In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon ...In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.展开更多
The experiment was conducted to study the impact of application of microbial inoculants, compared with no microbial fertilizer, on enzyme activity, microbial biomass and available nutrient contents in paddy soil in He...The experiment was conducted to study the impact of application of microbial inoculants, compared with no microbial fertilizer, on enzyme activity, microbial biomass and available nutrient contents in paddy soil in Heilongjiang Province. The application of soil phosphorus activator was able to increase the quantity of bacteria and fungi in soil, but its effect on actinomycetes in soil was not significant. The application of microbial inoculants increased the urease and sucrase activities in soil over the growing season, but only at the maturing stage soil acid phosphatase activity was enhanced with the applying soil phosphorus activator. The application of soil phosphorus activator increased alkali-hydrolyzable nitrogen and available phosphorus contents in soil, but did not increase available potassium content in soil. The optimal microbial inoculant application rate as applied as soil phosphorus activator was 7.5 kg hm-2.展开更多
Field experiment was conducted to study the effect of applying organic matter in wind blown soil on microbial biomass and enzyme activity.The results showed that microbial biomass and enzyme activity keep dynamic chan...Field experiment was conducted to study the effect of applying organic matter in wind blown soil on microbial biomass and enzyme activity.The results showed that microbial biomass and enzyme activity keep dynamic changes during wheat growing season in wind blown soil,and reached the peak level in wheat booting stage.Compared with chemical fertilizer,all the other treatments could increase the microbial biomass in different degree,the same as catalsae and alkaline phosphatase activity,But urease activity was slightly difference from them.展开更多
Through the pot experiment, the effects of different cropping patterns of soybean and maize seedlings on rhizosphere soil urease, catalase, polyphenol oxidase and invertase activities and microbial biomass carbon （MB...Through the pot experiment, the effects of different cropping patterns of soybean and maize seedlings on rhizosphere soil urease, catalase, polyphenol oxidase and invertase activities and microbial biomass carbon （MBC） and nitrogen （MBN） were studied. Six treatments of soybean-soybean, soybean-maize, soybean-mixed, maize-soybean, maize-maize and maize-mixed were conducted in pots. Results showed that catalase activity and invertase activity of maize-maize were the highest and significantly different from those of the other treatments except maize-soybean; soil polyphenol oxidase activity of soybean-maize was the highest, and reached significant level among the other treatments, but there was no significant difference of urease activity among treatment soils; MBC of maize-maize soil and MBN of maize-mixed soil reached the highest and significant levels compared with other treatments; MBC and C/N ratio had positive and very significant correlations with soil catalase activity and invertase activity, respectively. Therefore, different cropping patterns could affect rhizosphere soil enzyme activities and soil MBC and MBN, which influenced soil carbon and nitrogen mineralization.展开更多
The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw retur...The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.展开更多
To evaluate the influence of various Cr(Ⅵ) concentrations (0.05, 0.25, 0.50, 1.00 and 2.00 g/kg) on the activity of soil enzymes, the activities of catalase, polyphenol oxidase, dehydrogenase, alkaline phosphatase in...To evaluate the influence of various Cr(Ⅵ) concentrations (0.05, 0.25, 0.50, 1.00 and 2.00 g/kg) on the activity of soil enzymes, the activities of catalase, polyphenol oxidase, dehydrogenase, alkaline phosphatase in soils were investigated in the incubation experiment with a period of 35 d. The results indicate that all the tested Cr(Ⅵ) concentrations significantly inhibit dehydrogenase activity by over 70% after 35 d. The activity of alkaline phosphatase is slightly inhibited during the whole experiment except for on the day 7. Cr(Ⅵ) has no obvious effect on the activity of catalase in soil. On the contrary, Cr(Ⅵ) stimulates the activity of polyphenol oxidase. The results suggest that dehydrogenase activity can be used as an indicator for assessing the severity of chromium pollution.展开更多
