2022 Vol. 37, No. 9
Display Method:
2022, 37(9): 1109-1116.
doi: 10.19303/j.issn.1008-0384.2022.009.001
Abstract:
Objective Clustering of strains of Pseudomonas plecoglossicida, a major pathogen that causes the serious bacterial visceral white spot disease on Larimichthys crocea in winter and spring, was studied for disease control and epidemic prevention. Method The 16S rDNA and gyrB of 7 suspected P. plecoglossicida strains collected from different temporal and spatial sources were cloned and sequenced with evolutionary trees constructed. O and H antigen serums of these strains were prepared for agglutination tests. Result The 7 pathogens could be clustered into a same branch based on their sequences. Their O and H antigen sera agglutinated with those of the standard P. plecoglossicida reference without significant differences on titers, but not with that of P. fluoresenes, Vibrio alginolyticus, or V. harveyi. Conclusion It appeared that the 7 collected strains of P. plecoglossicida were genetically closely related and might have a common origin.
2022, 37(9): 1117-1125.
doi: 10.19303/j.issn.1008-0384.2022.009.002
Abstract:
Objective Four combinations of Porcine reproductive and respiratory syndrome (PRRS) vaccine including live vaccine and inactivated vaccine were designed to improve the best immune effect for piglets, which would provide the reference for the formulation of PRRS vaccine prevention and control program. Methods A total of 25 piglets aged 28–35 days were randomly divided into 5 groups. In group A, piglets were firstly immunized with the live vaccine of PRRS (CH-1R strain) from manufacturer A and secondly immunized with the inactivated vaccine of PRRS (CH-1a strain ) from manufacturer A at an interval of 14 days. In group B, they was firstly immunized with the live vaccine of PRRS (strain CH-1R) B and secondly inactivated with the inactivated vaccine of PRRS (CH-1a strain) from manufacturer B, respectively. In group C, they was immunized for two times with the inactivated vaccine of PRRS (CH-1a strain) from manufacturer A. The interval of two immunization was 14 days, and 2 mL vaccine was injected into each piglet muscle. In group D, they was immunized for two times with the inactivated vaccine of PRRS (CH-1a strain) from manufacturer B. Group E was the control. The levels of cytokines (IL-2, IFN-γ, IFN-α, TNF-α) in peripheral blood were detected before and 1, 3, 5, 7 days after immunization. Blood samples were collected before the first immunization, 14 days after the first immunization, and 7, 14, 21 and 28 days after the second immunization to detect the levels of antibodies anti-GP5 protein and N protein. All groups were challenged with PRRSV at the 28th day after the second immunization, and body temperature was detected for 21 days after PRRSV challenge, and necropsy was performed at the 21st day after the PRRSV challenge. Results The test results showed that the mRNA expression levels of cytokines in all groups showed different change trend in control group after first immunization, the IL-2 expression levels decreased along with the increase of day age, but it in group A, B were significantly higher than those of group C, D, E at the 3rd day; the expression level of IFN-γ in groups C and D were significantly higher than those in groups A and B at 3rd day, 5th day and 7th day; the expression level of IFN-α in group B was significantly higher than that in other groups at the 3rd day, 5th day and 7th day, and the expression level of TNF-α in group A was significantly higher than those in other groups at the 7th day. After PRRSV wide strain challenge, the temperature of the control group rose quickly and high, and the duration of high temperature was long. The temperature of piglets in groups B increased less, and quickly returned to normal temperature. After immunization, the antibody level, antibody positive rate and challenge protection rate were the highest in group B. Conclusion The immune effect of live vaccine and inactivated vaccine of PRRS combination immunization is better than that of inactivated vaccine combination immunization, and the immune effect of vaccine from manufacturer B is better than that from manufacturer A.
