2020 Vol. 35, No. 4
Display Method:
2020, 35(4): 359-365.
doi: 10.19303/j.issn.1008-0384.2020.04.001
Abstract:
Objective To construct and determine the functions of a recombinant expression vector which could stably and efficiently express the olfactory receptor AcerOr1 in Sf9 cells of Apis cerana. Method AcerOr1 was amplified and using T4 DNA ligase ligated into the insect expression vector pIB/V5-His treated by BamHI and EcoRI. The recombinant DNA was liposome-transfected onto Sf9. Subsequently, AcerOr1 expression was determined by Western blot, and protein subcellular localization by immunofluorescence. A full-wavelength multifunctional microplate reader was employed to determine the intracellular Ca2+ concentration before and after the recombinant receptor was stimulated separately with lauric acid, linolenic acid, α–terpineol, and undecanoic acid. Result The recombinant pIB/V5-AcerOr1 was successfully constructed with a stable, transfected vector expression. The recombinant expression vector was determined to be approximately 50 kDa and localized as predicted in the Sf9 cell membrane. The intracellular Ca2+ concentrations in the Sf9 cells transfected with pIB/V5-AcerOr1 increased correspondingly upon the stimulations by the floral substances. Conclusion The recombinant pIB/V5-AcerOr1 was successfully constructed with a stable expression in the Sf9 cell of the bees with the olfactory function verified by exposing the cells to aromatic chemicals.
2020, 35(4): 372-378.
doi: 10.19303/j.issn.1008-0384.2020.04.003
Abstract:
Objective Metabolites of Oncomelanias hupensis infested by parasite Schistosoma japonicum were analyzed to search for a biological control for the disease on the snails. Method Under microscopic examination, snails were determined whether or not being infested by the parasite. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the metabolites of the positive and negative snails for comparison. An orthogonal-partial least squares method was applied to differentiate the healthy and diseased subjects. Result Eighteen substances were found to present in the two categories of specimens with significant differences. Among them, benzyl alcohol, sucrose, dioctyl phthalate, and 3-hydroxybutyric acid showed 2.3 to 765 times higher in quantity on the healthy than the infested snails. Those identified metabolites were known to be associated with energy metabolism, protein synthesis and decomposition, signal transduction, and/or gene expression. Conclusion The chemical disparities on the metabolites between the healthy and diseased O. hupensis suggested that the S. japonicum parasitism seriously affected the nutritional metabolism, growth development, and reproductive capacity of the snails. The finding would aid further study on the interaction mechanism between the parasite and its host for the development of an effective biological control of the disease.
2020, 35(4): 379-391.
doi: 10.19303/j.issn.1008-0384.2020.04.004
Abstract:
Objective By adding Funneliformis mosseae to the sweet corn field, roles of AM fungi play on the nitrogen (N) utilization and the fungal diversity in rhizosphere soil were studied. Method Various N applications including no N (N0), 330 kg N·hm−2 (N22), 297 kg N·hm−2 (N19.8), and 264 kg N·hm−2 (N17.6) were used. In addition, at a same level of N, two split-plots with (AM+) or without (AM－) 315 kg·hm−2 of F. mosseae were included for the experimentation. Thus, 8 treatments with 3 replicates each were performed. Rhizosphere soil were sampled for chemical analysis and Illumina Hiseq 2500 sequencing to determine the diversity and community structure of the AM fungi. Result Among the AM+ treatments, the fresh bud yield of the corn plants increased by 32.6% at N0, 16.7% at N17.6, 8.0% at N19.8, and 0.8% at N22. In comparison to AM－, the N utilization of the plants on the AM+ plots with N17.6, N19.8, and N22 improved by 5.51%, 4.14%, and 6.19%, respectively. From the 1 558 461 valid sequences obtained, 15 771 OTUs were clustered at 97% similarity level to show a result of one class, 4 orders, 5 families, and 5 genera. Among the common genera, Glomus, Claroideoglomus, and Paraglomus, Glomus predominantly presented in the rhizosphere accounting for more than 21.82% of all species with a relative abundance ≥1%. The N22/AM+ treatment yielded higher Chao1 and richness indices than others (P＜0.05). The greatest abundance index as well as the lowest Shannon and Simpson indices were found with the N0/AM+ treatment. The addition of F. mosseae significantly increased the correlations between Shannon index, Simpson index and infection rate, spore density, and utilization rates of 4 types of N (NAE, PFP, NRE, and NPE) (P＜0.05). Conclusion The addition of F. mosseae in corn field altered the AM fungal community in the rhizosphere resulting in an increased crop yield. This study confirmed the significant promotional effect of AM fungi on the N utilization efficiency by sweet corn plants, which would effectively reduce the need for N fertilizer in the field.
