2020 Vol. 35, No. 8
Display Method:
2020, 35(8): 811-819.
doi: 10.19303/j.issn.1008-0384.2020.08.001
Abstract:
Objective A comprehensive indexing system to evaluate drought resistance of rice to be transplanted to maturity in cold regions was established and tested for screening suitable germplasms for the farming. Method Including panicle weight, grains per panicle, seed setting rate, and others, 13 traits were selected as indicators for the principal component and cluster analyses to study the drought resistance of 30 cold-region rice germplasms. Using the indicators from 25 of the specimens as input and the corresponding evaluation criteria as output, a learning model was formulated by the backward propagation (BP) of errors neural network algorithm. The remaining 5 germplasm specimens were reserved for validating the model on prediction accuracy. Subsequently, 3 transformed learning models were generated to compare their predictabilities and verify their suitability and stability for the application. Result The principal component analysis organized the 13 drought resistance indicators into 5 comprehensive indices with a cumulative contribution rate of 83.761%. Based on the results of the evaluation criteria on the 30 specimens, a cluster analysis divided the germplasms into the strongly drought resistant (SDR), drought resistant (DR), intermediately drought resistant (IDR), and drought sensitive (DS) types. Accordingly, Nongfeng 3055 was classified to be the SDR type, 12 germplasms the DR type, 6 germplasms the IDR type, and 11 germplasms DS. The correlation analysis indicated 6 indices, including panicle weight, grains per panicle, seed setting rate, grain yield, biomass, and economic coefficient, closely associated with the drought resistance indicators for the suitability evaluation on rice. Thus, taking these indicators for input and the evaluation criteria for output, BP neural network models were established for the quantitative prediction. The 3 transformed models exhibited high prediction accuracy and stability, along with a relative error between the predicted and actual values below 10%. Furthermore, the linearity coefficients, R2, of the models were all greater than 0.9. Conclusion The BP neural network models could satisfactorily render quantitative prediction with high accuracy and stability on drought resistance of rice for cultivation on locations. Using weight, grains per panicle, seed setting rate, grain yield, biomass, and economic coefficient as the resistance indicators, the models performed superior to the single regression analysis. They determined, among the 30 rice varieties investigated, Nongfeng 3055 to be a highly drought-resistant germplasm most suitable for cultivation in regions of cold climate.
2020, 35(8): 820-829.
doi: 10.19303/j.issn.1008-0384.2020.08.002
Abstract:
Objective Effects of shading on photosynthesis, growth, and aromatic composition of Pandan (Pandanus amaryllifolius) plants were studied for cultivation improvement. Method In a pot experimentation, pandan plants were grown under either full sun exposure or 30%, 60% or 90% shading. The photosynthesis, growth, and aromatics of the plants were monitored. Result The net photosynthetic rate, stomatal conductance, and count of the leaves on plants grown under 30% and 60% shading were significantly higher than those under either full sun exposure or 90% shading. On the other hand, the tiller number decreased significantly with increasing shading. Twenty-seven volatile aromatic compounds were identified regardless the difference in treatment. There were 10 aromatics, including 2-acetyl-1-pyrrolidine phytol, squalene, 1-propanol, acetol, 3-methyl-2-(5H)-furanone, neophytadiene, ethyl palmitate, 2,3-dihydrobenzofuran, and ethyl linoleate, commonly present, but differed significantly in relative content when the plants were under the varied shading. For instance, the contents of 2-acetyl-1-pyrroline, 3-methyl-2-(5H)-furanone, 2,3-dihydrobenzofuran, ethyl linoleate, and phytol were significantly higher under 30% and 60% shading, those of squalene and phytol significantly higher under 30% shading, and those of acetol, 2-acetyl-1-pyrroline, 3-methyl-2-(5H)-furanone, neophytadiene, ethyl palmitate, and ethyl linoleate significantly higher under 60% shading than the other treatments. Conclusion By artificially imposing 30% or 60% shading, pandan plants grew more vigorously generating more fragrant substances in the leaves than exposing naturally to the sun.
