yTwo exotic species, Sonneratia caseolaris (L.) Engl. and S. apetala B. Ham., were introduced to Futian Mangrove Forest Nature Reserve, Shenzhen Bay, in 1993 for afforestation. Winter cold caused frigid harm but did n...yTwo exotic species, Sonneratia caseolaris (L.) Engl. and S. apetala B. Ham., were introduced to Futian Mangrove Forest Nature Reserve, Shenzhen Bay, in 1993 for afforestation. Winter cold caused frigid harm but did not appear to be an obstacle to the introduction. The cold tolerance of the parental and filial generation increased in several years. The two Sonneratia spp. could propagate by seeds and disperse in Shenzhen Bay. While the two species grew faster than indigenous species, at the same time they promoted the growth of indigenous species, but they could not replace indigenous mangrove species. Suitable habitat was more important than the distance from the source in the natural spreading for the two species. The niche of the two species did not overlap with the niche of indigenous species. The two species did not self regenerate, although they could disperse on localized area in Shenzhen Bay. Therefore, it was unlikely that the two species would pose ecological disaster.展开更多
PCR-SSCP was used to analyze the polymorphism of leptin gene in 539 samples of six cattle breeds, namely Nanyang (NY), Qinchuan (QC), Jiaxianred (JXR), Xizhen (XZ), Luxi (LX), and Holstein cow (HOL) breeds...PCR-SSCP was used to analyze the polymorphism of leptin gene in 539 samples of six cattle breeds, namely Nanyang (NY), Qinchuan (QC), Jiaxianred (JXR), Xizhen (XZ), Luxi (LX), and Holstein cow (HOL) breeds. PCR products with a 330 bp were amplified and sequenced. The results showed that the frequencies of alleles A/B of NY, QC, JXR, XZ, LX, and HOL breeds were 0.558/0.442, 0.492/0.508, 0.571/0.429, 0.658/0.342, 0.591/0.409, and 0.615/0.385, respectively. The association of variations of leptin gene with growth traits in NY, QC, JXR breeds was analyzed. Some indexes of the individuals with genotype BB were higher than that with genotype AA and AB in NY breed, such as the indexes of body length, heart length, body weight, hucklebone width, body height, and average day gain. The height at hip cross of the individuals with genotype BB was higher than that of those with genotype AA and AB in QC breed (P 〈 0.05). So leptin gene may be one of the candidate genes for growth traits with height at hip cross, but not for body weight, heart length, and body length trait. However, the height at hip cross and hucklebone width of the individuals with genotype AB and BB were higher than that of those with genotype AA in JXR breed (P 〈 0.05), but the difference was not statistically significant in body weight and body sizes (body height, body length, and heart length). And the polymorphisms in leptin gene were caused by G→T transversion at the 66th bp position, A→C transversion at the 67th bp position and G→T transversion at the 299th bp position. These results may be applied to marker-assisted selection of Chinese cattle breeds.展开更多
Eupatorium adenophorum is one of main invasive plants in China and has caused great economic losses. A study was conducted to determine the biomass allocation, leaf morphology and growth response of E. adenophorum see...Eupatorium adenophorum is one of main invasive plants in China and has caused great economic losses. A study was conducted to determine the biomass allocation, leaf morphology and growth response of E. adenophorum seedlings that grew under five different intensities (relative irradiances RI 10%, 20 %, 30%, 55%, 100%) for 14 months. Results reveal that the species shows typical leaf morphological adaptation to different light conditions. The total biomass of seedlings increased with the increase of light intensity from 10% to 55% RI but decreased at RI 100% (full sunlight). Height growth increased with the increase of light intensity from 10% to 30% RI but decreased when light intensity was over 30% RI. At low light levels, plants enhanced light availability by means of increasing biomass allocation to leaves and formation of larger, thinner leaves with high specific leaf area (SLA), leading to a high leaf area ratio (LAR) and high stem strips length (SSL). The mean relative growth rate (RGR) of the plant increased with the light intensity increase and attained the maximum at 55% RI. The growth of seedlings at 30%-55% RI was much better than that at full light condition. This might be an adaptive strategy that supports the vigorous invasiveness of this species, because a high-shaded canopy could prevent other plant species from surviving and growing. This study indicates that E. adenophorum could adapt to different light conditions, especially to low light habit. This can explain its greater invasiveness.展开更多
Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( G...Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( Glycine max (L.) Merr.) measured in the past three decades (1970s, 1980s and 1990s) and their inter_relationships were analyzed. These parameters of soybean changed with development stages. It is shown that there was a strongly positive relationship between the yield of soybean and its net photosynthetic rate. Soybean varieties with high yield potential had higher P n , g s and Ψ than those with low yield potential. Their values of C i were remarkably lower. Such relationship was especially remarkable at the critical stage of pod_bearing. P n of soybean of high yield was obviously higher than that of low yield. Of the different stages, the highest P n was found in the pod_bearing stage and other values were higher, too. P n and Ψ of modern soybean varieties were higher and such was continuing. Increased partitioning of carbon to seed and the size of sink may also be important for yield formation when P n values were remarkably higher in the pod_bearing stage.展开更多
[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided the...[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.展开更多
[Objective] This study was to investigate the climatic factors affecting the regional eco-adaptability of ramie.[Method] Five experimental sites of different eco-types in ramie growing regions in Yangtze Valley were s...[Objective] This study was to investigate the climatic factors affecting the regional eco-adaptability of ramie.[Method] Five experimental sites of different eco-types in ramie growing regions in Yangtze Valley were set up to investigate the yield of Zhongzhu No.2,based on which we assessed the adaptability of Zhongzhu No.2 to various eco-regions and further analyzed the climatic factors causing the difference in eco-adaptability.[Result] Ramie yield varied largely among various experimental sites and the yield difference appeared to be well repeatable,with a differential value between the maximum and the minimum reaching 2.3 kg/20 m2.Analysis of the yield data,together with climatic factors in various ecological regions showed that yield of Zhongzhu No.2 was significantly correlated with rainfall,sunshine hours,relative humidity during its growing period.Of the climatic factors,sunshine hours and rainfall can positively promote yield increase,while relative humidity negatively regulate ramie yield.[Conclusion] The climatic indices,including rainfall,sunshine duration and relative humidity are a key factor causing yield difference in ramie among different regions of Yangtze Valley.展开更多
In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. To...In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. Total 240 1-d-old Cherry Valley ducks were selected, and they were randomly divided into 4 groups, including 1 control group and 3 treatment groups. There were 3 replicates for each group and there were 20 ducks for each replicate. The ducks in the control group were fed the basal diet, and the ducks in the 3 treatment groups were fed the basal diet added with Lactobacillus, Bacillus natto and florfenicol, respectively. The test lasted for 42 d. The results showed that the addition of Lactobacillus and Bacillus natto could improve the average daily weight gain and final average weight (P〈0.05) of Cherry Valley ducks, and reduce the glutamic-pyruvic transaminase ac- tivity, alkaline phosphatase activity and serum urinary nitrogen content in duck blood (P〈0.05) and reduce the creatinine content and total cholesterol content in Cherry Valley ducks (P〉0.05); at the same time, adding probiotics to feed could also in- crease the grass economic benefits of Cherry Valley ducks. In overall, the effects of adding probiotics were better than those of adding antibiotic.展开更多
Soil water stress was studied on the potted seedlings of five dominant tree species (Pinus koraienes Sieb.et Zucc., Fraxinus mandshurica Rupr., Juglans mandshurica Maxim, Tilia amurensis Rupr. and Quercus mongolica Fi...Soil water stress was studied on the potted seedlings of five dominant tree species (Pinus koraienes Sieb.et Zucc., Fraxinus mandshurica Rupr., Juglans mandshurica Maxim, Tilia amurensis Rupr. and Quercus mongolica Fisch.ex Turcz) from the broadleaved/Korean pine forest in Changbai Mountain. Leaf growth, water transpiration and photosynthesis were compared for each species under three soil moisture conditions: 85%-100% (high water, CK), 65%-85% (Medium water, MW) and 45%-65% (low water, LW) of 37.4% water-holding capacity in field. The results showed that the characteristic of typical drought-resistance of the leaves is significantly developed. The net photosynthetic rate and water use efficiency of Fraxinus mandshurica were higher in MW than those in CK. But for the other four species, the net photosynthetic rate and water use efficiency in CK were lower than those in MW and LW. The transpiration rate responding to soil moistures varied from species to species.展开更多