2020, 35(4): 392-397.
doi: 10.19303/j.issn.1008-0384.2020.04.005
Abstract:
Objective Agronomic characteristics and nutritional quality of colored rice grains from the mutated plants germinated from the irradiated seeds were analyzed. Method Dried rice seeds of Yangdao 6 (9311-CK) were irradiated by Co60 to self-cross breed stable mutants that bore grain hulls with reddish brown or black color. Agronomic traits and nutritional quality of the harvested grains were determined. Result R9311-01 of black grains and R9311-02 of reddish brown grains were obtained through the radiation treatment and select breeding. The mean ear length of R9311-01 and the 1000-grain weight of R9311-02 differed significantly from those of 9311-CK, but not the other agronomic traits. Aside from crude protein and total amino acid, the contents of fat, amylopectin, flavonoids, and anthocyanins in the grains of the mutant strains were significantly higher than those of control. Except the significantly higher lysine content in the grains of R9311-01, all other amino acids in the rice of either strain deviated significantly from control. Conclusion The grains of black R9311-01 and reddish brown R9311-02 mutant rice obtained by irradiation inherited most of the agronomic traits of the grains of their parents 9311-CK but showed an improved nutrient content. Consequently, the radiation treatment might provide a venue for breeding high quality rice varieties bearing colored grains.
2020, 35(4): 398-405.
doi: 10.19303/j.issn.1008-0384.2020.04.006
Abstract:
Objective Potential of applying an endophyte in plant roots, Piriformospora indica (Pi), to mitigate the ill-effect of excessive usage of plant growth regulators on rice paddies was investigated. Method Rice seedlings were hydroponically grown in a nutrient solution for 15 d. The height and chlorophyll content of the plants as well as the length, number, and vitality of the roots were monitored. ROS in the leaves was examined by a staining method. Effects of 2,4-D or PP333 treatment with or without Pi addition on the activities of antioxidant enzymes (i.e., SOD, POD, and CAT) in leaves were determined. Result Excessive applications of plant growth regulator can adversely affect or even retard the growth of rice plants. This study revealed that if a rice plant was inoculated with Pi it could become less vulnerable to the stress. Comparing 2,4-D treatment without Pi addition, the seedlings grew 26.02% taller, the roots 17.27% longer, the root count 30.77% more, the chlorophyll content 64.71% higher, and the root vitality 43.72% greater with the Pi addition. In the Pi+PP333 group, the plants were 36.79% taller and 23.64% higher in root vitality than without the presence of Pi. The leaf ROS of the rice seedlings increased with Pi, 2,4-D or PP333 in the nutrient solution. Either 2,4-D or PP333 treatment enhanced the SOD, POD and CAT activities, but the Pi inoculation did not exert any significant differences on them. Conclusion It appeared that P. indica could indeed alleviate the stress imposed on rice plants due to overuse of plant growth regulators. By inoculating Pi in the medium, the rice plants could overcome the interference by 2,4-D or PP333, grow well, and develop a robust root system. Restoration of the antioxidant system in rice by Pi might allow the plant to effectively mitigate the ill caused by over-exposure of plant growth regulators.
