2017 Vol. 34, No. 2
2017, 34(2): 197-206.
doi: 10.11833/j.issn.2095-0756.2017.02.001
Abstract:
The reform of rural collective economic property joint-stock cooperative system aimed to define property right and protect the interests of Rural Collective Economic Organization (RCEO) members. However, the dispersed shareholders' right is a kind of fair system with low efficiency and closed management mode is not good for collective economy to act actively, so it is necessary to actively explore the approach to realize the equity circulation. In this study, we used the survey data of 212 members from 15 villages in 4 counties (districts) of Zhejiang Province and Logit model to analyze the willingness of the RCEO members to participate in the equity circulation and the influencing factors from the micro perspective. The results indicated that the schooling years and the share numbers of household heads had a significant positive effect on the RCEO members' willingness to participate in the equity circulation at the 5% level. In the case of other factors unchanged, organization members' willing to participate in the equity transfer probability would be increased by 14.40 per cent as the household head's schooling increased by 1 year; the probability of member's willingness to participate in the transfer would be increased by 0.2 per cent as the member had one more share. Whether the household head had been a cadre (or leader of economic organization), and the members' awareness of equity integrity had a significant positive effect on members' willingness to participate in the equity transfer at 1% level. In the case of other factors unchanged, the transfer probability of members with their household heads being village cadres was 3.03 times as much as those whose household heads had never been village cadres. The transfer probability of members who had awareness of property integrity was 9.79 times as much as those had no awareness. The followings are the suggestions based on the above research results:①Refine the standard of property set and increase the shares of organization members; ② Publicize the knowledge of the shares power and the realization path, and enhance organization members' awareness to protect their own rights and interests; ③ Promote equity circulation step by step according to local conditions.
The reform of rural collective economic property joint-stock cooperative system aimed to define property right and protect the interests of Rural Collective Economic Organization (RCEO) members. However, the dispersed shareholders' right is a kind of fair system with low efficiency and closed management mode is not good for collective economy to act actively, so it is necessary to actively explore the approach to realize the equity circulation. In this study, we used the survey data of 212 members from 15 villages in 4 counties (districts) of Zhejiang Province and Logit model to analyze the willingness of the RCEO members to participate in the equity circulation and the influencing factors from the micro perspective. The results indicated that the schooling years and the share numbers of household heads had a significant positive effect on the RCEO members' willingness to participate in the equity circulation at the 5% level. In the case of other factors unchanged, organization members' willing to participate in the equity transfer probability would be increased by 14.40 per cent as the household head's schooling increased by 1 year; the probability of member's willingness to participate in the transfer would be increased by 0.2 per cent as the member had one more share. Whether the household head had been a cadre (or leader of economic organization), and the members' awareness of equity integrity had a significant positive effect on members' willingness to participate in the equity transfer at 1% level. In the case of other factors unchanged, the transfer probability of members with their household heads being village cadres was 3.03 times as much as those whose household heads had never been village cadres. The transfer probability of members who had awareness of property integrity was 9.79 times as much as those had no awareness. The followings are the suggestions based on the above research results:①Refine the standard of property set and increase the shares of organization members; ② Publicize the knowledge of the shares power and the realization path, and enhance organization members' awareness to protect their own rights and interests; ③ Promote equity circulation step by step according to local conditions.
2017, 34(2): 207-214.
doi: 10.11833/j.issn.2095-0756.2017.02.002
Abstract:
The forest carbon sequestration plays an important role in facing global climate change. Based on scenario simulation data of 82 rural households who have involved and non-involved in the first period of nation's first forest management of carbon sequestration trading project in Lin'an, this paper conducts a descriptive analysis of rural households' willingness in participating management of forest carbon sequestration trading project. Furthermore, the paper uses Ordered Logit (Ologit) model and make a quantitative analysis of factors influencing rural households' willingness in participating management of forest carbon sequestration. The research shows that the willingness of participating in the project is relatively high among the households who are younger, better educated, possessing larger area of forest land, higher forestry income and higher cognitive level of carbon sequestration; while it has been tested by model that factors such as education of rural households, family size, labor force of family and whether have been involved in the first period of forest carbon sequestration trading project, have significant impacts on the households' willingness to participate or continually participate in forest carbon sequestration trading project. Finally, based on the results of analysis, the paper put forward references from project promotion, propaganda of low carbon and the price of carbon sink to carry out the project of forest carbon sequestration trading reasonably.
The forest carbon sequestration plays an important role in facing global climate change. Based on scenario simulation data of 82 rural households who have involved and non-involved in the first period of nation's first forest management of carbon sequestration trading project in Lin'an, this paper conducts a descriptive analysis of rural households' willingness in participating management of forest carbon sequestration trading project. Furthermore, the paper uses Ordered Logit (Ologit) model and make a quantitative analysis of factors influencing rural households' willingness in participating management of forest carbon sequestration. The research shows that the willingness of participating in the project is relatively high among the households who are younger, better educated, possessing larger area of forest land, higher forestry income and higher cognitive level of carbon sequestration; while it has been tested by model that factors such as education of rural households, family size, labor force of family and whether have been involved in the first period of forest carbon sequestration trading project, have significant impacts on the households' willingness to participate or continually participate in forest carbon sequestration trading project. Finally, based on the results of analysis, the paper put forward references from project promotion, propaganda of low carbon and the price of carbon sink to carry out the project of forest carbon sequestration trading reasonably.
2017, 34(2): 215-224.
doi: 10.11833/j.issn.2095-0756.2017.02.003
Abstract:
Forest tending is a crucial practice in the forest ecosystem management, which has a profound impact on forest ecosystem carbon (C) and nitrogen (N) storage and its distribution. However, a great deal of uncertainty remains concerning how plant carbon and nitrogen distribution may be affected by forest tending. In this study, a natural Quercus (oak) secondary forest under different tending intensity treatments (21%, 35%, and 54%) with a control (nontending) was investigated in west mountains area of Henan Province. The characteristics of plant carbon storage as well as the distribution of plant carbon and nitrogen in four stand types with forest tending were studied. Trees under different tending intensity treatments were surveyed after two years of forest tending. Our results show that forest tending operations had a significant influence on plant carbon and nitrogen distribution. Prior to estimate the stand biomass, an estimation model of a single plant biomass was established based on the data of sixteen trees. The plant carbon content and nitrogen content of stem was higher than that of bark, branch, leaf, and root of Quercus in different forest tending treatments. Biomass and carbon storage for all tending intensities in the tree population followed the order of stem > branch > root > leaf > bark. Plant carbon storage for light intensity was 21.42 t·hm-2, for moderate intensity was 32.62 t·hm-2, for heavy intensity was 51.24 t·hm-2, and for the control was 14.35 t·hm-2. The biomass and plant carbon storage of understory vegetation and litter in different forest tending treatments followed the order of control > light > moderate > heavy. The plant carbon storage in different vegetation layers followed the order of overstory > litter > understory. Results showed that heavy intensity tending was more beneficial than other treatments to improve soil organic carbon content, soil total nitrogen content, and the accumulation of soil carbon. This study showed that forest tending was beneficial and could provide a basis for forest carbon sink evaluation to assist in scientific and reasonable forest tending management.
Forest tending is a crucial practice in the forest ecosystem management, which has a profound impact on forest ecosystem carbon (C) and nitrogen (N) storage and its distribution. However, a great deal of uncertainty remains concerning how plant carbon and nitrogen distribution may be affected by forest tending. In this study, a natural Quercus (oak) secondary forest under different tending intensity treatments (21%, 35%, and 54%) with a control (nontending) was investigated in west mountains area of Henan Province. The characteristics of plant carbon storage as well as the distribution of plant carbon and nitrogen in four stand types with forest tending were studied. Trees under different tending intensity treatments were surveyed after two years of forest tending. Our results show that forest tending operations had a significant influence on plant carbon and nitrogen distribution. Prior to estimate the stand biomass, an estimation model of a single plant biomass was established based on the data of sixteen trees. The plant carbon content and nitrogen content of stem was higher than that of bark, branch, leaf, and root of Quercus in different forest tending treatments. Biomass and carbon storage for all tending intensities in the tree population followed the order of stem > branch > root > leaf > bark. Plant carbon storage for light intensity was 21.42 t·hm-2, for moderate intensity was 32.62 t·hm-2, for heavy intensity was 51.24 t·hm-2, and for the control was 14.35 t·hm-2. The biomass and plant carbon storage of understory vegetation and litter in different forest tending treatments followed the order of control > light > moderate > heavy. The plant carbon storage in different vegetation layers followed the order of overstory > litter > understory. Results showed that heavy intensity tending was more beneficial than other treatments to improve soil organic carbon content, soil total nitrogen content, and the accumulation of soil carbon. This study showed that forest tending was beneficial and could provide a basis for forest carbon sink evaluation to assist in scientific and reasonable forest tending management.