Eight-month-old Wulong geese were fed with the diet with different proportions of Leymus chiesensis at the same energy and protein level. The activities of plasma Alkaline Phosphatase （AKP）, Acid Phosphatase （ACP）...Eight-month-old Wulong geese were fed with the diet with different proportions of Leymus chiesensis at the same energy and protein level. The activities of plasma Alkaline Phosphatase （AKP）, Acid Phosphatase （ACP）, Choline Esterace （CHE）, Lactic Dehydrogenase （LDH）, Glutamicoxalacetic Transaminase （GOT） and Glutamatepyruvate Transaminase （GPT） were determined and then their correlations with fiber digestibility and the apparent digestibility of Ca, R Met and Cys were analyzed. The results showed that the activity of AKP took on a significant downtrend as the increasing of Leymus chinensis proportion （P〈0.05）. There was a negative correlation between the AKP activity and the digestibility of crude fiber （CF）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） （P〈0.05）. However, there was a significant positive correlation between the AKP activity and the apparent digestibility of Ca, Met and Cys （P〈0.05）. Moreover, the activities of the other five enzymes had no significant correlation with the digestibility of CF, NDF, ADF, and the apparent digestibility of Ca, Met and Cys （P〉0.05）.展开更多
A fungus（WR-C1） decomposed cellulose was isolated from a hypothermal litter layer using Congo red medium as the preliminary screening culture medium and then using a filter as the secondary screening medium at low t...A fungus（WR-C1） decomposed cellulose was isolated from a hypothermal litter layer using Congo red medium as the preliminary screening culture medium and then using a filter as the secondary screening medium at low temperature. The experiment showed that the weight loss rate of filter paper on the 15 th days could reach 30.69%. A morphologic and ITS gene sequence analysis suggested that CF-C1 was Cladosporium. We mainly studied the effects of culture time, inoculation amount, initial p H and different sources of carbon, nitrogen and inorganic salt on the cellulase production of strain WR-C1. Under optimum cultural condition, the highest value of WR-C1 enzyme production and filter paper enzyme were 3.27 U · m L～（-1） and 0.51 U · m L～（-1）.展开更多
The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and...The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.展开更多
The objective of this incubation study was to comprehensively evaluate the effects of organic fertilizer and biochar,both individually and in combination,on soil respiration dynamics,key enzyme activities and the conc...The objective of this incubation study was to comprehensively evaluate the effects of organic fertilizer and biochar,both individually and in combination,on soil respiration dynamics,key enzyme activities and the concentrations of various organic carbon components in degraded mollisol.This study used a completely randomized factorial design with three application rates of organic fertilizer(M0:0,M1:13.64 g·kg^(-1),M2:27.27 g·kg^(-1))and biochar(C0:0,C1:1.36 g·kg^(-1),C2:2.73 g·kg^(-1)),resulting in nine treatments with four replicates each.Soil CO_(2) flux,organic carbon fractions including the total,active and microbial biomass carbon,and enzyme activities(sucrase,catalase and polyphenol oxidase)were measured over 120 days.Results indicated that the factors and their interactions significantly influenced all measured parameters.Soil respiration peaked at day 15,with M1C2 treatment exhibiting a rate of 10.90-fold higher than the control.The concentrations of the total,active and microbial biomass organic carbon reached maximum values on days 60,30 and 80,respectively.Notably,M2C1 treatment yielded the highest total organic carbon(86.35%increase)and microbial biomass carbon(17.84%increase).Enzyme activities were significantly enhanced,with the highest catalase activity observed for M0C2 treatment(10.14%increase).These results demonstrated that the co-application of organic fertilizer and biochar was a effective strategy for improving soil biological health and promoting carbon sequestration in degraded mollisol.The treatment combining a high rate of organic fertilizer with a low rate of biochar(M2C1)was identified as the most promising amendment strategy for fertility restoration.展开更多