2022, 37(9): 1126-1134.
doi: 10.19303/j.issn.1008-0384.2022.009.003
Abstract:
Objective Nutritional values of breast and leg meats of Peking duck Z9 line (PD), Jingxi hemp duck (JH), and Ji’an red feather duck (JR) were analyzed and compared. Method Sixty newly hatched ducklings of the 3 breeds/lines were purchased on a same day and raised with same forage under identical conditions for 300 d. Five male and female adult ducks from each flock of a same breed were randomly selected and slaughtered to collect breast and leg meats for analyses on chemical composition, amino acids, and fatty acids. The measured datas were preprocessed by Excel and subjected to a one-way ANOVA analysis using the SPSS 25 software. Result Of all nutrients, crude protein was highest in the breast and leg meats of JR; intramuscular fat and cholesterol contents were highest in the breast and leg meats of PD; and total, essential, and flavor amino acids were highest in the JR breast meat. In leg meat, JH had the highest contents of total and flavor amino acids, while JR the essential amino acids. Among the 3 breeds, JR had the most unsaturated fatty acids but the least saturated fatty acids in its breast and leg meats; in breast meat, PD and JR had significantly higher polyunsaturated fatty acids than JH; and in leg meat, JR was extremely significantly higher on monounsaturated fatty acids than JH and significantly higher than PD. Conclusion The meat nutritional quality of the 3 breeds of 300-d-old local ducks varied. Overall, JR appeared to be higher in that regard than PD or JH.
2022, 37(9): 1135-1144.
doi: 10.19303/j.issn.1008-0384.2022.009.004
Abstract:
Objective Aroma-regulating mechanism of the transcription factor JsMYB305 associated with terpene synthetases gene of jasmine flower was investigated. Method From the jasmine floral petal yeast database a two-hybrid library was constructed using the white buds and fully open flowers. Proteins that interacted with JsMYB305 were identified and verified by the yeast two-hybrid method. Result The full length of JsMYB305 was significantly self-activated, and the fragments of different lengths were amplified for verification. At a coding length less than or equal to 510 bp, JsMYB305 showed no self-activation. Applying a 510 bp pGBKT7-JsMYB305 as a bait, an interacting protein was obtained from the yeast two-hybrid library and identified to be salicylic acid carboxyl methyltransferase (SAMT). The yeast-directed two-hybrid validation indicated that JsMYB305 interacted with JsSAMT. Conclusion Since SAMT presents in the biosynthetic pathway of phenylpropane/propane, the JsMYB305 transcription factor was believed to also relate to the synthesis of similar aromatic substances in jasmine flowers.
2022, 37(9): 1145-1155.
doi: 10.19303/j.issn.1008-0384.2022.009.005
Abstract:
Objective Functions of DcbHLH14, a basic helix-loop-helix transcription factor of Dendrobium catenatum Lindl., in response to abiotic stresses were studied. Method DcbHLH14 was cloned from D. catenatum leaves using homologous cloning method for a bioinformatic analysis on the gene and expression in tissues. Gene expressions under low temperature, drought, and abscisic acid (ABA) stresses were determined. Result The ORF of DcbHLH14 was 1 269 bp and encoded 422 amino acids. It Conclusion It was postulated that DcbHLH14 responded to low temperature or drought stress through the ABA signaling pathway at transcription level. Hence, the tolerance of D. catenatum to the abiotic stresses could be manipulated by regulating the expression of the downstream functional gene.
2022, 37(9): 1156-1166.
doi: 10.19303/j.issn.1008-0384.2022.009.006
Abstract:
Objective A popular ornamental tree for landscaping, Handroanthus impetiginosus tends to differ in phenotypic traits between individual plants. This study aimed to collect information on the resources for selection and cultivation. Method Twenty different phenotypic traits of 62 H. impetiginosus plants collected from 12 population groups in 6 cities of Guangdong Province were used to calculate coefficient of variation (CV) and Shannon diversity index as well as conduct correlation, principal component, and clustering analysis. Result The CVs of these phenotypic traits varied between 13.53%–59.13%, while the Shannon diversity index between 0.79–4.08. High CV and diversity index connotated richness in phenotype diversity of the species. Their qualitative indices differentiated more greatly than quantitative ones, and the qualitative indices correlated with one another. Among the 6 principal components in the 20 traits, the indices associated with leaf, including width, area, length, petiolule length, and petiole length, were the major contributors which were followed by those related to the branch and trunk diameters at breast height and under branch height. A hierarchical clustering analysis divided the 62 H. impetiginosus plants into 4 population groups based on their phenotypic characteristics. Conclusion H. impetiginosus was richly diverse phenotypically. The indices related to branch and trunk ranked highest on CV, while those associated with leaf greatest on diversity index. The principal components of the traits, such as leaf-, branch-, and trunk-related indices, largely determined the phenotype of H. impetiginosus plants. The population Group II plants as classified by the cluster analysis had more dark color flowers, whereas Group I carried distinctive, attractive white blossoms that were valued generally for landscaping, cultivation, and breeding purposes.