The species diversity, structure and dynamic rules of insect communities in wetland can provide data of the insects for the protection, utilization and monitor- ing of wetland, which is an essential link to maintain t...The species diversity, structure and dynamic rules of insect communities in wetland can provide data of the insects for the protection, utilization and monitor- ing of wetland, which is an essential link to maintain the healthy ecological system of the wetland and protect the biodiversity in the wetland. A systematic study on the composition and succession of insect communities in the wetland, as well as the indication of insect groups can provide a theoretical basis for wetland protection and management, and thus promote the development of regional economy and en- vironmental protection.展开更多
The dynamic and static modulus of elasticity (MOE) between bluestained and non-bluestained lumber of Lodgepole pine were tested and analyzed by using three methods of Non-destructive testing (NDT), Portable Ultras...The dynamic and static modulus of elasticity (MOE) between bluestained and non-bluestained lumber of Lodgepole pine were tested and analyzed by using three methods of Non-destructive testing (NDT), Portable Ultrasonic Non-destructive Digital Indicating Testing (Pundit), Metriguard and Fast Fourier Transform (FFT) and the normal bending method. Results showed that the dynamic and static MOE of bluestained wood were higher than those of non-bluestained wood. The significant differences in dynamic MOE and static MOE were found between bulestained and non-bluestained wood, of which, the difference in each of three dynamic MOE (Ep. the ultrasonic wave modulus of elasticity, Ems, the stress wave modulus of elasticity and El, the longitudinal wave modulus of elasticity) between bulestained and non-bluestained wood arrived at the 0.01 significance level, whereas that in the static MOE at the 0.05 significance level. The differences in MOE between bulestained and non-bluestained wood were induced by the variation between sapwood and heartwood and the different densities of bulestained and non-bluestained wood. The correlation between dynamic MOE and static MOE was statistically significant at the 0.01 significance level. Although the dynamic MOE values of Ep, Em, Er were significantly different, there exists a close relationship between them (arriving at the 0.01 correlation level). Comparative analysis among the three techniques indicated that the accurateness of FFT was higher than that of Pundit and Metriguard. Effect of tree knots on MOE was also investigated. Result showed that the dynamic and static MOE gradually decreased with the increase of knot number, indicating that knot number had significant effect on MOE value.展开更多
It is of great importance for the analysis on genetic evolution mechanism, and rice breeding utilization by estimation and protection of genetic diversity of pre- sent DXWR (Oryza rufipogon Griff.). This study has s...It is of great importance for the analysis on genetic evolution mechanism, and rice breeding utilization by estimation and protection of genetic diversity of pre- sent DXWR (Oryza rufipogon Griff.). This study has summarized genetic diversity and protection achievements of DXWR from many aspects like varied conservations, years, generations, other species of wild rice and cultivated rice. In this study, a u- nified and scientific evaluation system of genetic diversity is encouraged to be built and suggestions on research prospect and ecological conservation of DXWR genetic diversity have been proposed.展开更多
Wheat samples were collected from Hetao Area, Inner Mongolia, and their poisonous, harmful and beneficial elements contents were analyzed. According to the standards for heavy metals in wheat green food, the Hg, Cd, A...Wheat samples were collected from Hetao Area, Inner Mongolia, and their poisonous, harmful and beneficial elements contents were analyzed. According to the standards for heavy metals in wheat green food, the Hg, Cd, As and Pb contents in the wheat samples collected from Qiantao Area were all below the national standards, indicating that they were green; and the heavy metals contents in the wheat samples collected from Houtao Area were basically in line with the pollutionfree food hygiene standards, indicating that they were not harmful to human body. Harmful elements Cd and Hg were more enriched in the wheat samples from Qiantao Area, but their contents were all lower than the national food standards, indicating that the wheat from Qiantao Area was not harmful to human health. The wheat from Houtao Area was rich in essential trace elements Cu, Zn, Se and K, and long-term consumption was beneficial to human health.展开更多
