2016 Vol. 31, No. 5
Display Method:
2016, 31(5): 445-448.
doi: 10.19303/j.issn.1008-0384.2016.05.001
Abstract:
To investigate the epidemiology of Avian Paramyxovirus type 1(APMV-1) in laying ducks, a total of 495 samples were collected from laying ducks in six provinces (Fujian, Zhejiang, Jiangxi, Guangdong, Guangxi and Jiangsu) during 2011-2015. All samples were tested by using reverse transcript PCR to detect APMV-1 infection, and pathogenicity of different virus isolates were determined in laying ducks. Results showed that positive rate of APMV-1 in laying duck was range from 3.4% to 10.7%, and this indicated that APMV-1 was circulated in ducks in different place unevenly. Pathogenicity analysis showed that lethality rate in Sheldrake infected with genotype VII APMV-1 was higher than that in Sheldrake infected with genotype IX APMV-1. The pathogenicity of APMV-1 in laying duck was decreased according to the increase in age, while the laying performance of the older Sheldrake was heavy affected under the infection of APMV-1.
To investigate the epidemiology of Avian Paramyxovirus type 1(APMV-1) in laying ducks, a total of 495 samples were collected from laying ducks in six provinces (Fujian, Zhejiang, Jiangxi, Guangdong, Guangxi and Jiangsu) during 2011-2015. All samples were tested by using reverse transcript PCR to detect APMV-1 infection, and pathogenicity of different virus isolates were determined in laying ducks. Results showed that positive rate of APMV-1 in laying duck was range from 3.4% to 10.7%, and this indicated that APMV-1 was circulated in ducks in different place unevenly. Pathogenicity analysis showed that lethality rate in Sheldrake infected with genotype VII APMV-1 was higher than that in Sheldrake infected with genotype IX APMV-1. The pathogenicity of APMV-1 in laying duck was decreased according to the increase in age, while the laying performance of the older Sheldrake was heavy affected under the infection of APMV-1.
2016, 31(5): 449-454.
doi: 10.19303/j.issn.1008-0384.2016.05.002
Abstract:
A bacterial strain,MJ15, that secreted high amount of proteases was isolated on a casein plate culture from the intestines of Anguilla anguilla. Activity of the enzyme was determined by using a fishmeal as the substrate for the digestion. By means of morphological observations, biolog identification, and phylogenetic analysis on 16S rRNA sequences,MJ15 was identified as Lactococcus lactis subsp.The activity of the crude protease it secreted peaked at 40℃ and pH 5.0.The thermal and alikali stabilities of the protease were relatively poor. The metal ions, K+, Na+, Cu2+, and Fe2+, enhenced the enzymatic activity, while Zn2+ or pepstatin Aslightly inhibited it.The Kmand Vmaxof the enzyme were determined to be 8.77 mgmL-1 and 53.48 gmin-1mL-1, respectively.
A bacterial strain,MJ15, that secreted high amount of proteases was isolated on a casein plate culture from the intestines of Anguilla anguilla. Activity of the enzyme was determined by using a fishmeal as the substrate for the digestion. By means of morphological observations, biolog identification, and phylogenetic analysis on 16S rRNA sequences,MJ15 was identified as Lactococcus lactis subsp.The activity of the crude protease it secreted peaked at 40℃ and pH 5.0.The thermal and alikali stabilities of the protease were relatively poor. The metal ions, K+, Na+, Cu2+, and Fe2+, enhenced the enzymatic activity, while Zn2+ or pepstatin Aslightly inhibited it.The Kmand Vmaxof the enzyme were determined to be 8.77 mgmL-1 and 53.48 gmin-1mL-1, respectively.
2016, 31(5): 455-459.
doi: 10.19303/j.issn.1008-0384.2016.05.003
Abstract:
Three types of cuttings and leaf-retention on a cutting branch of Syzygium samarangense were applied to study their effects on the survival rate,rooting and photosynthesis of the cuttings for propagation. The intelligent monitoring and controlling of agermchit rapid propagation system was used for the experimentation. The results showed that the survival rate of the green-colored cut branches was the highest;while those in brown color, the lowest. There were only minute differences between the green and the green-brown cuttings on the number, diameter, or length of the roots developed, but significant differences existed between the green and the brown cuttings, with the brown branches being the least among the three kinds of branches. The leaf-retention on a cutting branch affected significantly the rooting and survival rate of the cuttings for propagation. The highest survival rate and rooting ratesoccurred when 2 to 4 or 3 to 4 leaveswere allowed to remain on a cutting branch.But, none of the cuttings without any leaf survived the process. The content and fluorescence (i.e., effective quantum yield of photosystem) of chlorophylldid not differsignificantly between the green and the green-brown cuttings, regardless how many leaves were allowed to remain on them. For the brown cuttings, their chlorophyll content and yield were higher if 2 to 4 leaves were left on a cutting than other treatments.It was concluded that the green or green-brown cutbranches with 2 to 4 or 3 to 4 leaves remained on each cutting were best for the propagation of S. samarangense by means of cutting.