2022, 37(9): 1167-1175.
doi: 10.19303/j.issn.1008-0384.2022.009.007
Abstract:
Objective Variations in color and pigments on leaves of ornamental crabapple germplasms in season were used to classify the plants for establishing an evaluation system for landscaping. Method Luminosity L*, saturation C*, and hue angle h° as well as pigments in the upper, middle, and lower parts of the leaf of 48 ornamental crabapple germplasms were measured using a colorimeter and a spectrometer. Results ① The color measurements on all crabapple varieties in June distributed in the CIELCH space more concentrated in the upper part and gradually lessened toward the lower part of a leaf. The color was richer and the loci more scattered in the upper part as well. ② The relative contents of anthocyanin and carotenoid decreased, but that of chlorophyll increased, from the upper to the lower leaf. ③ The germplasms clustered by leaf color were classified into the green Group A that included bright green A1 and dark green A2, the brown Group B, and the red Group C that included reddish brown C1 and reddish purple C2. Conclusion Of all crabapple groups, Group A1 had a high relative chlorophyll content displaying bright green foliage; Group B had significantly varied color measurements and a significantly higher carotenoids content than the other groups making it suitable for breeding programs; and Group C1 had a high anthocyanin to chlorophyll ratio of （1.22±0.24） and an h° of (29.74±4.74)° rendering it the choice of a showy red-leaf crabapple variety.
2022, 37(9): 1176-1181.
doi: 10.19303/j.issn.1008-0384.2022.009.008
Abstract:
Objective A yeast cDNA library was constructed using the leaves from a cold tolerant Amur grape plant under low-temperature stress to facilitate the study of the resistance mechanism. Method As a well-known frost resistant Vitis amurensis Rupr., V. amuerensis cv. Zuoshan-1 was cultured in a pot experiment for a total RNA extraction from the seedling leaves after 0, 2, 4, 8, 12, and 24 h at 4 °C. The extract was then reverse transcribed into cDNA using the SMART technology to be purified. Short fragments were removed and ligated into pGADT7 3-frame plasmid vector to establish a primary cDNA library. After amplification, plasmid was extracted and transformed into yeast Y187 for the library construction, followed by a qualitative verification. Result The capacities of the 3 reading frame primary libraries were tested to be 1.7×106 cfu, 2.0×106 cfu, and 1.9×106 cfu with a recombination rate of 100%. The lengths of the inserted fragments were largely in the 500-2 000 bp region. The electrophoretic detected and sequenced encoded proteins corresponding to the inserted fragments were abundant and highly polymorphic. The titer of the finally obtained Y187 yeast library was approximately 4.0×108 cfu·mL−1. Conclusion A high quality yeast cDNA library using Amur grape leaves under low temperature was successfully constructed for future studies on the interacting proteins under cold stress that could induce injury impairing the growth, development, fruit quality, and yield of grape vines.
