance breeding.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 567-575. https://doi.org/10.11869/j.issn.100-8551.2021.03.0567Eucalyptus is a very important economic tree species in southern China. However, most cultivated Eucalyptus is sensitive to abiotic stresses such as low temperature, drought and salinity, which limit its planting region and the improvement of cultivation benefits. EgrNAC1 (Eucgr.I00058) is a NAC-like transcription factor gene in Eucalyptus grandis which is induced by low temperature, drought and salt treatment. To further explore its function in abiotic stress response, homozygous transgenic lines that overexpressed EgrNAC1 were obtained by ectopic expression in Arabidopsis thaliana. And, subjected to low temperature(-6℃), drought, high salt(300 mmol·L-1 NaCl)and ABA(0.5 μmol·L-1) treatment, the responses of transgenic lines to these abiotic stress were analyzed. The results showed that overexpression of EgrNAC1 in Arabidopsis could increase the tolerance of plants to low temperature. After 12 hours treatment at -6℃ and then 5 days of recovering, the survival rate of the transgenic lines of EgrNAC1-OE1 and EgrNAC1-OE8 were 88.9% and 81.5% respectively, while only 29.6% for wild type. Further analysis showed the expression levels of three CBF pathway related genes AtCBF1, AtCBF2 and AtRD29A were significantly up-regulated in the EgrNAC1 over-expression lines under low temperature. On the other hand, sensitivity to drought and salinity in transgenic plants were increased and ABA sensitivity showed a decrease compared to wild type These results implied that EgrNAC1 possibly act as a positive regulator in the low temperature response through regulating the expression of genes invoved in ICE-CBF pathway in Eucalyptus grandis, thereby improving the resistance of plants to low temperature stress. However, under drought and high salt stress, EgrNAC1 may play a negative regulatory role, and ABA signal transduction possibly be involved in this regulation process. This study provides valuable information for elucidating of the function of EgrNAC1 and benefits for molecular-assisted breeding of abiotic stress-resistance in Eucalyptus.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 576-585. https://doi.org/10.11869/j.issn.100-8551.2021.03.0576In order to select the most stable reference genes in Cypripedium japonicum for real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), the reference genes —IF3I1、CYP22、RPS4、UPL1、UBC2、TUBB3、RPL26B、RAN1、SAMDC、ACT3、PP2A3、EF1 were evaluated by RT-qPCR、geNorm、NormFinder and BestKeeper programs. Furthermore, two target genes SERK2 and ASK1were selected to verify the reliability of the suitable reference genes. The result showed among 9 samples analyzed, CYP22, UBC2, TUBB3 and RPS4 were the most stable genes. PP2A3, TIF3I1 showed the best expression stability in different tissues, while SAMDC and ACT3 were the least stable genes. The expression stability of TUBB3, UBC2 was the best in seeds and the most unstable genes were RAN1 and ACT3. And then, the target genes were chosen to verify the stability of TUBB3、UBC2、TUBB3+UBC2 and ACT3 in seeds at different developmental stages. The results suggested that the two target genes showed consistent expression profiles when normalized by the two reference genes TUBB3 and UBC2, while it is failed to standardize the expression data with TCT3 This study helps to improve the accuracy of gene expression analysis, and provides a theoretical basis for the selection of other internal reference genes of Cypripedium.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 586-594. https://doi.org/10.11869/j.issn.100-8551.2021.03.0586Dof protein was one of one zinc-finger structural protein families, which played an important role in plant growth and abiotic stress. In order to explore the function and expression characteristics of PheDof2 transcription factor in moso bamboo. The cDNA sequence of PheDof2 gene was cloned by RT-PCR from moso bamboo seedlings. The bioinformatics of PheDof2 were preliminary analyzed and it’s expression in moso bamboo shoots, flowers, and abiotic stress treatments of moso bamboo seedlings were analyzed. The result of sequence analysis showed that the open reading frame (ORF) of PheDof2 gene was 1 614 bp, encoding 527 amino acids, the molecular weight and isoelectric point of the encoded protein were 53.20 kDa and 5.37, respectively, which had a typical zf-dof domain. Bioinformatics analysis showed that PheDof2 possessed two exons and an intron, and multiple abiotic stress and photoresponsive elements were present in the promoter sequence. The evolutionary analysis showed that PheDof2 protein had close relationship with that in Brachypodium distachyon, the similarity was 79.05%. Quantitative real-time PCR showed that PheDof2 had the highest expression in leaf followed by in the root and the lowest in stem, taking participate in shoots rapid growth and flower development of moso bamboo. That revealed that PheDof2 was tissue specific expression gene. Under drought treatment, the expression level of PheDof2 in roots reached peak at 12 h, and the expression in young stems decreased to the lowest after 24 h treatment. With drought and ABA treatments, PheDof2 in the leaf was reduced to minimum at 6 h. These results showed that PheDof2 involved in drought stress and ABA mediated signal pathway of moso bamboo. The research provides a theoretical basis for resistance breeding and functions research of PheDof2 gene in moso bamboo.