2020 Vol. 35, No. 2
Display Method:
2020, 35(2): 124-129.
doi: 10.19303/j.issn.1008-0384.2020.02.002
Abstract:
Objective To provide theoretical basis for prevention and control of Orf in Fujian, the molecular characteristics and biological functions of ORFV011 genes of the vaccine strain and ORFV-PN strain were compared. Methods ORFV011 genes from the two strains were cloned and sequenced for comparison and analysis using bioinformatics software. Results The sequencing results indicated that both genes composed of 1 137 nucleotides coding 378 amino acids. The nucleotide sequence similarity of ORFV011 of the ORFV-PN strain was 98.6% with that of the vaccine strain, while 98.4% with that of the lentogen strain D1701. The amino acid sequence similarity of ORFV011 of the ORFV-PN strain with either the vaccine strain or the D1701 strain was the same at 98.7%. There were 16 nucleotide mutations and 5 amino acid variations in the gene of the ORFV-PN strain as compared to that of the vaccine strain. On the secondary structure, the encoded protein by ORFV011 gene of the ORFV-PN strain and the vaccine strain had 34.13% (or 129/378) and 30.42% (or 115/378) alpha helixes, respectively; 6.08% (or 23/378) and 6.88% (or 26/378) beta turns, respectively; 37.3% (or 141/378) and 39.15% (or 148/378) random coils, respectively; and, 22.49% (or 85/378) and 23.54% (or 89/378) extended strands, respectively. The predicted three-dimensional structure of ORFV011 of the ORFV-PN strain showed differences on the alpha helixes and random coils as compared with that of the vaccine strain. Conclusion It appeared that ORFV011 of the ORFV-PN strain deviated from that of the vaccine strain in sequence as well as secondary and three-dimensional structures. Thus, special attention must be placed in monitoring and controlling the Orf.
2020, 35(2): 130-139.
doi: 10.19303/j.issn.1008-0384.2020.02.003
Abstract:
Objective Molecular genetics of various Dusky Labiaet-barbel (Semilabeo obscures) was studied. Method The second-generation Illumina Hiseq 4000 high-throughput sequencing technology was employed to determine the sequences of the mitochondrial genomes of different species of S. obscures. Result The length of the individual mitochondrial genome was determined to be 16 598–16 599 bp containing 42.65%–42.7% GC. There were 13 protein-coding genes, 22 tRNA, 2 rRNA (i.e., 12S-rRNA and 16S-rRNA), and one control region. Except for the coded ND6, the values of GC-skew of the genomes were all negative; while those of AT-skew in COXI, ND3 and ND6 were negative as well; but those of AT-skew in others were positive. The 13 protein-coding genes consisted of 3 794 aa with the preference codon (RSCU＞2) including the termination codon Arg (CGA), Gly (GGA), Leu (CTA), Pro (CCA), Ser (TCA) and the termination codon Stp (TAA). These S. obscures appeared to relate most closely with Pseudogyrinocheilus prochilus and somewhat with Ptychidio jordani, Rectoris posehensis and Parasinilabeo assimilis. Conclusion The structures and sequences of the mitochondrial genomes of S. obscures as determined were in line with those of typical fish counterparts.
2020, 35(2): 140-149.
doi: 10.19303/j.issn.1008-0384.2020.02.004
Abstract:
Objective Physiological role of NPR1 gene plays in the development of induced systemic resistance (ISR) in Oncidium hybridum was studied. Method NPR1 of the orchid was cloned using RACE technique, and bioinformatics and phylogenenetic analyses on the gene conducted. After co-cultured with Piriformospora indica or treated with salicylic acid (SA) or methyl jasmonate (MeJA) to induce ISR, the orchids were analyzed for the treatment effect against soft rot disease caused by Erwinia chrysanthemi. And, expressions of NPR1 during the treatments were investigated. Result Two full-length cDNA sequences were cloned. They were of a same type, one named OgNPR1-1 with a length of 1 804 bp encoding 555 amino acids, and the other, OgNPR1-2 1 902 bp encoding 556 amino acids. Their expressions were slightly upregulated by the inoculation of symbiotic P. indica. However, as both P. indica and E. chrysanthemi were present in the orchids, the expressions were significantly upregulated. It indicated that, in the presence of P. indica, the orchid plants became significantly more resistant to E. chrysanthemi inhibiting spread of the soft rot disease. On the other hand, the symbiosis of P. indica did not upregulated the expressions of the two genes more than the treatment by exogenous SA or MeJA on the orchids. Conclusion The expression of NPR1 in the orchids inoculated with the symbiotic P. indica was significantly upregulated in the presence of E. chrysanthemi. Although the increased expression by P. indica was lower than what induced by exogenous SA or MeJA hormone treatment, nonetheless, the orchids benefitted from the symbiosis and became more resistance to the soft rot disease.