2020, 35(4): 406-413.
doi: 10.19303/j.issn.1008-0384.2020.04.007
Abstract:
Objective Effects of planting density and nitrogen (N) application on the yield and agronomic efficiency on N (AEN) of winter potato were studied to improve the crop cultivation practices. Method Minshu 1 , a major winter potato cultivar, was used to determine the effects of planting density and N application rate on tuber yield, AEN, and leaf photosynthesis of the plants in a split plot experimentation. Three planting densities at 47 600 plant·hm−2 (D4.76), 66 700 plant·hm−2 (D6.67), and 109 600 plant·hm−2 (D10.96) were implemented on a main plot, and 4 varied N inputs applied at the rates of 0 kg·hm−2 (N0), 75 kg·hm−2 (N75), 150 kg·hm−2 (N150), and 300 kg·hm−2 (N300) on a subplot. Result Both planting density and N input significantly affected the tuber yield and AEN of the potato plants. The two independent variables also significantly interacted to result in varied effects. Increasing the planting density improved the total yield and AEN of the potato plants, as D6.67 delivered the highest yield, while D10.96 the highest AEN, among all treatments. With N300, the total potato yields under D6.67 and D10.96 were 21.3% and 21.2%, respectively, whereas, AEN 20.5% and 49.2%, respectively, higher than those under D4.76. N applications significantly affected the tuber production with the highest yield found with N150. There was no significant difference on the yield between N75 and N150 under D4.76 or D6.67. But, as the planting became denser under D10.96, the N75 treatment produced significantly less potatoes than N150. AEN of the plants decreased with increasing N input. As compared to N75, N150 and N300 showed significantly reduced AEN by 41.2% and 75.2%, respectively. N application promoted the gas exchange parameters and SPAD on the leaves of the potato plants. High planting density was detrimental to photosynthetic efficiency, as shown by the leaf Pn of D10.96 being lower than that of D6.67. There was a significant correlation between the photosynthetic characteristics and potato yield of a plant. Conclusion In the experimentation, the highest tuber yield of 32.2 t·hm−2 was achieved when the potato were planted at 66 700 plant·hm−2 and fertilized with 150 kg N·hm−2. The greatest AEN of 156.5 kg·kg−1 was achieved with a planting density of 109 600 plant·hm−2 and a N input of 75 kg·hm−2. Thus, planting potato plants either at a high density with increased N application or at a low or medium density with reduced N input could improve the tuber yield and AEN of the plants.
2020, 35(4): 414-421.
doi: 10.19303/j.issn.1008-0384.2020.04.008
Abstract:
Objective Sugarcane cultivars exhibiting the characteristics of high-yield, sugar content and stress-resistance from various sources were screened for a germplasm collection in preparation for a 3 000 hm2 experimental station on the development of a sustainable sugar industry in Guangxi. Method The agronomic traits of 10 sugarcane varieties were compared in a one-year-new-planting followed by another year of ratooning on Xinxing Farm in Liuzhou, Guangxi from March 2016 till January 2018. Result During the two planting years, the LZ (including GR) series showed superior performances on yield and sugar content. Under the one-year-new-planting, the cultivars LZ02-186, LZ07-53, GR2, and LZ03-81 produced more sugar per plant than CK (ROC22). In the ratoon year, GR2 delivered significantly higher yield and sugar. The sugar yield was 16.32 t·hm−2, which was 57.7% higher than that of CK, while those of LZ02-186 and LZ03-81 were higher than CK as well. Conclusion Cultivar GR2 demonstrated desirable ratooning and resistance characteristics with high yield and sugar content and was a prime candidate for further investigation. Nonetheless, LZ02-186 and LZ03-81 that exhibited excellent traits on the number of productive stalks, cane yield, and stress-resistance were also recommended to be included in the germplasm collection.
2020, 35(4): 422-428.