To investigate the effects of different diluents on the quality of the boar semen stored at 17℃, and assess the relationship between sperm motility and the relative levels of enzymes, three commercial diluents （Dilu...To investigate the effects of different diluents on the quality of the boar semen stored at 17℃, and assess the relationship between sperm motility and the relative levels of enzymes, three commercial diluents （Diluent I, Diluent II and Diluent III） and three boar breed semens （Yorkshire, Landrace and Duroc） were utilized. The sperm motility, effective survival time, survival index, catalase （CAT）, the total anti-oxidative capacity （T-AOC） and malondialdehyde （MDA） levels were evaluated. The results showed that there were significant interaction effects between diluents and breeds on the boar sperm motility （P〈0.001）, survival time （P〈0.001）, CAT levels （P〈0.001） and T-AOC levels （P〈0.001）, but neither effects nor interaction effects between diluents and breeds on survival index （P〉0.05）. All of the parameters varied significantly with the increase of the storage time （P〈0.001）. The survival time increased 12.9% in Yorkshire boar semen diluted with Diluent III than with Diluent II, while the survival time increased 6.6% in Landrace boar semen diluted with Diluent II than with Diluent III. Both CAT and T-AOC levels were significantly positive correlated with sperm motility in all the three boar breeds （P〈0.001）, while MDA levels were significantly negative correlated with sperm motility （P〈0.001）. These results indicated that Diluent III and Diluent II were the optimal commercial diluents for Yorkshire and Landrace boar semen stored at 17 ℃, respectively.展开更多
A 45-day experiment was carried out to evaluate the growth performance, digestive enzymes activity and biochemical response of Cirrhinus mrigala fed graded levels of oil. Three isonitrogenous purified diets （6%, 8% ...A 45-day experiment was carried out to evaluate the growth performance, digestive enzymes activity and biochemical response of Cirrhinus mrigala fed graded levels of oil. Three isonitrogenous purified diets （6%, 8% and 10% of oil） were formulated. A total of 108 juveniles of Cirrhinus mrigala （5.95±0.25） g were equally distributed in triplicate groups in nine plastic tanks of 100 L capacity and fed under natural light cycle. Growth performance of the fish significantly reflected the effect of inclusion levels of oil tested but the diet with 8% lipid had the best significant growth performance [% weight gain, Feed Conversion Ratio （FCR） and Specific Growth Rate （SGR）], across different experimental groups. Levels of secretion of digestive enzymes in the fish fed different experimental diets resulted in significant values of （p〈0.05） amylase and lipase, while Aspartate transaminase （AST）, Alanine transaminase （ALT）, Lactate dehydrogenase （LDH） and Malate dehydrognnase （MDH） values in the muscle and liver decreased significantly （F〈0.05） as the levels of oii in the diet increased. However, serum biochemical parameters did not record any significant difference 6o〉0.05） with the exception of the total lipid across diets. The study confirmed the inclusion effect of graded levels ofoil in juvenile Mrigal diet, but the inclusion should not be more than 8% to avert growth depression.展开更多
The secondary bud burst can cause around 10%-20%yield losses in black currants,an economically important crop in parts of Europe,Asia and North America.The metabolism of reactive oxygen species(ROS)has been linked to ...The secondary bud burst can cause around 10%-20%yield losses in black currants,an economically important crop in parts of Europe,Asia and North America.The metabolism of reactive oxygen species(ROS)has been linked to bud dormancy and its early release(secondary bud burst)in several fruit crops.But the relationship between ROS metabolism and the secondary bud burst is still not well understood in black currants.In the present study,two black currant cultivars(Adelinia and Heifeng)with opposing tendency of exhibiting the secondary bud burst were sprayed with abscisic acid(ABA)and gibberellic acid(GA_(3))to either inhibit or induce the secondary bud burst.The results showed that ABA inhibited the secondary bud burst by reducing the contents of ROS(H_(2)O_(2),O_(2)-·)in buds;decreasing the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT);and increasing the contents of oxidized glutathione(GSSG)and ascorbic acid(AsA).GA_(3) effectively induced the secondary bud burst by increasing ROS contents;increasing the activities of several antioxidant enzymes,such as SOD,POD,CAT,glutathione reductase(GR),ascorbate peroxidase(APX)and the contents of reduced glutathione(GSH);and decreasing the contents of AsA.The experimental results showed that GA_(3) treatment increased the content of ROS,accelerated the metabolism of reactive oxygen species,and promoted the second burst of black currants.However,ROS metabolism was at a low level under ABA treatment,and the buds remained dormant.These results suggested that ROS metabolism might play an important role in the two black currants of the secondary bud burst.展开更多
基金Supported by the Special Fund for Agro-scientific Research in Public Interest in China(201503119-06-01)。
文摘In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.