2020, 35(8): 830-836.
doi: 10.19303/j.issn.1008-0384.2020.08.003
Abstract:
Objective Micro-morphology of ovaries from the wild tea germplasms in Yunxiao and Zhao'an was examined to facilitate the identification and resource collection of tea germplasms in Fujian. Method The morphological characteristics of the ovaries from 29 wild tea germplasms were studied under a field emission scanning electron microscope (FE-SEM). Result The germplasms collected in Yunxiao and Zhao'an were classified by the morphology of their ovaries into the glabrous and trichome types. Those had a few, scarce or none trichomes on the ovary accounted for 72.4% of all. The trichomes were found mainly on the top of an ovary that determined the overall density and classification of a germplasm. The exine ornamentation on an ovary could be concave, flat or convex in appearance. Those on the ovaries of Yunxiao germplasms were mostly concave, while those of Zhao'an largely flat. Conclusion This study made the first report on the abovementioned observations. The micro-morphology of the ovary-glabrous germplasms displayed distinct difference on the exine ornamentation between the cultivars collected from Yunxiao and Zhao'an.
Growth, Development, and Fruit Quality and Yield of Varieties of Pear under Rain-shelter Cultivation
2020, 35(8): 837-844.
doi: 10.19303/j.issn.1008-0384.2020.08.004
Abstract:
Objective Application of rain-shelter for pear cultivation in southern hot and humid regions was evaluated according to the growth, development, and fruit quality and yield of the selected varieties. Method Indicators on shoots, leaves, flower buds, phenology, fruit quality, and fruit yields of different types of pear varieties were monitored with individual tree tracking to compare the effects of rain-shelter and open-field cultivations. Result Compared with open field cultivation, rain-sheltering prolonged the fruit development and vegetative periods, increased the fruit forming percentage of inflorescence and individual flower, weakened the growth of shoots and leaves, improved the fruit appeal, and lowered the firmness and acidity but increased the total sugar content of the fruits. Grown under rain-shelter, the 3 early maturing pear varieties that were susceptible to early defoliation significantly or extremely significantly increased on their flower-to-bud ratio, weight of 100 flower buds, yield per plant, and weight of single fruit; while Cuiyu and Cuiguan, among them, significantly increased in soluble solids. The two mid-season maturing varieties that were less prone to early defoliation decreased significantly or extremely significantly on their flower-to-bud ratio, weight of 100 flower buds, and single fruit weight; while Huanghua showed a 22.42% decrease on yield per plant and a significant reduction on soluble solids. For the 3 green pear varieties, rain-sheltering helped them to become less susceptible to fruit rust, as Cuiyu turned out to be extremely significantly reduced on the appearances of rust-infected fruits, rusty peels, and spotty fruits. Conclusion The early maturing, early defoliation-susceptible varieties of pear that are resistant to rust could be candidates for the perennial film-covering rain-shelter cultivation. Whereas, fruit bagging would be necessary on the rust-sensitive, early maturing varieties to avoid early defoliation under rain-shelter cultivation. For the mid-season maturing varieties that are not prone to early defoliation, open field cultivation would be more appropriate. If rain-sheltering was applied to these mid-season maturing varieties, they should be covered with film only in the early and middle stage of growth and development, and the film should be removed following fruit harvesting.
2020, 35(8): 845-850.
doi: 10.19303/j.issn.1008-0384.2020.08.005
Abstract:
Objective Changes and classification on leaf color of various varieties of ornamental crabapple were studied to facilitate the germplasm collection and utilization. Method Color values and pigment content of leaves on 42 specimens of ornamental crabapple (Malus spp.) were determined using chromometer and spectrometer. Result ① The distributions of the CIELCH color space measurements on luminance (L*), color saturation (C*), and hue (h*) of the leaves from July to September showed it to be relatively scattered in July, stratified in August, and shifting to the left on the values in September. ② The leaf color in July clustered the 42 crabapple varieties into Group A with the ranges of L*=28.95−32.63 and C*=12.32−14.60; Group B, L*=26.98−32.11 and C*=9.09−13.39; and, Group C, L*=32.10−35.22 and C*=14.33−18.01. L* and C* of these 3 groups differed significantly in the order of C＞A＞B. Trees in Group C appeared bright and full in color and were classified as bright green varieties. ③ The relative pigment (chlorophyll) content in leaves of Group B was 4.285%, which was significantly higher than that of Group A at 3.786% and Group C at 3.785%. With the deep green color and low L* and C*, Group B was named the dark green varieties, while Group A was simply termed green varieties. Conclusion The 9 ornamental crabapple varieties in Group C were judged to have the highest potential commercial value among all in the season.