Three types of cuttings and leaf-retention on a cutting branch of Syzygium samarangense were applied to study their effects on the survival rate,rooting and photosynthesis of the cuttings for propagation. The intelligent monitoring and controlling of agermchit rapid propagation system was used for the experimentation. The results showed that the survival rate of the green-colored cut branches was the highest;while those in brown color, the lowest. There were only minute differences between the green and the green-brown cuttings on the number, diameter, or length of the roots developed, but significant differences existed between the green and the brown cuttings, with the brown branches being the least among the three kinds of branches. The leaf-retention on a cutting branch affected significantly the rooting and survival rate of the cuttings for propagation. The highest survival rate and rooting ratesoccurred when 2 to 4 or 3 to 4 leaveswere allowed to remain on a cutting branch.But, none of the cuttings without any leaf survived the process. The content and fluorescence (i.e., effective quantum yield of photosystem) of chlorophylldid not differsignificantly between the green and the green-brown cuttings, regardless how many leaves were allowed to remain on them. For the brown cuttings, their chlorophyll content and yield were higher if 2 to 4 leaves were left on a cutting than other treatments.It was concluded that the green or green-brown cutbranches with 2 to 4 or 3 to 4 leaves remained on each cutting were best for the propagation of S. samarangense by means of cutting.
2016, 31(5): 460-464.
doi: 10.19303/j.issn.1008-0384.2016.05.004
Abstract:
Effect of the time length of vernalization on the physiological and biochemical properties of various pea plants was investigated. Four different pea varieties were vernalizedat 4℃ for 0,6,12, and 18 ds after sprouting.The pea leaves were sampled 10 ds after growth for measurements on theprotective enzyme activities, MDA, and soluble protein content. The results showed that, as compared with control, the longer the vernalization was, the higher the activities of protective enzymes (i.e., peroxidase, superoxide dismutase, and catalase) in the leaves of the plant. The enzymatic acitivities peaked with a 12 d vernalization, and began to decline afterward. During the same period of time, the MDA content in the leaves increased slowly initially followed by a rapid rise on the 12th day.The soluble proteins in leaves increased at first, but varied after 12 d vernalization. Statistically at P0.05, these results were significantly different.
Effect of the time length of vernalization on the physiological and biochemical properties of various pea plants was investigated. Four different pea varieties were vernalizedat 4℃ for 0,6,12, and 18 ds after sprouting.The pea leaves were sampled 10 ds after growth for measurements on theprotective enzyme activities, MDA, and soluble protein content. The results showed that, as compared with control, the longer the vernalization was, the higher the activities of protective enzymes (i.e., peroxidase, superoxide dismutase, and catalase) in the leaves of the plant. The enzymatic acitivities peaked with a 12 d vernalization, and began to decline afterward. During the same period of time, the MDA content in the leaves increased slowly initially followed by a rapid rise on the 12th day.The soluble proteins in leaves increased at first, but varied after 12 d vernalization. Statistically at P0.05, these results were significantly different.
2016, 31(5): 465-470.
doi: 10.19303/j.issn.1008-0384.2016.05.005
Abstract:
Endo-PG plays an important role in the ripening of Chinese Bayberry (Myrica rubra) fruit by causing its softening and inducing textural changes. 45 Chinese Bayberry accessions were tested to detect single nucleotide polymorphisms (SNPs) in the endo-PG gene by PCR-based sequencing of a 1866 bp long DNA fragment. A total of 178 SNPs were identified, of which 60 were singleton variable sites and another 118 were parsimony informative sites. The nucleotide diversity value (Pi) was 0.27. A total of 12 haplotypes were identified and a dendrogram was constructed for endo-PG using the neighbor-joining (NJ) clustering method. The results indicated that the 45 accessions were clustered into four groups and that the clustering correlated with fruit hardness. Additionally, some cultivars (e.g. Biqi) were found to have two alleles, conferring pronounced phenotypic differences between allelic combinations and could thus be divided into different groups, while some other cultivars (e.g. Dongkui) had relatively high homozygosity.