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 595-604. https://doi.org/10.11869/j.issn.100-8551.2021.03.0595To study the systematic transcriptomic changes of human erythroleukemia cells (HEL) stimulated with polysaccharide fraction of Sargassum fusiforme (SFPS Ⅱ). HEL cells were treated with SFPS Ⅱ for 24 hours, the differentially expressed genes was analyzed by transcriptome technology. The genes were analyzed with Gene Oncology (GO) Term and Kyoto Encyclopedia of Gene and Genomes (KEGG) to screen the significantly enriched signals. The differently expressed genes were verified with the real-time quantitative PCR (RT-qPCR). After treated with SFPS Ⅱ, the cell proliferation of HEL cells were inhibited, cell viability was reduced in a concentration-dependent manner, while showed less toxic effect in normal human embryonic lung (MRC-5) cells. Compared with the control, a total of 1 248 differentially expressed genes (DEGs) were identified, including 219 up-regulated genes and 1 029 down-regulated genes. GO analysis indicated that differentially expressed genes mainly exercised in the molecular functions of DNA conformation change, sulfate transmembrane transport, response to tumor necrosis factor and regulation of extrinsic apoptotic signaling pathway. Pathway enrichment analysis showed that these genes involving in Rap 1 signaling pathway and immune response. Finally, with 16 DEGs which were randomly selected, and confirmed by RT-qPCR, the differentially expressed genes resulted from SFPS Ⅱ treating in HEL cells were significantly correlated with the biological processes and signaling pathways related to cancer. That could provide a theoretical basis for revealing the antitumor mechanism of sulfated polysaccharide from Sargassum fusiforme.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 605-612. https://doi.org/10.11869/j.issn.100-8551.2021.03.0605
In order to compare the differences of different clones of diploid and tetraploid Robinia pseudoacacia tissue culture plantlets, the morphological and physiological indexes of the diploid and artificially induced tetraploid tissue culture plantlets of Robinia pseudoacacia were determined and analyzed. The results showed that the growth and stress resistance of most tetraploid Robinia pseudoacacia clones were better than that of diploid clones; there were abundant variations between and with diploid and tetraploid Robinia pseudoacacia clones in different morphological and physiological indices, but the variation of tetraploid Robinia pseudoacacia was more abundant; there were complex correlations among the tested indices. Comprehensive consideration should be taken in selection and breeding. According to the results of the experiment and the breeding objectives, the excellent tetraploid Robinia pseudoacacia clones can be selected to enrich the germplasm resources of Robinia pseudoacacia and increase its genetic diversity.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 613-622. https://doi.org/10.11869/j.issn.100-8551.2021.03.0613Haematococcus pluvialis (Chlorophyta) is the optimal organism for producing strong antioxidant astaxanthin. Carbon source is one of the most important factors affecting astaxanthin production in H. pluvialis. In order to investigate the role of CO2 and sodium acetate (NaAc) on the growth and astaxanthin accumulation, the effects of two carbon sources on the algal dry weight, astaxanthin content, activities of growth-related enzymes and the transcriptional levels of related genes in H. pluvialis. were compared by biochemical determination and real-time quantitative PCR methods Results showed that at green vegetative stage, the dry weight of this algae was 1.81 times in 0.16% CO2 group relative to that of the control group on day 8; soluble protein content and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity was significantly increased; the activities and transcriptional expression of phosphoenolpyruvate carboxylase (PEPC) and malate dehydrogenase (MDH) were up-regulated by the high CO2 concentration. The dry weight of NaAc group was 1.56 times of that in the control group on day 8; Rubisco activity and its large subunit mRNA content were repressed, yet the activities and their transcriptional levels of PEPC and MDH were promoted by the addition of NaAc at green vegetative stage. At red cyst stage, the alga grew well, and its biomass and astaxanthin production were 1.96 times and 2.40 times of those in the control group on day 8, respectively, the mRNA levels of three astaxanthin synthesis-related enzymes were higher than control group on day 3 by high CO2 concentration, and