2020, 35(2): 150-160.
doi: 10.19303/j.issn.1008-0384.2020.02.005
Abstract:
Objective Characteristics and contents of minerals in Oolong tea germplasms were studied to facilitate the classification, cultivar selection, and new variety breeding on tea plants. Method Contents of 18 minerals in 34 Oolong tea germplasms were determined by ICP-OES, and classified using principal component and cluster analyses. Result The average mineral contents in the specimens were found to be in the order of K＞P＞S＞Mg＞Ca＞Mn＞Al＞Fe＞Na＞Zn＞Ba＞Cu＞B＞Ti＞Ni＞Cr＞Co＞Se. The coefficients of variation ranged from 15.75% on P to 69.43% on Ti. The average genetic diversity indices varied from 1.27 on Ti to 2.21 on Zn. The contents of B, K, Mg, Mn, Na, Ni, P, S, Se, and Zn followed the normal distribution pattern, while those of Al, Ba, Ca, Co, Cr, Cu, Fe, and Ti a skew distribution, according to a W test. The correlations among these minerals were complex. The principal component analysis classified the 18 minerals into 5 groups that covered 77.40% of the total. By the cluster analysis, the 34 tea germplasms were grouped into 3 categories. Conclusion Mainly Mn, Ca, Mg, Al, K, P and S, the mineral compositions in the 34 Oolong tea germplasms differed. Based on their varied contents, the germplasms were classified into 3 types including (a) high P, Zn and low Al, Ca, Mn, Mg, (b) high Al, Ca, Mn, Mg, K, S, and (c) low K, P, S, Zn. Five Oolong teas with high mineral accumulation capacity and nutritional value were Zhilanxiang, Benshan, Ruixiang, Tieguanyin, and Huangdan, which were considered desirable cultivars for large scale cultivation and new variety breeding as well as product development for marketing.
2020, 35(2): 161-168.
doi: 10.19303/j.issn.1008-0384.2020.02.006
Abstract:
Objective Regularity and characteristics of as well as factors affecting the late-stage inflorescence of pear trees relating to fruit bearing of the plants were studied. Method Occurrence time and location of late-stage flowers on pear trees as well as physiological and environmental factors affecting the inflorescence were systematically monitored in the field. Result The late-stage flowers started to appear on a pear tree 10 days or more after regular inflorescence in spring and lasted till September. They showed up 70.27% of the time during the period when pears formed from regular flowers were rapidly expanding on a plant, 16.89% when the fruits were slowly enlarging, 7.93% when the fruits were rapidly enlarging, and 4.46% when the fruits were storing and accumulating nutrients. They were found mostly on tip of annual auxiliary shoots (94.64% of total), some on tip of mid-long shoots at 4.29%, and a few on tip of perennial adventitious buds at 1.07%. Compared with the regular flowers, the late comers were longer on the inflorescence axis with 3 or 4 small leaves on the base, bigger on the spacing between individual flowers, lengthier on the stalks, and smaller on the receptacle. They also started blooming from the center rather than the peripheral of a inflorescence. Of all, 43.23% of the fruit-setting from the late-stage flowers occurred in the rapid expanding period of regular fruits, 16.61% in the slow fruit enlarging period, 29.44% in the rapid fruit enlarging period, and 29.48% in time of nutrient storing and accumulating on Huanghua pear plants. The late-stage flowers found on the auxiliary shoots would generally develop and form fruits that ripened on the tree. Such result was observed on the pear plants with ample nutrient supply, of the varieties that showed a high rate of bud formation and long florescence period, and/or during the years encountering stresses such as serious diseases, pest infestation and/or climatic changes that affected fruit development. Conclusion The late-stage flowers on a pear tree were largely found in the rapid expanding time of the regular fruits and on the tip of annual auxiliary shoots. They had longer inflorescence axis, wider spacing between flowers, lengthier stalks, and smaller receptacles than the regular flowers on a same plant. Their blooming sequence was opposite to the regular inflorescence. The late-stage flowers on the auxiliary shoots that bloomed early generally developed fully into fruits that matured into edible product for marketing. At time of yield decline due to diseases, the late fruit bearing compensated somewhat the loss. The delay could also inadvertently alter the fruit harvesting. Therefore, if late-stage inflorescence was desired, applying fertilization coupled with external stress to induce changes on the plant physiology could be a plausible approach.
