10 October 2019, Volume 33 Issue 10
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1883-1892. https://doi.org/10.11869/j.issn.100-8551.2019.10.1883In order to explore and utilize rice resistant blast germplasms, a total of 67 Zhangpu wild rices from 2 natural populations in Fujian Province were assessed for blast resistance of seedling, leaf and panicle by natural infection, and the resistant blast genotypesby were detected functional molecular markers of resistance genes Pi9, Pid2, Pi5, Pi2, Pi54 and Pikm. The results showed that there was a obvious difference of blast disease grade in various growth stages, and the coefficient of variation ranged from 31.65% to 43.46%.The average blast disease grade was 7.51, 5.15 and 5.84 at seedling, tillering and maturing stage, respectively. The blast resistance for three various stages showed no significant difference between 2 natural populations from Shihutan and Gutang. M1044, M2010 and M2016 exhibited moderate resistance(three grade),indicating that Zhangpu wild rice had a poor resistance and was susceptible to blast. The correlation analysis indicated that there was a closely significant positive correlation between seedling and leaf blast, with the correlation coefficient of 0.82. Panicle neck blast was highly significantly correlated with both seedling and leaf blast, and the correlation coefficients were 0.33 and 0.41, respectively. Among 67 Zhangpu wild rice materials, 4 rice accessions owned Pi9, 17 accessions have PiS, 23 accessions have Pi54 and 2 materials have Pik. None had both Pi2 and Pid2 resistant genes. The number of resistant genes in these materials ranged from 0 to 3, among which 30 materials did not contain the tested resistance genes, 29 rice materials contained 1 resistance gene, 7 materials had 2 resistance genes and 1 accesion contained 3 resistance genes.These results can provide a theoretical reference for further excavation and utilization of Zhangpu wild rice germplasms.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1893-1904. https://doi.org/10.11869/j.issn.100-8551.2019.10.1893In order to further understand the molecular mechanism of stress regulation of tomato ERF transcription factor, two ERF genes, SlERF83 and SlERF109, were cloned from tomato cultivar Zheza-301 in this study, their sequence and expression were analyzed. The results indicated that the ORF lengths of SlERF83 and SlERF109 tenes were 678 and 669 bp, which encoded 225 and 222 amino acids, respectively. SlERF83 and SlERF109 were hydrophilic proteins and contained a conserved AP2-domain. Phylogenetic analysis showed that SlERF83 and SlERF109 belonged to B1 group of ERF subfamily of AP2/ERF family. SlERF83 and SlERF109 proteins contained one α-helix and three β-sheets according to the protein three-dimensional structure analysis. Yeast one-hybrid and β-galactosidase activity assays demonstrated that SlERF83 transcription factor could bind to GCC-box. Some stress-related cis-elements existed in the promoter regions of SlERF83 and SlERF109 genes. The expression level of SlERF83 and SlERF109 were detected by RT-qPCR. The results showed that the expression level of SlERF83 and SlERF109 genes were inhibited under salt or drought stress. SA induced the expression level of the two ERF genes. MeJA increased the expression level of SlERF83 and decreased the expression level of SlERF109. The expression level of SlERF83 and SlERF109 were downregulated after tomato yellow leaf curl virus infection. These results indicated that SlERF83 and SlERF109 may involve in response to biotic and abiotic stresses in tomato. The results of this study provides a theoretical basis for revealing the molecular mechanism of ERF transcription factor regulating the stress of tomato.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1905-1912. https://doi.org/10.11869/j.issn.100-8551.2019.10.1905The AG gene belongs to the MADS-box family and plays an important role in the determination of floral meristem characteristics and floral organ development. To analysis the gene expression pattern of AG in bamboo, a complete cDNA sequence named BoAG-like was cloned from in vitro flower buds of Bambusa oldhamii by using the rapid amplification of cDNA ends technology. The results showed that: BoAG-like gene was 792 bp in length, prossessed AGI and AGII regions which were unique to the AG gene. The BoAG-like protein shared more than 80% similarity with the AG-like homologous proteins including OsMADS58 of Oryza sativa, ZAG1 of Zea mays, and PhMADS3 of Phyllostachys edulis, all belonged to the euAG line of the C gene. Tertiary structure of BoAG-like protein showed that this protein displayed a similar tertiary structure with OsMADS58 of Oryza sativa and BdMADS18 of Brachypodium distachyon, but still with significant differences. RT-qPCR analysis revealed that the expression level of BoAG-like in flower organs was much higher than that in vegetative organs, and increased with the development of flower organs. The expression level of BoAG-like gene in B. oldhamii was significantly different among different parts of flower buds, with the highest level in the pistil and the lowest in the lemma. This study provides a guideline for further research of the molecular mechanism of bamboo flower development.