2023 Vol. 38, No. 9
Display Method:
2023, 38(9): 1011-1016.
doi: 10.19303/j.issn.1008-0384.2023.09.001
Abstract:
Objective Disease symptoms and reproduction of the attenuated strain S C30(NDRV-S-C30) of novel duck reovirus on inoculated Muscovy ducklings were studied. Method Specific primers were designed to establish a RT-qPCR method for detecting the NDRV nucleic acid in two-day-old Muscovy ducklings intramuscularly injected with NDRV-S-C30. Symptoms of viremia in the blood and viral shedding in the throat and cloaca were observed on the infected ducklings. Viral replication in the birds was monitored on samples of sera, liver, and spleen as well as cloaca and throat swabs collected in 1, 2, 3, 4, 6, 8, 10, 12, and 14 d after the vaccination (dpv) for NDRV nucleic acid detection by RT-qPCR. Result A specific RT-qPCR assay developed for the NDRV detection showed the viral shedding in the throat appeared in 2–8 dpv and in the cloaca in 2–10 dpv and peaked in 4–6 dpv, the viremia in 1–4 dpv and peaked in 1–2 dpv, and the NDRV-S in the liver within 3–6 dpv and in the spleen 1–8 dpv. Conclusion NDRV-S-C30, a attenuated strain, showed virus shedding through the oral cavity and cloaca after immunization of young ducks. It only caused a weak viral bloodstream response and had weak replication ability in the liver. It had lost the ability to cause pathological damage to susceptible target organs. The occurrences and time durations of the viral shedding and viremia in the Muscovy ducklings caused by NDRV-S-C30 were determined. The information would aid the evaluation of immunization efficacy in combating the disease caused by the attenuated virus strain.
2023, 38(9): 1017-1023.
doi: 10.19303/j.issn.1008-0384.2023.09.002
Abstract:
Objective A method for detecting SIgA antibodies of porcine epidemic diarrhea virus (PEDV) was established. Methods Using a purified PEDV ZJ08 strain as coating antigen and the antibody for secretory component(SC) labeled by horseradish peroxidase (HRP) as secondary antibody, an indirect ELISA assay with optimized conditions was developed to detect the specific SIgA antibody of PEDV. Result The optimized assay applied a working antigen concentration of 0.6 μg per well, a 1∶5 sample dilution, a coating at 37 ℃ for 1 h, and an 100× dilution of the labeled antibody for 1.5 h incubation at 37 ℃. Other than the target detection, the assay did not react with porcine rotavirus or transmissible gastroenteritis virus. The inter- or intra-batch variations of the assay on test results were less than 10%. On the milk from vaccinated pigs, a 98.1% positive detection on IgA, which was significantly higher than 69.2% on SIgA and merely 70.6% on combined IgA and SIgA, was achieved indicating the deficiency of a single IgA test for an accurate determination on the mucosal immunity of the animal. Conclusion The established assay appeared to appropriately reveal the specific SIgA antibody produced in pigs for protection of the livestock from PEDV by the vaccination.
2023, 38(9): 1024-1029.
doi: 10.19303/j.issn.1008-0384.2023.09.003
Abstract:
Objective An RT-qPCR method to accurately detect gyrovirus 3 (GyV3) was established. Methods A pair of specific primers and an FAM-labeled fluorophobe were designed according to the conserved region of GyV3 VP2 in Genbank database. Reaction conditions of a rapid TaqMan RT-qPCR assay were optimized, and specificity, sensitivity, repeatability, and simulation tests conducted to verify the applicability of the methodology. Results The assay exhibited a high sensitivity with a minimum detection limit of 1.585 copies·μL−1, a specificity free of cross-reactivity with other prevalent avian pathogens, and a reproducibility with less than 1% coefficients of variation on intra- and inter-batch determinations. On a simulated sample with an added recombinant plasmid to the chicken liver tissue DNA, the assay positively identified GyV3 with same result as did the SYBR Green Ⅰ PCR. Conclusion The newly developed TaqMan RT-qPCR assay showed high sensitivity, specificity, repeatability, and rapid turn-around time in detecting GyV3. It was considered appropriate for clinical diagnosis and epidemiological investigation on the virus.