Endo-PG plays an important role in the ripening of Chinese Bayberry (Myrica rubra) fruit by causing its softening and inducing textural changes. 45 Chinese Bayberry accessions were tested to detect single nucleotide polymorphisms (SNPs) in the endo-PG gene by PCR-based sequencing of a 1866 bp long DNA fragment. A total of 178 SNPs were identified, of which 60 were singleton variable sites and another 118 were parsimony informative sites. The nucleotide diversity value (Pi) was 0.27. A total of 12 haplotypes were identified and a dendrogram was constructed for endo-PG using the neighbor-joining (NJ) clustering method. The results indicated that the 45 accessions were clustered into four groups and that the clustering correlated with fruit hardness. Additionally, some cultivars (e.g. Biqi) were found to have two alleles, conferring pronounced phenotypic differences between allelic combinations and could thus be divided into different groups, while some other cultivars (e.g. Dongkui) had relatively high homozygosity.
2016, 31(5): 471-474.
doi: 10.19303/j.issn.1008-0384.2016.05.006
Abstract:
Floweringstages and relationship between the bud and pollen developments of Cliviaminiatawere studied. The results showed thatthe florescenceof the floral plant could be divided into 5 distinctive stages:squaring, flower budding, opening, fully opening, and withering.From the flower budding to the early opening stage, the pollenswere monocytes with the tegals in peachy pink color.At the time, the buds began to loose up but yet to open widely, it was considered the best time forsampling microspore culture on the plant.
Floweringstages and relationship between the bud and pollen developments of Cliviaminiatawere studied. The results showed thatthe florescenceof the floral plant could be divided into 5 distinctive stages:squaring, flower budding, opening, fully opening, and withering.From the flower budding to the early opening stage, the pollenswere monocytes with the tegals in peachy pink color.At the time, the buds began to loose up but yet to open widely, it was considered the best time forsampling microspore culture on the plant.
2016, 31(5): 475-479.
doi: 10.19303/j.issn.1008-0384.2016.05.007
Abstract:
Effect of osmosis onthe growth of and polysaccharide accumulation in theprotocorms of Dendrobium candidum on a culture medium were studied.The liquid medium wasadded with mannitolat varied concentrations to alter theosmotic pressure for the experiment. The results showed that,at low concentrations of mannitol, the growth andpolysaccharide synthesis ofthe protocorms were enhanced,but significantly inhibited at high concentrations. During the cultivation,the vigor, growth, polysaccharidecontent, andyield of the protocormsincreased when the mannitol concentration in the medium was 0-20 gL-1.After 35d culturein the medium with 20 gL-1 mannitol,the dry weight, polysaccharide content, andyield ofthe protocormspeaked with the maximized values of 17.30 gL-1, 361.52 mgg-1, and 6255.38 mgL-1, respectively. However,when the mannitol concentration was raised to 30-40 gL-1,all of those indices hit a downward trend suggesting the high osmotic pressure could be detrimental to theprotocorm cultivation.
Effect of osmosis onthe growth of and polysaccharide accumulation in theprotocorms of Dendrobium candidum on a culture medium were studied.The liquid medium wasadded with mannitolat varied concentrations to alter theosmotic pressure for the experiment. The results showed that,at low concentrations of mannitol, the growth andpolysaccharide synthesis ofthe protocorms were enhanced,but significantly inhibited at high concentrations. During the cultivation,the vigor, growth, polysaccharidecontent, andyield of the protocormsincreased when the mannitol concentration in the medium was 0-20 gL-1.After 35d culturein the medium with 20 gL-1 mannitol,the dry weight, polysaccharide content, andyield ofthe protocormspeaked with the maximized values of 17.30 gL-1, 361.52 mgg-1, and 6255.38 mgL-1, respectively. However,when the mannitol concentration was raised to 30-40 gL-1,all of those indices hit a downward trend suggesting the high osmotic pressure could be detrimental to theprotocorm cultivation.
2016, 31(5): 480-486.
doi: 10.19303/j.issn.1008-0384.2016.05.008
Abstract:
The arthropod community of transgenic 741 poplar was analyzed from three aspects of community structure, temporal structure and nutritional structure.The results show that:on compositive structure,main compositive groups of the community structure were Coleoptera、LepidopteraAraneae,Homoptera and Hymenoptera in Pb29 and CK; On nutrition strcture, function groups on every nutrition level were similar between Pb29 and CK,but in Pb29 leaf-eating pest on bascal species largely decreased,the rate of intermediate species increase,top species have no obviously changing;on temporal structure, numbers of individual and species of Lepidoptera in Pb29 and CK has similarly changing tendency,function groups and every nutritionalasses with individual numbers and species,there have similarly changing tendency.