2017, 34(2): 225-232.
doi: 10.11833/j.issn.2095-0756.2017.02.004
Abstract:
Raising chickens under trees or bushes could improve the soil. To research the influence of the surface layer's (0-20 cm) soil aggregate composition, fractal dimension, physical and chemical properties, microbial population, and enzyme activities for different chicken raising densities and to probe relationships between fractal dimension and soil physical and chemical properties, microbial population, and enzyme activities; citrus orchards in the Sichuan Basin low mountain hilly area were selected with four chicken density treatments (0, 600, 1 200, and 2 400 chichens per hm2) and each treatment had three replications; the 12 plots of 20 m×20 m each were arranged in a randomized block design. Soils in the surface layer (0-20 cm) in each plot were collected, by snake-shaped five-point sampling method, to determine soil properties, such as soil aggregate composition and fractal dimension. Results showed a significant (P < 0.05) increase of 1.9%-5.0% in content of the >0.25 mm particle-sized soil aggregates (dry-sieved) and 7.3%-24.5% in water-stable aggregates (wet-sieved) in citrus orchards that were raising chickens, with both increasing as chicken density increased. Soil fractal dimension ranged from 2.174 to 2.760 and significantly (P < 0.05) decreased as chicken density (by 1.3%-8.7%) and the >0.25 mm particle-sized soil aggregates (dry-sieved) and water-stable aggregates (wet-sieved) increased. Soil fractal dimension was significantly correlated with the content of >0.25 mm (r=-0.929, P < 0.05) and >0.50 mm (r=-0.915, P < 0.05) particle-sized water-stable aggregates (wet-sieved). Raising chickens in citrus orchards significantly (P < 0.05) decreased soil bulk density (except 600 chichens per hm2), significantly (P < 0.05) improved soil total porosity (except 600 chichens per hm2), and significantly (P < 0.05) increased nutrient content, microbial population, and enzyme activities; soil fertility also increased as chicken density increased. Soil physical and chemical properties, microbial population, and enzyme activities were significantly (P < 0.05) correlated with soil fractal dimension. These findings indicated that raising chickens in citrus orchards could improve soil aggregate composition and soil fertility with fractal dimension of the soil aggregate and water-stable aggregate decreasing; fractal dimension of soil aggregate could also be used as an important comprehensive quantitative index to evaluate soil physical and chemical properties when raising chickens in a forest ecosystem.
Raising chickens under trees or bushes could improve the soil. To research the influence of the surface layer's (0-20 cm) soil aggregate composition, fractal dimension, physical and chemical properties, microbial population, and enzyme activities for different chicken raising densities and to probe relationships between fractal dimension and soil physical and chemical properties, microbial population, and enzyme activities; citrus orchards in the Sichuan Basin low mountain hilly area were selected with four chicken density treatments (0, 600, 1 200, and 2 400 chichens per hm2) and each treatment had three replications; the 12 plots of 20 m×20 m each were arranged in a randomized block design. Soils in the surface layer (0-20 cm) in each plot were collected, by snake-shaped five-point sampling method, to determine soil properties, such as soil aggregate composition and fractal dimension. Results showed a significant (P < 0.05) increase of 1.9%-5.0% in content of the >0.25 mm particle-sized soil aggregates (dry-sieved) and 7.3%-24.5% in water-stable aggregates (wet-sieved) in citrus orchards that were raising chickens, with both increasing as chicken density increased. Soil fractal dimension ranged from 2.174 to 2.760 and significantly (P < 0.05) decreased as chicken density (by 1.3%-8.7%) and the >0.25 mm particle-sized soil aggregates (dry-sieved) and water-stable aggregates (wet-sieved) increased. Soil fractal dimension was significantly correlated with the content of >0.25 mm (r=-0.929, P < 0.05) and >0.50 mm (r=-0.915, P < 0.05) particle-sized water-stable aggregates (wet-sieved). Raising chickens in citrus orchards significantly (P < 0.05) decreased soil bulk density (except 600 chichens per hm2), significantly (P < 0.05) improved soil total porosity (except 600 chichens per hm2), and significantly (P < 0.05) increased nutrient content, microbial population, and enzyme activities; soil fertility also increased as chicken density increased. Soil physical and chemical properties, microbial population, and enzyme activities were significantly (P < 0.05) correlated with soil fractal dimension. These findings indicated that raising chickens in citrus orchards could improve soil aggregate composition and soil fertility with fractal dimension of the soil aggregate and water-stable aggregate decreasing; fractal dimension of soil aggregate could also be used as an important comprehensive quantitative index to evaluate soil physical and chemical properties when raising chickens in a forest ecosystem.
2017, 34(2): 233-238.
doi: 10.11833/j.issn.2095-0756.2017.02.005
Abstract:
To determine the cause of leaf chlorosis of Cinnamomum camphora, soil physicochemical properties were analyzed and evaluated. Results showed that in the 0-30 cm layer, soil bulk density in yellowing plots was significantly greater (P < 0.05) than that in non-yellowing plots; whereas, in the 30-60 cm layer there were no significant differences. Soil pH in yellowing plots was 8.28-8.64 and in non-yellowing plots was 6.57-7.45. For both 0-30 cm and 30-60 cm layers, yellowing plots were significantly greater than non-yellowing plots (P < 0.05) for soil organic matter (SOM), total nitrogen (N), available phosphorus (P), available iron (Fe), and manganese (Mn). The yellowing plots were greater than non-yellowing plots in the 0-30 cm layer for SOM (62.84%), total N (67.44%), available P (74.55%), available Fe (137.47%), and Mn (71.25%), and in the 30-60 cm plots for SOM (30.89%), total N (57.57%), available P (134.06%), available Fe (86.93%), and Mn (71.38%). No significant differences were found for available potassium, Zn, and Cu. Thus, soil alkalinity and low available Fe were the main factors causing C. camphora yellowing.
To determine the cause of leaf chlorosis of Cinnamomum camphora, soil physicochemical properties were analyzed and evaluated. Results showed that in the 0-30 cm layer, soil bulk density in yellowing plots was significantly greater (P < 0.05) than that in non-yellowing plots; whereas, in the 30-60 cm layer there were no significant differences. Soil pH in yellowing plots was 8.28-8.64 and in non-yellowing plots was 6.57-7.45. For both 0-30 cm and 30-60 cm layers, yellowing plots were significantly greater than non-yellowing plots (P < 0.05) for soil organic matter (SOM), total nitrogen (N), available phosphorus (P), available iron (Fe), and manganese (Mn). The yellowing plots were greater than non-yellowing plots in the 0-30 cm layer for SOM (62.84%), total N (67.44%), available P (74.55%), available Fe (137.47%), and Mn (71.25%), and in the 30-60 cm plots for SOM (30.89%), total N (57.57%), available P (134.06%), available Fe (86.93%), and Mn (71.38%). No significant differences were found for available potassium, Zn, and Cu. Thus, soil alkalinity and low available Fe were the main factors causing C. camphora yellowing.
Organic matter in forest soils determined with spectrophotometry and optimized by orthogonal testing
2017, 34(2): 239-243.
doi: 10.11833/j.issn.2095-0756.2017.02.006
Abstract:
To rapidly and accurately measure organic matter in forest soils, organic matter from standard soil material was oxidized by potassium dichromate with external heating conditions, Cr (Ⅳ) was reduced to Cr (Ⅲ), absorbance of Cr (Ⅲ) was determined by spectrophotometry, and the rate of organic matter was quantified by comparison with a standard curve. Orthogonal testing with digestion temperature, digestion time, and sulfuric acid amount, was utilized and the effects on the determination results were investigated. Results showed that for organic matter digestion in soils, the optimal digestion temperature was 135℃, the digestion time was 60 min, and the amount of sulfuric acid was 6 mL. The determined mass fractions of organic matter in the soil were in agreement with the certified ones with a relative standard deviation (RSD) (n=6) of 1.3%, a relative error of-0.6%, a recovery rate range of 95.2%-98.6%, and a method detection limit (MDL) of 0.5 mg·g-1. Based on the t test, all results determined with this novel method were not significantly different from the standard forestry method. This investigation method was simple, accurate, and could meet the requirements for extensive application when determining organic matter in forest soils.
To rapidly and accurately measure organic matter in forest soils, organic matter from standard soil material was oxidized by potassium dichromate with external heating conditions, Cr (Ⅳ) was reduced to Cr (Ⅲ), absorbance of Cr (Ⅲ) was determined by spectrophotometry, and the rate of organic matter was quantified by comparison with a standard curve. Orthogonal testing with digestion temperature, digestion time, and sulfuric acid amount, was utilized and the effects on the determination results were investigated. Results showed that for organic matter digestion in soils, the optimal digestion temperature was 135℃, the digestion time was 60 min, and the amount of sulfuric acid was 6 mL. The determined mass fractions of organic matter in the soil were in agreement with the certified ones with a relative standard deviation (RSD) (n=6) of 1.3%, a relative error of-0.6%, a recovery rate range of 95.2%-98.6%, and a method detection limit (MDL) of 0.5 mg·g-1. Based on the t test, all results determined with this novel method were not significantly different from the standard forestry method. This investigation method was simple, accurate, and could meet the requirements for extensive application when determining organic matter in forest soils.