the activities of Rubisco, PEPC, MDH were higher than those in the control group. However, the biomass and astaxanthin yield in the NaAc group were 1.54- and 1.85- fold higher of the control group on day 8, respectively; some algal cells began to turn red, meanwhile, the mRNA levels of three astaxanthin synthesis-related enzymes were increased rapidly on day 1; PEPC and MDH activities were stimulated, yet Rubisco activity was depressed in the NaAc group. In summary, the addition of CO2 or NaAc significantly promoted the accumulation of biomass and astaxanthin in H. pluvialis; CO2 was effective in maintaining the algal cell activity, while NaAc accelerated the astaxanthin accumulation. This work provides a reference for the astaxanthin production practice in H. pluvialis.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 623-634. https://doi.org/10.11869/j.issn.100-8551.2021.03.0623Black spot is one of the most important diseases in cruciferous vegetables and caused by the fungi of Alternaria species. The process of Alternaria spp. invading plants is divided into two steps, the first step is to induce programmed cell death of the plant cells in the infected area by releasing toxins, and then to decompose the dead cells by cell wall degrading enzymes. Meanwhile, plants can resist the infection of the fungi by the innate immune system, plant endogenous hormones and phytoalexins. This paper reviewed the interaction process of cruciferous plants and Alternaria spp., and the changes of the genomic (pathogenic and resistant genes), transcriptomic (regulatory factors), metabolic (toxins and phytoalexins) and proteomic (enzymes) in both plants and fungi during this process and their interaction mechanisms, which might provide valuable information for the breeding of cruciferous vegetables against black spot disease.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 635-642. https://doi.org/10.11869/j.issn.100-8551.2021.03.0635In order to explore the characteristics and influencing factors on stable isotopes of Qinghai rape honey, a detection method using elemental analysis-stability isotope ratio mass spectrometry (EA-IRMS) was established to obtain the total δ13C value of rape honey and its δ13C, δ15N, δ2H, δ18O values of endogenous proteins. The stable isotope variations of rape honey and its endogenous proteins were analyzed across different years and producing areas in Qinghai. The relationship between stable isotope of endogenous protein in rape honey endogenous protein and the origin environment was also discussed. The results showed that the δ13C and δ15N values of endogenous proteins in Qinghai rape honey were considerably stable, and there were no significant differences among different years and different origins. The δ18O values of inter-annual in endogenous proteins of rape honey samples were significantly different, as well as δ18O and δ2H values of endogenous proteins from different regions. For the environment factors, δ18O value in endogenous proteins of rape honey was negatively correlated with precipitation during the production season (r=-0.822). The results of this study provided theoretical basis and technical support for the authenticity identification and origin traceability of Qinghai rape honey.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 643-650. https://doi.org/10.11869/j.issn.100-8551.2021.03.0643In order to develop potato whole flour resources with high-quality, scanning electron microscope (SEM), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were employed to investigate the differences in processing properties, thermodynamics and structural properties of potato flour modified by ultrasonic technology and propylene oxide. The results demonstrated that the solubility of potato flour modified by ultrasound (UF, 18.33%) and propylene oxide (HF, 17.33%) were significantly higher than that of untreated potato flour (PF). The drainage power of UF and HF (both 0.28%) were significantly lower than that of PF, while transparency increased to 76.90% and 90.14% for UF and HF, respectively. The iodine blue value of UF and HF (8.10 and 6.61) also decreased significantly compared to PF(P<0.05). Moreover, the diffraction peaks of UF, HF and PF were similar in shape, and the reactions mainly occurred in amorphous regions. SEM images revealed that UF and HF exhibited obvious bonding phenomenon with disappearance of debris and floccule. In a word, the crystallinity, solubility, freeze-thaw stability, transparency and thermal stability of the two kinds of modified potato flour were improved, while the iodine blue value reduced, thus improving the processing quality of potato flour. This study provides a theoretical basis for the development and utilization of potato flour.