2023, 38(9): 1030-1036.
doi: 10.19303/j.issn.1008-0384.2023.09.004
Abstract:
Objective Expression of heat shock protein (HSP) gene under oxidative stress in the presence of curcumin was studied to understand the toxicological function of the protein and the pharmacological mechanism of curcumin in hepatocytes of Oreochromis nilotica. Methods Tilapia hepatocytes and those pretreated with curcumin for 24 h were subjected to H2O2 stress for 0, 1, or 2.5 h. The expressions of HSP70, HSP90α, HSP90β, HSP60, and HSP75, as well as 5 small molecule HSP genes, i.e., HSP30, HSPB1, HSPB7, HSPB8, and HSPB11, in the cells were determined by qPCR. Results The H2O2 treatment for 1 h significantly increased the expression of HSPB1 and decreased that of HSP30 in the tilapia hepatocytes, while the treatment that lasted for 2.5 h significantly increased the expressions of HSP90a and HSPB1. A pretreatment of curcumin for 24 h on the cells not only significantly elevated the expressions of HSP70, HSP90α, HSP30, and HSPB1 over control but also on those of HSP70, HSP90α, and HSP30 under 1 h H2O2 stress, as well as those on HSP90α, HSP30, and HSPB1 under 2.5 h H2O2 stress. However, no significant differences in other HSPs were observed. Conclusion As a spontaneous response of tilapia hepatocytes to oxidative stress, H2O2 affected significantly the expressions of HSP90a, HSP30, and HSPB1 in the cells. By pretreating the hepatocytes with curcumin, expressions of these genes could be uplifted boosting the cellular antioxidant capacity to better resist the stress and maintain viability.
2023, 38(9): 1037-1046.
doi: 10.19303/j.issn.1008-0384.2023.09.005
Abstract:
Objective Effects of major ingredients used in formulating fermented livestock forage on probiotics in animals fed with it were analyzed. Method Brown sugar, fish meal, soybean meal, and their combinations were used to formulate liquid culture media in an orthogonal experiment. Structure and diversity of the microbial community in the fermentation broths were determined using the high throughput 16S rDNA sequencing technique. Result The fermentation broth became darker as the concentration increased. The addition of soybean or fish meal raised the contents of organic matters and nitrogen, and the fermentation significantly altered the microbial community with a much-enriched diversity and abundance of the broth. At the beginning of the fermentation, Proteobacteria was the predominant phylum with Xanthomonas being the outstanding genus. In the end, Firmicutes with genera Lactobacillus and Weissella became dominant. The microbial community was significantly affected by the ingredients included in the fermentation medium. For instance, brown sugar enhanced the proliferation of Pseudomonas,Xanthomonas, Weissella, Pediococcus, and Lactobacillales, fish meal facilitated that of Psychrobacter, Weissella, and Pseudomonas but inhibited Lactobacillales, while soybean meal promoted the growth of Acetobacter, Lactobacillales, Psychrobacter, Weissella, and Pediococcus. Conclusion It appeared that a culture medium high on brown sugar and soybean meal but low on fish meal could significantly enhance the abundance of Lactobacillus and Weissella in the fermentation broth to be use as a forage for feeding the livestock.
2023, 38(9): 1047-1053.
doi: 10.19303/j.issn.1008-0384.2023.09.006
Abstract:
Objective Distant hybridization between non-heading and leafy Chinese cabbages was applied to breed improved yield, quality, and resistance to high temperature variety. Method Three F1 hybrids were bred by the distant crossing method between 3 non-heading Chinese cabbage cultivars and 3 leafy Chinese cabbage varieties. Genetic inheritability on the agronomic characteristics of the hybrids were analyzed. Result Plant weight was shown to be the most stable agronomic property passed on in the hybridization. Whereas the easily distinguishable color of the leaves had the highest coefficient of variation among all indicators was the choice for hybrid screening. Significant heterosis of the hybrids over their parents or the average results was found on the height, width, and weight of a plant, the lengths of leaf and petiole, and the width of petiole. Conclusion The distant hybridization between D2 and Q2 bred non-heading Chinese cabbages with desirable agronomic characteristics, and that between D3 and Q3 rendered high yield varieties.
2023, 38(9): 1054-1063.