2017, 34(2): 244-252.
doi: 10.11833/j.issn.2095-0756.2017.02.007
Abstract:
A field experiment was conducted to determine the effect of dead pig (DPB) and bamboo (BB) bio-chars as well as their application patterns on yield and nitrogen (N) content in vegetables and on soil properties (pH, electrical conductivity, and N content) in an Ipomoea aquatica-Brassica chinensis rotation system at Banqiao Town, Lin'an City, Zhejiang Province, China. Treatments included (1) a control (no biochar); (2) one application of 20 t·hm-2 of 20-0-BB and (3) 20-0-DPB prior to the first I. aquatica crop; and two applications of biochars with 10 t·hm-2 being applied prior to the I. aquatica season and the remaining biochars[(4) 10-10-DPB or (5) 10-10-BB] being applied prior to the B. chinensis season at an application rate of 10 t·hm-2. The treatments were laid out based on randomized complete block design with four replications. The plant shoots of I. aquatica and Brassica chinensis in each plot were harvested after growth for 65 and 40 days, respectively. At each harvest time, five plants and five soil cores (0-200 mm) respectively from each plot were randomly collected and bulked for chemical analysis. Results showed that in the I. aquatica crop season, the 20-0-DPB treatment significantly increased (P < 0.05) the I. aquatica crop yield and soil pH. Also, the 20-0-DPB and 10-10-DPB treatments significantly increased (P < 0.05) yield of B. chinensis; whereas, the 20-0-BB and 10-10-BB treatments significantly decreased (P < 0.05) the I. aquatica crop yield. Additionally, the 20-0-DPB and 20-0-BB treatments significantly increased N (P < 0.05) in roots of I. aquatica Forsk but not in B. chinensis. The 10-10-DPB treatment significantly increased (P < 0.05) B. chinensis root N. Finally, biochar treatments had no significant effect on soil nitrate or vegetable shoot N. In conclusion, the dead pig biochar was more effective than the bamboo bio-char for increasing soil pH and vegetable yield with one application of dead pig biochar at 20 t·hm-2 appearing to be better than two split applications.
A field experiment was conducted to determine the effect of dead pig (DPB) and bamboo (BB) bio-chars as well as their application patterns on yield and nitrogen (N) content in vegetables and on soil properties (pH, electrical conductivity, and N content) in an Ipomoea aquatica-Brassica chinensis rotation system at Banqiao Town, Lin'an City, Zhejiang Province, China. Treatments included (1) a control (no biochar); (2) one application of 20 t·hm-2 of 20-0-BB and (3) 20-0-DPB prior to the first I. aquatica crop; and two applications of biochars with 10 t·hm-2 being applied prior to the I. aquatica season and the remaining biochars[(4) 10-10-DPB or (5) 10-10-BB] being applied prior to the B. chinensis season at an application rate of 10 t·hm-2. The treatments were laid out based on randomized complete block design with four replications. The plant shoots of I. aquatica and Brassica chinensis in each plot were harvested after growth for 65 and 40 days, respectively. At each harvest time, five plants and five soil cores (0-200 mm) respectively from each plot were randomly collected and bulked for chemical analysis. Results showed that in the I. aquatica crop season, the 20-0-DPB treatment significantly increased (P < 0.05) the I. aquatica crop yield and soil pH. Also, the 20-0-DPB and 10-10-DPB treatments significantly increased (P < 0.05) yield of B. chinensis; whereas, the 20-0-BB and 10-10-BB treatments significantly decreased (P < 0.05) the I. aquatica crop yield. Additionally, the 20-0-DPB and 20-0-BB treatments significantly increased N (P < 0.05) in roots of I. aquatica Forsk but not in B. chinensis. The 10-10-DPB treatment significantly increased (P < 0.05) B. chinensis root N. Finally, biochar treatments had no significant effect on soil nitrate or vegetable shoot N. In conclusion, the dead pig biochar was more effective than the bamboo bio-char for increasing soil pH and vegetable yield with one application of dead pig biochar at 20 t·hm-2 appearing to be better than two split applications.
2017, 34(2): 253-260.
doi: 10.11833/j.issn.2095-0756.2017.02.008
Abstract:
Soil organic matter (SOM), an important soil quality indicator and a highlighted object of study in soil science, has shown a close relationship to fertilizer applications. Long-term chemical nitrogen (N) fertilization induced a decrease in soil pH, but the decrease could be overcome by organic fertilization which would mitigate soil acidification, promote SOM accumulation, and increase crop yields. The objective of this study was to show past and present SOM levels as well as relationships between crop yield and SOM. Six fertilization regimes (no fertilizers, chemical nitrogen-phosphorous-potassium (NPK) fertilizers, organic and chemical fertilizers, chemical fertilizers with returned straw, organic and chemical fertilizers with returned straw, and organic and inorganic compound fertilizers) from a long-term fertilization experiment with a wheat-maize rotation in Fuyang City, Anhui Province were applied and analyzed with a correlation analysis between crop yield and SOM. Results of the correlation analysis demonstrated a significant (P < 0.05) and positive correlation (r=0.598 4) for the wheat season and a highly significant (P < 0.01) and positive correlation (r=0.443 7) for the maize season. Thus, a partial replacement of chemical fertilizer by organic manure could improve crop yields and SOM accumulation.
Soil organic matter (SOM), an important soil quality indicator and a highlighted object of study in soil science, has shown a close relationship to fertilizer applications. Long-term chemical nitrogen (N) fertilization induced a decrease in soil pH, but the decrease could be overcome by organic fertilization which would mitigate soil acidification, promote SOM accumulation, and increase crop yields. The objective of this study was to show past and present SOM levels as well as relationships between crop yield and SOM. Six fertilization regimes (no fertilizers, chemical nitrogen-phosphorous-potassium (NPK) fertilizers, organic and chemical fertilizers, chemical fertilizers with returned straw, organic and chemical fertilizers with returned straw, and organic and inorganic compound fertilizers) from a long-term fertilization experiment with a wheat-maize rotation in Fuyang City, Anhui Province were applied and analyzed with a correlation analysis between crop yield and SOM. Results of the correlation analysis demonstrated a significant (P < 0.05) and positive correlation (r=0.598 4) for the wheat season and a highly significant (P < 0.01) and positive correlation (r=0.443 7) for the maize season. Thus, a partial replacement of chemical fertilizer by organic manure could improve crop yields and SOM accumulation.
2017, 34(2): 261-267.
doi: 10.11833/j.issn.2095-0756.2017.02.009
Abstract:
To discuss the change of carbohydrates of Phyllostachys edulis in the process of rapid growth, kits and 3, 5-dinitrosalicylic acid colorimetry were used to measure the contents of starch, sucrose, glucose, fructose and cellulose in the bamboo stump, the lower, middle and upper of Ph. edulis bamboo shoot at dusk (0 h), 4 h and 8 h after dusk, respectively. Results showed that the carbohydrates mass fractions among different parts in Ph. edulis in the progress of rapid growth existed differences and had different degree of change over time. The starch mass fractions, decreased significantly in all the parts of bamboo stump 8 h after dusk, dropped by 28.7% and 61.5% in the bamboo stump and the middle, respectively; the mass fractions of sucrose, glucose and fructose in the bamboo stump dropped by 29.4%, 39.2% and 21.4%, respectively; in the middle of bamboo shoot, sucrose, glucose and fructose mass fractions dropped by 36.9%, 54.3% and 26.6%; 4 h after dusk cellulose mass fraction in the lower of bamboo stump increased by 25.5%. There were significant positive correlations in mass fractions between the starch with any of sucrose, glucose or fructose in the bamboo stump, the lower and middle of Ph. edulis bamboo shoot, and there were significant negative correlations in mass fractions between starch with any of glucose or fructose in the upper. There were significant negative correlations in mass fractions between cellulose with any of starch, sucrose, glucose or fructose in the lower. After dark, cellulose in the lower of bamboo shoots had more deposition than the other parts, the elongation in the middle was fast, and it consumed more soluble sugar. The upper growth was slowly, and consumed little soluble sugar. Bamboo stump as an important part reserving starch, provided plenty of carbohydrates for rapid growth of bamboo shoots.