An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were c...An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were captured and identified into 7 families, 15 genera and 21 species in 4 orders (Rodentia, Insectivora, Scandentia and Carnivora), while t4 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura, The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain. The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity, abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking lice and their corresponding hosts. A certain species of hosts usually have their fixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mammal host in different oriented areas of Erhai Lake are homologous. The results strongly suggest a close relationship of co-evolution between sucking lice and their hosts.展开更多
Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study e...Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study ecology from genes to the biosphere. Among this trend, N:P stoichiometry is used actively in ecological interactions since nitrogen (N) and phosphorus (P) are the two most important elements in most ecosystems. This article reviews the application of N:P stoichiometry to the studies of ecological problems at different levels, including ecosystem, community and species. Meanwhile, we also provide the cellular basis of N:P stoichiometry, identify the shortages in the use of N:P stoichiometry theory, and put forward some perspectives for future research to be conducted.展开更多
According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey f...According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species di-versity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densi-ties of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Com-paring with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment.展开更多
[Objective] The aim was to review on vulnerability evaluation of grassland ecosystem under climate change.[Method] In the research,vulnerability evaluation methods of ecosystem under climate changes,at home and abroad...[Objective] The aim was to review on vulnerability evaluation of grassland ecosystem under climate change.[Method] In the research,vulnerability evaluation methods of ecosystem under climate changes,at home and abroad,and the related cases and research progress in China were reviewed.In addition,the future of evaluation research was predicted.[Result] Ecosystem vulnerability to climate change is an important part of climate change research.It is necessary and urgent to improve evaluation methods and reduce uncertainty of future vulnerability evaluation to make evaluation more comprehensive and objective.Furthermore,evaluation on effects of human activity on natural ecosystem vulnerability should be highlighted.[Conclusion] The research provided reference for establishment of a new management model for ecosystem adaptability to climate and sustainable development of grasslands in northern China.展开更多
In order to investigate the appIication effects of microbial ecoIogical agents as repIacements for antibiotics in weaned pigIets, a total of 120 28 d oId healthy Duroc ×Landrace ×Large White weaned pigIets...In order to investigate the appIication effects of microbial ecoIogical agents as repIacements for antibiotics in weaned pigIets, a total of 120 28 d oId healthy Duroc ×Landrace ×Large White weaned pigIets with simiIar bogy weights and body fats and cIose birth dates were seIected. They were randomIy divided into three groups, incIuding controI group (CK), antibiotic group (A) and microbial ecoIogical agent group (MEA). The growth performance, health status and economic benefits of the weaned pigIets were measured. The resuIts showed that the A and MEA groups couId better enhance the immunity of weaned pigIets and improve the economic benefits in the whoIe experimental period compared to the CK group (P〈0.01). How-ever, there were no significant differences in pigIet immunity and economic benefits between the A and MEA groups (P〉0.05). It is indicated that the Rujunbao, a mi-crobial ecoIogical agent, can be promoted in weaned pigIet production as a repIace-ment for antibiotic.展开更多
文摘yTwo exotic species, Sonneratia caseolaris (L.) Engl. and S. apetala B. Ham., were introduced to Futian Mangrove Forest Nature Reserve, Shenzhen Bay, in 1993 for afforestation. Winter cold caused frigid harm but did not appear to be an obstacle to the introduction. The cold tolerance of the parental and filial generation increased in several years. The two Sonneratia spp. could propagate by seeds and disperse in Shenzhen Bay. While the two species grew faster than indigenous species, at the same time they promoted the growth of indigenous species, but they could not replace indigenous mangrove species. Suitable habitat was more important than the distance from the source in the natural spreading for the two species. The niche of the two species did not overlap with the niche of indigenous species. The two species did not self regenerate, although they could disperse on localized area in Shenzhen Bay. Therefore, it was unlikely that the two species would pose ecological disaster.