doi: 10.19303/j.issn.1008-0384.2023.09.007
Abstract:
Objective Effects of different fruit-bagging pouches on the coloration and the expression of the gene related to anthocyanin synthesis in kiwifruits on low latitude lands were studied. Method Composite, yellow-, black-, and white-colored pouches were used to bag the Hongyang kiwifruits in an experiment. Variations caused by the treatments on the chlorophyll, flavonoids, and color in the mesocarp as well as those on the anthocyanin, soluble sugar, soluble starch, color, and expression of the gene related to anthocyanin synthesis in the endocarp at different growth stages of the kiwifruits were monitored. Result The anthocyanin content and colorimetric a, h, and L in the endocarp of the kiwifruits bagged in the white pouches were significantly lower than those of the fruits enveloped in the black or composite pouches. The chlorophyll in mesocarp was higher and the expressions of the anthocyanin synthesis genes AcCHI, AcDFR2, and AcF3GGT1 the lowest during several sampling periods. The fruits bagged in the composite pouches contained significantly more anthocyanin in the endocarp and less chlorophyll in the mesocarp with corresponding a, b, and chromaticity angle than those in the other kinds of pouch. The fruits also had a higher soluble sugar content in the endocarp and mesocarp, and a significantly higher expression level on AcF3GT1 in the endocarp, except on the 140 d. Overall, the degrees of the effects on coloration and gene expression of the kiwifruits by bagging with the yellow or black pouch lied in between those with the white and the composite pouches. Conclusion Kiwifruits bagged in the composite pouches had a chartreuse-colored pulp and a more reddish colored endocarp with lower chlorophyll but higher anthocyanin content than those in the other kinds of pouch. The significantly elevated AcF3GT1 expression by any of the bagging treatments suggested an important role the gene might play in the anthocyanin synthesis in the fruits.
2023, 38(9): 1064-1072.
doi: 10.19303/j.issn.1008-0384.2023.09.008
Abstract:
Objective Developments of flower buds and pollen grains, optimum medium for stamen callus induction, and proper conditions for seedling propagation and differentiation of Paeonia delavayi were investigated. Method Dominant pollen grain development stages were examined under an optical microscope on the paraffin sections of red P. delavayi hard buds with visible color. On an MS solid medium, various plant growth regulators in different concentrations were added to determine the optimal formulation for the induction, proliferation, and differentiation of stamen callus. Result (1) The prevailing stage of pollen grain development for the redP. delavayi, Y2-Y4, occurred in the mid-mononuclear period when the bud diameter was 10-17 mm but the color had yet to show. At T1-T2, the bud grew to a diameter ranging from 12 mm to 15 mm with less than 30% of the bud showing its color. That was in the single-core sideline period. When the diameter of a stamen reached 15-19 mm with a colored area greater than 30%, the T3-T4 stage was in the binuclear period. (2) The stamens were most effectively disinfected with running water for 30min followed by a rinse with 1% sodium hypochlorite for 8min. (3) The stamen could be optimally induced during the single-core sideline period. (4) The medium for optimal stamen callus induction was formulated with MS + 0.2 mg NAA·L−1 + 0.5 g PVP·L−1, and that for the proliferation MS + 0.5 mg NAA·L−1 + 0.25 mg 6-BA·L−1 + 0.5 mg GA3·L−1 + 1 g PVP·L−1. Conclusion This study clearly revealed the floral bud size, appearance, and dominant pollen grain development stages of the red P. delavayi and determined the optimal medium formulations and culture conditions for inducing, proliferating, and differentiating the stamen callus.
2023, 38(9): 1073-1081.
doi: 10.19303/j.issn.1008-0384.2023.09.009
Abstract:
Objective Contents of minerals and rare-earth elements in the alpine black teas from Shouning, Fujian were analyzed for grade classification. Methods On 60 Jinmudan alpine black tea of various grades, sensory evaluation and chemical analysis were performed. A chemometric method was applied on the data to construct a grade discrimination model for the tea. Results Based on the analytical data, 15 minerals detected in the specimens were ranked by their contents as K＞Ca＞Mg＞Mn＞Al＞Fe＞Na＞Zn＞Cu＞Pb＞Sn＞Se＞As＞Cd＞Hg. Among them, K, Ca, Mg, and Mn were more abundant and accounted for 96.78% of the total. The rank on the 15 rare-earth elements was Ce＞La＞Y＞Nd＞Gd＞Pr＞Dy＞Er＞Yb＞Sm＞Eu＞Ho＞Lu＞Tb＞Tm, with Ce, La, Y, and Nd being the dominant at contribution rate of 82.44%. For constructing a grading model, 14 characteristic elements, including Cu, Al, Sn, Ce, Tm, Lu, Se, Mn, Dy, Ho, Gd, Tb, Er, and Yb, were selected by the analysis of variance (ANOVA) combined with receiver operating characteristic curve (ROC curve) (P＜0.05, AUC＞0.7). A discriminant model of multi-layer perceptual neural network with a discriminant rate of 90.48% on the training group and 94.44% on the test group was established. Conclusion K, Ca, Mg, Mn, and other minerals were richly found in the Shouning Jinmudan alpine black teas. The constructed multivariate statistical model based on the chemical composition could be used to classify the grades of the teas.