2020, 35(2): 169-177.
doi: 10.19303/j.issn.1008-0384.2020.02.007
Abstract:
Objective To search for applicable molecular markers for studying Brassica juncea. Method SSR sites were searched from transcriptional sequencing of B. juncea. Potential primers were designed using Primer 3.0, and polymorphisms of 44 B. juncea germplasms detected from randomly selected 50 pairs of primers for the investigation. Result Totally, 55,636 unigenes were obtained from the transcriptome sequencing. The entire sequence was 48,193,376bp with 9,526 SSR loci identified from 7,834 unigenes at a rate of 14.08%. Of the loci, 1,371 contained more than one SSR locus and 572 compound loci. Of the major repeat types, 51.12% were trinucleotide dominated by AGA/TCT (18.30%), and 41.91% dinucleotide dominated by AG/CT (34.74%). Using Primer 3.0, from 21,282 pairs of SSR primers, 50 were randomly selected for the PCR amplification. Out of 44 amplifications, 41 showed clear and reproducible bands, and 17 with polymorphisms. The 44 germplasms were classified into 4 distinctive groups by UPGMA. Conclusion The SSR markers with high frequency and polymorphism could be acquired from the transcriptome to be used for the genetic diversity analysis and mapping construction on B. juncea.
2020, 35(2): 178-186.
doi: 10.19303/j.issn.1008-0384.2020.02.008
Abstract:
Objective Effect of low temperature storage on the aromatic constituents in Rose damascene flowers was evaluated. Method Aromatics of R. damascene flowers were extracted by steam distillation. Samples of extract were collected every hour for 4 h to be chemically analyzed by gas chromatography-mass spectrometry. Result The floral water extract of either the refrigerated or the fresh roses had the same typical fragrance and similar chemical compositions. Among the characteristic aromatic compounds, phenylethyl alcohol and citronellol in the extracts were not significantly affected by the low-temp treatment, and geraniol might have been converted to nerol. On the other hand, terpenes were reduced, with the relative contents of ketones, such as methyl heptanone, lowered and (Z)-citral and (E)-citral increased,which increased the aromatic quality but reduced the storage time of floral water. There were no significant effects detected on esters, phenols or other aromatics. Conclusion Low-temp storage of R. damascene flowers did not seem to significantly reduce the aromatic quality of the water extract and could be applied to extend the shelf life of the flowers.
2020, 35(2): 187-191.
doi: 10.19303/j.issn.1008-0384.2020.02.009
Abstract:
Objective Characteristics and full genomic sequence of Chilliveinal mottle virus (ChiVMV), one of the most recurring viral pathogens infecting chili pepper plants in South-East Asia were studied to decipher the evolution of the virus for improved estimation on its potential threat to Solanacae crops. Method The ChiVMV gene from Hunan isolate (ChiVMVhn) was sequenced using the small RNA high-throughput sequencing and RT-PCR. Molecular characteristics of the gene were analyzed by Mega, RDP, and DnaSP software. Result The gene of ChiVMVhn contained 9,704 nucleotides (excluding 3’-poly A) and shared 84%-94% identity with those from the other ChiVMVs. The phylogenetic analysis suggested that ChiVMVhn represented an evolutionary isolate distinctive from those reported previously elsewhere in the world. The nucleotide substitution in ChiVMVhn gene was R=3.29 and dominated by C/T. Conclusion RNA mutation, rather than recombination, in the genes was seen crucial in the evolution of ChiVMVhn. Further studies on varieties of ChiVMV would considerably aid the scientific understanding on the evolution and pathogenic potential of the virus.