文摘The experiment was conducted to study the impact of application of microbial inoculants, compared with no microbial fertilizer, on enzyme activity, microbial biomass and available nutrient contents in paddy soil in Heilongjiang Province. The application of soil phosphorus activator was able to increase the quantity of bacteria and fungi in soil, but its effect on actinomycetes in soil was not significant. The application of microbial inoculants increased the urease and sucrase activities in soil over the growing season, but only at the maturing stage soil acid phosphatase activity was enhanced with the applying soil phosphorus activator. The application of soil phosphorus activator increased alkali-hydrolyzable nitrogen and available phosphorus contents in soil, but did not increase available potassium content in soil. The optimal microbial inoculant application rate as applied as soil phosphorus activator was 7.5 kg hm-2.
基金Heilongjiang Province Science Plan Project( 960 67)
文摘Field experiment was conducted to study the effect of applying organic matter in wind blown soil on microbial biomass and enzyme activity.The results showed that microbial biomass and enzyme activity keep dynamic changes during wheat growing season in wind blown soil,and reached the peak level in wheat booting stage.Compared with chemical fertilizer,all the other treatments could increase the microbial biomass in different degree,the same as catalsae and alkaline phosphatase activity,But urease activity was slightly difference from them.
基金Supported by the Scientific Research Foundation for Doctor of Northeast Agricultural UniversityInnovative Team Fund of Northeast Agricultural University
文摘Through the pot experiment, the effects of different cropping patterns of soybean and maize seedlings on rhizosphere soil urease, catalase, polyphenol oxidase and invertase activities and microbial biomass carbon （MBC） and nitrogen （MBN） were studied. Six treatments of soybean-soybean, soybean-maize, soybean-mixed, maize-soybean, maize-maize and maize-mixed were conducted in pots. Results showed that catalase activity and invertase activity of maize-maize were the highest and significantly different from those of the other treatments except maize-soybean; soil polyphenol oxidase activity of soybean-maize was the highest, and reached significant level among the other treatments, but there was no significant difference of urease activity among treatment soils; MBC of maize-maize soil and MBN of maize-mixed soil reached the highest and significant levels compared with other treatments; MBC and C/N ratio had positive and very significant correlations with soil catalase activity and invertase activity, respectively. Therefore, different cropping patterns could affect rhizosphere soil enzyme activities and soil MBC and MBN, which influenced soil carbon and nitrogen mineralization.
基金Supported by the National Key Research and Development Plan Project(2016YFD0300909-04)。
文摘The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.
基金Projects(2006AA06Z374, 2007AA021304) supported by the National High-Tech Research and Development Program of ChinaProject(2008SK2007) supported by the Key Program of Science and Technology of Hunan Province, China
文摘To evaluate the influence of various Cr(Ⅵ) concentrations (0.05, 0.25, 0.50, 1.00 and 2.00 g/kg) on the activity of soil enzymes, the activities of catalase, polyphenol oxidase, dehydrogenase, alkaline phosphatase in soils were investigated in the incubation experiment with a period of 35 d. The results indicate that all the tested Cr(Ⅵ) concentrations significantly inhibit dehydrogenase activity by over 70% after 35 d. The activity of alkaline phosphatase is slightly inhibited during the whole experiment except for on the day 7. Cr(Ⅵ) has no obvious effect on the activity of catalase in soil. On the contrary, Cr(Ⅵ) stimulates the activity of polyphenol oxidase. The results suggest that dehydrogenase activity can be used as an indicator for assessing the severity of chromium pollution.