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1913-1920. https://doi.org/10.11869/j.issn.100-8551.2019.10.1913In order to explore the function of Phosphoglycerate mutase (PGAM) gene in mollusks, a cofactor-dependent PGAM(named McdPGAM) was cloned by RACE-PCR method from individuals of purple and yellow genus of Hyriopsis cumingii. Its sequence characteristics and expression pattern were analyzed. The results showed that HcdPGAM gene contained a 753 bp open reading frame, which encoded a protein of 250 amino acids with a highly conserved histidine phosphatase domain (4-250 aa). HcPGAM protein shared high homology with PGAM from other animals (58.8%-82.0%). RT\|qPCR analysis showed that HcdPGAM was expressed in all of the six examined tissues from the purple-mussels and yellow-mussels, relative higher transcription level was detected in adductor muscle tissue, and significantly higher expression level was detected in the purple-mussels than that of yellow ones, which indicating that HcdPGAM was related to the energy metabolism, growth and development of H.cumingii, and it was a potential marker for selected breeding of mollusks. Moreover, the induction of Aeromonas hydrophila significantly up-regulated the expression level of HcdPGAM gene (at 24 h and 48 h), demonstrating that HcdPGAM gene was also playing an important role in the immune-related energy metabolism of mollusks against bacterial infection. The results of present study providing basic information for further study on the roles of PGAM, and for screening specific molecular markers between different color pedigrees of pearl mussel H.cumingii.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1921-1927. https://doi.org/10.11869/j.issn.100-8551.2019.10.1921WOX (wuschel-related homeobox) is a transcription factor that is only expressed in plants and is involved in a variety of plant development and stress responses. In order to explore the related information of WOX transcription factor in castor bean genome, bioinformatics methods were carried out. 11 members of castor bean WOX transcription factor family were identified and their basic information including phylogeny, gene structure, conserved motif and physicochemical properties were characterized and analyzed. The results showed that 11 members were divided into three phylogenetic branches through phylogenetic relationships. The exons and gene structures shares high similar among same phylogenetic branch members, but their physicochemical properties were different. The RT-qPCR technology was used to detect the expression of 5 castor RcWOXs genes in root, stem and leaf of castor under drought and salt stress. The results showed that the expression of RcWOXs in different tissues was specific; except the expression of RcWOX10 was repressed by drought stress, the expression of RcWOX2, RcWOX4, RcWOX8 and RcWOX9 were up\|regulated induced under stress, indicating that RcWOX transcription factor has a regulatory effect in castor stress. Our data provides a reference for further studies on the function of castor WOX transcription factor family in response to stress.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1928-1939. https://doi.org/10.11869/j.issn.100-8551.2019.10.1928In order to study explore the biological function of transcription factors in Gossypium barbadense fibers, taking the fibers of the Gossypium barbadense for 8 periods as the research object, and reverse-synthesized ds-cDNA by SMART technology. Uniform processing with DSN, and a homogenization yeast cDNA library of sea-island cotton fiber with pGADT7 as a vector was constructed, and the protein interacting with GbTCP5 of Gossypium barbadense was screened by yeast two-hybrid system. The primers containing NcoⅠ and EcoRI restriction sites were designed based on the CDS region of the cloned GbTCP5 gene to construct the bait vector pGBKT7-GbTCP5. Co-transformation of yeast strain Y2HGold after self-activation and toxicity detection, screening for GbTCPS interacting proteins. Real-time PCR showed that the expression of GbTCP5 gene was higher at the beginning and elongation of fiber development, and higher in petals and calyx than other tissues. Through the quality test of the library, the constructed homologous cDNA library has a library capacity of 9.15×107 cfu·mL-1, the recombination rate is 100%, and the insert size is between 500~2000 bp. The bait vector pGBKT7-GbTCP5 was screened and rotated by yeast two-hybrid system, and finally confirmed four interacting proteins, namely GbTCP20, GbTCP42, GbTCP45 and GbAHP1 proteins. The construction and screening of the homogenized cDNA library of the island cotton fiber laid a foundation for further study of the mechanism of the interaction between the Gossypium barbadense cotton transcription factor and its interaction protein during fiber development.