2022, 37(9): 1182-1186.
doi: 10.19303/j.issn.1008-0384.2022.009.009
Abstract:
Objective To systematically study the tissue culture and rapid propagation technology of edible rose flaming fire, and establish the tissue culture and rapid propagation technology system to solve the bottleneck problem of seedling industrialized production of edible rose flaming fire. Methods The best disinfectant and treatment time of explants were selected through comparative test; Through orthogonal test, the best plant growth regulators and concentration levels were selected for bud proliferation culture, and the best rooting basic medium, and plant growth regulators and their concentrations were selected. Result (1) The explants treated with 0.1% HgCl2 for 8 min and then 6% sodium hypochlorite solution for 3–6 min was the best for tissue cluture of flaming fire; (2) The optimum medium formula for bud propagation was MS+6-BA 2.0 mg·L-1+NAA 0.2 mg·L-1+TDZ 0.06 mg·L-1, and the multiplication coefficient was 3.47; (3) The improved rooting medium for bud seedlings was 1/2MS+NAA 0.2 mg·L-1+IBA 0.01 mg·L-1, the rooting rate of which was 89.44%, and the root system was strong. Conclusion The tissue culture and rapid propagation technology system of edible rose flaming fire established by the comparative experiment for explant disinfection, and the orthogonal experiment for bud proliferationand rooting culture, can provide technical support for the industrialized production of edible rose seedlings of flaming fire, and promote the popularization and application of edible roses in agriculture.
2022, 37(9): 1187-1193.
doi: 10.19303/j.issn.1008-0384.2022.009.010
Abstract:
Objective Identification and characteristics of Hsp70 family in Setosphaeria turcica were studied to facilitate elucidating their roles in the growth, development, and pathogenicity of the microbe. Methods Members of StHsp70 family were identified from the S. turcica genome database. Physicochemical properties, subcellular localization, phylogenetic evolution, conserved motifs, and domains of the genes analyzed by bioinformatics methods. Results Eleven members, StHsp70-1 to StHsp70-11, were identified from the database. Most of them were predicated to locate in the cytoplasmic as well as in endoplasmic reticulum, mitochondrial, and nucleus in lesser amounts. The phylogenetic analysis divided the members into 7 categories including Classes A−F that showed a high homology with the heat shock proteins SSA, SSB, SSC, KAR2, SSE, and SSZ of Saccharomyces cerevisiae, respectively, and Class G that had none with what were found in yeasts. All StHsp70s contained conserved motif 5, but motif 6 existed in Class A−D only. Class G had only motifs 2−4 making the class significantly different from the others. The variations in subcellular localization might be the reason of the significant N-terminal differences in the NBD domains of the Hsp70 classes of S. turcica from those of yeast. Whereas the considerably varied C-terminal structure and extensibility among the classes, especially on the StHsp70s of Class G, might contribute to the diversity of substrates. Conclusion The 11 members of Hsp70 family of S. turcica could be divided into 7 classes with 4 members in Class G being significantly different from the others in physicochemical properties and structure. It indicated that the genes were of multifunctional molecular chaperones.
2022, 37(9): 1194-1202.
doi: 10.19303/j.issn.1008-0384.2022.009.011
Abstract:
Objective Microbial communities in rhizosphere soils of healthy sweet potato plants and those infected by the stem rot disease (SPSR) were compared for ecological disease control. Method Rhizosphere soil samples at fields of healthy and SPSR-infected sweet potatoes in between north and south planting regions and disease occurring western hilly areas of Huangyan, Taizhou City, Zhejiang Province, were collected. Enzyme activity and microbial community in the soil were analyzed using the traditional and high throughput sequencing techniques. Results Compared with the rhizosphere soils of non-infected plants, those associated with the SPSR-infected sweet potatoes exhibited significant inhibition on the activities of urease, invertase, and alkaline phosphatase as well as significant increases on the microbial diversity and richness such as Chao1 and Shannon indices. At phylum level, the average relative abundance of dominant microbes, such as Actinobacteria, Verrucomicroba, and Bacteroidetes, were significantly lower in the SPSR soil, but that of Chloroflexi and Candidate-division-wps-2 significantly higher. At genus level, the average relative abundance of GP1, Firmicutes-unclassified, and Gemmatimonas was higher in the SPSR samples, while that of Streptomycetaceae-unclassified, Streptacidiphilus, and Burkhoideria lower. Conclusion In the rhizosphere soils of SPSR-infected sweet potato plants, the activities of some important soil enzymes were low. At both phylum and genus levels, the great variations in the abundance of dominant microorganisms existed between the healthy and SPSR rhizosphere soils.