2020, 35(8): 851-856.
doi: 10.19303/j.issn.1008-0384.2020.08.006
Abstract:
Objective Appropriate cell line, expression vector, and transfection reagent were selected to enhance the transient expression of GFP recombinant protein for quick and efficient production of the proteins in CHO cells. Methods Targeting GFP, various eukaryotic vectors were employed to carry the gene protein for transfection into ExpiCHO-S cells. Four days after transfection, number and intensity of expression fluorescence on the recombinant plasmids by different vectors were recorded. Four more days later, the cells were lysed, and the lysate supernatant harvested to verify the gene expressions by SDS-PAGE. Meanwhile, GFP recombinant plasmids in the supernatant were purified on a His Trap FF affinity chromatography column to quantify the protein expressions by western blot. Results The recombinant plasmids, pCDNA3.1-GFP and pCDNA3.4-GFP had the expression fluorescence the greatest in number, pCIneo-GFP the highest on intensity, while pCMVHA the fewest in number and the lowest on intensity. SDS-PAGE and western blot showed the expressions of the first 3 recombinant plasmids were higher than those of pCHO-GFP or pCMVHA-GFP. Conclusion The GFP recombinant plasmids constructed with the eukaryotic vectors, pCDNA3.1, pCDNA3.4, and pCIneo, exhibited the greatest expressions and were considered the choice vectors for future studies requiring transient expression.
2020, 35(8): 857-862.
doi: 10.19303/j.issn.1008-0384.2020.08.007
Abstract:
Objective A duplex PCR assay for simultaneous detection on hyper- and low-virulent Staphylococcus aureus strains in rabbits was developed. Methods The assay was based on the specific primers targeting the nuc and pvl genes in a hyper-virulent and a low-virulent strain of S. aureus isolated from rabbits in Fujian. Primer concentration and annealing temperature for the assay were optimized, and detection specificity, sensitivity, and accuracy determined. Results The optimized primer concentration was 0.6 μmol·L−1 and annealing temperature 59.6 ℃ for the assay. Only the hyper- and low-virulent S. aureus isolated from rabbits were detected with no cross-reactions on the commonly found pathogens, such as Pasteurella multocida , Bordetella bronchiseptica, Klebsiella pneumonia , and Escherichia coli , nor on the negative control. The methodology was highly sensitive with a detection limit of 10 pg genomic DNA on the hyper-virulent strain and 100 fg on the low-virulent strains. The coefficients of variation of intra- and inter-assay were 0 indicating high repeatability on both applications. In addition, the test results of the duplex PCR assay were 100% coincident with those obtained by the PCR assays targeting nuc and pvl individually. Conclusion The newly developed duplex PCR assay could simultaneously detect the two virulent S. aureus strains with high specificity, sensibility, repeatability, and accuracy.
2020, 35(8): 863-868.
doi: 10.19303/j.issn.1008-0384.2020.08.008
Abstract:
Objective A LAMP (loop-mediated isothermal amplification) assay for rapid, visible and sensitive detection of Fusarium oxysporum on the succulent plant, Echeveria Perle von Nürnberg, was developed for early prevention and control of the disease. Method Based on the elongation factor 1α (EF-1α ) sequence of F. oxysporum , LAMP primers were designed. Template DNA from the infected stems were used to optimize the reaction temperature and time. Specificity and sensitivity of the assay were verified on the detection on infected plants from the field. Result The newly developed LAMP assay at 65 °C for 60 min effectively detected F. oxysporum on Echeveria . The assay gave the positive yellowish green result only on F. oxysporum of Echeveria . It had a detection limit of 10 fg·μL−1 and was 100% positive on detecting F. oxysporum from 15 Echeveria samples showing typical stem rot symptoms. Conclusion The established LAMP assay had high specificity and sensitivity with visual and low false positive results. It was considered suitable for rapid detection of F. oxysporum on Echeveria Perle von Nürnberg in the field.
2020, 35(8): 869-875.
doi: 10.19303/j.issn.1008-0384.2020.08.009
Abstract:
Objective Omethoate-degrading bacteria were isolated from shed soil to determine their capacities in decomposing the pesticide for possible application in the field. Method Single carbon source culture was used to screen microbes for the potential purpose followed by morphological observation and 16S RNA sequencing for identification. The pesticide-degrading ability of the isolates was determined by molybdate blue spectrophotometry and HPLC, then verified by a shaking flask method in the laboratory. The culture broth for the challenge test containing the selected isolates, one at a time, was artificially added with omethoate at various concentrations. Result A strain, ZZY-C13-1-9, could grow normally when the pesticide was at 1 000 mg·L−1. It was identified as Pseudomonas abietaniphila and capable of degrading 92.3% of omethoate at 400 mg·L−1 level in the nutrient broth within 240 h at the condition of 30 ℃ and 180 r·min−1. In addition, the strain was found to tolerant DDVP and Dipterex in high concentration as well. In a laboratory test at 25–34 ℃ on soil with a moisture content of 25%–30% and omethoate at 200 mg·L−1, ZZY-C13-1-9 decomposed 59.2% of the pesticide in 45 d. Conclusion A bacterium capable of effectively degrading omethoate in soil was successfully isolated, identified, and characterized.