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1940-1948. https://doi.org/10.11869/j.issn.100-8551.2019.10.1940In order to investigate the association between Toll like receptor 1 (TLR1) gene and mastitis resistance in Chinese Holstein cattle, a DNA pooling was constructed in Chinese Holstein cattle. The single nucleotide polymorphism (SNP) of TLR1 gene of Chinese Holstein cattle was detected by PCR amplification and direct sequencing, and the SNPs loci which had a significant effect on the immunity of Chinese Holstein cattle were screened. At the same time, the online software was used to predict the function of the protein encoded by the TLR1 gene of Chinese Holstein cattle. The results showed that Chinese Holstein TLR1 gene encodes 727 amino acids and constitutes an unstable water-soluble protein. After PCR amplification, a total of 8 SNPs loci were found in the amplified fragments, namely A61T-TLR1, C632A-TLR1,C1408T-TLR1, C1451T-TLR1, A1461G-TLR1, A1475C-TLR1, G1550A-TLR1 and G1596A-TLR1. Among them, C632A-TLR1, C1451T-TLR1, A1461G-TLR1, A1475C-TLR1 and G1596A-TLR1 resulted in missense mutation. The allele frequencies of SNPs loci with five missense mutations were mutated from the original lysine(Lys), phenylalanine(Phe), alanine(Ala), isoleucine(Ile), andvaline(Val) to methionine(Met), leucine(Leu), valine(Val), valine(Val) and isoleucine(Ile), and the allele frequencies of the five missense mutation SNPs were slightly different before and after the mutation, and the rest are significantly different. The DNA pooling combined with direct sequencing technology to detect 8 SNPs of TLR1 gene, which can be used as a genetic marker for Chinese Holstein cow mastitis. The results of protein function prediction show that there are many factors associated with immune related factors. The results of this study provide a theoretical basis for the resistance breeding of Chinese Holstein cattle in molecular field.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1949-1958. https://doi.org/10.11869/j.issn.100-8551.2019.10.1949The object of present study is to establish a system for evaluating commodity fruit quality and taste in grafted cucumber using pumpkin(Cucurbita moschata)germplasms as rootstock and develop novel pumpkin germplasms for rootstocks. Xin Tai Mi Ci cucumber seedlings, were grafted onto 102 pumpkin rootstocks. 13 indices of morphological and agronomic traits were measured in 102 graft combinations. A comprehensive evaluation method containing principal component, membership functions and system clustering was applied to analyze indices in different graft combinations, with Xin Tai Mi Ci as control. The results showed that 13 indices of morphological and agronomic traits displayed wide variations among the graft combinations. According to principal component analysis, the cumulative contributions rate of the first five principal components reached up to 86.226%. Several indices involved in production, fertility and taste were main factors resulting in differences among the graft combinations. By system clustering analysis, 102 graft combinations were divided into 4 groups. In membership function analysis, seven germplasms including Shi Bing Nan Gua 5Bb636-3(N67) and San He 13-s08z13-3(N91) which have desirable traits were selected as the optimal rootstock among the 102 graft combinations. This study would provide a basis theory for screening suitable pumpkin rootstocks for grafted cucumber and pumpkin breeding.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1959-1966. https://doi.org/10.11869/j.issn.100-8551.2019.10.1959In order to improve the fruit quality of melon, and to identify the characteristics of melon varieties that could satisfy the demanding of most consumer and different market trends, three melon varieties, Cucumis melo L. var. saccharinus Naud. cv. X228, Cucumis melo L. var. makuwa Makino cv. B154 and Cucumis melo L. var. conmmon Makino cv. H227 were selected to investigate the physiological mechanism of sucrose accumulation during fruit ripening. Fruit were sampled at each growth stages, and the fruit soluble solid content (Brix grade) and sugar (glucose, fructose, sucrose) content, as well as activities of sucrose phosphate synthase(SPS), sucrose synthase(SS), acid invertase(AI) and neutral invertase(NI) were measured. Results showed that the sucrose contents were significantly different among the varieties; glucose and fructose were the major sugars and only a little amount of sucrose was accumulated in immature and mature H227 fruits, while sucrose is the major sugar in B154 and X228 fruits. During fruit development, the contents of glucose and fructose in three melon varieties were not changed dramatic ally, and there were no pronounced differences in glucose and fructose contents among three varieties. The sucrose contents in B154 and X228 fruits increased remarkably during fruit development with obvious turning points. Moreover, the rise of sucrose content was accompanied by the increase of SPS activity and the decreases of AI and NI activities, while the relationship between the content of sucrose and SS was not significant. According to the changes of sucrose content in developing melon fruits, melon could be divided into two sucrose accumulation types: sucrose accumulation type, i.e. X228 and B154, and low-sucrose accumulation type, i.e. H227. In the sucrose accumulation type, the sucrose content increased accompanied by the increase of SPS activity and the decrease of AI and NI activities. In the low- sucrose accumulation type, the low sucrose content may be caused by low SPS activity. The results provided the theoretical foundation for the innovative use of melon germplasm resources and the research on regulation of sugar accumulation in melon fruits.