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 651-659. https://doi.org/10.11869/j.issn.100-8551.2021.03.0651In order to prepare Skipjack tuna seasoning with good flavor, Skipjack tuna cooking liquor (STCL) was used as raw material in this experiment. Based on enzymolysis and deodorization, electronic nose and sensory evaluation combined with principal component analysis (PCA) and linear discriminant analysis (LDA) were employed to aoptimize the Maillard progress of Skipjack tuna cooking liquid. At the same time, the amino acid composition and essential amino acid nutrition of Maillard product from enzymatic hydrolysate were also analyzed. The results showed that the electronic nose combined with LDA exhibited more capability of distinguish difference in the odor changes of Maillard reaction products than PCA analysis. The optimal conditions of Maillard reaction of Skipjack tuna cooking liquid were as follows: xylose-glucose ratio,1:2; heating temperature,110℃; reaction time, 45 min. Under these conditions, the product was yellow-brown with rich fish flavor. The total amino acids amount was 7.036 g·100 g-1, and the essential amino acids content was 2.888 g·100 g-1. EAAI was 64.034, and the value of nutrition was high. Thus, it is an ideal material for developing Skipjack tuna seasonings. The results provide theoretical basis for the development of Skipjack tuna seasoning.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 660-666. https://doi.org/10.11869/j.issn.100-8551.2021.03.0660In previous studies, the inhibiting activities of the commercially available chitosan on the fungus was significantly improved after hydrolysis. For the development of the fungicidal activities, chitosan hydrolysates was prepared using chitosanase from fermentation of Bacillus cereus ncps116 in this study. The fungicidal activities and reducing sugar content were analyzed in the process of enzymatic hydrolysis with time going. The most active hydrolysate was chosen to be tested the minimum antibacterial concentration and the optimum pH. Inhibition to the hyphae and spore was investigated under electron microscopy. The results showed that the activity was increased by the hydrolysis. It increased firstly and then decreased with time going within 24 h, which was related to sugar content. The hydrolysates with too low (≤44.24 μg·mL-1) or too high (≥1 900 μg·mL-1) reducing sugar content, which mean that hydrolysis was insufficient or complete, showed bad activities with he diameters of the inhibtion zone around 13 and 9 mm, respectively. The hydrolysate at 6 h showed the most significant fungicidal activities, which affected the growth of the tested pathogenic fungi, including Verticillium dahliae, Physalospora piricola, Fusarium oxysporum f.sp. niveum, with a 4 to 8-fold improvement at minimum fungicidal concentration around 0.125%~0.250%. The concentration of reducing sugar was tested to be 383.34 μg·mL-1. Besides, the hydrolysates exhibited the most high antifungal bioactivity at pH 4.0~4.7. Furthermore, the hydrolysates could cause disrupt and abnormal growth of fungal hyphae, such as folds and vesicles. And the inhibition to the spore and mycelial growth was irreversible for a long time. In a word, the hydrolysis could significantly improve the fungicidal activities of chitosan, which provided a research basis for the further application on chitosan in agricuture.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 667-673. https://doi.org/10.11869/j.issn.100-8551.2021.03.0667Food-borne pathogens and spoilage bacteria are the main causes of food-borne diseases and food spoilage. Traditional food preservation agents, such as fungicides and preservatives, not only destroy the unique flavor of food, but also cause chemical pollution, which are harmful to human’s health. As a new type of green "non-thermal" processing technology, irradiation has the characteristics of low environmental impact, safety, convenience and high efficiency, and it has been widely used in food processing industry. Based on recent domestic and international research progress, this manuscript described the mechanisms and advantages of food irradiation and sterilization technology as well as its application in processing meat products and degrading harmful residues. In addition, the factors that affect the irradiation effects on meat products were discussed to provide references for further development of irradiation technology in meat products processing and preservation.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 674-680. https://doi.org/10.11869/j.issn.100-8551.2021.03.0674In order to study the nitrogen uptake and distribution pattern in different kinds of soybean varieties, four kinds of mainly-planted soybean varieties in Sanjiang plain of Heilongjiang province were used as test materials, and15N tracer method of leaves nitrogen application in R5 period was adopted to investigate the nitrogen uptake and distribution of different kinds of soybean varieties and organs. The results showed that the dry matter accumulation, nitrogen accumulation and marked nitrogen accumulation of soybean organs reached the highest level on the nitrogen application of 4.5 kg·hm-2. In different type of varieties, the dry matter accumulation of Hefeng 50 (the emi-determinate and sharp leaf variety) reached the highest level on organs of