doi: 10.19303/j.issn.1008-0384.2020.04.009
Abstract:
Objective In order to further understand the regulatory mechanism of steroidal saponins biosynthesis and metabolism of Anoectochilus roxburhii, the full-length cDNA of ArF26G gene was cloned and its expression pattern in the stem and leaf was analyzed. Method The full-length cDNA of ArF26G gene was cloned by RACE. Prokaryotic expression vector was constructed with pET-28a (+), and induced by IPTG. The expression levels of ArF26G gene in stem and leaf of Anoectochilus roxburhii at different temperatures and planting times were analyzed by fluorescence quantitative PCR. Result The full-length cDNA of ArF26G gene is 1 982 bp with an 1 764 bp ORF, which encoded a protein of 587 amino acids containing a conservative domain of Glycosyl hydrolase 1 (GH1) superfamily. ArF26G is located in chloroplast and a putative chloroplast transit peptide of 33 amino acid residues at the N-terminus. The molecular weight of ArF26G protein is 66.48 kD, and the theoretical isoelectric (pI) is 5.31, and the instability coefficient is 37.92, it is a stable protein. Prokaryotic expression vector pET-28a-ArF26G was constructed and induced successfully by IPTG in E. coli BL21 (DE3). The results of fluorescence quantitative PCR analysis showed that the expression of ArF26G in stem was significantly higher than that in leaf, and the highest expression of tissue culture seedlings was at 25℃. When the planting time was up to 4 months and 5 months, the expression of ArF26G gene in the stem was 11.9 times and 23.3 times as much as that in the stem of tissue culture seedlings treated at 25℃ respectively. Conclusion In this study, the full-length cDNA of ArF26G gene was cloned. The expression of ArF26G gene was the highest at 25℃ or planting for 5 months.
2020, 35(4): 429-436.
doi: 10.19303/j.issn.1008-0384.2020.04.010
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Objective Glycerol-3-phosphate acyltransferase (CsGPAT) involving the glycerolipid metabolic pathway was cloned from fresh leaves of Tieguanyin tea (Camellia sinensis) plants for bioinformatics analysis and expression analysis of different withering temperature. To understand the significance of GPAT gene in the process of tea withering, in order to provide a theoretical basis for temperature regulation in the process of tea withering. Method By screening the transcriptome data on withering oolong tea, the homologous GPAT sequence was obtained. Software including ExPASy Protparam, SMART, SignalP 4.1 Server, PSORT, prediction protein, etc. were used to obtain its bioinformatics; the SWISS-MODEL online tool applied to arrive at its 3D protein structure; and, NCBI Blastp employed to analyze its homologous alignment on the amino acid sequence. RNA from the tea leaves was extracted for qRT-PCR to determine the real-time expression as well as for cloning the full length of GPAT. Result The cloned CsGPAT (IDcsa:CSA000941.1/ IDcss:TEA019813.1) had a full length of 1 554 bp encoding a predicted protein of 497 amino acids. The bioinformatics showed CsGPAT not a signal peptide but a stable hydrophobic protein with a PlsC domain of phospholipid biosynthetic function that closely related to Camellia oleifera. Its expression peaked at the withering temperature of 20℃. Conclusion The expression of CsGPAT in the tea leaves was up-regulated when the withering temperature was relatively low. It suggested a crucial role the gene played in oolong tea processing.
2020, 35(4): 437-442.
doi: 10.19303/j.issn.1008-0384.2020.04.011
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Objective A lectin gene from Agaricus bisporus AS2796 was isolated to study the functions of the agglutinin protein in mushrooms. Method Based upon the reported sequences, a primer was designed to amplify the lectin gene with the total DNA as templates. A 432 bp PCR product was purified and connected to the prokaryotic expression vector pET-28a carrying the His label, then transformed into E. coli BL21 (DE3). The IPTG-induced expression product was subsequently purified by affinity chromatography and identified by Western blot. Result The amplified lectin gene was 432 bp with correctly constructed recombinant expression plasmid, pET-lectin. The recombinant agglutinin protein was about 18 kDa and more than 95% pure after purification, Conclusion For the first time, a lectin gene was successfully isolated from A. bisporus and amplified. The agglutinin protein obtained could be used to further study its bioactivity and biosynthesis.