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1967-1974. https://doi.org/10.11869/j.issn.100-8551.2019.10.1967To better utilize the invasive plant Ageratum conyzoides L. and improve the freshness preservation of Citrus reticulate Blanc Ponkan, this study screened the optimal nanoscale composite micro-emulsion system based on pseudo-ternary phase diagrams by using A. conyzoides L. essential oil as the oil phase, Tween-80 as the surfactant, ethanol as the cosurfactant, and sodium carbonate and carboxymethyl chitosan solutions as the aqueous phase. Its antimicrobial activities against Penicillium italicum, Penicillium digitatum and Penicillium expansum were assayed at different concentrations (2.5, 5.0, 10.0 and 20.0 mg·mL-1), as well as its C. reticulate Blanc Ponkan contamination inhibitory effect. The fruits of C. reticulate Blanc Ponkan were treated with optimal concentration of the micro-emulsion system to investigate the freshness preservation effect in different storage conditions (25℃ and 4℃). The results showed that the optimal formulation of the compound micro-emulsion system (A80) was A. conyzoides L. essential oil: ethanol: Tween-80: 3% sodium carbonate: 0.5% carboxymethyl chitosan=0.13∶0.38∶0.13∶1∶3 with particle size of 34.47 nm. At concentration of 20 mg·mL-1, the micro-emulsion system exhibites the best antimicrobial activities against P. italicum, P. digitatum and P. expansum, with inhibition rates of 64.86%, 60.23% and 86.96%, respectively. Meanwhile, its contamination inhibition rate for living C. reticulate Blanc Ponkan was 76.48%. The compound micro-emulsion A80 at this concentration level had the best preservation effect on C. reticulate Blanc Ponkan stored at 4℃. After 30 d of storage, the weight loss rate of C. reticulate Blanc Ponkan was 22.24%, while the weight loss rate of control group was 26.47%. Besides, the rotting rate was 11.33%, which was 50% lower than the control group. Treatment of C. reticulate Blanc ‘Ponkan’ with the prepared compound micro-emulsion system of A. conyzoides L. essential oil could not only effectively inhibit microbes and delay the dehydration and weight loss, but also prolong its preservation life of citrus fruits. The results could provide certain theoretical basis for the development of A. conyzoides L. essential oil as natural preservative and for the storage, as well was preservation of C. reticulate Blanc Ponkan.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1975-1982. https://doi.org/10.11869/j.issn.100-8551.2019.10.1975In order to study the effects of heating treatments on the phenolic compounds release and antioxidant activity of lotus leaf during simulated digestion, vacuum microwave, hygrothermal steam and boiling treatments on different growth stages lotus leaf were investigated. The results showed that the release of phenolic substances of lotus leaves was positively correlated with the diameter of the sample, the highest release of total phenolic content (TPC) of 56 cm leaves diameter. Under the different simulated gastric fluid treatment and different heat treatment, the total phenolic contents, total flavonoid contents, the antioxidant capacity of FRAP ( ferric ion reducing antioxidant power) and the ABTS (2, 2?-azino-bis(3-ethylbenzthiozoline-6)-sulphonic acid) radical scavenging was the highest in V56 lotus leave by vacuum microwave. Compared with the control group, the TPC release of lotus leaves under vacuum microwave treatment were higher for simulated gastric fluid treatment. But the TPC release of boiling treated samples was lower than control group. There was no change in the release of the lotus leaf TPC treated by hygrothermal steam treatment of simulated gastric fluid. However, the total flavonoid contents (TFC) release of different heating groups was lower than control group. Both the TPC and TFC release of lotus leaves treated by different heating methods were increased under the simulated intestinal fluid treatment. The FRAP antioxidant capacities of lotus leaves treated by vacuum microwave and hygrothermal steam treatments were increased after simulated gastric fluid digestion, but the FRAP antioxidant capacities of lotus leaves treated by boiling were reduced. The FRAP antioxidant capacities of lotus leaves treated by vacuum microwave were increased after simulated intestinal fluid digestion. The ABTS radical scavenging of simulated gastric fluid digested microwave treated lotus leaves were lower than that treated by deionized water. However, compared with the control group, the ABTS radical scavenging of lotus leaves treated by three different heating treatments were all increased after simulated intestinal fluid digestion. The results of the present study could provide technical support for the utilization of lotus leaf.