2023, 38(9): 1082-1093.
doi: 10.19303/j.issn.1008-0384.2023.09.010
Abstract:
Objective Aromatics in various floral organs of Michelia platypetala Hongyun were analyzed for selective breeding and extended utilization of the fragrant components. Method Headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were employed to determine the aromatic components in the tepals, stamens, and pistils of Michelia platypetala Hongyun at flower budding, early blooming, and full blooming stages. And conduct Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS-DA). Result One hundred volatiles of 11 types were identified. Terpenoids and alkanes were the major ones that constituted over 80% of all. The contents of ketones, aldehydes, alcohols, heterocyclic compounds, and olefins were relatively low. Identify 100 types of floral aroma components, screen and list 49 substances based on the main aroma components (relative content>1%) and unique aroma components of each floral organ at different stages. The subsequently conducted PCA and PLS-DA analyses placed the aromatics in 13 distinct components at VIP＞1, indicating significant differences in the aromatic components of the three flower organs. The main aroma components of Michelia platypetala Hongyun perianth slices γ-cadinene and 1,2-Dimethoxybenzene have vanilla and sweet cream flavors, respectively, presenting a woody and herbaceous aroma. During the bud stage, the unique components of the petals, such as esters such as 2-Phenethyl hexanoate ester and ethers such as 2-Isopropyl-5-methylanisole, add a sweet and burnt wood flavor to the petals, presenting a floral and herbaceous aroma. The ketone substance D-carvone, a unique component of the early blooming petals, adds a stimulating flavor to the perianth slices, presenting a mint aroma. The main aroma components of stamens γ-Junipene and δ-Elemene has a vanilla and sweet flavor, respectively, presenting a woody and herbaceous aroma. The unique components of aldehydes and ketones at each flowering stage of stamens, such as Benzaldehyde and 3-Thujanone, add almond flavor and stimulating flavor to the stamens, presenting a fruity and woody aroma. Main aroma components of pistil γ-Junipene, (+)-Aromandendrene, and δ- Elemene has a vanilla, woody, and sweet flavor, respectively, presenting a woody and herbaceous aroma. Bud stage pistils specific components of alcohols γ-Terpineol alcohol for pistils added pine flavor and clove flavor, presenting a woody aroma. Conclusion The aroma components of the organs of Michelia platypetala Hongyun are rich. The main aroma components are terpenoids and alkanes, and the main aroma releasing site is the stamen during the bud stage. During the flowering process, the aroma characteristics are constantly changing due to the relative content and types of various aroma components, making each flower organ present unique and diverse floral fragrance in three flowering periods.
2023, 38(9): 1094-1102.
doi: 10.19303/j.issn.1008-0384.2023.09.011
Abstract:
Objective Structure of the chloroplast genome from Uraria crinita, a plant used as food as well as herbal medicine in Lingnan area of China, was studied. Methods The whole chloroplast genome was obtained by high-throughput sequencing and then assembled, annotated, and analyzed by bioinformatic means. Results The genome was an annular quadripartite molecule of 149 774 bp that harbored 128 genes. It had a low GC content of 38.2% containing 26 015 codons that mostly ended with A or T. There were 110 loci of simple sequence repeat detected with the mononucleotide largely formed by A or T. An alignment and phylogenetic analysis on the sequence indicated a close relationship between U. crinita and U. lagopodioides. Conclusion The chloroplast genome and structure of U. crinita were unveiled for the first time to aid future studies on the cultivation, breeding, genetics, and utilization of the valuable plant.
2023, 38(9): 1103-1111.
doi: 10.19303/j.issn.1008-0384.2023.09.012
Abstract:
Objective Actinomycetes collected from the rhizosphere soils of old tea plants were isolated to screen for species unknown previously and their potential pathogenic inhibitory effect. Method Soil specimens were gathered from the target lots at Shuixian, Fujian to isolate actinomycetes by plate culture. Phylogenetic trees based on 16S rRNA gene for the isolates were constructed and diversity index calculated in the tea plant rhizosphere soils. Result (1) Eighty-one actinomycete strains were obtained that belonged to Streptomyces(54.32%), Arthrobacter (27.16%), Microbacterium (11.11%), Kitasatospora(4.94%), and Curtobacterium (2.47%). (2) In comparing with the reference strain, 20 of the 81 taxa showed less than 98.65% similarity. (3) Seven strains of the Streptomyces significantly inhibited the growth of Lasiodiplodia theobromae, of which, the one code-named WYS-24 reached the highest rate at 63.92%. Conclusion Abundantly diverse actinomycetes resided in the rhizosphere of old tea plants in Wuyishan region. They were a rich resource for in-depth studies and development for biological inhibitors against plant pathogens.