roots, stems and leaves. The dry matter accumulation of Hefeng 48(the emi-determinate and round leaf variety) reached the highest level on organs of petioles, pod skin, seeds and the whole plant. The nitrogen accumulation of Henong 64(the indeterminate and round leaf variety) reached the highest level on organs of roots, stems, leaves, seeds and the whole plant. The nitrogen accumulation of Hefeng 55(the indeterminate and sharp leaf variety) reached the highest level on organs of petioles and pod skin. The marked nitrogen accumulation of Hefeng 48 (the emi-determinate and round leaf variety) got the highest level on organs of roots, stems and petioles. The marked nitrogen accumulation of Henong 64 (the indeterminate and round leaf variety) reached the highest level on leaf organs and Hefeng 55 (the indeterminate and sharp leaf variety) reached the highest level on seed organs. The marked nitrogen accumulation and distribution ratio reached the highest level in the same treatment on organs of roots, leaves, petioles and pod skin. As well, the highest levels of marked nitrogen accumulation and distribution ratio were not in the same treatment on organs of stem and seeds. The results of this study provided a theoretical basis for the leaf nitrogen utilization mechanism and production application of leaf nitrogen fertilizer in different soybean variety types.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 681-687. https://doi.org/10.11869/j.issn.100-8551.2021.03.0681Mecoprop is a chiral auxin herbicide possessing one chiral center and two enantiomers and R-MCPP exhibits more significant herbicidal activity than S-MCPP. In order to Fig out the differences of absorption and metabolism of MCPP enantiomers in dicotyledons, the experiment an absorption, translocation and subcellular distribution of 14C-MCPP enantiomers in Arabidopsis thaliana had been carried out under laboratory conditions with 14C-MCPP enantiomers as tracer agent and Arabidopsis thaliana as plant material. The result showed that the plant took up the two enantiomers differently, with the absorption ratio of 85.75%(S-MCPP) and 90.45%(R-MCPP). As for translocation, R-MCPP had an increased translocation capacity with longer translocation time before equilibrium state and higher translocation ratio. Once reaching the balance, the translocation ratio of R-MCPP was 1.5 times greater than that of S-MCPP. Subcellular distribution test indicated that more of two MCPP enantiomers existed in the cytoplasm, followed by in cytoderm and organelle. The distribution ratio of S-MCPP (39.60%) in cytoderm was higher than that of R-MCPP (28.74%), indicating higher fixation of S-MCPP in cytoderm. Whereas the R-MCPP in organelle was 10.55% higher than 4.11% for S-MCPP, indicating that some herbicidal receptors were easier to be exposed to R-MCPP. According to the above results, the research, to a certain extent, elucidated the significant enantioselectivity of chiral MCPP on herbicidal activity in model dicotyledon Arabidopsis thaliana.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 688-696. https://doi.org/10.11869/j.issn.100-8551.2021.03.0688In order to investigate the effects of different early and late rice combinations on growth characteristics, yield formation and rice quality under double-cropping and direct seeding conditions, three early rice varieties (QLY2012, TLY 83, XZX45) and two late rice varieties (YY1538 and TY398) were used as experimental materials in this experiment. Four combination modes were designed, inbred indica rice XZX45 planted as control treatment (CK): XZX45-XZX45; Early indica-Late japonica (M1): QLY2012-YY1538; Early Indica-Late Indica (M2 same variety planted as early rice and late rice): QLY2012 - QLY 2012; Early Indica and Late Indica (M3 different varieties planted as early rice and late rice): TLY83 - TY398, with control (CK): XZX45-XZX45. The annual growth period, population quality, yield composition, annual yield, rice quality and RVA characteristic spectrum of rice starch were studied. The results showed that, these combinations were all heading safely, and the longest annual growth period was M1 (222 days), which was 16 days longer than CK; the highest annual total yield was M1 (14.82 t·hm-2), which increased 1.56 t·hm-2 compared with CK, with an increase rate of 11.76%; the second was M2, its annual total yield was 14.29 t·hm-2, which increased by 1.03 t·hm-2 and the growth rate was 7.77% compared with CK, and the annual total yield of M3 increased by 5.28% compared with CK. The analysis on the characteristics of population quality and yield components of different early and late rice collocation modes in double-cropping and direct-seeding rice, showed that the collocation mode with higher annual yield had the characteristics of large dry matter accumulation from heading stage to maturity stage, large leaf area index from booting stage to maturity stage, large spike size, high seed setting rate and daily yield of early and late rice. M1, M2 and M3 treatments had better rice quality and RVA profile than CK, but no significant difference was observed in early rice. Generally speaking, the collocation mode (M1) guarantees annual yield, and rice quality is better than other modes, which can provide a reference for portable cultivation of double-cropping rice.