2020, 35(2): 192-199.
doi: 10.19303/j.issn.1008-0384.2020.02.010
Abstract:
Objective From the perspective of micro-ecology, effect of varied cultivation practices on fungal diversity in the rhizosphere soil of winder potato fields were studied to improve the cultivation in Guangxi. Methods The Illumina Miseq high-throughput sequencing was used to compare the fungal diversity in the rhizosphere soils at fields under either black film mulching (BFM), rice straw mulching (RSM) or conventional practice (CK). Results The fungal diversity index in rhizosphere soil was higher under BFM than the other two. The difference on the Simpson indices of BFM and RSM was significant (P＜0.05). The species and relative abundance of dominant strains in the soils differed among the treatments and potato growth period. Ascomycota was the most dominant phylum found in the soils under all 3 methods with its relative abundance being the greatest under BFM. The dominant fungi genus under BFM was Cephalotrichum, under RSM Agrocybe, and under CK Mortierella. In late stage of potato growth, BFM resulted in a higher relative abundance of Mortierella,Cephalotrichum, Clonostachys, and Acremonium than did CK, but the lowest in the relative abundance of Fusarium among all treatments. Conclusion The application of a black film for mulching on the ground (BFM) at potato growing fields significantly improved the species abundance, structure, and diversity of fungal community in the rhizosphere soil over the other practices. It facilitated the decomposition and transformation of organic matters in soil, the growth and proligeration of beneficial microorganisms, and the stability of the rhizosphere microbial environment for optimal growth and development of potatoes. On the other hand, the use of rice straws in RSM appeared to mitigate the soil-borne disease caused by Fusarium on the potato.
2020, 35(2): 200-209.
doi: 10.19303/j.issn.1008-0384.2020.02.011
Abstract:
Objective Characteristics of soil infiltration in agroforestry on karst mountains were studied, and their infiltration patterns fitted to simulation models. Method Through experiments in the field, the soil infiltration characteristics and factors affecting agroforestry of forest+medicinal herb, forest+grain crop, and forest+grass types were analyzed by comparing with a monocultural economic forest setting. The infiltration patterns were entered in 4 commonly applied mathematical models for best fitting. Result ① The initial, stable and average infiltration rates as well as the total infiltration amounts of the 3 agroforestry types were higher than those of the monocultural forestry. They decreased in the soil layers of increasing depth. The infiltration curves showed 3 distinctive stages with varied durations (t), i.e., rapid reduction phase (t≤10 min), slow reduction phase ( Conclusion All 3 tested agroforestry types improved the soil infiltration to varying extents by affecting the soil porosity and bulk density on karst mountains. The agroforestry of forest+medicinal herb type appeared to provide the greatest impact on soil infiltration, followed by forest+grass, and the infiltration pattern could best be described by the Horton or the general empirical model.
2020, 35(2): 210-216.
doi: 10.19303/j.issn.1008-0384.2020.02.012
Abstract:
Objective Correlation between the high-performance liquid chromatography (HPLC) fingerprints and the DPPH radical scavenging activities of catechins from varieties of teas was studied. Method From 5 categories of teas including green tea, white tea, northern Fujian oolong, southern Fujian oolong, and black tea, 25 specimens were collected and extracted with 70% methanol. The extracts were used to determine polyphenols content by the Folin-Ciocalteu method, the free radical scavenging activity by [1,1-diphenyl-2-picrylhydrazylradical2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl, DPPH] assay, and the fingerprints by HPLC for a principal component analysis. A correlation model between the HPLC fingerprints and DPPH radical scavenging activity was established by a partial least squares regression analysis and validated by the Pearson analysis. Result The HPLC fingerprints of the 25 specimens had 8 common compounds. The established regression model showed a coefficient of determination of R2=0.900 9. The 3 compounds, epigallocatechin gallate (EGCG), epigallocatechin (EGC), and epicatechin gallate (ECG), exhibited the strongest and significant correlations with DPPH radical scavenging activity. On the other hand, gallic acid (GA) correlated inversely with the scavenging activity. The Pearson analysis showed a result consistent with what the partial least squares regression test did. Conclusion It appeared that the antioxidant activity of catechins in the various teas could be satisfactorily predicted by HPLC fingerprints.