The arthropod community of transgenic 741 poplar was analyzed from three aspects of community structure, temporal structure and nutritional structure.The results show that:on compositive structure,main compositive groups of the community structure were Coleoptera、LepidopteraAraneae,Homoptera and Hymenoptera in Pb29 and CK; On nutrition strcture, function groups on every nutrition level were similar between Pb29 and CK,but in Pb29 leaf-eating pest on bascal species largely decreased,the rate of intermediate species increase,top species have no obviously changing;on temporal structure, numbers of individual and species of Lepidoptera in Pb29 and CK has similarly changing tendency,function groups and every nutritionalasses with individual numbers and species,there have similarly changing tendency.
2016, 31(5): 487-490.
doi: 10.19303/j.issn.1008-0384.2016.05.009
Abstract:
The 2nd and 5th instar of Ectropis oblqua larvae were exposed to UV-B for 0, 30, 60, 90, 120, or 150 min to determine the effects of the irradiation on the development time as well as the rates of pupation, pupa emergence, and deformity of the larvae. The results showed that, as compared with control,the development for the 2nd instar larvae was significantly delayed, the abnormal pupation and mortality rates significantly increased, and the pupation rate, pupal weight, and emergence rate reduced. On the other hand,the sustained irradiation did not exert significant effect on the growth or development of the 5 instar larvae. Under a same irradiation treatment, the mortality and pupation rates of the 2nd and 5th instar differed significantly,but the abnormal pupation rate was not significantly different from that of control, while the eclosion rate of the 2nd instar generally lower than that of the 5th instar counterpart. The eclosion rate of the 2nd instar after being exposed to UV-B for 150min significantly differed from that of control or the 5th instar larvae.
The 2nd and 5th instar of Ectropis oblqua larvae were exposed to UV-B for 0, 30, 60, 90, 120, or 150 min to determine the effects of the irradiation on the development time as well as the rates of pupation, pupa emergence, and deformity of the larvae. The results showed that, as compared with control,the development for the 2nd instar larvae was significantly delayed, the abnormal pupation and mortality rates significantly increased, and the pupation rate, pupal weight, and emergence rate reduced. On the other hand,the sustained irradiation did not exert significant effect on the growth or development of the 5 instar larvae. Under a same irradiation treatment, the mortality and pupation rates of the 2nd and 5th instar differed significantly,but the abnormal pupation rate was not significantly different from that of control, while the eclosion rate of the 2nd instar generally lower than that of the 5th instar counterpart. The eclosion rate of the 2nd instar after being exposed to UV-B for 150min significantly differed from that of control or the 5th instar larvae.
2016, 31(5): 491-496.
doi: 10.19303/j.issn.1008-0384.2016.05.010
Abstract:
Potted seedlings of Eucalyptus urophyllaE.grandis DH32-29 were used to study the effect of the coating,sulfate, steam,or active fertilizations on the soil and the carbon (C),nitrogen (N),and phosphorus (P)contents as well as stoichiometric characteristics of the leaves of the plants. The results showed that (1) all fertilization scould significantly increase C, N, and P in the soil and the leaves; (2) C in soil and C, N, and P in leaves were higher by using active fertilization in the soil than those 3 other treatments, while N and P in the soil were less with the active fertilization than without; (3)the ratios of C:N and C:P in soil were significantly lower with the fertilizations than control without added fertilizer; (4) C:N in leaves was significantly lower with fertilization than control, and N:P significantly higher than control, while the ratios of C:N and N:P in leaves were similar among the different fertilizations but lower than control; (5) a weak inverse correlationship was oberved between C and P contents in the potting soil; (6)the C, N, and C, N, P stoichiometric ratio in soil did not correlate tothe C, N, P, and stoichiometric ratio in leaves, but in the soil,N significantly correlated with C:N; (7)highly significant correlations between the N, P, C:N, C:P, N:P in soil and the C, N, P, and stoichiometry in leaves were found.
Potted seedlings of Eucalyptus urophyllaE.grandis DH32-29 were used to study the effect of the coating,sulfate, steam,or active fertilizations on the soil and the carbon (C),nitrogen (N),and phosphorus (P)contents as well as stoichiometric characteristics of the leaves of the plants. The results showed that (1) all fertilization scould significantly increase C, N, and P in the soil and the leaves; (2) C in soil and C, N, and P in leaves were higher by using active fertilization in the soil than those 3 other treatments, while N and P in the soil were less with the active fertilization than without; (3)the ratios of C:N and C:P in soil were significantly lower with the fertilizations than control without added fertilizer; (4) C:N in leaves was significantly lower with fertilization than control, and N:P significantly higher than control, while the ratios of C:N and N:P in leaves were similar among the different fertilizations but lower than control; (5) a weak inverse correlationship was oberved between C and P contents in the potting soil; (6)the C, N, and C, N, P stoichiometric ratio in soil did not correlate tothe C, N, P, and stoichiometric ratio in leaves, but in the soil,N significantly correlated with C:N; (7)highly significant correlations between the N, P, C:N, C:P, N:P in soil and the C, N, P, and stoichiometry in leaves were found.