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 697-703. https://doi.org/10.11869/j.issn.100-8551.2021.03.0697This study aims to explore the effect of biogas fertilizer combined with mechanical deep application on aggregates distribution, soil organic carbon content and mineralization characteristics in Citrus orchard. Five treatments were designed as the regular fertilizing as control (CK, chemical fertilizer, 2500 kg·hm-2), and four biogas fertilization treatments (T1, T2, T3 and T4), with the amount of 45, 135, 180, and 270 t·hm-2 to detect the distribution of SOC. Moreover, mineralization characteristic was determined by laboratory culture test. The result showed that the mean weighted diameter (MWD) of soil aggregates was significantly increased by biogas fertilization, as compared with CK, with the increase amplitude of 76.9%, 35.8%, 26.9% and 33.6%, respectively. The content of soil organic carbon was from 10.09 to 14.38 g·kg-1 in treatments, with T3 being the highest, followed by T4. The distribution of organic carbon in soil aggregates was different among treatments; the soil aggregates in diameter of 0.25-2 mm was the main organic carbon carrier in CK, T3 and T4; and soil aggregates in the diameter of >
5 mm was the main organic carbon carrier in T1 and T2. The SOC mineralization rates were higher at the initial stage (15 d) from 168.42 to 190.84 mg CO2-C·kg-1 among treatments, leading the SOC mineralization was more than half of the total cumulative amount (58.46%~62.09%). Combined with the simulated results of kinetic equation, the ratio of potential mineralization of organic carbon (C0) and easy mineralization of organic carbon (C1) in total soil organic carbon was low in T3 and T4, indicating that the organic carbon of orchard soil could be increased by mechanical deep application of biogas fertilizer. This study could provide a scientific basis for rational application of biogas fertilizer in Citrus orchard. -
Effects of Combination of Reduced Chemical Fertilizer and Chinese Milk Vetch on Rice Yield StabilityJournal of Nuclear Agricultural Sciences. 2021, 35(3): 704-713. https://doi.org/10.11869/j.issn.100-8551.2021.03.0704In order to investigate effects of long-term combination of reduced chemical fertilizer with various amounts of Chinese milk vetch (Astragalus sinicus L.) on rice yield and rice yield stability. Based on a 10-year long-term experiment, the respond of rice yield and its change trend, rice yield stability, contribution rate of fertilizer and soil nutrient to ten fertilization patterns were analyzed: non-fertilization (CK), chemical fertilizer (100%F), 20% reduced chemical fertilizer combined with 22 500 kg·hm-2 A. sinicus (80%F+GM1), 20% reduced chemical fertilizer combined with 30 000 kg·hm-2 A. sinicus (80%F+GM2), 20% reduced chemical fertilizer combined with 37 500 kg·hm-2 A. sinicus (80%F+GM3), 20% reduced chemical fertilizer combined with 45 000 kg·hm-2 A. sinicus (80%F+GM4), 40% reduced chemical fertilizer combined with 22 500 kg·hm-2 A. sinicus (60%F+GM1), 40% reduced chemical fertilizer combined with 30 000 kg·hm-2 A. sinicus (60%F+GM2), 40% reduced chemical fertilizer combined with 37 500 kg·hm-2 A. sinicus (60%F+GM3), and 40% reduced chemical fertilizer combined with 45 000 kg·hm-2 A. sinicus (60%F+GM4). Results showed that fertilization significantly increased the annual average yield of rice. The rice yield of 20% and 40% reduction of chemical fertilizer combined with A. sinicus increased by 36.81%-40.07% and 6.27%-8.80% compared with no fertilization and chemical fertilizer, respectively. The results of stability parameter based on AMMI model showed that, under the conditions of reduced 20% and 40% chemical fertilizer, the yield stability was the best when combined with the application of 45 000 kg·hm-2 A. sinicus, followed by 37 500 kg·hm-2 A. sinicus. The fertilizer contribution rate of reduced chemical fertilizer combined with A. sinicus increased by 4.55%-6.42% compared with chemical fertilizer, with the treatment of reduced 40% chemical fertilizer combined with 37 500 kg·hm-2 A. sinicus being the highest. The contribution rate of fertilizer was very significantly negatively related to the contribution rate of soil fertility (P<0.01). Reduced chemical fertilizer combined with A. sinicus significantly increased the contents of soil organic matter, alkali-hydrolyzed nitrogen and available phosphorus. Rice yield was very significantly positively correlated with soil organic matter, alkali-hydrolyzed nitrogen and available phosphorus (P<0.01), and rice yield stability parameter was very significantly negatively correlated with soil alkali-hydrolyzed nitrogen (P<0.01). Considering the benefits of high yield, stable yield of rice and reducing the usage of chemical fertilizer, we determined that applying 60% chemical fertilizer combined with 37 500 kg·hm-2 A. sinicus was the optimum fertilization pattern. Our findings can provide scientific guidance for reasonable fertilization in the rice-growing area of south Henan province.