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1983-1993. https://doi.org/10.11869/j.issn.100-8551.2019.10.1983In order to find out the effects of 4℃ chilled storage and -18℃ frozen storage on rumen smooth muscle lipid and protein oxidation and processing characteristics of yak, the yak rumen of PE film and PE vacuum packaging were used as research objects to determine their lipid oxidation (thiobarbituric acid), protein oxidation (carbonyl, total sulfhydryl, surface hydrophobicity) and processing quality (pressure loss rate, cooking loss, shear force, texture characteristics) during storage. The results showed that different degrees of lipid and protein oxidation occurred in the rumen under different storage temperatures and packaging methods. Compared with film packaging, vacuum packaging can delay the occurrence of yak rumen lipid and protein oxidation, and -18℃ frozen storage to be more significant. In addition, under the condition of chilling (freezing) storage, the pressure loss rate and cooking loss rate of yak rumen in different packaging yak were significantly increased (P<0.05), the shear force was decreased significantly (P<0.05), and the hardness was decreased first and then increased. The processing quality of film packaging was better than vacuum packaging when they were stored for 0-5 days in chilled and 0-28 days in frozen storage. In summary, during chilling (freezing) storage, the lipid and protein oxidation occurred in the yak rumen under the two packaging methods, but vacuum packaging can effectively delay the occurrence of oxidation reaction. Furthermore, when chilled for 0-5 days and frozen for 0-28 days, the film packaging was more beneficial to improve the rumen processing quality and increase its tenderness and springiness. But long-term storage will lead to a decline in rumen processing characteristics, and the rumen changes of film packaging were the most significant under chilled conditions. The results of this study can provide a reference for the control of food quality during rumen storage.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 1994-2002. https://doi.org/10.11869/j.issn.100-8551.2019.10.1994The study aimed to investigate the effect of drying temperature on quality characteristics of restructured duck meat granules. The low-field nuclear magnetic resonance (LF-NMR) method was used to analyze the water distribution of restructured duck meat granules after hot air drying at different temperatures, and the quality characteristics, such as sensory evaluation, color, TBARS, texture properties and microstructures were examined and compared. The results showed that with the increase of drying temperature, the time for the restructured duck meat granules to reach the drying end was shortened; the proportion of immobilized water and bound water gradually increased, while free water decreased; the cohesiveness and L*, a* and b* values gradually increased; the TBARS value, hardness and chewiness all showed a tendency of increasing at first and then decreasing, with a maximum at 60℃. In addition, scanning electron microscopic results showed that a more compact structure of the restructured duck meat granules was formed with the increase of drying temperature. Sensory evaluation of the product showed that the overall acceptability of the product was highest when the drying temperature was 60℃. Overall, the optimum drying temperature of the restructured duck meat granules was determined to be 60℃. The results could provide a theoretical basis for the process of restructured duck meat granules.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2003-2012. https://doi.org/10.11869/j.issn.100-8551.2019.10.2003To explore application of NIR spectroscopy in analysis of single rice seed protein content, we compared the near-infrared (NIR) spectral characteristics of rice seeds under different NIR measurement modes, and then established quantification models with relative good accuracy for protein content in single rice kernels and rice grains by using the seeds from the ion-beam-induced indica rice cultivar 9311 mutant library. Our results revealed that, for the assessment of protein content in single brown-rice kernels, the quantitative models based on the transflectance and transmittance NIR measurements gave rise to better accuracy than that based on the diffuse-reflectance measurement, and the best PLS regression was obtained with external validation set having coefficient of determination R2=0.97 and root mean square errors of prediction (RMSEP)=0.27%. For the assessment of protein content in single rice grains, it is still hard to establish one quantitative model under diffuse-reflectance measurement because of the effect of rice husk. The quantitative model based on the transflectance NIR spectral data yielded a relatively higher accurate result (RMSEP=0.81%), while the optimal result was obtained under the transmittance measurement resulting in R2=0.96 and RMSEP=0.24%. This work may provide a practical solution for rapid screening of single rice seeds.