2016, 31(5): 497-502.
doi: 10.19303/j.issn.1008-0384.2016.05.011
Abstract:
In the experimentation fields at Guilin Academy of Agricultural Sciences, the soil (0-6 cm in depth) on the plot, where soybeans, sugarcanes, or peartrees was gown, was sampled to study the variation and spatial distribution of its water content. The results showed that (a) rainfall was the key factor affecting the water content in the surface soil; (b) tillage affected the overall water content to a certain extent; (c) the water content in the soil of the pear tree plotwas the highest, followed by that of the sugarcane field, and the soybean lot had the lowest water content in soil; (d) the spatial distributions of water content in these areas, which varied onmoisture levels,hada moderate degree of spatial correlation; (e) the spatial distributions of water content in soilwere affected by the rainfall, and also human factors in varingdegrees;and (f)the vegetation coverages and artificial disturbances were factors in the spatial variability of the water content in the soils, however, since the distribution at localities with relatively high water levels were stable, the soil might be able tomakenecessary adjustments by itself. The information obtained could benefit studies ondrought prevention for agricultural lands, irrigation for farming, and management for reducing soil erosion in the karst regions in the province.
In the experimentation fields at Guilin Academy of Agricultural Sciences, the soil (0-6 cm in depth) on the plot, where soybeans, sugarcanes, or peartrees was gown, was sampled to study the variation and spatial distribution of its water content. The results showed that (a) rainfall was the key factor affecting the water content in the surface soil; (b) tillage affected the overall water content to a certain extent; (c) the water content in the soil of the pear tree plotwas the highest, followed by that of the sugarcane field, and the soybean lot had the lowest water content in soil; (d) the spatial distributions of water content in these areas, which varied onmoisture levels,hada moderate degree of spatial correlation; (e) the spatial distributions of water content in soilwere affected by the rainfall, and also human factors in varingdegrees;and (f)the vegetation coverages and artificial disturbances were factors in the spatial variability of the water content in the soils, however, since the distribution at localities with relatively high water levels were stable, the soil might be able tomakenecessary adjustments by itself. The information obtained could benefit studies ondrought prevention for agricultural lands, irrigation for farming, and management for reducing soil erosion in the karst regions in the province.
2016, 31(5): 503-507.
doi: 10.19303/j.issn.1008-0384.2016.05.012
Abstract:
To improve the efficiency of anaerobic,low-temperature bioconversion of waste materials to methane, 3 groups of psychrophilic microflora were studied. Dried cow manure was collected from local cattle farms for an enrichment culture at 15℃.From the culture,Group #5 microflora was identified as a potential source for further investigation. The microbes of the group were inoculated in the waste water effluent from a pig farm to obtaine the low-temperature resistant Group Y5S. The microbial communities of Y5S,#5, and YJ (a microflora group originated from pig farm sewer)were compared. In all 3 groups, microbes belong to the phylums of Firmicutes, Bacteroidetes, Synergistetes, Proteobacteria, Spirochaetes, and Verrucomicrobia were found.They shared 85 core microbiomes of Clostridia class in Firmicutes phylum,as indicated by the high-throughput sequencing.At genus level,these psychrophiles included Acetobacterium, Citrobacter, Clostridium, Desulfobulbus, Desulfomicrobium,Hydrogenophaga, Oscillospira, Parabacteroides, Ruminococcus, Sedimentibacter, Sphingomonas, Sulfurospirillum, Syntrophomonas, Trichococcus,and Devosia. Synergistetes in the mocroflora of Y5S seemed to suggest that this kind of microorganism might play an important role in the biogas fermentation.
To improve the efficiency of anaerobic,low-temperature bioconversion of waste materials to methane, 3 groups of psychrophilic microflora were studied. Dried cow manure was collected from local cattle farms for an enrichment culture at 15℃.From the culture,Group #5 microflora was identified as a potential source for further investigation. The microbes of the group were inoculated in the waste water effluent from a pig farm to obtaine the low-temperature resistant Group Y5S. The microbial communities of Y5S,#5, and YJ (a microflora group originated from pig farm sewer)were compared. In all 3 groups, microbes belong to the phylums of Firmicutes, Bacteroidetes, Synergistetes, Proteobacteria, Spirochaetes, and Verrucomicrobia were found.They shared 85 core microbiomes of Clostridia class in Firmicutes phylum,as indicated by the high-throughput sequencing.At genus level,these psychrophiles included Acetobacterium, Citrobacter, Clostridium, Desulfobulbus, Desulfomicrobium,Hydrogenophaga, Oscillospira, Parabacteroides, Ruminococcus, Sedimentibacter, Sphingomonas, Sulfurospirillum, Syntrophomonas, Trichococcus,and Devosia. Synergistetes in the mocroflora of Y5S seemed to suggest that this kind of microorganism might play an important role in the biogas fermentation.