2020, 35(8): 876-882.
doi: 10.19303/j.issn.1008-0384.2020.08.010
Abstract:
Objective Information on the species diversity and spatial distribution of nectar-producing plants in National Wuyishan Nature Reserve was collected for promoting the beekeeping industry, increasing the honey production, enriching the residents’ income in the surrounding communities. In addition, it might aid on the planning of a pilot bee releasing project at the Reserve. Method By foot survey and plant sociology techniques, the species, quantity, and distribution of nectar-producing plants in the National Wuyishan Nature Reserve were gathered. The diversity and vertical distribution pattern of the plants in the wild were subjected to variance analysis, cluster analysis, and β diversity measure. Result In the Reserve, there were 338 species of plants that produced nectars for honey bees. They belonged to 149 genera in 61 families and were mainly auxiliary, rather than major plants. The plants flowered mostly in spring, less in autumn and winter. Their potential honey-producing value was estimated to be medium to high. The distribution and numbers of families and genera of these nectar-producing plants were similar at elevations below 1,200m but differed significantly comparing to 1,200-1,500m, 1,500-1,800m, 1,800-2,100m. A single peak distribution pattern was observed at all altitudes. The cluster analysis and the Cody index of the β diversity measure indicated that nectar-producing plants were richly present at low altitudes, especially in 600-900m. Conclusion The resource of nectar-producing plants were rich in the National Wuyishan Nature Reserve. Their distribution closely related to the ecosystem at different altitudes of the mountain.
2020, 35(8): 883-890.
doi: 10.19303/j.issn.1008-0384.2020.08.011
Abstract:
Objective Effects of pre-soaking seeds in isosteviol solution on germination and seedling growth of Brassica napus under salt stress were studied. Method Seeds of Qinyou No. 2, a variety of B. napus , were pre-soaked in isosteviol solutions of different concentrations to determine the rate, index, and vigor of the seeds, as well as the height, chlorophyll content, root length and activity, malonaldehyde (MDA) content, and antioxidant enzyme activity of the seedlings under salt stress. Result Salt stress inhibited the germination of B. napus seeds with a threshold concentration at NaCl 140 mmol ·L−1. By pre-soaking the seeds in a 1×10−8 mol·L−1 isosteviol solution, the root activity, chlorophyll content, and SOD activity in cotyledons of the seedlings were significantly increased. Compared to CK2 (seeds pre-soaked in deionized water prior to germination in a NaCl 140 mmol ·L−1 medium), the isosteviol treatment increased 27.33% on root activity, 36.94% on chlorophyll content, and 83.31% on SOD activity, while significantly reduced MDA content by 32.11% in the cotyledons. When a 1×10−9 mol·L−1 isosteviol solution was used for the pre-soaking, the POD and CAT activities were significantly increased by 140.80% and 47.25%, respectively, over those under CK2. The pre-soaking treatment also significantly improved the germination rate, index, and vigor of the seeds, and significantly increased the height and root length of the seedlings. Conclusion Pre-soaking the seeds with an isosteviol solution of appropriate concentration (i.e., 1×10−9−1×10−8 mol·L−1) enhanced the salt resistance of B. napus reducing the adverse effects on the seed germination and seedling growth caused by the salt stress.
2020, 35(8): 891-895.
doi: 10.19303/j.issn.1008-0384.2020.08.012
Abstract:
Objective Effects of exogenous treatment of glycine betaine (GB) on seeds and seedlings of Astragalus membranaceus under salt stress was studied to decipher the stress alleviation. Method The seeds and seedlings of A. membranaceus (Fisch.) Bge.var.mongholicus (Bge.) Hsiao (Am H) and A. membranaceus (Fisch.) Bge. (Am B) under 100 mmol·L−1 NaCl stress were treated with GB 0–40 mmol·L−1. The rate, potential, and index of seed germination as well as the seedling vigor index and relative salt damage occurrence percentage to the plants were determined. The activities of SOD, CAT, POD, APX, GR and DHAR in the seedlings were analyzed. Result Addition of GB 30 mmol·L−1 to the salt containing medium increased the germination rate of Am H seeds by 159.07% and of Am B seeds by 167.01%, while reduced the relative rate of salt damage on Am H seedlings by 74.38% and on Am B seedlings by 76.18% in comparison to those without the addition. Under salt stress, the seedlings treated with GB 10–30 mmol·L−1 raised on the SOD, CAT, POD, APX, GR and DHAR activities in varying degrees. In general, the activity increases were greater on seedlings of Am B than those of Am H. Conclusion The addition of GB 30 mmol·L−1 effectively ameliorated the adverse effects of the salt stress on the seeds and seedlings of A. membranaceus and more pronounced on Am B than on Am H.