基金This work was supported by the National 863 Project (No. 2006AA10Z197)Phenom Innovative Foundation of Henan Province (No.0521001900)+1 种基金the National Natural Sciences Foundation of China (No. 30471238)Project Supporting of Excellent Researchers of Northwest A&F University and Plan of Dezhou University of Person with Ability(No. 06rc012).
文摘PCR-SSCP was used to analyze the polymorphism of leptin gene in 539 samples of six cattle breeds, namely Nanyang (NY), Qinchuan (QC), Jiaxianred (JXR), Xizhen (XZ), Luxi (LX), and Holstein cow (HOL) breeds. PCR products with a 330 bp were amplified and sequenced. The results showed that the frequencies of alleles A/B of NY, QC, JXR, XZ, LX, and HOL breeds were 0.558/0.442, 0.492/0.508, 0.571/0.429, 0.658/0.342, 0.591/0.409, and 0.615/0.385, respectively. The association of variations of leptin gene with growth traits in NY, QC, JXR breeds was analyzed. Some indexes of the individuals with genotype BB were higher than that with genotype AA and AB in NY breed, such as the indexes of body length, heart length, body weight, hucklebone width, body height, and average day gain. The height at hip cross of the individuals with genotype BB was higher than that of those with genotype AA and AB in QC breed (P 〈 0.05). So leptin gene may be one of the candidate genes for growth traits with height at hip cross, but not for body weight, heart length, and body length trait. However, the height at hip cross and hucklebone width of the individuals with genotype AB and BB were higher than that of those with genotype AA in JXR breed (P 〈 0.05), but the difference was not statistically significant in body weight and body sizes (body height, body length, and heart length). And the polymorphisms in leptin gene were caused by G→T transversion at the 66th bp position, A→C transversion at the 67th bp position and G→T transversion at the 299th bp position. These results may be applied to marker-assisted selection of Chinese cattle breeds.
基金This study is supported by Doctor Fund Project of Educa-tion Department (20050290003), Knowledge Innovation Project of Chinese Academy of Sciences (KSCX1-SW-13-0X-0X) and the National Natural Science Foundation of China (30470337)
文摘Eupatorium adenophorum is one of main invasive plants in China and has caused great economic losses. A study was conducted to determine the biomass allocation, leaf morphology and growth response of E. adenophorum seedlings that grew under five different intensities (relative irradiances RI 10%, 20 %, 30%, 55%, 100%) for 14 months. Results reveal that the species shows typical leaf morphological adaptation to different light conditions. The total biomass of seedlings increased with the increase of light intensity from 10% to 55% RI but decreased at RI 100% (full sunlight). Height growth increased with the increase of light intensity from 10% to 30% RI but decreased when light intensity was over 30% RI. At low light levels, plants enhanced light availability by means of increasing biomass allocation to leaves and formation of larger, thinner leaves with high specific leaf area (SLA), leading to a high leaf area ratio (LAR) and high stem strips length (SSL). The mean relative growth rate (RGR) of the plant increased with the light intensity increase and attained the maximum at 55% RI. The growth of seedlings at 30%-55% RI was much better than that at full light condition. This might be an adaptive strategy that supports the vigorous invasiveness of this species, because a high-shaded canopy could prevent other plant species from surviving and growing. This study indicates that E. adenophorum could adapt to different light conditions, especially to low light habit. This can explain its greater invasiveness.