2016, 31(5): 508-514.
doi: 10.19303/j.issn.1008-0384.2016.05.013
Abstract:
Cellulase was added to the hot water extraction of polysaccharides from Chlorella pyrenoidosa in an attempt to facilitate the process. The single factor test and the response surface methodology were used to optimize the conditions. It was found that whenthe substrate:liquid ratio of 1:30(gmL-1) with 2%(w/w) of cellulase addition was extracted at 93℃ for 2 h, an expected 6.13% yield on polysaccharidescould be obtained (the actual yield was 5.870.24%). Subsequently, the polysaccharides obtained was tested for its scavenging activities on DPPH,O2-, and hydroxyl free radicals.The results confirmed itsantioxidant abilities agains O2- and hydroxyl free radicals.
Cellulase was added to the hot water extraction of polysaccharides from Chlorella pyrenoidosa in an attempt to facilitate the process. The single factor test and the response surface methodology were used to optimize the conditions. It was found that whenthe substrate:liquid ratio of 1:30(gmL-1) with 2%(w/w) of cellulase addition was extracted at 93℃ for 2 h, an expected 6.13% yield on polysaccharidescould be obtained (the actual yield was 5.870.24%). Subsequently, the polysaccharides obtained was tested for its scavenging activities on DPPH,O2-, and hydroxyl free radicals.The results confirmed itsantioxidant abilities agains O2- and hydroxyl free radicals.
2016, 31(5): 515-520.
doi: 10.19303/j.issn.1008-0384.2016.05.014
Abstract:
Flavor of the brewed white tea in relation to its constituents of free amino acids (FAA) was studied. The descriptive statistics, ANOVA, principal component analysis(PCA), and linear category identification were applied for the analysis. The FAA contents on 46 samples collected from 3 white tea-producing areas in the province were determined by using an automated analyzer. The results showed that(1)the total FAA in the tea ranged from 16.19 mgg-1 to 51.00 mgg-1, with an average of 39.36 mgg-1; (2) the highest FAA content of(45.788.39)mgg-1 was found in Kung Mee tea, followed by that of Silver Needle Pekoe tea at(38.156.12)mgg-1, while the lowest was White Peony tea at(34.019.16)mgg-1; (3) theanine in the tea accounted for 52.90% of the total FAA contributing to the cool and delightful taste of the tea; (4) proline, glycine, aspartic, and threonine were the main source of the sweetness of Silver Needle Pekoe tea; (5) leucine, histidine, and methionine brought about the hint of bitterness in Silver Needle Pekoe tea; (6) proline, valine, aspartic, and alanine gave the sweet note in Kung Mee tea; (7) phenylalanine, isoleucine, leucine, and valine tended to be slightly bitter on the taste; and, (8) glutamic acid might render the umami and sour tastes in Silver Needle Pekoe and Kung Mee teas; (9)the correct rate in classifying the white teas based on FAA constituents was found to be 100%. Subsequently,using the same model, 27 commercial samples of Kung Mee, Silver Needle Pekoe, and White Peony teas were evaluated to show the rates of correct identification to be 100%, 88.89%, and 88.89%, respectively. It was, thus, concluded that FAA composition of the 4 categories of amino acids in tea, combined with PCA and LDA analytical methods, could be used to accurately distinguish the white teas.
Flavor of the brewed white tea in relation to its constituents of free amino acids (FAA) was studied. The descriptive statistics, ANOVA, principal component analysis(PCA), and linear category identification were applied for the analysis. The FAA contents on 46 samples collected from 3 white tea-producing areas in the province were determined by using an automated analyzer. The results showed that(1)the total FAA in the tea ranged from 16.19 mgg-1 to 51.00 mgg-1, with an average of 39.36 mgg-1; (2) the highest FAA content of(45.788.39)mgg-1 was found in Kung Mee tea, followed by that of Silver Needle Pekoe tea at(38.156.12)mgg-1, while the lowest was White Peony tea at(34.019.16)mgg-1; (3) theanine in the tea accounted for 52.90% of the total FAA contributing to the cool and delightful taste of the tea; (4) proline, glycine, aspartic, and threonine were the main source of the sweetness of Silver Needle Pekoe tea; (5) leucine, histidine, and methionine brought about the hint of bitterness in Silver Needle Pekoe tea; (6) proline, valine, aspartic, and alanine gave the sweet note in Kung Mee tea; (7) phenylalanine, isoleucine, leucine, and valine tended to be slightly bitter on the taste; and, (8) glutamic acid might render the umami and sour tastes in Silver Needle Pekoe and Kung Mee teas; (9)the correct rate in classifying the white teas based on FAA constituents was found to be 100%. Subsequently,using the same model, 27 commercial samples of Kung Mee, Silver Needle Pekoe, and White Peony teas were evaluated to show the rates of correct identification to be 100%, 88.89%, and 88.89%, respectively. It was, thus, concluded that FAA composition of the 4 categories of amino acids in tea, combined with PCA and LDA analytical methods, could be used to accurately distinguish the white teas.