To discuss the change of carbohydrates of Phyllostachys edulis in the process of rapid growth, kits and 3, 5-dinitrosalicylic acid colorimetry were used to measure the contents of starch, sucrose, glucose, fructose and cellulose in the bamboo stump, the lower, middle and upper of Ph. edulis bamboo shoot at dusk (0 h), 4 h and 8 h after dusk, respectively. Results showed that the carbohydrates mass fractions among different parts in Ph. edulis in the progress of rapid growth existed differences and had different degree of change over time. The starch mass fractions, decreased significantly in all the parts of bamboo stump 8 h after dusk, dropped by 28.7% and 61.5% in the bamboo stump and the middle, respectively; the mass fractions of sucrose, glucose and fructose in the bamboo stump dropped by 29.4%, 39.2% and 21.4%, respectively; in the middle of bamboo shoot, sucrose, glucose and fructose mass fractions dropped by 36.9%, 54.3% and 26.6%; 4 h after dusk cellulose mass fraction in the lower of bamboo stump increased by 25.5%. There were significant positive correlations in mass fractions between the starch with any of sucrose, glucose or fructose in the bamboo stump, the lower and middle of Ph. edulis bamboo shoot, and there were significant negative correlations in mass fractions between starch with any of glucose or fructose in the upper. There were significant negative correlations in mass fractions between cellulose with any of starch, sucrose, glucose or fructose in the lower. After dark, cellulose in the lower of bamboo shoots had more deposition than the other parts, the elongation in the middle was fast, and it consumed more soluble sugar. The upper growth was slowly, and consumed little soluble sugar. Bamboo stump as an important part reserving starch, provided plenty of carbohydrates for rapid growth of bamboo shoots.
2017, 34(2): 268-275.
doi: 10.11833/j.issn.2095-0756.2017.02.010
Abstract:
To determine the effects of high temperature, drought, combined high temperature and drought, and re-watering on protective enzymes and lipid peroxidation of Phyllostachys edulis seedlings, an experiment was set up with treatments:1) optimal temperature (day 28℃/night 22℃) and normal hydration (75% of field water-holding capacity) as a control group, 2) optimal temperature and drought (35% of field water-holding capacity), 3) high temperature (day 40℃/night 22℃) and normal hydration, and 4) combined stress followed by re-watering to determine the effects on antioxidase, hydrogen peroide (H2O2), and malondialdehyde (MDA). Samples were respectively collected on Day 7 after the start of treatment, and at 9:00 am on Day 0, 1, 3 after re-watering, sample weight of each group is 1.0 g. Results showed that 1) With high temperature SOD activity increased the most (P < 0.01), and with drought POD activity was greatest (P < 0.05); after drought the H2O2 level was significantly higher (P < 0.01) than other conditions. After combined stress, POD and APX activities increased the most (P < 0.01), and the level of MDA was higher than other treatments (P < 0.05). 2) On Day 1 after re-watering, H2O2 increased (P < 0.05) leading to an increase of POD and CAT activity (P < 0.05) with APX activity decreasing then increasing (P < 0.05). On Day 3 after re-watering, levels of MDA and H2O2 returned to levels of the control group, but with the combined-stress treatment, SOD, POD, and CAT activities continuously decreased (P < 0.05) and APX activity and H2O2 levels decreased and then increased (P < 0.05) with MDA levels continuing to rise (P < 0.05). On Day 3 after re-watering MDA and H2O2 were at high levels and significantly higher than those of drought conditions (P < 0.05). Thus, the protective mechanism for Ph. edulis seedlings with high temperature was CAT, with drought was POD, and with combined-stress conditions were APX and POD, with SOD playing an important role in anti lipid peroxidation for all three stresses.
To determine the effects of high temperature, drought, combined high temperature and drought, and re-watering on protective enzymes and lipid peroxidation of Phyllostachys edulis seedlings, an experiment was set up with treatments:1) optimal temperature (day 28℃/night 22℃) and normal hydration (75% of field water-holding capacity) as a control group, 2) optimal temperature and drought (35% of field water-holding capacity), 3) high temperature (day 40℃/night 22℃) and normal hydration, and 4) combined stress followed by re-watering to determine the effects on antioxidase, hydrogen peroide (H2O2), and malondialdehyde (MDA). Samples were respectively collected on Day 7 after the start of treatment, and at 9:00 am on Day 0, 1, 3 after re-watering, sample weight of each group is 1.0 g. Results showed that 1) With high temperature SOD activity increased the most (P < 0.01), and with drought POD activity was greatest (P < 0.05); after drought the H2O2 level was significantly higher (P < 0.01) than other conditions. After combined stress, POD and APX activities increased the most (P < 0.01), and the level of MDA was higher than other treatments (P < 0.05). 2) On Day 1 after re-watering, H2O2 increased (P < 0.05) leading to an increase of POD and CAT activity (P < 0.05) with APX activity decreasing then increasing (P < 0.05). On Day 3 after re-watering, levels of MDA and H2O2 returned to levels of the control group, but with the combined-stress treatment, SOD, POD, and CAT activities continuously decreased (P < 0.05) and APX activity and H2O2 levels decreased and then increased (P < 0.05) with MDA levels continuing to rise (P < 0.05). On Day 3 after re-watering MDA and H2O2 were at high levels and significantly higher than those of drought conditions (P < 0.05). Thus, the protective mechanism for Ph. edulis seedlings with high temperature was CAT, with drought was POD, and with combined-stress conditions were APX and POD, with SOD playing an important role in anti lipid peroxidation for all three stresses.
2017, 34(2): 276-282.
doi: 10.11833/j.issn.2095-0756.2017.02.011
Abstract:
To understand the allelopathic effects of composted tomato residues on cucumber and Chinese cabbage vegetables, five concentrations (10.0, 20.0, 30.0, 40.0, and 50.0 g·L-1) of extracts from composted tomato residues and a control (ck) (0.0 g·L-1) were applied to germinating seeds and seedlings during growth and then employed seed germination bioassay method to measure the germination rate, germination rate, seedling length, and fresh weight of cucumber and Chinese cabbage and finally evaluated. Results showed that the germination rate, seedling length, and fresh weight of cucumber and Chinese cabbage were promoted at low aqueous extract concentrations (10.0-20.0 g·L-1). Also, the germination rate and germination index of cucumber and Chinese cabbage as well as the seedling length and fresh weight of cucumber were inhibited at a high concentration (>40.0 g·L-1). Root growth of cucumber and Chinese cabbage for all concentrations was inhibited. Also, the root length of cucumber treated with extracts was significantly lower (P < 0.05) than ck. Overall, the extracts from composted tomato residues showed some inhibitory effect on cucumber seedling growth and a certain role in promoting on the growth of Chinese cabbage seedlings, but both of them did not reach the significant level. Thus, to a certain extent, the tomato residues could alleviate its inhibition effect after composting.
To understand the allelopathic effects of composted tomato residues on cucumber and Chinese cabbage vegetables, five concentrations (10.0, 20.0, 30.0, 40.0, and 50.0 g·L-1) of extracts from composted tomato residues and a control (ck) (0.0 g·L-1) were applied to germinating seeds and seedlings during growth and then employed seed germination bioassay method to measure the germination rate, germination rate, seedling length, and fresh weight of cucumber and Chinese cabbage and finally evaluated. Results showed that the germination rate, seedling length, and fresh weight of cucumber and Chinese cabbage were promoted at low aqueous extract concentrations (10.0-20.0 g·L-1). Also, the germination rate and germination index of cucumber and Chinese cabbage as well as the seedling length and fresh weight of cucumber were inhibited at a high concentration (>40.0 g·L-1). Root growth of cucumber and Chinese cabbage for all concentrations was inhibited. Also, the root length of cucumber treated with extracts was significantly lower (P < 0.05) than ck. Overall, the extracts from composted tomato residues showed some inhibitory effect on cucumber seedling growth and a certain role in promoting on the growth of Chinese cabbage seedlings, but both of them did not reach the significant level. Thus, to a certain extent, the tomato residues could alleviate its inhibition effect after composting.
2017, 34(2): 283-293.
doi: 10.11833/j.issn.2095-0756.2017.02.012
Abstract:
To reveal the salt tolerance of 5 landscape plant species, Photinia×fraseri, Ligustrum japonicum 'Howardi', Ilex crenata, Euonymus japonicus, Rhododendron pulchrum, a pot experiment for 2-year-old seedlings was conducted to investigated the 5 plants' growth status and physiology indexes under different salinity (NaCl) treatments, design with 4 treaments consisting of 0.28 g·kg-1 control), 1.00, 2.00 and 4.00 g·kg-1 soil salt mass fraction. Membership function value method was adopted to comprehensively evaluate salt tolerance of the 5 plants. The results show that the 5 plants showed different degree of salt-damaged symptoms; When soil salt mass fraction was 4.00 g·kg-1, Hododendron pulchrum, Photinia×fraseri and Ilex crenata were all death, Ligustrum japonicum 'Howardi' and Euonymus japonicus survival rate reached 60.00% and 66.67% respectively. The biomass deceased under salt stress, Hododendron pulchrum decline the largest, 30.03%-64.72%, whlie Ilex crenata decline the least, 10.34%-44.46%;Photinia×fraseri, Ligustrum japonicum 'Howardi' and Euonymus japonicus decline range was 20.54%-47.10%, 18.76%-51.90% and 26.71%-52.48%, respectively. With the increasing of salt content, the net photosynthetic rate, stomatal conductance and transpiration rate were decreased, but the utilization of CO2 were increased. There were no visible change of K+, whereas Na+ concentration and Na+/K+ ratio all rose significantly with the increasing of salinity concentration. The most increases of Na+ was Euonymus japonicus, 6.60-24.31 times more than the ck, and the least increases is Ligustrum japonicum 'Howardi', compared with the ck increased by 1.44-1.82 times. The membership function was used to rank their salt tolerance followed in the order:Ligustrum japonicum 'Howardi' > Euonymus japonicus > Ilex crenata > Photinia×fraseri > Rhododendron pulchrum.