2020, 35(2): 217-225.
doi: 10.19303/j.issn.1008-0384.2020.02.013
Abstract:
Objective A green, environmentally friendly, safe and efficient process to extract polyphenols from tea was explored and optimized using the response surface method. Methods Tieguanyin tea was used for the extraction with deep eutectic solvents (DESs). After the DES was selected and a single factor experiment conducted, the time, temperature and water content in solvent were optimized for the process with respect of polyphenol extraction rate by a response surface experimentation. Antioxidant capacity of the extract was determined according to the DPPH radical scavenging rate. Results Lactic acid and betaine of a molar ratio of 2:1 with a water content of 30% and a substrate-to-solvent ratio of 1:40 (g:mL) were chosen for the extraction at 60oC for 40 min. The response surface method optimized the process to apply a moisture content of 32.15% of DESs for a 46.79 min-extraction at 62.48℃ with a yield of polyphenols at 15.42%. The polyphenol extract was analyzed by HPLC to show a gallic acid content of 1.40%, catechins of 84.99%, and the remainders of 13.61%. The semi-scavenging concentration (IC50) of the extract was 73.89 μg·mL-1, which was 37.80% higher than that of ascorbic acid. Conclusion The newly developed DESs extraction significantly improved the polyphenol extraction rate from Tieguanyin tea over the conventional process.
2020, 35(2): 226-234.
doi: 10.19303/j.issn.1008-0384.2020.02.014
Abstract:
Objective Optimum preparation and antibacterial properties of a natural preservative extracted from bamboo sawdust were studied. Method Utilizing bamboo sawdust, a natural preservative was prepared with the ethyl acetate reflux method. Processing conditions were optimized by the response surface methodology based on the results of a single factor test. In vitro antimicrobial activity of the extract was determined. Result The finalized process applied 300 W ultrasonic power on the mixture of solvent-to-substrate ratio at 20 ∶ 1 to extract at 89℃ for 2 h. The product yield reached 4.77%. The extracted preservative displayed peak antimicrobial effects on Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Aspergillus niger with the average inhibition diameters of 9.33 mm at a concentration of 0.025 00 g·mL−1, 15.67 mm at a concentration of 0.012 5 0g·mL−1, 10.00 mm at a concentration of 0.050 00 g·mL−1, and 6.67 mm at a concentration of 0.100 00 g·mL−1, respectively. Conclusion The natural preservative prepared by the newly developed extraction method showed strong in vitro antimicrobial effect, and the optimized process could be upscaled to fully utilize the bamboo sawdust.
2020, 35(2): 235-242.
doi: 10.19303/j.issn.1008-0384.2020.02.015
Abstract:
Objective To overcome the shortcomings of time-consuming, labor-intensive and inaccurate conventional data collection of pest monitoring at vegetable fields, a system utilizing the internet of things technology was developed and tested. Method By coupling the use of sex pheromone to trap pests with the application of internet of things, a means to automatically count target pests in the field was designed. A pheromonal lure combined with a high voltage power grid was installed in vegetable fields to trap and kill pests for accurate insect counting. Infrared sensors were used to detect the presence of pests, and the collected data transmitted through a 4G network. Utilizing the .net platform, pest monitoring management website and APP, WeChat official digital plant protection account, and other supporting software were developed for easy access by users to browse and query data remotely with computer, mobile phone, WeChat connection or other terminals. One of the major pests infesting vegetables, Spodoptera litura (Fabricius), was targeted in the experiments held at the vegetable fields in Tong'an, Xiamen and Youxi, Sanming. Result The insect trapping effects were 276.14% in Tong'an and 162.60% in Youxi. The counting accuracy of the system were 93.52% in Tong'an and 81.59% in Youxi. Both the trapping rate and counting accuracy delivered by the system in the tests were considered acceptable. Conclusion The newly designed intelligent pests monitoring system automatically and accurately monitored the pests in the vegetable fields. It could be used to generate information for infestation forecasting.