2016, 31(5): 521-526.
doi: 10.19303/j.issn.1008-0384.2016.05.015
Abstract:
Staticadsorption and desorption of 4 macroporous resins were evaluated for the purification of polyphenols from pruns, Prunus salicina Lindl. The dynamic conditions for the filtration process were optimized using theinhibitory activity of the filtered polyphenols on xanthine oxidase as a yardstick.As a result, HP-20 was chosen as the resin for the filtration. HP-20 had asaturation time of 6 h under static adsorption,and anequilibrium timeof 2 h for thedesorption. On the filtration process, the optimized conditions were determined to includeafeeding solution atthe concentration of 1.0 mgmL-1, a solution loadingrate at 2.0 mLmin-1, and the use of 80% ethanol for elution at the rate of 2.0 mLmin-1. After the filtration, the oncentration of the polyphenolsolution increased from 25.47% to 74.89%, the IC50on the enzyme inhibition reduced from 179.21 gmL-1 to 72.35 gmL-1, and the anti-enzymatic efficacy increased 2.47 times.
Staticadsorption and desorption of 4 macroporous resins were evaluated for the purification of polyphenols from pruns, Prunus salicina Lindl. The dynamic conditions for the filtration process were optimized using theinhibitory activity of the filtered polyphenols on xanthine oxidase as a yardstick.As a result, HP-20 was chosen as the resin for the filtration. HP-20 had asaturation time of 6 h under static adsorption,and anequilibrium timeof 2 h for thedesorption. On the filtration process, the optimized conditions were determined to includeafeeding solution atthe concentration of 1.0 mgmL-1, a solution loadingrate at 2.0 mLmin-1, and the use of 80% ethanol for elution at the rate of 2.0 mLmin-1. After the filtration, the oncentration of the polyphenolsolution increased from 25.47% to 74.89%, the IC50on the enzyme inhibition reduced from 179.21 gmL-1 to 72.35 gmL-1, and the anti-enzymatic efficacy increased 2.47 times.
2016, 31(5): 527-531.
doi: 10.19303/j.issn.1008-0384.2016.05.016
Abstract:
The mechanical properties of xanthan extracted from Xanthomonasaxonopodis FJAT-10151 has optimized. The rheology properties of mixed gum of xanthan with konjac gum was studied in order to provide basic data and reference for development and application. The rheology properties of mixed gum were discussed according to the viscosity variation with different conditions including mixed gum ratio, concentration, pH, heating temperature, heating time and potassium chloride content. The mixed gum was non-Newtonious liquid and the best ratio was 2:3;It's viscosity rised with its pH, and up to the highest at pH 8, then drop.The viscosity of the mixed gum increased with temperaturereaching its highest at 60℃, but decreased with prolonged heating. Neither potassium chloride nor freezing-thawing exerted a significant effect on the viscosity of the mixed gum. Upon optimization, at 0.5% concentration of the mixed gum, the mixed gum was heated at 60℃ for 30 min to the peak viscosity of 454.337 Paos and consistency coefficient was 9117.
The mechanical properties of xanthan extracted from Xanthomonasaxonopodis FJAT-10151 has optimized. The rheology properties of mixed gum of xanthan with konjac gum was studied in order to provide basic data and reference for development and application. The rheology properties of mixed gum were discussed according to the viscosity variation with different conditions including mixed gum ratio, concentration, pH, heating temperature, heating time and potassium chloride content. The mixed gum was non-Newtonious liquid and the best ratio was 2:3;It's viscosity rised with its pH, and up to the highest at pH 8, then drop.The viscosity of the mixed gum increased with temperaturereaching its highest at 60℃, but decreased with prolonged heating. Neither potassium chloride nor freezing-thawing exerted a significant effect on the viscosity of the mixed gum. Upon optimization, at 0.5% concentration of the mixed gum, the mixed gum was heated at 60℃ for 30 min to the peak viscosity of 454.337 Paos and consistency coefficient was 9117.