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 714-721. https://doi.org/10.11869/j.issn.100-8551.2021.03.0714Annual Populus×euramericana Neva was applied as the studying material, and the magnetic device was used to manage the 1/2-Hoagland nutrient solution containing 0 or 100 mol·L-1 Cd(NO3)2·4H2O four groups performed in our study. The nitrogen content, nitrogen key metabolic enzyme activity, amino acid content and root morphological characteristics in different tissues were measured by lab analysis, aiming to explore the effect of magnetic treatment of irrigation water on nitrogen metabolism in Populus×euramericana Neva seedling stage under cadmium stress. The results were as follows: The content of $NH_4^+$-N, $NO_3^-$-N, and TN in leaves increased by magnetic treatment when exposed to cadmium stress. Similarly, $NH_4^+$-N and TN content in the roots was also promoted by the magnetization, while $NO_3^-$-N content was decreased. The activities of NR, NiR, GR, GOGAT in the leaves, and the enzyme activities of NR, GS and GOGAT in the roots were stimulated by the magnetic treatment under Cd stress. On the contrary, the activity of NiR in roots was inhibited by the magnetization. The magnetization improved the synthesis of Cys and Gln in leaves, and reduced the content of Glu and Gly when stressed to Cd conditions. Meanwhile, magnetization promotes the synthesis of Cys, Glu, Gln and Gly in the roots. The magnetic treatment induced a promotion in the root system and was beneficial to the formation of root morphology by Cd exposure. The above results indicated that magnetization can regulate the absorption and transportation of mineral nutrients by affecting root morphology. The synthesis of nitrogen assimilation and free amino acids can be improved by stimulating the key enzyme activity of nitrogen metabolism, which is of great significance for poplars to adapt to the stress conditions performed by the heavy metal.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 722-736. https://doi.org/10.11869/j.issn.100-8551.2021.03.0722Two indica rice varieties (conventional indica rice Huanghuazhan and hybrid indica rice F you 498) were used to investigate the effect of seeding densities (50g/plate and 100g/plate) and seeding methods (mechanized drilling seeding, mechanized broadcasting, artificial broadcasting) on tillering characteristics of machine--transplanted rice. The results showed that 4/0 to 9/0 and 4/0 to 8/0 of the main stem were the dominant leaf positions for formatting primary tillers and effective tillers, respectively, which contributed to approximately 50% of grain yield. The superior leaf position for secondary tillers group emergence was 3/0 to 7/0, and 4/0 to 7/0 for ear-bearing, which contributed 30.20% to yield. The 5/0 leaf position was superior in formatting the primary and secondary effective tillers. Among different sowing methods, the tiller emergence rate and effective tillers percentage of mechanized drilling were higher than those of mechanized broadcasting and artificial broadcasting. The largest and smallest contribution to the yield of superior leave positions for primary tillers was the mechanized broadcasting (51.90%) and mechanized drilling seeding (46.50%), respectively. Mechanized drilling seeding made the largest yield contributions rate of secondary tillers in dominant leaf position (33.30%). Compared to 50 g/plate, 100 g/plate treatment led a higher contribution percentage of main stem and primary tillers, but a lower contribution percentage of secondary tillers. Mechanized drilling with lower seeding density increased the number of grains per panicle and 1000-grain weight between the main stem, the primary and the secondary tillers, which possessed higher effective tillers percentage of secondary tillers. Overall, the coordinated regulation of mechanized drilling with sparse sowing density could improve rice yield by increasing the emerging and effective percentage of tillers at the superior leaf positions. The results of this study can be used to select better seeding methods for machine-transplanted seedlings, and provide a theoretical and practical basis for the rational use of dominant leaf position of machine transplanting.