文摘Eight-month-old Wulong geese were fed with the diet with different proportions of Leymus chiesensis at the same energy and protein level. The activities of plasma Alkaline Phosphatase （AKP）, Acid Phosphatase （ACP）, Choline Esterace （CHE）, Lactic Dehydrogenase （LDH）, Glutamicoxalacetic Transaminase （GOT） and Glutamatepyruvate Transaminase （GPT） were determined and then their correlations with fiber digestibility and the apparent digestibility of Ca, R Met and Cys were analyzed. The results showed that the activity of AKP took on a significant downtrend as the increasing of Leymus chinensis proportion （P〈0.05）. There was a negative correlation between the AKP activity and the digestibility of crude fiber （CF）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） （P〈0.05）. However, there was a significant positive correlation between the AKP activity and the apparent digestibility of Ca, Met and Cys （P〈0.05）. Moreover, the activities of the other five enzymes had no significant correlation with the digestibility of CF, NDF, ADF, and the apparent digestibility of Ca, Met and Cys （P〉0.05）.
基金Supported by the Post-doctoral Research Starting Fund of Heilongjiang Province(LBH-Q13020)
文摘A fungus（WR-C1） decomposed cellulose was isolated from a hypothermal litter layer using Congo red medium as the preliminary screening culture medium and then using a filter as the secondary screening medium at low temperature. The experiment showed that the weight loss rate of filter paper on the 15 th days could reach 30.69%. A morphologic and ITS gene sequence analysis suggested that CF-C1 was Cladosporium. We mainly studied the effects of culture time, inoculation amount, initial p H and different sources of carbon, nitrogen and inorganic salt on the cellulase production of strain WR-C1. Under optimum cultural condition, the highest value of WR-C1 enzyme production and filter paper enzyme were 3.27 U · m L～（-1） and 0.51 U · m L～（-1）.
文摘The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.
基金Supported by the Special Fund for Agro-scientific Research in Public Interest in China(201503119-06-01)。
文摘The objective of this incubation study was to comprehensively evaluate the effects of organic fertilizer and biochar,both individually and in combination,on soil respiration dynamics,key enzyme activities and the concentrations of various organic carbon components in degraded mollisol.This study used a completely randomized factorial design with three application rates of organic fertilizer(M0:0,M1:13.64 g·kg^(-1),M2:27.27 g·kg^(-1))and biochar(C0:0,C1:1.36 g·kg^(-1),C2:2.73 g·kg^(-1)),resulting in nine treatments with four replicates each.Soil CO_(2) flux,organic carbon fractions including the total,active and microbial biomass carbon,and enzyme activities(sucrase,catalase and polyphenol oxidase)were measured over 120 days.Results indicated that the factors and their interactions significantly influenced all measured parameters.Soil respiration peaked at day 15,with M1C2 treatment exhibiting a rate of 10.90-fold higher than the control.The concentrations of the total,active and microbial biomass organic carbon reached maximum values on days 60,30 and 80,respectively.Notably,M2C1 treatment yielded the highest total organic carbon(86.35%increase)and microbial biomass carbon(17.84%increase).Enzyme activities were significantly enhanced,with the highest catalase activity observed for M0C2 treatment(10.14%increase).These results demonstrated that the co-application of organic fertilizer and biochar was a effective strategy for improving soil biological health and promoting carbon sequestration in degraded mollisol.The treatment combining a high rate of organic fertilizer with a low rate of biochar(M2C1)was identified as the most promising amendment strategy for fertility restoration.