2016, 31(5): 532-537.
doi: 10.19303/j.issn.1008-0384.2016.05.017
Abstract:
To expedite the degradation of agricultural wastes, such as cornstalks,combinations of multiple species of microorganisms were applied for the fermentation.The National Standard Determination Methods on cellulose and lignin contents in cornstalk were used. It was found that the addition of equal parts of S-3 and the white rot fungi (in 8:8 ratio) as the inoculantto a substrate of one part of cornstalks mixed with 2.5 parts of water and allowing the mixture to ferment at 30℃ for 17 dayscould result in an optimal biodegradation of the waste material with a 35.60% degradation rate on celluloses and 37.41% on lignins.
To expedite the degradation of agricultural wastes, such as cornstalks,combinations of multiple species of microorganisms were applied for the fermentation.The National Standard Determination Methods on cellulose and lignin contents in cornstalk were used. It was found that the addition of equal parts of S-3 and the white rot fungi (in 8:8 ratio) as the inoculantto a substrate of one part of cornstalks mixed with 2.5 parts of water and allowing the mixture to ferment at 30℃ for 17 dayscould result in an optimal biodegradation of the waste material with a 35.60% degradation rate on celluloses and 37.41% on lignins.
2016, 31(5): 538-544.
doi: 10.19303/j.issn.1008-0384.2016.05.018
Abstract:
Unlike humans, the insect olfactory mechanism has many important effects on insect behavior, including habitat choosing, food-hunting, gathering, tropism, reproduction, signal communication, etc. The research of the insect olfactory mechanism can interpret some common mechanism of smell happened and the connection between the smell activity with the whole life activities. Thus,it provides a scientific basis for the research of olfaction higher animals, particularly humans.In addition, using this kind of life activity characteristics of insect to control pest is also a kind of important means in Integrated pest management. In recent years, with the rapid development of the insect behavior, biochemistry, molecular biology and insect electrophysiology, many bioactive molecules and genes associated with olfaction were found, and they interpret the possible reaction mechanism of sense of smell at the molecular level. In this paper, the author summarized the progress on odorant recognition, odorant-receptor interaction at the molecular level and the mechanism of electrochemical signal transduction.What's more, the article introduces the process that the scent signals transform into electrical signal via the olfactory sensors, then encoded and integrated by insect antennal lobe, eventually passed to the forebrain, and the molecular components and physiological or biochemical reaction in the insect body throughout this process.
Unlike humans, the insect olfactory mechanism has many important effects on insect behavior, including habitat choosing, food-hunting, gathering, tropism, reproduction, signal communication, etc. The research of the insect olfactory mechanism can interpret some common mechanism of smell happened and the connection between the smell activity with the whole life activities. Thus,it provides a scientific basis for the research of olfaction higher animals, particularly humans.In addition, using this kind of life activity characteristics of insect to control pest is also a kind of important means in Integrated pest management. In recent years, with the rapid development of the insect behavior, biochemistry, molecular biology and insect electrophysiology, many bioactive molecules and genes associated with olfaction were found, and they interpret the possible reaction mechanism of sense of smell at the molecular level. In this paper, the author summarized the progress on odorant recognition, odorant-receptor interaction at the molecular level and the mechanism of electrochemical signal transduction.What's more, the article introduces the process that the scent signals transform into electrical signal via the olfactory sensors, then encoded and integrated by insect antennal lobe, eventually passed to the forebrain, and the molecular components and physiological or biochemical reaction in the insect body throughout this process.
2016, 31(5): 545-552.
doi: 10.19303/j.issn.1008-0384.2016.05.019
Abstract:
Using blast-resistant varieties for cultivation is one of the most effective, economical and environmentally friendly ways to prevent the disease on rice (Oryzae sativa L.). However, it has been noticed recently that the resistance of somedisease tolerant-rice being promoted for the purpose began to diminish or even disappear. The phenomenon was attributed to the disappearance of host resistance genes or the mutations on avirulence genes of the plants. This article reviews the relevant pathogenic mechanisms, possible cause(s) for the reduction or loss on the blast-resistance, potential remedies, and search for the avirulence genes for cloning and recoverying in an attempt to resolve the problem at hand.
Using blast-resistant varieties for cultivation is one of the most effective, economical and environmentally friendly ways to prevent the disease on rice (Oryzae sativa L.). However, it has been noticed recently that the resistance of somedisease tolerant-rice being promoted for the purpose began to diminish or even disappear. The phenomenon was attributed to the disappearance of host resistance genes or the mutations on avirulence genes of the plants. This article reviews the relevant pathogenic mechanisms, possible cause(s) for the reduction or loss on the blast-resistance, potential remedies, and search for the avirulence genes for cloning and recoverying in an attempt to resolve the problem at hand.
