2020 Vol. 35, No. 7
Display Method:
2020, 35(7): 691-698.
doi: 10.19303/j.issn.1008-0384.2020.07.001
Abstract:
Objective Light responses of potato plants bearing colored tubers were studied. Method Gas exchanges of potato leaves on 2 common varieties of yellow and white tubers and 4 of different colored tubers were determined. Collected data were fitted to the simulation models of rectangular hyperbola (RH), non-rectangular hyperbola (NRH), modified rectangular hyperbolic (MRH), and exponential function (EM). Photosynthetic parameters including maximum photosynthetic rate (Pn-max), light saturation point (LSP), light compensation point (LCP), dark respiration rate (Rd), and apparent quantum yield (AQY) on the plants were analyzed. Result (1) All 4 models could adequately simulate the responses under low light, and RH, NRH, and EM failed to predict on photoinhibition. On the other hand, MRH accurately covered the entire light spectrum with a correlation coefficient (R2) greater than 0.99, as well as the smallest root mean square error and mean absolute error, among all models. (2) Pn-max of the colored potatoes were lower than those of the common varieties. They were 6.7%–34.2% lower than that of Favorita and 14.8%–40.0% than that of Minshu 1. Aside from Hongmei, the other 3 colored potatoes showed LSP below 1 000 μmol·m−2·s−1, which was much less than those of the common varieties. No significant difference on the utilization under low light by the two categories of potatoes was observed. (3) Among the 4 colored varieties, Hongmei had the highest Pn-max and LSP, but lowest on the ability to use low light, while Mincaishu 3 exhibited the highest low light utilization. (4) The light response processes of stomatal conductance (Gs) and transpiration rate (Tr) were similar to that of net photosynthetic rate (Pn). They rose rapidly as the light intensity increased and then leveled off or declined. In contrast, the intercellular CO2 concentration (Ci) showed a sharp decline before stabilization. Conclusion The Pn-max and LSP of potato varieties that bore colored tubers were significantly lower than those of the common varieties indicating a lower photosynthetic potential and apparent photoinhibition. The information might lead to improved breeding and cultivation practices of colored potatoes.
2020, 35(7): 699-708.
doi: 10.19303/j.issn.1008-0384.2020.07.002
Abstract:
Objective By immersing buds in varied concentrations of sodium azide solutions to induce mutagenesis in vitro on 3 soybean germplasms, optimized induction conditions were determined based on the effect on the low-temp tolerance of the mutants under stress. Methods Young buds of Changshutedawang (CSTDW), Taiwan 292, and Jianhe soybean germplasms were immersed in sodium azide solutions of different concentrations for the in vitro mutagenesis induction. After the optimized induction treatment (immersing buds at 0.8mmol sodium azide/L for 48h), the plants were subjected to low-temp stress at 4 ℃ for 4d prior to the physio-biochemical determinations. Results The mortality rate of the treated plants was only slightly higher than the median lethal dose（LD50）. Under the low-temp stress, the contents of osmosis regulating substance and photosynthetic pigment in the mutant plants were higher than those in control. At room temperature, the increases on the germplasm was in the order of Taiwan 292＞CSTDW＞Jianhe, and the SOD and CAT in Taiwan 292 and Jianhe were significantly increased. Under low temperature, the antioxidant capacities differed among the germplasms. Overall, Jianhe was higher than CSTDW and followed by Taiwan 292. Specifically, SOD and POD activity increased in Jianhe, POD increased in CSTDW, and SOD and POD slightly increased and CAT decreased in Taiwan 292. Compared to control, Taiwan 292 had the greatest antioxidant activities showing an increased POD and slightly decreased SOD activity, CSTDW was next in line with no significant change, and Jianhe had the least with decreased activities on both SOD and POD. The MDA contents of CSTDW and Taiwan 292 increased initially followed by a decline, while Jianhe maintained an increasing trend. The overall increased levels ranked Taiwan 292＞ CSTDW＞ Jianhe. Conclusion The induced mutagenesis increased the osmosis regulating substance and photosynthetic pigment contents in the 3 soybean germplasms. The improvement on low-temp tolerance was higher for CSTDW and Taiwan 292 but lower for the local Jianhe soybean. After mutagenesis and low-temp treatment, Taiwan 292 performed well with a heightened antioxidant capacity. On the other hand, Jianhe changed significantly on the enzymatic activity, the condition was favorable for the plants at room temperature but disadvantageous at low temperatures. In all, the low-temp tolerance of the soybean germplasms generated by sodium azide-induced mutagenesis were found to be Taiwan 292＞CSTDW＞Jianhe.