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2013-2022. https://doi.org/10.11869/j.issn.100-8551.2019.10.2013To investigate the effects of inoculating Bacillus velezensis SW5 on fermentation characteristics of anchovy fish sauce, low-value anchovy was used as the raw material, and Bacillus velezensis SW5 inoculated as the sole. The content of amino acid nitrogen (AAN), volatile base nitrogen (TVB-N), pH, total acid were evaluated, and the volatile components of fermented fish sauce were determined by headspace solid-phase micro-extraction method (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). The results showed that the AAN of treatment group 1 was the highest (0.76 g/100 mL) on the sixth day, reaching the standard of commercial secondary fish sauce. Totally, 82 kinds of volatile compounds mainly alcohol, acid, aldehyde, ketone, furan, alkane and other compounds were detected in three tested groups and commercial fish sauce Zhoushan. Volatile compounds (45 species) in the inoculated group increased compared with the tested group (35 species).Therefore, the use of the Bacillus velezensis SW5 to ferment fish sauce can shorten the fermentation time and increase the variety of volatile flavor compounds. Bacillus velezensis SW5 can be used as an excellent microbial strain for fermentation processing of marine protein source.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2023-2032. https://doi.org/10.11869/j.issn.100-8551.2019.10.2023In order to achieve high value utilization of processing by-products of Dosidicus gigas, and structural different enzymes was used to separate sucker ring teeth (SRT) of processing by by\|products of Dosidicus gigas ot obstain the optimum enzyme. Then single factor method and response surface experiment were used to investigate the effects of important hydrolysis parameters on isolation rate of SRT. Infrared spectra (IR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were used to analyze the composition and structural characteristics of SRT. The results indicated that the optimum conditions for enzymatic separation of Dosidicus gigas sucker ring teeth were determined as follows, enzyme dosage of 1 700 U·g-1, enzymatic hydrolysis temperature of 43℃, and enzymatic hydrolysis time of 34 min. Under these conditions, isolation rate and protein content were 96.2% and 86.75%, respectively. IR analysis revealed that the main components of SRT was mainly composed of protein, and no contain chitin was found. The microstructure was a porous architecture composed of parallel tubular elements. Thermal stability analysis shows that SRT had a melting peak at 118.6℃ with a certain thermoplasticity. At the same time, SRT also exhibited a considerable acid and alkali resistance. The present study would provide theoretical basis and foundation for exploration and utilization of SRT.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2033-2039. https://doi.org/10.11869/j.issn.100-8551.2019.10.2033In order to analyze the effects of temperature and water activity(aw)on the growth and toxicity of Aspergillus flavus in rice, we studied the molecular mechanism of temperature and water activity regulating the growth and toxin production of Aspergillus flavus on rice. Hunan paddy and Heilongjiang rice were selected as the raw materials. Analysis of fungi and determination of AFB1 content in rice was done by high performance liquid chromatography. Finally, the effect of rice water activity and temperature on the expression of key genes of aflatoxin biosynthesis was investigate by fluorescence quantitative PCR. A. flavus grew very slowly when temperature ≤ 25℃ and aw ≤ 0.75.For the growth of A. flavus in rice, the maximum amounts of AFB1 in the rice was produced by A. flavus at 33℃ and aw was 0.96. The most suitable conditions for the growth of Aspergillus flavus were at 33℃ and aw was 0.90. As for paddy, the maximum amounts of AFB1 in the rice was produced by A. flavus at 37℃ and aw was 0.94. The most suitable conditions for the growth of Aspergillus flavus were at 37℃ and awwas 0.92.The optimum conditions for the growth and AFB1 production of Aspergillus flavus on rice were not uniform. The expression of toxin producing genes was promoted at 25℃, but the toxin was inhibited in the process of transcriptional synthesis. The expression of sporulation genes and some structural genes were inhibited, thereby inhibiting the production of toxin. Therefore, it is important to keep low aw and temperature for preventing the infection of Aspergillus flavus and AFB1 contamination during storage. The results of this study provide a theoretical basis to develop control methods for the whole course of Aspergillus flavus during storage and processing.