To reveal the salt tolerance of 5 landscape plant species, Photinia×fraseri, Ligustrum japonicum 'Howardi', Ilex crenata, Euonymus japonicus, Rhododendron pulchrum, a pot experiment for 2-year-old seedlings was conducted to investigated the 5 plants' growth status and physiology indexes under different salinity (NaCl) treatments, design with 4 treaments consisting of 0.28 g·kg-1 control), 1.00, 2.00 and 4.00 g·kg-1 soil salt mass fraction. Membership function value method was adopted to comprehensively evaluate salt tolerance of the 5 plants. The results show that the 5 plants showed different degree of salt-damaged symptoms; When soil salt mass fraction was 4.00 g·kg-1, Hododendron pulchrum, Photinia×fraseri and Ilex crenata were all death, Ligustrum japonicum 'Howardi' and Euonymus japonicus survival rate reached 60.00% and 66.67% respectively. The biomass deceased under salt stress, Hododendron pulchrum decline the largest, 30.03%-64.72%, whlie Ilex crenata decline the least, 10.34%-44.46%;Photinia×fraseri, Ligustrum japonicum 'Howardi' and Euonymus japonicus decline range was 20.54%-47.10%, 18.76%-51.90% and 26.71%-52.48%, respectively. With the increasing of salt content, the net photosynthetic rate, stomatal conductance and transpiration rate were decreased, but the utilization of CO2 were increased. There were no visible change of K+, whereas Na+ concentration and Na+/K+ ratio all rose significantly with the increasing of salinity concentration. The most increases of Na+ was Euonymus japonicus, 6.60-24.31 times more than the ck, and the least increases is Ligustrum japonicum 'Howardi', compared with the ck increased by 1.44-1.82 times. The membership function was used to rank their salt tolerance followed in the order:Ligustrum japonicum 'Howardi' > Euonymus japonicus > Ilex crenata > Photinia×fraseri > Rhododendron pulchrum.
2017, 34(2): 294-300.
doi: 10.11833/j.issn.2095-0756.2017.02.013
Abstract:
To explore salt tolerance of Sophora japonica with functional endophytic fungi, eight strains of fungi (H-1 through H-8) were used to inoculate S. japonica seedlings along with 200 mmol·L-1 NaCl stress added by root-irrigation. Seedling height, root/shoot ratio, dry weight, water content, chlorophyll content, proline content, malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) activities were detected. Results showed that with 200 mmol·L-1 NaCl stress, the changes of seedling biomass were basically the same as the tendency of physiological index varied. The H-1, H-3, H-4, and H-6 strains improved salt resistance of S. japonica seedlings. Strain H-3 was significantly higher than the control (P < 0.05) for seedling height (148%), dry weight (117%), root/shoot ratio (121%), and water content (104%). Compared to the control, MDA was 88% and Pro was 151%, the difference reached significant level (P < 0.05). Strain H-5 had the opposite affect with seedling height (69%), dry weight (83%), and root/shoot ratio (78%), which were all significantly lower than the control (P < 0.05); also proline was 81% and POD activity was 72% of the control, and the difference reached significant level (P < 0.05). Over all, H-1, H-3, H-4, and H-6, the dominant strains among the tested endophytes, would have great potential for application.
To explore salt tolerance of Sophora japonica with functional endophytic fungi, eight strains of fungi (H-1 through H-8) were used to inoculate S. japonica seedlings along with 200 mmol·L-1 NaCl stress added by root-irrigation. Seedling height, root/shoot ratio, dry weight, water content, chlorophyll content, proline content, malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) activities were detected. Results showed that with 200 mmol·L-1 NaCl stress, the changes of seedling biomass were basically the same as the tendency of physiological index varied. The H-1, H-3, H-4, and H-6 strains improved salt resistance of S. japonica seedlings. Strain H-3 was significantly higher than the control (P < 0.05) for seedling height (148%), dry weight (117%), root/shoot ratio (121%), and water content (104%). Compared to the control, MDA was 88% and Pro was 151%, the difference reached significant level (P < 0.05). Strain H-5 had the opposite affect with seedling height (69%), dry weight (83%), and root/shoot ratio (78%), which were all significantly lower than the control (P < 0.05); also proline was 81% and POD activity was 72% of the control, and the difference reached significant level (P < 0.05). Over all, H-1, H-3, H-4, and H-6, the dominant strains among the tested endophytes, would have great potential for application.
2017, 34(2): 301-309.
doi: 10.11833/j.issn.2095-0756.2017.02.014
Abstract:
Plant photosynthesis is most sensitive to environmental factors and physiological processes, and it is subject to varying degrees of external environmental impacts. In August 2013 with high summer temperatures and in August 2014 with normal summer temperatures, daily dynamics of photosynthetic characteristics in five common tree species (Ginkgo biloba, Cinnamomam camphora, Michelia chapensis, Magnolia grandiflora, Magnolia denudata) were monitored using a Portable LCPRO+ Photosynthesis System (LCPRO+, ADC Bioscientific). Results showed that with extremely hot temperatures photosynthetic response characteristics of different species differed, but overall they had the same pattern. In a normal summer the "midday depression" appeared around 12:00 noon, but for extremely high temperatures it occurred around 08:00 with the net photosynthetic rate (Pn) remaining low after noon and having no recovery phenomenon. In 2013 elevated temperatures caused the transpiration rate (Tr) and stomatal conductance (Gs) to decrease rapidly with all five species having lower Pn and higher intercellular CO2 concentration (Ci). For photosynthetic parameters, analysis of species in different years showed that physiological differences between different species were significantly influenced by Ci (P < 0.05); whereas, the impact of environmental factors on photosynthetic parameters showed significance with Pn(P < 0.01), Tr(P < 0.05), and Gs(P < 0.02) in different species. For ecosystem water use efficiency (EWUE) the smallest change was with camphor trees (20.3%). When the temperature reached the optimum temperature of 35℃, camphor Pn was significantly higher than the other species. Thus, the camphor tree was more able to adapt to extremely hot weather than other test species.
Plant photosynthesis is most sensitive to environmental factors and physiological processes, and it is subject to varying degrees of external environmental impacts. In August 2013 with high summer temperatures and in August 2014 with normal summer temperatures, daily dynamics of photosynthetic characteristics in five common tree species (Ginkgo biloba, Cinnamomam camphora, Michelia chapensis, Magnolia grandiflora, Magnolia denudata) were monitored using a Portable LCPRO+ Photosynthesis System (LCPRO+, ADC Bioscientific). Results showed that with extremely hot temperatures photosynthetic response characteristics of different species differed, but overall they had the same pattern. In a normal summer the "midday depression" appeared around 12:00 noon, but for extremely high temperatures it occurred around 08:00 with the net photosynthetic rate (Pn) remaining low after noon and having no recovery phenomenon. In 2013 elevated temperatures caused the transpiration rate (Tr) and stomatal conductance (Gs) to decrease rapidly with all five species having lower Pn and higher intercellular CO2 concentration (Ci). For photosynthetic parameters, analysis of species in different years showed that physiological differences between different species were significantly influenced by Ci (P < 0.05); whereas, the impact of environmental factors on photosynthetic parameters showed significance with Pn(P < 0.01), Tr(P < 0.05), and Gs(P < 0.02) in different species. For ecosystem water use efficiency (EWUE) the smallest change was with camphor trees (20.3%). When the temperature reached the optimum temperature of 35℃, camphor Pn was significantly higher than the other species. Thus, the camphor tree was more able to adapt to extremely hot weather than other test species.
2017, 34(2): 310-318.
doi: 10.11833/j.issn.2095-0756.2017.02.015
Abstract:
Phoebe zhennan is vulnerable to low temperature, triggering the physiological and phenotypic damages in plants. To make scientific and accurate evaluations for cold-resistance with two types of P. zhennan (large-leaf and small-leaf), a comparison of physiological and biochemical characteristics between the two types was conducted using 1-year-old seedlings with artificial low temperature stress, using complete randomized block design, with three replication. A membership function method was conducted, and analysis included a principal components analysis. Results showed that the relative conductivity of the two leaf types increased significantly with low temperature stress; whereas, contents of malondialdehyde (MDA), soluble sugar, soluble protein and proline, and the activity of peroxidase (POD) and superoxide dismutase (SOD) increased significantly, peaked at 0.1℃ and-4.0℃ in small-leaf and large-leaf type, respectively, and then decreased significantly. The leaf relative conductance rate of the large-leaf type fluctuated from 8.0 to-8.0℃, but the small-leaf type continued to rise higher significantly than the large-leaf type. The increases in MDA, soluble protein, and proline content in the large-leaf type were lower significantly than those of the small-leaf type, and peak values of soluble protein and proline were higher significantly in the large-leaf type. Analysis revealed that the small-leaf type exhibited cold damage at 0.1℃, but the large-leaf type resisted damage to-4.0℃ stress, which provides important clues for the breeding and introduction cultivation in P. zhennan.