2022, 37(9): 1203-1208.
doi: 10.19303/j.issn.1008-0384.2022.009.012
Abstract:
Objective A two-hybrid eDNA library was constructed for studying the interaction between tomato spotted wilt tospovirus (TSWV) and Frankliniella occidentalis to decipher the mechanism of the disease transmission by thrip and the factors involved in the virus infection. Method A highly infected F. occidentalis population was created by inoculating TSWV into the thrip nymphs. Thereby, a yeast two-hybrid three-frame cDNA library on TSWV-infected F. occidentalis was constructed using the SMART technology. Result The established 3 reading frame cDNA libraries had the capacities of 3.0×106, 2.0×106, and 2.0×106 cfu. The actual amplification base of the library was more than 1.5×106 cfu or 5 ×105 cfu each with an average insert fragment of 0.5–3.0 kb in length. From the library 16 clones were randomly selected, sequenced, and compared with the GenBank database for of homology verification on the insert fragments. Conclusion The established cDNA library had an ample capacity and high recombination rate adequate for studies on the interactions between TSWV and F. occidentalis.
2022, 37(9): 1209-1215.
doi: 10.19303/j.issn.1008-0384.2022.009.013
Abstract:
Objective To find out the pathogen of tomato damping-off in Yinchuan area of Ningxia, and lay a foundation for disease control and disease resistance breeding. Methods Possible pathogenic microbes of the disease on tomatoes were isolated by the conventional tissue isolation method and identified based on their morphology, pathogenicity, and rDNA-ITS sequence. Result Of the two suspected species, Pathogen No. 1 had oval or nearly spherical sporangia with papillae and long stalks. It was preliminarily determined as Phytophthora capsici. The spherical ovipositor of Pathogen No. 2 had straight stalks with spherical, smooth oospores that did not fully fill the sacs and the wide rod- or lemon-like-shaped male organ grew laterally. It was presumed to be Pythium aphanidermatum. After inoculation on tomato cotyledons the inoculation of either of the two isolates caused the seedling stem constriction and plant collapse showing the typical symptoms of dark brown spots at infected sites. The phylogenetic trees constructed based on the ITS sequences of the two isolates confirmed No. 1 to belong in the branch of P. capsici, and No. 2 of P. aphanidermatum. Conclusion The pathogens that caused damping-off on tomato plants in Yinchuan were positively identified to be strains of P. capsici and P. aphanidermatum.
2022, 37(9): 1216-1224.
doi: 10.19303/j.issn.1008-0384.2022.009.014
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Objective Fertility and organic carbons in soil as affected by long-term post-harvest incorporation of spent rice straws on a typical red earth, two-cropping rice field in southern China were studied for better farming management. Method On the lots, treatments with applications of no fertilizer (CK), chemical fertilizer (NPK), or spent rice straws+chemical fertilizer (M) were implemented. After the late season, 2nd crop of rice was harvested in 2020, samples in the tillage layer (0-20 cm) at the test lots were collected to determine the organic carbons (OC), microbial biomass carbon (MBC), nitrogen, and other fertility indicators in the soil. Result The long-term incorporation of straw discards by plowing them back into the field along with chemical fertilizer significantly improved the soil fertility. The M treatment altered the OC composition with significantly increased free particulate carbon (FPOC) and soluble particulate carbon (DOC), over CK (P＜0.05). The carbon pool in soil was enriched more than NPK treatment, especially, the content of granular OC of 2.32 g·kg−1 was significantly higher under M treatment than 1.94 g·kg−1 under NPK. Compared with CK, the MBC increased by 21.94% under NPK, and even higher, by 25.98%, under M. In addition, M also raised the nutrients, such as alkali-hydrolyzable nitrogen (AN), available phosphorus (AP), and available potassium (AK), in the soil at the two-crop rice fields. Conclusion By turning discarded straws into the rice field after harvest along with chemical fertilization, the carbon pool, OC composition, nutrients in the soil, as well as farming management, were significantly improved. Aside from AP, pH and total phosphorus (TP) were the other important factors affecting the carbon pool in the rice field. With the incorporation of spent straws as described in this article AP in soil benefitted as well.