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2040-2047. https://doi.org/10.11869/j.issn.100-8551.2019.10.2040To understand the control effect of glyphosate on weeds in transgenic glyphosate-resistant potato fields and its safety to potatoes and the environment, 20 d after the seedling emergence of potatoes, the stems and leaves of potato and weeds were sprayed by glufosinate water agent with different active ingredients of 0(G0), 847.5(G1), 1 271.25(G2) and 1 695 g·hm-2(G3). Differences among different treatments about the content of MDA and Pro, the activities of SOD and CAT in potato leaves on 1, 4, 11 and 20 d after spraying glufosinate, the average height, stem diamter, fresh and dry weight of rhizome and leaf of potato plants, and the number of weeds on 30 and 45 d after spraying glufosinate, and the nutrient quality and per plant yield of mature potato tubers were analyzed. The results showed that at each stage after spraying glufosinate, the content of MDA and Pro, the activities of SOD and CAT in potato leaves treated with each test dose of glufosinate were not significantly different from those of sprayed water. The fresh and dry weight of potato rhizome and leaf in every treatment were significantly higher than those in treatment with water. While the potato plant height, stem diameter and nutrient quality of mature potato tubers in each dose treatment were not significantly different from those in treatment with water, indicating that the test dose of glufosinate had no significant effect on potato growth and development. Compared with water, each dose of glufosinate could significantly control weeds, and then increased the yield of potato per plant. The control effect of plant and fresh weight on weeds, the potato per plant yield of each treatment were very different, and 3 treatments followed the order of G3>G2>G1. Therefore, the glyphosate with an active ingredient of 1 695 g·hm-2can well control weeds in field of transgenic glufosinate-resistant potato and does not cause phytotoxicity and glufosinate residue to potato and soil.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2048-2057. https://doi.org/10.11869/j.issn.100-8551.2019.10.2048To accelerate the development of mechanical transplanting cultivation techniques of double rice, field experiments were conducted to study the characteristics of yield and yield components among three types of populations (super-high-yield:>9 000 kg·hm-2, high-yield: 8 250~9 000 kg·hm-2, middle-yield: 7 000~8 250 kg·hm-2) under mechanical transplanting, with four combinations of early rice (Zhuliangyou30, Liangyou287, Zhongjiazao17 and Zhongzao35) and four combinations of late rice (Hyou518, WufengyouT025, Wuyou308 and Tianyouhuazhan). The results showed that, the panicles, grains per panicle and total spikelets all increased significantly with the increase of yield level, while there was no significant difference in filled grain percentage and 1000-grain-weight. Significant positive linear correlation was existed between the total spikelets and grain yield. The total spikelet number should be greater than 42 000 per m2as yield was above 9 000 kg·hm-2. In order to enlarge the total spikelets of double rice, it mainly depended on enriching panicles from middle-yield to high-yield. From high-yield to super-high-yield, the enlarging of total spikelets of early rice can be realized by enriching panicles appropriately, and increasing grains per panicle on the basis of enriching panicles appropriately was an important approach to enlarging total spikelets of late rice. The basic characteristics of super-high-yielding machine-transplanted double rice were enriching the amount of total spikelets by obtaining more and bigger panicles and keeping normal filled grain percentage and 1000-grain-weight. The study provids theoretical and practical basis for mechanized transplanting technology of double rice.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2058-2067. https://doi.org/10.11869/j.issn.100-8551.2019.10.2058To explore optimum fertilizer application levels of nitrogen, phosphorus and potassium, the “3414” fertilizer experiment was conducted to study the effects of combined application nitrogen(N), phosphorus(P) and potassium(K) combined application on dry matter accumulation, yield and economic benefits of summer adzuki bean. By analyzing the interaction effect of fertilizer factors, a ternary quadratic model was established with fertilizer application levels as variables dry matter accumulation, yield and well as economic benefits as objective functions. Results showed that the mean value of dry matter accumulation and the mean value of yield of 13 fertilization treatments were 1.26 and 1.17 folds that of no fertilization treatment, respectively with significant differences (P<0.05). Compare with no fertilization treatment, excessive N fertilization and decrement N fertilization had lower economic benefits, while excessive K fertilization had no significant difference, and the other treatments had higher economic benefits by average 11.05%. With the increase of nitrogen, phosphorus and potassium application, the dry matter accumulation, grain yield and economic benefits first increased and then decreased. The influence factors followed the order of as N>P>K for dry matter accumulation and N>K>P for grain yield. Each decrement fertilization had the highest agronomic use efficiency. The fertilization of N, P and K had interaction effect: N and P as well as N and K both had positive effect on dry matter accumulation, grain yield and economic benefits: P and K had positive effect on dry matter accumulation and negative effect on grain yield and economic benefits. Through integrated optimizing of dry matter accumulation, grain yield and economic benefits, and the model screening, the results showed that the optimum combination for dry matter accumulation≥6 500 kg·hm-2, yield≥2 350 kg·hm-2, economic benifits≥17 800 yuan·hm-2 were N 67.6~76.4 kg·hm-2, P2O5 85.8~105.0kg·hm-2, K2O 52.5~67.5kg·hm-2, respectively, and their proportion for N∶P2O5∶K2O was 1∶0.99∶0.75. This study provided theoretical supports on fertilizer utilization economically and efficiently for summer adzuki bean production.