基金Supported by the National Swine Industry Technology System(CARS-36)the Scientifc and Technological Project of Yangling Demonstration Zone(2014NY-22)
文摘To investigate the effects of different diluents on the quality of the boar semen stored at 17℃, and assess the relationship between sperm motility and the relative levels of enzymes, three commercial diluents （Diluent I, Diluent II and Diluent III） and three boar breed semens （Yorkshire, Landrace and Duroc） were utilized. The sperm motility, effective survival time, survival index, catalase （CAT）, the total anti-oxidative capacity （T-AOC） and malondialdehyde （MDA） levels were evaluated. The results showed that there were significant interaction effects between diluents and breeds on the boar sperm motility （P〈0.001）, survival time （P〈0.001）, CAT levels （P〈0.001） and T-AOC levels （P〈0.001）, but neither effects nor interaction effects between diluents and breeds on survival index （P〉0.05）. All of the parameters varied significantly with the increase of the storage time （P〈0.001）. The survival time increased 12.9% in Yorkshire boar semen diluted with Diluent III than with Diluent II, while the survival time increased 6.6% in Landrace boar semen diluted with Diluent II than with Diluent III. Both CAT and T-AOC levels were significantly positive correlated with sperm motility in all the three boar breeds （P〈0.001）, while MDA levels were significantly negative correlated with sperm motility （P〈0.001）. These results indicated that Diluent III and Diluent II were the optimal commercial diluents for Yorkshire and Landrace boar semen stored at 17 ℃, respectively.
文摘A 45-day experiment was carried out to evaluate the growth performance, digestive enzymes activity and biochemical response of Cirrhinus mrigala fed graded levels of oil. Three isonitrogenous purified diets （6%, 8% and 10% of oil） were formulated. A total of 108 juveniles of Cirrhinus mrigala （5.95±0.25） g were equally distributed in triplicate groups in nine plastic tanks of 100 L capacity and fed under natural light cycle. Growth performance of the fish significantly reflected the effect of inclusion levels of oil tested but the diet with 8% lipid had the best significant growth performance [% weight gain, Feed Conversion Ratio （FCR） and Specific Growth Rate （SGR）], across different experimental groups. Levels of secretion of digestive enzymes in the fish fed different experimental diets resulted in significant values of （p〈0.05） amylase and lipase, while Aspartate transaminase （AST）, Alanine transaminase （ALT）, Lactate dehydrogenase （LDH） and Malate dehydrognnase （MDH） values in the muscle and liver decreased significantly （F〈0.05） as the levels of oii in the diet increased. However, serum biochemical parameters did not record any significant difference 6o〉0.05） with the exception of the total lipid across diets. The study confirmed the inclusion effect of graded levels ofoil in juvenile Mrigal diet, but the inclusion should not be more than 8% to avert growth depression.
基金Supported by Academic Backbone Project of Northeast Agricultural University(20XG04)the National Key R&D Program of China(2018YFD1000200)Heilongjiang Province Postdoctoral Startup Fund(LBH-Q17029)。
文摘The secondary bud burst can cause around 10%-20%yield losses in black currants,an economically important crop in parts of Europe,Asia and North America.The metabolism of reactive oxygen species(ROS)has been linked to bud dormancy and its early release(secondary bud burst)in several fruit crops.But the relationship between ROS metabolism and the secondary bud burst is still not well understood in black currants.In the present study,two black currant cultivars(Adelinia and Heifeng)with opposing tendency of exhibiting the secondary bud burst were sprayed with abscisic acid(ABA)and gibberellic acid(GA_(3))to either inhibit or induce the secondary bud burst.The results showed that ABA inhibited the secondary bud burst by reducing the contents of ROS(H_(2)O_(2),O_(2)-·)in buds;decreasing the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT);and increasing the contents of oxidized glutathione(GSSG)and ascorbic acid(AsA).GA_(3) effectively induced the secondary bud burst by increasing ROS contents;increasing the activities of several antioxidant enzymes,such as SOD,POD,CAT,glutathione reductase(GR),ascorbate peroxidase(APX)and the contents of reduced glutathione(GSH);and decreasing the contents of AsA.The experimental results showed that GA_(3) treatment increased the content of ROS,accelerated the metabolism of reactive oxygen species,and promoted the second burst of black currants.However,ROS metabolism was at a low level under ABA treatment,and the buds remained dormant.These results suggested that ROS metabolism might play an important role in the two black currants of the secondary bud burst.