2020, 35(7): 709-716.
doi: 10.19303/j.issn.1008-0384.2020.07.003
Abstract:
Objective A new high-quality, high-yield Dendrobium officinale variety suitable for cultivation in Fujian was bred. Method The capsules of D. officinale were obtained from natural pollination of L-2, a wild species found at Guanzhaishan in Liancheng County. From the offspring seedlings, LF-9 with the most desirable agronomic traits, growth potential, and stem yield was selected and rapidly propagated in tissue culture. Result After years of experimental cultivations at various localities, LF-9 excelled L-2 （CK） in quality evaluation, by microstructure observation, and with molecular identification. It was named Fuhu 1 and rendered in two-year regional tests an average fresh stem yield of 4,77 7.5 kg·hm-2, which was 17.7% higher than that of CK. At harvest, merely 0.9% of the plants were infected by the blight disease. The infection rate was 50.0% lower than that of CK. For the black spot disease, the occurrence rate was 7.3%, which was 29.8% lower that of CK. On the contents of functional ingredients, Fuhu 1 contained 51.8% polysaccharides, i.e., 8.8% higher than CK, and 15.3% alcohol soluble, i.e., 82.1% higher than CK. Conclusion D. officinale var. Fuhu 1 was certified by the Committee of Identifying Variety in Fujian Province in 2016 （Fujian Medicine No. 2016001）. It was a superior variety with highly desirable agronomic properties including high yield, high quality, and strong disease resistance and considered a promising new D. officinale for commercial cultivation in Fujian.
2020, 35(7): 725-730.
doi: 10.19303/j.issn.1008-0384.2020.07.005
Abstract:
Objective The molecular markers of the cultivated strain of Ganoderma sinense, Zizhi S2 (aka Wu-Zhi No. 2), recently popularized in Fujian and surrounding provinces were studied to facilitate the authentication of the medicinal fungus. Method Relevant primers of Zizhi S2 showing clear and stable bands and polymorphism were screened using PCR. Phylogenetic tree of UPMGA clustering analysis on the verified authentic cultivars was constructed to determine their relationship by genetic distance as well as antagonistic reaction. Subsequently, sequences of the selected primers were blasted on the genome of Zizhi S2 to validate the methodology. Result There were 2 RAPD-PCR and 3 ISSR-PCR primers found to clearly and stably amplify the specific or polymorphic bands. However, the sites and numbers on the scaffolds of the Zizhi S2 genome that matched the sequences of the 5 primers were not same. Conclusion It was confirmed that three primers(ISSR13, S1326, and S1506)could be effectively used for identification of Zizhi cultivated strains based on sequences alignment with the genome of G. sinense strain Zizhi S2.
2020, 35(7): 739-745.
doi: 10.19303/j.issn.1008-0384.2020.07.007
Abstract:
Objective A TaqMan RT-PCR method was established for detecting porcine circovirus 3 （PCV3） infection in swine. Method Specific primers and probe were designed by Oligo 7 software targeting the Rep gene after genetic comparison. Result The established TaqMan RT-PCR method could detect 42.2 copies·uL−1 with no positive signal on common porcine infectious diseases indicating high specificity of the methodology. On the constructed positive plasmids, the coefficients of variation for the intra- and inter-assays were less than 1.48% showing a high detection reproducibility. From the 193 clinical specimens collected in Fujian from 2014 to 2018, the newly developed method showed a high prevalence of PCV3 at 65.80% and high co-infection with PCV2 at 52.85%. Conclusion The established TaqMan RT-PCR method was made available for studying the function of Rep in PCV3.
2020, 35(7): 753-763.