2020, 35(4): 443-449.
doi: 10.19303/j.issn.1008-0384.2020.04.012
Abstract:
Objective To determine the appropriate time and seeding rate for sowing seeds of Chinese milk vetch (Astragalus sinicus L.) in the rice producing areas in Fujian. Method Four dates, i.e, September 30, October 25, November 20, and December 15, were selected to sow the Chinese milkvetch seeds at a rate of 15.0, 22.5 or 30.0 kg·hm−2 in the rice field. From the 12 varied treatments, growth and yield as well as the content and cumulation of nutrients of the plants at flowering stage were monitored. Result As the sowing time pushed toward end of a year, the plant height, stem girth, branch count, and nutrient accumulation of the Chinese milk vetch declined, while the nitrogen, phosphorus, and potassium contents increased at first, then decreased. The amount of seeds used in sowing did not result in a significant difference on yield. Overall, higher yields and nutrients accumulation in the hay were observed when the plants were sowed before December 15. They peaked at a seeding rate of 22.5 kg·hm−2 on September 30 with a hay yield of 6.94 t·hm−2 and accumulated nitrogen of 144.01 kg·hm−2, phosphorus of 14.45 kg·hm−2, and potassium of 116.01 kg·hm−2. Conclusion The seeding at a rate of 22.5 kg·hm−2 on September 30 appeared to be most desirable for obtaining high yield and quality of the hay in Fujian. It was found ineffective to compensate the production reduction due to late sowing by increasing the seeding amount.
2020, 35(4): 450-455.
doi: 10.19303/j.issn.1008-0384.2020.04.013
Abstract:
Objective Effects of various dehydration methods on the content and physiochemical properties of polysaccharides in the dried Laminaria japonica were studied. Method Fresh L. japonica was dried by applying 2 W·g−1 microwave-and-vacuum (MV1), 4 W·g−1 microwave-and-vacuum (MV2), vacuum (VD), hot air (HA) or solar exposure (SE). Yield, SO42−, viscosity, scavenging activities on hydroxyl and superoxide anion free radicals of the polysaccharides in the dried kelp were determined. Result Among the tried drying methods, SE produced kelp significantly lower on the yield (i.e., 7.87%), SO42− content, viscosity, as well as the in vitro antioxidant activity of polysaccharides in L. japonica than HA or VD (P＜0.05). On the other hand, MV2 rendered dried kelp with the highest polysaccharides content at 13.83%, while MV1 with the greatest antioxidant activity (P＜0.05). Conclusion Different drying L. japonica methods resulted in varied properties of the polysaccharides and kelp. By combining microwave and vacuum, the dehydration process maximally retained the functional components and antioxidant activity of the fresh kelp.
2020, 35(4): 456-464.
doi: 10.19303/j.issn.1008-0384.2020.04.014
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Objective Deep-learning and computation were applied to analyze the images collected by drones on the status of tassel on corn plants in the field for estimating crop growth and forecasting production. Method Drones, or unmanned aerial vehicles (UAV), flying at a height of 25 m above corn crop in the field were used to generate RGB images showing the position and size of tassel on the plants at heading stage. Under the deep-learning framework of MXNet, the data sets on a 3-to-1 training-to-testing ratio were fed into 4 models of the ResNet50-based Faster R-CNN, the ResNet50-based SSD, the mobilenet-based SSD, and YOLOv3. The algorithms provided by the models were tested to intelligently extract information from the images for an accurate and rapid report on the status of corn tassel. Results mThe 236 UAV-collected images were cropped individually into 1024×1024 size. Those of poor quality were discarded to result in 100 labeled datasets using the Labelme software. The mAPs of the 4 models were 0.73, 0.49, 0.58 and 0.72, respectively. The highest accuracy rate of 93.79% on the test was obtained from the Faster R-CNN model, followed by 89.9% from SSD_ResNet50, 89.6% from SSD_mobilenet, and 20.04% from YOLOv3. On processing speed, SSD_mobilenet was the fastest at 8.9 samples·s−1, followed by YOLOv3 at 3.47 samples·s−1, SSD_ResNet50 at 7.4 samples·s−1, and Faster R-CNN at 2.6 samples·s−1. Among the 4 models, YOLOv3 was the largest, 241 Mb in size, while SSD_mobilenet the smallest 55.519 Mb. Conclusion Considering the scarcity of available resources on the airborne UAV platform, as well as the detection accuracy, processing speed, and size of the programs, the SSD_mobilenet model was selected as the choice for the field surveying of corn tassel by UAV.