文摘Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( Glycine max (L.) Merr.) measured in the past three decades (1970s, 1980s and 1990s) and their inter_relationships were analyzed. These parameters of soybean changed with development stages. It is shown that there was a strongly positive relationship between the yield of soybean and its net photosynthetic rate. Soybean varieties with high yield potential had higher P n , g s and Ψ than those with low yield potential. Their values of C i were remarkably lower. Such relationship was especially remarkable at the critical stage of pod_bearing. P n of soybean of high yield was obviously higher than that of low yield. Of the different stages, the highest P n was found in the pod_bearing stage and other values were higher, too. P n and Ψ of modern soybean varieties were higher and such was continuing. Increased partitioning of carbon to seed and the size of sink may also be important for yield formation when P n values were remarkably higher in the pod_bearing stage.
基金Supported by National Natural Science Foundation of China(31370613)Major State Basic Research Development Program of China(973 Program)(2011CB403202)Fundamental Research Funds for the Central Universities(DL12CA01)~~
文摘[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.
基金Supported by Modern Agricultural Industry Technology System(nycytx-19-E16)Natural Science Foundation of Hunan Province(10JJ3063)~~
文摘[Objective] This study was to investigate the climatic factors affecting the regional eco-adaptability of ramie.[Method] Five experimental sites of different eco-types in ramie growing regions in Yangtze Valley were set up to investigate the yield of Zhongzhu No.2,based on which we assessed the adaptability of Zhongzhu No.2 to various eco-regions and further analyzed the climatic factors causing the difference in eco-adaptability.[Result] Ramie yield varied largely among various experimental sites and the yield difference appeared to be well repeatable,with a differential value between the maximum and the minimum reaching 2.3 kg/20 m2.Analysis of the yield data,together with climatic factors in various ecological regions showed that yield of Zhongzhu No.2 was significantly correlated with rainfall,sunshine hours,relative humidity during its growing period.Of the climatic factors,sunshine hours and rainfall can positively promote yield increase,while relative humidity negatively regulate ramie yield.[Conclusion] The climatic indices,including rainfall,sunshine duration and relative humidity are a key factor causing yield difference in ramie among different regions of Yangtze Valley.
基金Supported by Project of Jiangsu Agri-animal Husbandry Vocational College(NSFZN1309)~~
文摘In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. Total 240 1-d-old Cherry Valley ducks were selected, and they were randomly divided into 4 groups, including 1 control group and 3 treatment groups. There were 3 replicates for each group and there were 20 ducks for each replicate. The ducks in the control group were fed the basal diet, and the ducks in the 3 treatment groups were fed the basal diet added with Lactobacillus, Bacillus natto and florfenicol, respectively. The test lasted for 42 d. The results showed that the addition of Lactobacillus and Bacillus natto could improve the average daily weight gain and final average weight (P〈0.05) of Cherry Valley ducks, and reduce the glutamic-pyruvic transaminase ac- tivity, alkaline phosphatase activity and serum urinary nitrogen content in duck blood (P〈0.05) and reduce the creatinine content and total cholesterol content in Cherry Valley ducks (P〉0.05); at the same time, adding probiotics to feed could also in- crease the grass economic benefits of Cherry Valley ducks. In overall, the effects of adding probiotics were better than those of adding antibiotic.
基金national key basic develop-ment of China (G1999043407), grant from the National Natural Science Foundation of China (No. 30271068) and KZ-CX-SW-01-01B of the Chinese Academy of Sciences.
文摘Soil water stress was studied on the potted seedlings of five dominant tree species (Pinus koraienes Sieb.et Zucc., Fraxinus mandshurica Rupr., Juglans mandshurica Maxim, Tilia amurensis Rupr. and Quercus mongolica Fisch.ex Turcz) from the broadleaved/Korean pine forest in Changbai Mountain. Leaf growth, water transpiration and photosynthesis were compared for each species under three soil moisture conditions: 85%-100% (high water, CK), 65%-85% (Medium water, MW) and 45%-65% (low water, LW) of 37.4% water-holding capacity in field. The results showed that the characteristic of typical drought-resistance of the leaves is significantly developed. The net photosynthetic rate and water use efficiency of Fraxinus mandshurica were higher in MW than those in CK. But for the other four species, the net photosynthetic rate and water use efficiency in CK were lower than those in MW and LW. The transpiration rate responding to soil moistures varied from species to species.