Phoebe zhennan is vulnerable to low temperature, triggering the physiological and phenotypic damages in plants. To make scientific and accurate evaluations for cold-resistance with two types of P. zhennan (large-leaf and small-leaf), a comparison of physiological and biochemical characteristics between the two types was conducted using 1-year-old seedlings with artificial low temperature stress, using complete randomized block design, with three replication. A membership function method was conducted, and analysis included a principal components analysis. Results showed that the relative conductivity of the two leaf types increased significantly with low temperature stress; whereas, contents of malondialdehyde (MDA), soluble sugar, soluble protein and proline, and the activity of peroxidase (POD) and superoxide dismutase (SOD) increased significantly, peaked at 0.1℃ and-4.0℃ in small-leaf and large-leaf type, respectively, and then decreased significantly. The leaf relative conductance rate of the large-leaf type fluctuated from 8.0 to-8.0℃, but the small-leaf type continued to rise higher significantly than the large-leaf type. The increases in MDA, soluble protein, and proline content in the large-leaf type were lower significantly than those of the small-leaf type, and peak values of soluble protein and proline were higher significantly in the large-leaf type. Analysis revealed that the small-leaf type exhibited cold damage at 0.1℃, but the large-leaf type resisted damage to-4.0℃ stress, which provides important clues for the breeding and introduction cultivation in P. zhennan.
2017, 34(2): 319-325.
doi: 10.11833/j.issn.2095-0756.2017.02.016
Abstract:
To examine water consumption of eucalypt plantation species and to provide guidance for plantation establishment and tending, sap flow of plantation grown Eucalyptus urophylla×Eucalyptus grandis was continuously measured using the thermal diffusion stem flow meter (Germany, SF-G) which allowed analyses of water use characteristics during both dry and rainy seasons. Stand meteorological conditions were determined synchronously to enable a correlation analysis for differences between sap flow and meteorological factors in both dry and rainy seasons. Results showed that diurnal variations of sap flow displayed typical single-peaked curves in both dry and rainy seasons. The start (07:15) and peak (11:30) times for sap flow during the rainy season were earlier than those in the dry season (07:45 and 13:00) with the peak sap flow in the rainy season being 1.3 times more than in the dry season. Time duration for relatively high levels of flow were longer in the rainy season than in the dry. In both dry and rainy seasons, variation and total stem sap flow observed during the first half of the night were significantly greater (P < 0.01) than those observed after midnight. Likewise, the variation in total stem sap flow observed during the entire rainy season was significantly greater (P < 0.01) than that observed during the dry season. The average daily (3.99 kg·d-1) and monthly (122.4 kg·month-1) fluxes during rainy season were significantly greater (P < 0.05) than fluxes in the dry season (daily-2.64 kg·d-1 and monthly-80.00 kg·month-1). The main meteorological factors, such as vapor pressure deficit, photosynthetically active radiation (PAR), air humidity, and air temperature, were not correlated to seasonal sap flow of E. urophylla×E. grandis. However, flow density during the rainy season was highly significant (P < 0.01) and positively correlated (r=0.39) with wind velocity and significantly (P < 0.05) and negatively correlated (r=-0.08) with rainfall. The above results show that the rainy season is a fast growth period of E. urophylla×E. grandis, with high water consumption, also is the important period for water and fertilizer management.
To examine water consumption of eucalypt plantation species and to provide guidance for plantation establishment and tending, sap flow of plantation grown Eucalyptus urophylla×Eucalyptus grandis was continuously measured using the thermal diffusion stem flow meter (Germany, SF-G) which allowed analyses of water use characteristics during both dry and rainy seasons. Stand meteorological conditions were determined synchronously to enable a correlation analysis for differences between sap flow and meteorological factors in both dry and rainy seasons. Results showed that diurnal variations of sap flow displayed typical single-peaked curves in both dry and rainy seasons. The start (07:15) and peak (11:30) times for sap flow during the rainy season were earlier than those in the dry season (07:45 and 13:00) with the peak sap flow in the rainy season being 1.3 times more than in the dry season. Time duration for relatively high levels of flow were longer in the rainy season than in the dry. In both dry and rainy seasons, variation and total stem sap flow observed during the first half of the night were significantly greater (P < 0.01) than those observed after midnight. Likewise, the variation in total stem sap flow observed during the entire rainy season was significantly greater (P < 0.01) than that observed during the dry season. The average daily (3.99 kg·d-1) and monthly (122.4 kg·month-1) fluxes during rainy season were significantly greater (P < 0.05) than fluxes in the dry season (daily-2.64 kg·d-1 and monthly-80.00 kg·month-1). The main meteorological factors, such as vapor pressure deficit, photosynthetically active radiation (PAR), air humidity, and air temperature, were not correlated to seasonal sap flow of E. urophylla×E. grandis. However, flow density during the rainy season was highly significant (P < 0.01) and positively correlated (r=0.39) with wind velocity and significantly (P < 0.05) and negatively correlated (r=-0.08) with rainfall. The above results show that the rainy season is a fast growth period of E. urophylla×E. grandis, with high water consumption, also is the important period for water and fertilizer management.
2017, 34(2): 326-331.
doi: 10.11833/j.issn.2095-0756.2017.02.017
Abstract:
The canker disease of Carya cathayensis caused by Botryosphaeria dothidea, is one of the diseases in China that has resulted in serious damage and even death for the tree. To overcome the serious disease threat to the C. cathayensis industry, Bacillus amyloliquefaciens subsp. plantarum CGMCC 11640, which has shown a strong inhibitive activity in vitro against Botryosphaeria dothidea, was obtained by screening with the dual-culture method and cultured in medium mixtures with ratios of sterilized fermentation supernate to PDA being 1:9, 2:8, and 5:5(volume ratio). Then, the inhibitory mechanisms of strain CGMCC 11640 against Botryosphaeria dothidea were further explored by scanning electron microscopy (SEM). Results revealed that the Botryosphaeria dothidea strain growth rate for the three volume ratio mediums were restrained by 75.8% for 1:9, 88.8% for 2:8, and 94.3% for 5:5. The SEM results showed that both bacterial cells and their sterilized fermentation supernate exhibited strong inhibition activity in vitro against Botryosphaeria dothidea and that the hyphae and spores of Botryosphaeria dothidea exhibited atrophy and introcession. Thus, CGMCC 11640 inhibited Botryosphaeria dothidea by destroying cell membranes (e.g. punching holes in them) and walls of hyphae and spores resulting in leakage of plasmatic material from the inside of the cells.
The canker disease of Carya cathayensis caused by Botryosphaeria dothidea, is one of the diseases in China that has resulted in serious damage and even death for the tree. To overcome the serious disease threat to the C. cathayensis industry, Bacillus amyloliquefaciens subsp. plantarum CGMCC 11640, which has shown a strong inhibitive activity in vitro against Botryosphaeria dothidea, was obtained by screening with the dual-culture method and cultured in medium mixtures with ratios of sterilized fermentation supernate to PDA being 1:9, 2:8, and 5:5(volume ratio). Then, the inhibitory mechanisms of strain CGMCC 11640 against Botryosphaeria dothidea were further explored by scanning electron microscopy (SEM). Results revealed that the Botryosphaeria dothidea strain growth rate for the three volume ratio mediums were restrained by 75.8% for 1:9, 88.8% for 2:8, and 94.3% for 5:5. The SEM results showed that both bacterial cells and their sterilized fermentation supernate exhibited strong inhibition activity in vitro against Botryosphaeria dothidea and that the hyphae and spores of Botryosphaeria dothidea exhibited atrophy and introcession. Thus, CGMCC 11640 inhibited Botryosphaeria dothidea by destroying cell membranes (e.g. punching holes in them) and walls of hyphae and spores resulting in leakage of plasmatic material from the inside of the cells.
2017, 34(2): 332-339.
doi: 10.11833/j.issn.2095-0756.2017.02.018
Abstract:
Expressed sequence tags (ESTs) are used for microsatellite development. EST derived from simple sequence repeats (EST-SSRs), one of the most common new microsatellite markers, are more likely to be embedded in functional gene sequences, to be less costly and time effective, and may provide more information. In the present study, analysis of 5 659 publicly available expressed sequence tags of pineapple (Ananas comosus) was conducted with the Webstat online program. Results of 636 (SSRs), identified electronically in 617 ESTs, showed that the average density was one SSR per 7.39 kb of ESTs screened. Dinucleotide (42.61%), trinucleotide (29.25%), and hexanucleotide (20.13%) repeats were the dominant types among the obtained motifs. The least frequent was tetranucleotide repeats (3.46%). TC/AG was most abundant in the dinucleotide motif. Of the 30 functional pairs, 27 primer pairs showed polymorphisms by polymerase chain reaction (PCR) amplifications. Thus, the EST-SSRs developed here with the first large-scale development of SSR markers in pineapple have the potential to be used for development of genetic and physical maps, quantitative trait loci mapping, genetic diversity studies, association mapping, and finger printing cultivars.