doi: 10.19303/j.issn.1008-0384.2020.07.009
Abstract:
Objective Effect of arbuscular mycorrhizal fungi (AMF) and organic fertilizer applied in sweet corn field on the microbial genes relating to the carbon (C) cycling in the rhizosphere was studied to decipher the biological mechanism and the soil C-transformation. Method Seven treatments with triplicates each were applied on the sweet corn fields including (1) no N fertilizer (CK), (2) optimized fertilization (OF), (3) organic N fertilizer to replace 10% of chemical N fertilizer (ORF10), (4) organic N fertilizer to replace 20% of chemical N fertilizer (ORF20), (5) ORF10 with added Glomus versiforme (ORF10+AMF), (6) ORF20 with added G. versiforme (ORF20+AMF), and (7) CK with added G. versiforme (CK+AMF). Genes related to C-cycling in the treated rhizosphere soils were analyzed using GeoChip 5.0 technology. Result Addition of AMF in fertilizing the sweet corn plants significantly increased the yield. By adding AMF to CK, ORF10, and ORF20, the treatments increased the number of fresh buds on the plants by 32.6%, 8.6%, and 8.9%, respectively. The results of gene sequencing on the soil samples showed that the AMF/organic fertilizer combinations significantly altered the structure of the microbial C-cycle genes. The signal strength of key functional genes associated with C-cycling, such as C-decomposition, C-fixation, and methane metabolism, were generally stronger under CK+AMF and ORF20+AMF than the other treatments. According to the redundancy analysis, the respiration, total nitrogen, pH, total potassium, organic matter, available phosphorus, and total phosphorus in rhizosphere soil were the major environmental factors affecting the functions of the C-cycle-related genes. Conclusion The application of organic fertilizer and G. versiforme in sweet corn field significantly increased the fresh bud count on the plants. It changed the structure of the microbial C-cycle genes in rhizosphere soil positively affecting the decomposition and fixation of C as well as the methane metabolism of the ecosystem.
Functional Microorganisms in Tomato Stalks/Maize Straws Co-compost Unveiled by Integrated Meta-omics
2020, 35(7): 764-772.
doi: 10.19303/j.issn.1008-0384.2020.07.010
Abstract:
Objective The integrated meta-omics was applied to reveal the functional microorganisms in the tomato stalks/maize straws compost. Method Sampling from the pile of a compost of tomato stalks and maize straws in the ratio of 3:1 (m: m) at the height of 20–50 cm was carried out once every week for lignocellulosic enzyme assay. When a peak enzymatic activity appeared, specimens were collected and the integrated meta-omic analysis that combined high-throughput pyrosequencing and Orbitrap studies was conducted. Result The greatest population of fungi in the compost belonged to the phylum Ascomycota, in which, Thermomyces was the most abundant accounting for 70.5%. Thermomyces is known to secret endo-1,4-β-xylanase that degrades hemicellulose in biomass. Of the total bacteria population, Actinobacteria, Proteobacteria, and Firmicutes phyla made up 87.0%, and the two genera of Actinobacteria, Thermobifida and Saccharomonospora, accounted for 16.5% and 1.36%, respectively. Thermobifida is capable of degrading cellulose with its 4 endoglucanases and 3 cellobiohydrolases. It also secrets enzymes associated with hemicellulose and pectate degradation. Saccharomonospora produces a β-xylanase, 2 serine proteases and 2 trypsins involved in the decomposition of hemicelluloses and proteins. Idiomarina was the major genus of Proteobacteria found in the compost with a relative abundance of 15.6%. It involves in protein degradation. Although low in abundance (merely 1.23%), Planifilum of Firmicutes phylum plays an import role in degrading hemicelluloses. Conclusion The integrated meta-omics that combined pyrosequencing and Orbitrap analysis provided a new tool for studying the community structure and functions of the microorganisms in a complex habitat such as a compost of different bio-materials. With the information obtained, ways to accelerate the composting process could be explored.
2020, 35(7): 773-780.
doi: 10.19303/j.issn.1008-0384.2020.07.011
Abstract:
Objective Correlation between the diversity of AM fungal community and the fertility of rhizosphere soil of avocado orchards in Guangxi, Yunnan, and Guangdong provinces was studied. Method Spores of AM fungi collected from the field samples were isolated by wet screening and identified morphologically. The fungal diversity and nutrient contents in the soil specimens were determined. Result Thirty-three species from 3 genera of AM fungi were isolated and identified. They included 22 species of Glomus, 7 of Acaulospora, and 4 of Scutellospora. Among them, G. manihotis, A. rehmii, S. rubra, and S. reticulate were dominate species, and G. claroideum, G. luteum, G. reticulatum, G. coronatum, G. verruculosum, A. scrobiculata, and S. verrucose were Conclusion The AM fungi in avocado rhizosphere soil were highly diverse with Glomus being the predominant species, and the population inversely correlated to the phosphorus content in soil.