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2068-2076. https://doi.org/10.11869/j.issn.100-8551.2019.10.2068To investigate the potential physiological mechanism of Amygdalus davidiana seedlings in response to cadmium (Cd) stress, a pot experiment was conducted to determine the features of physiological response and Cd enrichment characteristics in Amygdalus davidiana seedlings were analyzed. The obtained results showed that the relative content of
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2077-2085. https://doi.org/10.11869/j.issn.100-8551.2019.10.2077A pot experiment was carried out to explore the effect of different nitrogen levels on the growth of I. indigotica and quality of medicinal materials. The response of the biomass accumulation, the photosynthetic parameters, the contents of soluble sugar, free amino acid, nitrate nitrogen and main active components of I. indigotica under 0(N0), 2.5 (N1), 5.0 (N2), 10.0 (N3), 15.0 mmol·L-1(CK) nitrogen levels were investigated. The results showed that dry weights of leaves and roots increased with the increase of nitrogen concentration, and the root-shoot ratios increased initially and then decreased. The content of soluble sugar in leaves showed a trend of decreasing initially and then increasing with the increase of nitrogen concentration. The soluble sugar content in roots showed the different trend as that in leaves. In the nitrogen concentration range of 2.5~15.0 mmol·L-1, the soluble sugar content in roots increased initially and then decreased. The contents of free amino acid in roots and leaves increased initially and then decreased with increasing of nitrogen concentration. The free amino acid content under N3 treatment was the highest. The nitrate nitrogen contents in roots and leaves showed a trend of decreasing initially and then increasing. The nitrate nitrogen content under N3 treatment was significantly lower than that of the other treatments. The net photosynthetic rate(Pn), transpiration rate(Tr) and stomatal conductance(Gs) of leaves increased initially then decreased with the increase of nitrogen concentration, and the intercellular CO2 concentration(Ci) decreased. The content of indigo in leaves gradually increased with the increase of nitrogen concentration, and the content of indirubin showed a trend of decreasing initially and then increasing. The content of total flavonoid in leaves showed a tendency of declining with the increase of nitrogen concentration. The content of (R,S)-epigoitrin in roots increased initially and then decreased with the increase of nitrogen concentration, and the content was highest under N3 treatment. The results indicated appropriate nitrogen supply is conducive to the accumulation of indigo and (R,S)-epigoitrin, while low nitrogen condition is favorable for increasing the contents of indirubin and total flavonoid. The (R,S)-epigoitrin yield in per plant was the highest under N3 treatment, indicating that suitably reduced nitrogen application could obtain Radix Isatidis with higher contents of active components. The study provides a theoretical reference for the reasonable application of nitrogen in the standardized cultivation of I. indigotica Fort.
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Journal of Nuclear Agricultural Sciences. 2019, 33(10): 2086-2093. https://doi.org/10.11869/j.issn.100-8551.2019.10.2086In order to explore the ecological adaptability of the new flue-cured tobacco strains HKDN-2 in Southern Hunan Province tobacco cultivation regions,the experiment with Yunyan87 and K326 as the contrast and multi-index fuzzy evaluation was carried. The result showed that botanical traits,growth vigor and major agronomic traits of HKDN-2 were superior to the control(K326 and Yunyan87); the field growth period was no difference with the control;appearance quality evaluation weight total score of B2F and C3F were more than the control 1.5~1.8 in turn; economic character index(economic character index,ECI)was significantly more than the control,and chemical components usability index(chemical components usability index,CCUI) of B2F and C3F were more than the control 2.7~3.1 and 2.9~3.1, respectively. It showed good resistance to the main diseases in the field,and multi-index fuzzy evaluation ranked of ECI,appearance quality & CCUI ranks the No.1. It is preliminarily indicated that new flue-cured tobacco strain HKDN-2 has good value for extension and application with good ecological adaptability in Southern Hunan Province Tobacco Cultivation Region.The results provide a reference for selection,demonstration and application of new flue-cured tobacco variety(strain).