2023, 38(9): 1112-1116.
doi: 10.19303/j.issn.1008-0384.2023.09.013
Abstract:
Objective The glycoside hydrolase gene LtGH88 of Lasiodiplodia theobromae was cloned to study the mechanism of canker in Cinnamomum camphora, which is the major pathogen that causes the disease. Methods The LtGH88 encoding sequence was cloned by PCR from tissues of C. camphora infected by L. theobromae to determine the characteristics and functions of the protein by bioinformatic methods. Expression of the gene was detected by real-time quantitative PCR, and functions analyzed using the Agrobacterium tumefaciens mediated transient transformation in Nicotianaben thamiana. Results The full open reading frame of LtGH88 was 1 152 bp with a molecular weight of 42.8 kDa and a theoretical isoelectric point of 4.56. The predicted secondary structure of the protein consisted of 49.09% α helix, 11.23% extended chain, and 34.99% random coil. A signal peptide of 1-18 amino acids was located at the N terminus. The protein belonged to the glycoside hydrolase family 88 (GH88) capable of degrading pectin. LtGH88 was significantly expressed in the early stage of the infection. It did not cause cell necrosis in the leaf of N. thamiana but was able to inhibit the hypersensitive response (HR) induced by Bax. Conclusion It was postulated that LtGH88 in L. theobromae inhibited the immune response of C. camphora facilitating the pathogenic invasion and colonization on the host plant.
2023, 38(9): 1117-1123.
doi: 10.19303/j.issn.1008-0384.2023.09.014
Abstract:
Objective Bacteria capable of effectively degrading spent straws were isolated, and conditions for the enzymatic reaction analyzed. Method On a medium containing sodium carboxymethyl cellulose and Congo red, potential strains capable of decomposing fibrous material were isolated from sampled forest soil and compost. Enzymatic activities of the isolates were examined, and conditions determined. Result Bacillus licheniformis was identified as the strain with the greatest carboxymethyl cellulase activity. It demonstrated a filter paper degrading activity of 14.21 U·mL−1, a xylanase activity of 24.03 U·mL−1, and an ability to decompose 21.2% of corn straws. On corn straws, the selected isolate was observed to show the maximum digestion with an overall activity up to 48.63 U·mL−1 by using KNO3 for nitrogen source at pH 7 and 30 ℃. Conclusion B. licheniformis was a cellulose-degrading bacterium that could be used to decompose spent corn straws for waste disposal.
2023, 38(9): 1124-1132.
doi: 10.19303/j.issn.1008-0384.2023.09.015
Abstract:
Objective Sequestration and stability of phytoliths and phytolith-occluded carbon (PhytOC) in plant organs, ground litter, and soil in three typical coniferous forests at Mt. Funiu in Henan province were analyzed to better understand the long-term carbon fixation in the eco-system. Method Contents of phytoliths, C in phytoliths, PhytOC, and SiO2 in the plant organs, ground litter, and 0-50 cm soil in Cedrus deodara, Sabina chinensis, and Platycladus orientalis forests at Mt. Funiu were collected according to the mass balance method. Result The contents of phytoliths, C in phytoliths, PhytOC, and SiO2 in various organs of the trees and soil of the forests in the area varied significantly. The phytolith contents in the plant organs ranged 1.49-3.27 g·kg−1 for C. deodara, 1.44-2.56 g·kg−1 for S. chinensis , and 1.86-2.90 g·kg−1 for P. orientalis, while the PhytOC at the C. deodara forest, 0.030-0.114 g·kg−1, at the S. chinensis forest, 0.036-0.085 g·kg−1, and at the P. orientalis forest, 0.038-0.083 g·kg−1. The production fluxes estimated by this study indicated that the soil PhytOC storage at the S. chinensis forest was 1.64 t·hm−2, which was higher than 1.17 t·hm−2 at the C. deodara forest and 0.77 t·hm−2 at the P. orientalis forest. The estimated PhytOC turnover time for the S. chinensis forest soil was 1 813.16 a, which was significantly longer than 218.78 a for the C. deodara forest soil or 556.44 a for the P. orientalis forest soil. Conclusion Significant variations existed on the phytolith content in the plant organs and the PhtyOC production rate and turnover time of the soil at the 3 forests. By optimizing and/or re-establishing the coniferous S. chinensis forest in the mountain, the biogeochemical carbon sink of the environment could be significantly enriched.