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 737-744. https://doi.org/10.11869/j.issn.100-8551.2021.03.0737To investigate effect of mulching on ridge-furrow for harvesting rainwater on the activity and gene expression of starch synthesis key enzyme and starch accumulation of rain-fed potato tuber during tuber formation, using Qingshu 9 as experimental material, the cultivated patterns included whole plastic mulching on double ridges and single ridge mulching with plastic film, the bare land flat sowing was set as control. The activity and gene expression of key enzymes in starch synthesis and starch accumulation indexes were determined by Ultraviolet-Visible Spectrophotometer and Fluorescence Quantitative PCR. The results showed that, compared with the control, under the whole plastic mulching on double ridges and single ridge mulching with plastic film, the soluble starch synthase (SSS) activity was increased significantly by 77.70% and 22.63%, respectively, and SSIII gene expression was increased significantly by 32.26% and 119.35%, respectively. Meantime, the activity of ADP-glucose pyrophosphorylase (AGPP), granule-bound starch synthase (GBSS) and ADP-glucose pyrophosphorylase AGPase, soluble starch synthase SSII, granule-bound starch synthase GBSSI, starch branching enzyme SBEI, and starch branching enzyme SBEII gene expression levels showed significant decrease, but the activity of starch branching enzyme (SBE) was not affected during the whole process of potato tuber formation. Compared with the control, the total starch content, amylase content and ratio of amylose to amylopectin were increased significantly by 5.04%, 17.57% and 27.81% under the whole plastic mulching on double ridges, respectively, while the starch accumulation index was decreased significantly by single ridge mulching with plastic film. SSS enzyme activity showed a significant negative correlation with GBSSI gene expression, and a significant positive correlation with amylase content and amylose to amylopectin ratio. The other key enzyme activity showed no significant correlation with the key enzyme gene expression and the starch accumulation index. The results are of great significance for selecting production measures of potato with high quality starch in the eastern arid area of Qinghai province.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 745-752. https://doi.org/10.11869/j.issn.100-8551.2021.03.0745In order to improve the added value of Ginkgo biloba leaves and reduce environmental pollution, humic acid content was used as evaluation index, and the single-factor orthogonal test was used to optimize the process parameters of EM strain to ferment Ginkgo biloba residue to prepare bio-organic fertilizer, the relevant components in organic fertilizer were also determined. Meanwhile, the efficiency of organic fertilizer for Ginkgo biloba residue was verified.Results showed that the optimized solid state fermentation process of organic fertilizer were fermentation duration 6 days, mate rial-liquid ratio 71.43%,Ginkgo biloba addition amount 26.95%, and glucose addition amount 1.62%. Under this condition,the content of humic acid was 39.36%. The effective living bacteria, organic matter and heavy metal content was in accordance with NY884-2012 biological organic fertilizer standards, which increased the germination index of Brassica Chinensis seeds, and promoted the development of Brassica Chinensis seedlings’ root system and plant were confirmed by hydroponic and pot experiments.After futher analysis,Brassica Chinensis seedlings were promoted by activating seedlings’ rhizosphere dehydrogenase and nitrate reductase, and quality of Brassica Chinensis were improved by promoting the accumulation of proline, soluble sugar, total flavonoids, and titratable acids in the cabbage seedlings. Therefore, Ginkgo biloba bio-organic fertilizer possesses practical application value to applied and popularized in agricultural production.
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Journal of Nuclear Agricultural Sciences. 2021, 35(3): 753-759. https://doi.org/10.11869/j.issn.100-8551.2021.03.0753In order to investigate the alleviation of maize seeding by soaking sugar to copper stress, maize was taken as experimental materials to study the effects of 342.3 mg·L-1 sucrose soaking treatments on the physiological and biochemical indexes of maize seedlings treated with 0, 100, 200, and 400 mg·L-1 CuSO4, then Grey Correlation Analysis of between the physiological and biochemical indexes and recovery index of maize under copper stress were carried out. Our results showed that, sugar soaking could significantly improve plant height, relative plant height,root length, relative root length, superoxide dismutase (SOD), peroxidase (POD), and hydrogen peroxide(CAT) of maize seedlings. The ranking of grey relational degree of physiological and biochemical indexes and recovery index of maize under copper stress was: relative root length(0.799)> relative plant height (0.775)> root length(0.767)> proline content(0.749)>POD(0.74)> soluble protein content(0.699)> soluble sugar content(0.673)>CAT(0.664)> chlorophyll content(0.647)>SOD(0.601)> plant height(0.579). Thus, sucrose immersion could effectively relieve copper stress of maize seedlings to some extent. In order to improve the selection efficiency on copper resistance of sucrose soaked maize seed, we should strengthen the selection of strong correlation indexes such as relative root length, relative plant height, root length, proline content, POD, soluble protein content, soluble sugar content, CAT and so on. These results provide references for maize resistance breeding.