2020, 35(8): 896-901.
doi: 10.19303/j.issn.1008-0384.2020.08.013
Abstract:
Objective Effect of different concentration of CO2 in confined environment on quality of sesame was studied for a green and economic storage technology of the food material. Method Sesame were packed in aluminum foil bags under vacuum and fill with CO2 gas and air in various proportion using a gas mixing device. The changes on 5 indicators, i.e., acid, peroxide, and iodine values, and crude fat and protein contents, of the stored sesame were determined every 2 months according to the national standard method. Result In storage, the acid and peroxide values of the bagged sesame increased gradually with increasing time. After 6 months, the acid value drastically increased reaching up to 0.700 0 meq·kg−1. Then, the increased slowed down till the end. The upward trend on peroxide value was less dramatic. When a bag was filled with more than 50% of CO2, the rises on acid and peroxide became slower than when less CO2 gas was used; the iodine value decreased slightly but not significantly; and, the crude fat and protein contents decreased gradually. And, the higher CO2 proportion in the package, the slower the decrease became. When a bag was filled 100% with CO2, the decline on fat reduced by 0.42% and that on protein by 0.28%. Comparing to control, which had 3.05% decrease on fat and 15.02% on protein, the effects were statistically significant (P ＜0.05). Conclusion Oxygen in package significantly affected the quality of the stored sesame. By including more than 50% of CO2 gas in a bag, the increases on acid and peroxide values were significantly reduced, and the reduction of fat and protein delayed, and the onset of rancidity of the sesame postponed. In other words, the original quality of the sesame could basically be maintained at a premium level for a year at room temperature by the controlled atmosphere storage with CO2.
2020, 35(8): 902-910.
doi: 10.19303/j.issn.1008-0384.2020.08.014
Abstract:
Objective Means to upgrade the resolution of the images obtained by the currently available Slentinel-2 optical imagery technology were explored for better identification of rapeseed crops in mountainous southwest China. Method Sentinel-2 images of rapeseed crops acquired from the satellite in space were modified using image reconstruction and fusion technology to increase the spatial resolution by varying the spectral bands. Image quality as to how accurate it could recognize rapeseed crops was evaluated based on a random forest, complex terrain model. Result ① The fusion treatment significantly enhanced the contrast on minute details and texture changes, greatly improved the sharpness, and increased the brightness of the images. Meanwhile, the gray curves of the main features remained basically unchanged before and after the treatment. ② The enhanced spatial resolution effectively facilitated vegetation classification. The overall accuracy and Kappa coefficient differed slightly at the resolution of 2m. However, the crop mapping accuracy was significantly improved from 91.30% to 95.65% by the red edge bands applied. ③ Different red edge bands exhibited varying effects on the recognition accuracy. The combination of C2 (visible light B2, B3, and B4-red edge B5-near infrared B8) and C1 (visible light B2, B3, and B4-near infrared B8) increased the accuracy by 4.75%. The combined C3 (visible light B2, B3, B4-red edge B5, and B6-near infrared B8) and C2 enhanced the accuracy by 1.21%. Although both red edge B5 and B6 bands could improve the overall accuracy, B5 was more effective than B6. The combination of C4 (visible light B2, B3, B4-red edge B5, B6, 7-near infrared B8) and C3 resulted in an increase on the mapping accuracy by 4.35% as well as a user accuracy by 0.57%. The red edge B7 was most effective of all. The random forest model showed, under the improved conditions, the normalized importance metrics of characteristic band for the blue band B2 to be 0.94; for the green band B3, 0.82; for the red band B7, 0.89; and, for the red edge B5, 0.75. The results, consistent with those obtained under the band combinations, indicated that B7 and B5 bands contributed more significantly to the accuracy improvement. Conclusion The spatial resolution of Sentinel-2 images could be significantly enhanced through image reconstruction and fusion. The accuracy of rapeseed crop identification by various band combinations was analyzed by the quantitative measurements of the importance of characteristic bands under the random forest classification model to arrive at the conclusion. As the first comprehensive study of its kind, the information obtained would be of value for further applications of the Sentinel-2 imaging system.