2020, 35(7): 781-787.
doi: 10.19303/j.issn.1008-0384.2020.07.012
Abstract:
Objective To screen and isolate a cellulase-producing microbe for efficient, rapid and natural composting cattle waste. Method At 3 cow manure composting plants in the Three Gorges Reservoir area in Chongqing, samples for microbial analysis were collected. The agar dilution method was applied to isolate bacillus strains from the compost specimens. Cellulase activity of the strains was determined for the screening by the hydrolytic circle method and the CMC enzyme saccharification method. Selected strains were morphologically examined and further identified by physiological, biochemical, and molecular biological methods. Based on 16S rRNA sequence, phylogenetic tree of the final selection was constructed using the molecular biological software MEGA6.0 for confirmation. Result Out of 57 isolates from the compost specimens, 10 strains showed varying degrees of cellulase activity. Among them, X10 had the highest activity at 31.9 U·mL−1 and was identified on the 16S rRNA phylogenetic tree to be Bacillus amyloliquefaciens. Conclusion X10 was a species of B. amyloliquefaciens that was highly productive in secreting cellulase to enhance the degradation of cow manure in compost.
2020, 35(7): 788-794.
doi: 10.19303/j.issn.1008-0384.2020.07.013
Abstract:
Objective A chewable tablet product made with plum ingredients was prepared and its phenol content, antioxidant properties, and hypouricemic effect analyzed. Method Chewable tablets were prepared with substances and extract from Furong plums (Prunus sallcina Lindi. cv. Furong). Product formula was refined to achieve desired sensory quality judged by a panel and phenolic content determined by HPLC. Antioxidant activity of the tablets was represented by in vitro scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl free radicals, and hypouricemic effect determined by xanthine oxidase-xanthine reaction system. Result The chewable tablets were prepared with 40% of plum powder, 20% of plum polyphenols powder, 20% of wheat bran powder cultivated by edible fungi, 10% of microcrystalline cellulose, and 10% of maltodextrin. The tablets were purplish red in color, smooth and clean without cracks or rough edges in shape, lightly sweet and sour in taste, and solid and chewy in texture. The phenols in them included epicatechin, proanthocyanidins, catechins, proanthocyanidins B, and anthocyanins. The scavenging abilities on DPPH and hydroxyl radicals were not significantly different from those of Vc, with IC50 of 0.07 mg·mL−1 on DPPH and 0.79 mg·mL−1 on hydroxyl radicals. The IC50 on inhibiting xanthine oxidase was 258.96 μg·mL−1. Conclusion The prepared chewable plum tablets contained a variety of phenols that exhibited desirable in vitro antioxidant and hypouricemic effects and could be further developed into a commercial functional food product.
2020, 35(7): 801-810.
doi: 10.19303/j.issn.1008-0384.2020.07.015
Abstract:
Objective Composition and antioxidant activity of polysaccharides （TPS） in Wuyi Mingcong tea germplasms from plantations at Mt. Wuyi were determined for better utilization of the existing resource and new variety breeding. Method Samples of 31 Wuyi Mingcong tea germplasms were collected for polysaccharides extraction. The extraction rate and contents of neutral sugar, uronic acid, protein and tea polyphenol were determined. Methods of D-deoxyribose-iron system and DPPH assay were adopted to evaluate the scavenging activities on DPPH· and hydroxyl （·OH） free radicals. A clustered heatmap and subordinate function method were employed to characterize and classify the various TPS. Result The TPS extraction rates on the tea germplasm samples ranged from 1.73% to 3.39%. The extracts contained 25.75-67.21% neutral sugars, 11.10-22.57% uronic acid, 2.24-7.42% protein, 3.81-9.68% polyphenols. The average scavenging activity of TPS on DPPH· was 55.61%, ranging from 25.47% to 84.30%, and that on ·OH 54.20%, ranging from 34.98% to 78.38%. The coefficients of variation on 7 TPS traits ranged from 16.74% to 23.71% and on genetic diversity indices from 1.93 to 2.18. The hierarchical cluster and heatmap analyses showed that the contents of uronic acid, protein, and polyphenols significantly correlated with the free radical scavenging activities of the TPS extracts, but not between the extraction rate or neutral sugar and the antioxidant activity. The 31 germplasms could be divided into 3 classes. The top 5 germplasms on the average subordinate function value were Camellia sinensis （L.） O. Kuntze cv. Jiulonglan, cv. Yuchan, cv. Yudan, cv. Baijiguan, and cv. Hongjiguan. Conclusion The composition and antioxidant activity of TPS in the 31 Wuyi Mingcong teas varied significantly. The uronic acid, protein, and polyphenols in TPS exerted significant effect on its antioxidant activity. TPS in Jiulonglan, Yuchan, Yudan, Baijiguan, and Hongjiguan appeared to be higher on antioxidant activity among the germplasms. These 5 varieties could be applied for breeding new varieties to make oolong teas for the health food market.