Expressed sequence tags (ESTs) are used for microsatellite development. EST derived from simple sequence repeats (EST-SSRs), one of the most common new microsatellite markers, are more likely to be embedded in functional gene sequences, to be less costly and time effective, and may provide more information. In the present study, analysis of 5 659 publicly available expressed sequence tags of pineapple (Ananas comosus) was conducted with the Webstat online program. Results of 636 (SSRs), identified electronically in 617 ESTs, showed that the average density was one SSR per 7.39 kb of ESTs screened. Dinucleotide (42.61%), trinucleotide (29.25%), and hexanucleotide (20.13%) repeats were the dominant types among the obtained motifs. The least frequent was tetranucleotide repeats (3.46%). TC/AG was most abundant in the dinucleotide motif. Of the 30 functional pairs, 27 primer pairs showed polymorphisms by polymerase chain reaction (PCR) amplifications. Thus, the EST-SSRs developed here with the first large-scale development of SSR markers in pineapple have the potential to be used for development of genetic and physical maps, quantitative trait loci mapping, genetic diversity studies, association mapping, and finger printing cultivars.
2017, 34(2): 340-348.
doi: 10.11833/j.issn.2095-0756.2017.02.019
Abstract:
To obtain an optimal method for image enhancement of GF-2 forestry area data, six frequently-used methods were analyzed:Brovey transformation; hue, saturation, and value (HSV) transformation; Principle Component (PC) spectral sharpening; high pass filter (HPF) spectral sharpening; Gram-Schmidt spectral sharpening; and Pansharp transformation. Qualitative and quantitative analyses were used to assess the effect and quality of the fusion images. Indexes include mean, average gradient, high-frequency information integration, correlation index, entropy index and second moment index. Among them, correlation index and second moment index were calculate by ENVI, other indexes were all by Matlab. Furthermore, to access an appropriate fusion method for GF-2 forestland data extraction, fusion images were classified by performance of fusion methods at two information extraction levels based on an object-oriented classification method. All the transformations used the same parameter and methods on each level, and use the same samples to classify and accuracy check. Results showed that correlation index and high-frequency information integration of HSV transformation could reach 0.823 and 0.570, respectively. In addition, the entropy index and second moment index could improved 25% and 50% compared to original multiple image, respectively. It had a better visual effect with obvious enhanced clarity and texture features. For classification experiments, HSV and Brovey transformations had their own superiority for the extraction of different classes with the HSV transformation having the highest overall classification accuracy of 85.1% and the Brovey transformation having the highest accuracy on the second level of 75.7%. The other four methods had different advantages for quality and information extraction of the fusion images. Thus, the final selection of fusion methods should consider practical forestry application and image information which could provide a reference for GF-2 images to be applied on a large scale in forested areas.
To obtain an optimal method for image enhancement of GF-2 forestry area data, six frequently-used methods were analyzed:Brovey transformation; hue, saturation, and value (HSV) transformation; Principle Component (PC) spectral sharpening; high pass filter (HPF) spectral sharpening; Gram-Schmidt spectral sharpening; and Pansharp transformation. Qualitative and quantitative analyses were used to assess the effect and quality of the fusion images. Indexes include mean, average gradient, high-frequency information integration, correlation index, entropy index and second moment index. Among them, correlation index and second moment index were calculate by ENVI, other indexes were all by Matlab. Furthermore, to access an appropriate fusion method for GF-2 forestland data extraction, fusion images were classified by performance of fusion methods at two information extraction levels based on an object-oriented classification method. All the transformations used the same parameter and methods on each level, and use the same samples to classify and accuracy check. Results showed that correlation index and high-frequency information integration of HSV transformation could reach 0.823 and 0.570, respectively. In addition, the entropy index and second moment index could improved 25% and 50% compared to original multiple image, respectively. It had a better visual effect with obvious enhanced clarity and texture features. For classification experiments, HSV and Brovey transformations had their own superiority for the extraction of different classes with the HSV transformation having the highest overall classification accuracy of 85.1% and the Brovey transformation having the highest accuracy on the second level of 75.7%. The other four methods had different advantages for quality and information extraction of the fusion images. Thus, the final selection of fusion methods should consider practical forestry application and image information which could provide a reference for GF-2 images to be applied on a large scale in forested areas.
2017, 34(2): 349-354.
doi: 10.11833/j.issn.2095-0756.2017.02.020
Abstract:
To optimize forest stand structure, to regulate succession, to promote the development of a forest stand, and to improve stand yield and natural regeneration capacity, technologies for classification and management methods and were proposed based on scale, age, location, function, and application of an individual forest for an integral forest stand. The procedure included four parts:(1) the existing forest stand classification method was used as a general guide for such factors as distribution patterns, regeneration, succession, and space utilization so as to match requirements for structurally optimized operations. (2) The forest in this study was classified into seven categories, i.e. timber trees, timber reserve trees, associated trees, successional trees, seed trees, regeneration trees and trees for intermediate cuttings. This structural classification facilitated forest tending and provided a basis for determining the proper intensity and method of intermediate cuttings. (3) For intermediate cuttings, the number of tree varieties, the cutting intensity, as well as the composition of trees varied with changes in structural differences of forest stands. Except for the cleaning of suppressed trees under a certain size, arrangement of the main story, the successional story, and the regeneration story should be considered when selecting trees for intermediate cuttings. (4) Optimization should be considered from the aspect of a general forest stand based on existing stand structure as well as tree proportion and composition to achieve a low intermediate cutting intensity of 5.1%-19.5%. In this way, disturbance will be reduced, regeneration will be improved, tree varieties will be regulated, and forest stand structure will be optimized.
To optimize forest stand structure, to regulate succession, to promote the development of a forest stand, and to improve stand yield and natural regeneration capacity, technologies for classification and management methods and were proposed based on scale, age, location, function, and application of an individual forest for an integral forest stand. The procedure included four parts:(1) the existing forest stand classification method was used as a general guide for such factors as distribution patterns, regeneration, succession, and space utilization so as to match requirements for structurally optimized operations. (2) The forest in this study was classified into seven categories, i.e. timber trees, timber reserve trees, associated trees, successional trees, seed trees, regeneration trees and trees for intermediate cuttings. This structural classification facilitated forest tending and provided a basis for determining the proper intensity and method of intermediate cuttings. (3) For intermediate cuttings, the number of tree varieties, the cutting intensity, as well as the composition of trees varied with changes in structural differences of forest stands. Except for the cleaning of suppressed trees under a certain size, arrangement of the main story, the successional story, and the regeneration story should be considered when selecting trees for intermediate cuttings. (4) Optimization should be considered from the aspect of a general forest stand based on existing stand structure as well as tree proportion and composition to achieve a low intermediate cutting intensity of 5.1%-19.5%. In this way, disturbance will be reduced, regeneration will be improved, tree varieties will be regulated, and forest stand structure will be optimized.
2017, 34(2): 355-360.
doi: 10.11833/j.issn.2095-0756.2017.02.021
Abstract:
Air-coupled ultrasonic techniques, allowing contactless nondestructive testing using air as the coupling media instead of a liquid, have proven to be reliable and indispensable for nondestructive wood testing; however, instrumentation is still not widely available domestically. To help familiarize prospective users, the principle of the air-coupled ultrasonic was described first. Subsequently, a scanning imaging system was developed and its structure comprising a pulser and receiver, a gantry scanner, and computer software, was described in detail. Two-dimensional scanning imaging was conducted with a single-spindle accuracy of 0.01 mm and a maximum scanning area of 500 mm×300 mm. Scanning parameters, such as frequency, amplitude, and gain, were set conveniently according to the sample under testing. Metasequoia glyptostroboides board and Cunninghamia lanceolata finger jointed board were utilized to test the designed scanning imaging system. Results showed that amplitude of the received signal was sensitive to cracks, knots, and density. The constructed images provided information on knots, cracks, and finger joints, including location, shape, and size. Based on preliminary experimental results, the developed scanning imaging system could be used for non-destructive detection of defects including knots and cracks and could be utilized to scan a wooden material for in-plane distribution of density.