2022, 37(9): 1225-1229.
doi: 10.19303/j.issn.1008-0384.2022.009.015
Abstract:
Objective Physiological response and molecular mechanism of different salt-tolerant rice lines in dealing with high salt stress were studied to facilitate screening and breeding resistant varieties. Methods Salt-tolerant rice X1, X2, and X3 as well as salt-sensitive X20 and X30 were treated by a high salt condition of 1/2KB solution with 200 mmol·L−1 NaCl. The physiological metabolism and expression of functional genes of the two contrasting groups of rice were compared. Results Under the stress, the proline and soluble sugar contents, superoxide dismutase and catalase activities, and expressions of OsP5CS1, OsProt, OsCu/Zn-SOD, OsAPX2, OsNCED3, and OsNCED5 of the salt-tolerant rice were significantly higher, whereas the malondialdehyde and hydrogen peroxide contents significantly lower, than those of the salt-sensitive counterparts. Conclusion The salt-tolerant rice lines resisted the high salt exposure mainly by increasing osmotic regulation, activating oxygen scavenging, and accentuating functional gene expression of the plants.
2022, 37(9): 1230-1236.
doi: 10.19303/j.issn.1008-0384.2022.009.016
Abstract:
Objective Impact on soil erosion by rainfalls under different water and soil conservation programs applied on the slope lands in southern China was analyzed. Methods Information on rainfall, runoff, sediment, and others relevant factors was collected at a slope runoff observation site in Jianan from 2018 to 2020 and analyzed. Results The rainfall in the area concentrated from March to June in a year amounting to more than 1/3 of the annual precipitation. However, the peak precipitation and soil erosivity on the site did not always coincide in a same month. Some conservation strategies or land use models mitigated the erosion to varying extents. For instance, by planting Paspalum notatum on the horizontal terraces with ladder walls at tea plantations (T3), the soil loss was reduced to a rate of merely 2.47 t·hm−2. And a similar practice at fruit orchards (T9) resulted in a minimum soil erosion of 2.07 t·hm−2 under heavy rainfall. Conclusion Planting P. notatum on terraces with ladder walls at a tea plantation or a fruit orchard could apparently effectively curtail erosion of soil by rainfall. It could be an applicable conservation measure for a land of similar geographic and climatic conditions.
2022, 37(9): 1237-1244.
doi: 10.19303/j.issn.1008-0384.2022.009.017
Abstract:
Objective A fungal strain highly efficient in dissociating low-grade phosphorus ore for fertilization was isolated to determine the applicability. Method Soil samples at Guizhou Tongren Tobacco Planting Base were screened using the sand culture method for fungi that exhibited capability to solubilize phosphate. The selected isolate was identified by physiological, biochemical, and molecular biological tests. Conditions for optimal phosphate solubilization were determined by single factor and orthogonal experiments. Effect of the fungal addition on fertilization was verified by a pot test conducted on tobacco seedlings. Result The selected isolate was code-named JL-7 and, subsequently, identified to be a strain of Aspergillus fumigatiaffinis. The optimized conditions to maximize the phosphate-solubilization of JL-7 applied an inoculation at the rate of 1×105 cfu·mL−1 with an initial pH of 6 to incubate at 26 ℃ for 8 d. The process dissolved a low-grade phosphorus ore material up to 967.4 mg·kg−1 with the resulting solution reduced to approximately pH 2.9. In the pot experiment, the Yunyan 87 tobacco seedlings grown on a medium with the addition of a JL-7-inoculated phosphorus fertilizer had the stem girth, plant height, and maximum leaf area increased by 44.60%, 57.29%, and 62.90%, respectively, over control. Meanwhile, the pot soil increased 48.5% on available phosphorus, 3.7% on available potassium, and 9.1% on alkali-hydrolysable nitrogen after the planting as well. Conclusion The identified strongly phosphate-solubilizing Fungus JL-7 displayed a significant and consistent ability of dissolving phosphate. It was considered a potential candidate to be widely promoted as a microbial fertilization enhancer.