Air-coupled ultrasonic techniques, allowing contactless nondestructive testing using air as the coupling media instead of a liquid, have proven to be reliable and indispensable for nondestructive wood testing; however, instrumentation is still not widely available domestically. To help familiarize prospective users, the principle of the air-coupled ultrasonic was described first. Subsequently, a scanning imaging system was developed and its structure comprising a pulser and receiver, a gantry scanner, and computer software, was described in detail. Two-dimensional scanning imaging was conducted with a single-spindle accuracy of 0.01 mm and a maximum scanning area of 500 mm×300 mm. Scanning parameters, such as frequency, amplitude, and gain, were set conveniently according to the sample under testing. Metasequoia glyptostroboides board and Cunninghamia lanceolata finger jointed board were utilized to test the designed scanning imaging system. Results showed that amplitude of the received signal was sensitive to cracks, knots, and density. The constructed images provided information on knots, cracks, and finger joints, including location, shape, and size. Based on preliminary experimental results, the developed scanning imaging system could be used for non-destructive detection of defects including knots and cracks and could be utilized to scan a wooden material for in-plane distribution of density.
2017, 34(2): 361-368.
doi: 10.11833/j.issn.2095-0756.2017.02.022
Abstract:
Understanding variation of wood crystallinity, an important indicator of timber quality measurement, of Cunninghamia lanceolata, one of the most widely planted timber trees in southern China, is important for C. lanceolata clonal selection and wood processing technology improvements. For an inexpensive and less time-consuming method of rapid crystallinity determination, near infrared spectrum technology was tested. Using 164 C. lanceolata clones from 11 different geographic origins such as Guangxi, Hunan, and Guizhou Provinces, a near infrared spectroscopy prediction model of wood crystallinity was established by the partial least squares (PLS) method in combination with X-ray diffraction techniques, and then evaluated. Next, unknown samples were predicted through the model, and the variation of crystallinity was analyzed. Results showed that when using a spectral region of 6 000-4 000 cm-1, the second derivative spectrum, and PLS method, the calibration model had the best prediction effect. The calibration model correlation coefficient was r=0.987 5, and the root mean square error of calibration (RMSEC) was 0.318. Verifying the model revealed r=0.921 3 and root mean square error of prediction (RMSEP) was 0.742. Using unknown samples not involved in modeling to evaluate the model, predicted and measured r=0.905 0 with an average standard deviation of 0.301. So, the model could predict the crystallinity of C. lanceolata. Then, wood crystallinity determination results of 164 C. lanceolata clones showed that the average value was 44.52%, the range was 40.49%-49.75%, and the value between 42.06% and 47.28% took up 72.86%. According to the distribution of geographical provenances, the average wood crystallinity of C. lanceolata had a minimum of 43.45% from Jing County, Hunan, and a maximum of 45.23% from Liping County, Guizhou. The variance analysis showed no significant difference among the provenances, but there were significant differences for clones (P=0.000 3). The results indicate that near infrared spectroscopy could be used for the establishment of reliable prediction model, and the selection of improved varieties should be carried out among clones.
Understanding variation of wood crystallinity, an important indicator of timber quality measurement, of Cunninghamia lanceolata, one of the most widely planted timber trees in southern China, is important for C. lanceolata clonal selection and wood processing technology improvements. For an inexpensive and less time-consuming method of rapid crystallinity determination, near infrared spectrum technology was tested. Using 164 C. lanceolata clones from 11 different geographic origins such as Guangxi, Hunan, and Guizhou Provinces, a near infrared spectroscopy prediction model of wood crystallinity was established by the partial least squares (PLS) method in combination with X-ray diffraction techniques, and then evaluated. Next, unknown samples were predicted through the model, and the variation of crystallinity was analyzed. Results showed that when using a spectral region of 6 000-4 000 cm-1, the second derivative spectrum, and PLS method, the calibration model had the best prediction effect. The calibration model correlation coefficient was r=0.987 5, and the root mean square error of calibration (RMSEC) was 0.318. Verifying the model revealed r=0.921 3 and root mean square error of prediction (RMSEP) was 0.742. Using unknown samples not involved in modeling to evaluate the model, predicted and measured r=0.905 0 with an average standard deviation of 0.301. So, the model could predict the crystallinity of C. lanceolata. Then, wood crystallinity determination results of 164 C. lanceolata clones showed that the average value was 44.52%, the range was 40.49%-49.75%, and the value between 42.06% and 47.28% took up 72.86%. According to the distribution of geographical provenances, the average wood crystallinity of C. lanceolata had a minimum of 43.45% from Jing County, Hunan, and a maximum of 45.23% from Liping County, Guizhou. The variance analysis showed no significant difference among the provenances, but there were significant differences for clones (P=0.000 3). The results indicate that near infrared spectroscopy could be used for the establishment of reliable prediction model, and the selection of improved varieties should be carried out among clones.
2017, 34(2): 369-373.
doi: 10.11833/j.issn.2095-0756.2017.02.023
Abstract:
To compare basic physical and mechanical properties and electric heating properties of bamboo/wood composite electro-thermal plywood, four kinds of common adhesives:phenol-formaldehyde (PF), melamine-urea-formaldehyde (MUF), aqueous polymer isocyanate (API), and epoxy (EP), were applied. The bamboo/wood composite electro-thermal plywood treated by four kinds of adhesives were tested according to the China national standard and industrial standard:GB/T 18103-2013, LY/T 1700-2007. Results showed that the plywood treated by PF did not peel after the immersion test, and its modulus of rupture (MOR) (68.25 MPa) and modulus of elasticity (MOE) (5 670.57 MPa) were highest. The damp and hot dimensional stability of PF plywood was better than standard requirements, and the decreasing rate of resistance was maximal at 50.8%. Also, the heating and cooling rates with PF plywood were fastest. In contrast, all plywood treated by API peeled after the immersion test, and the MOR (36.37 MPa) and MOE (4 458.72 MPa) of MUF plywood were lowest. The damp and hot dimensional stability with both MUF plywood and API plywood failed. The decreasing rate of resistance for EP treated plywood reached 26.7%, which was the lowest among the four adhesives used; the rapid heating and cooling period of bambool wood composite electro-thermal plywood was 20 min. In general, the heating rate of PF plywood was the fastest, and the cooling rate for API plywood was the slowest. Overall, the phenolic resin (PF) was a suitable adhesive to make bamboo/wood composite electro-thermal plywood.
To compare basic physical and mechanical properties and electric heating properties of bamboo/wood composite electro-thermal plywood, four kinds of common adhesives:phenol-formaldehyde (PF), melamine-urea-formaldehyde (MUF), aqueous polymer isocyanate (API), and epoxy (EP), were applied. The bamboo/wood composite electro-thermal plywood treated by four kinds of adhesives were tested according to the China national standard and industrial standard:GB/T 18103-2013, LY/T 1700-2007. Results showed that the plywood treated by PF did not peel after the immersion test, and its modulus of rupture (MOR) (68.25 MPa) and modulus of elasticity (MOE) (5 670.57 MPa) were highest. The damp and hot dimensional stability of PF plywood was better than standard requirements, and the decreasing rate of resistance was maximal at 50.8%. Also, the heating and cooling rates with PF plywood were fastest. In contrast, all plywood treated by API peeled after the immersion test, and the MOR (36.37 MPa) and MOE (4 458.72 MPa) of MUF plywood were lowest. The damp and hot dimensional stability with both MUF plywood and API plywood failed. The decreasing rate of resistance for EP treated plywood reached 26.7%, which was the lowest among the four adhesives used; the rapid heating and cooling period of bambool wood composite electro-thermal plywood was 20 min. In general, the heating rate of PF plywood was the fastest, and the cooling rate for API plywood was the slowest. Overall, the phenolic resin (PF) was a suitable adhesive to make bamboo/wood composite electro-thermal plywood.
2017, 34(2): 374-380.
doi: 10.11833/j.issn.2095-0756.2017.02.024
Abstract:
With degradation of the living environment, urban and rural areas have had an irreversible tendency bringing a series of serious consequences. At the same time, the public has expressed a strong desire to improve their living environment. Bamboo not only protects and improves the environment, but also promotes the physical and mental health of mankind through its eco-environmental functions. Aiming at the hotspots in environmental science research, and from the viewpoint of improving the microclimatic environment, purifying the air, releasing negative air ions, and fixing carbon, this paper summarizes recent research progress concerning the environmental effects of bamboo. Future work in this field should focus on expanding the scope of bamboo, improving research methods for quantitative experimentation on environmental effects, and establishing an evaluation system for bamboo ecological and environmental services.
With degradation of the living environment, urban and rural areas have had an irreversible tendency bringing a series of serious consequences. At the same time, the public has expressed a strong desire to improve their living environment. Bamboo not only protects and improves the environment, but also promotes the physical and mental health of mankind through its eco-environmental functions. Aiming at the hotspots in environmental science research, and from the viewpoint of improving the microclimatic environment, purifying the air, releasing negative air ions, and fixing carbon, this paper summarizes recent research progress concerning the environmental effects of bamboo. Future work in this field should focus on expanding the scope of bamboo, improving research methods for quantitative experimentation on environmental effects, and establishing an evaluation system for bamboo ecological and environmental services.