基金Supported by the Open Project of the Key Laboratory for the Development and Application of Characteristic Biological Resources of the Institutions of Higher Education in Yunnan Province(GXKJ201626)~~
文摘The species diversity, structure and dynamic rules of insect communities in wetland can provide data of the insects for the protection, utilization and monitor- ing of wetland, which is an essential link to maintain the healthy ecological system of the wetland and protect the biodiversity in the wetland. A systematic study on the composition and succession of insect communities in the wetland, as well as the indication of insect groups can provide a theoretical basis for wetland protection and management, and thus promote the development of regional economy and en- vironmental protection.
基金This paper was supported by "Wood-inorganic Res-toration Material" in "Technique Introduction and Innovation of Bio-macromolecule New Material" of Introducing Overseas Advanced Forest Technology Innovation Program of China ("948" Innovation Pro-ject, Number: 2006-4-C03)
文摘The dynamic and static modulus of elasticity (MOE) between bluestained and non-bluestained lumber of Lodgepole pine were tested and analyzed by using three methods of Non-destructive testing (NDT), Portable Ultrasonic Non-destructive Digital Indicating Testing (Pundit), Metriguard and Fast Fourier Transform (FFT) and the normal bending method. Results showed that the dynamic and static MOE of bluestained wood were higher than those of non-bluestained wood. The significant differences in dynamic MOE and static MOE were found between bulestained and non-bluestained wood, of which, the difference in each of three dynamic MOE (Ep. the ultrasonic wave modulus of elasticity, Ems, the stress wave modulus of elasticity and El, the longitudinal wave modulus of elasticity) between bulestained and non-bluestained wood arrived at the 0.01 significance level, whereas that in the static MOE at the 0.05 significance level. The differences in MOE between bulestained and non-bluestained wood were induced by the variation between sapwood and heartwood and the different densities of bulestained and non-bluestained wood. The correlation between dynamic MOE and static MOE was statistically significant at the 0.01 significance level. Although the dynamic MOE values of Ep, Em, Er were significantly different, there exists a close relationship between them (arriving at the 0.01 correlation level). Comparative analysis among the three techniques indicated that the accurateness of FFT was higher than that of Pundit and Metriguard. Effect of tree knots on MOE was also investigated. Result showed that the dynamic and static MOE gradually decreased with the increase of knot number, indicating that knot number had significant effect on MOE value.
基金Supported by National Natural Science Foundation of China(30960189)the National Public Benefit(Agricultural)Research Foundation of China(201103007)+1 种基金Special Funds for Establishment of Modern Agricultural and Industrial Technology System(NXCYTY-01)Project supported by Jiangxi Academy of Agricultural Science for Innovation(2010CQN008)~~
文摘It is of great importance for the analysis on genetic evolution mechanism, and rice breeding utilization by estimation and protection of genetic diversity of pre- sent DXWR (Oryza rufipogon Griff.). This study has summarized genetic diversity and protection achievements of DXWR from many aspects like varied conservations, years, generations, other species of wild rice and cultivated rice. In this study, a u- nified and scientific evaluation system of genetic diversity is encouraged to be built and suggestions on research prospect and ecological conservation of DXWR genetic diversity have been proposed.
基金Supported by Land Resources Survey Research Project of China Geological Survey(200414200005)~~
文摘Wheat samples were collected from Hetao Area, Inner Mongolia, and their poisonous, harmful and beneficial elements contents were analyzed. According to the standards for heavy metals in wheat green food, the Hg, Cd, As and Pb contents in the wheat samples collected from Qiantao Area were all below the national standards, indicating that they were green; and the heavy metals contents in the wheat samples collected from Houtao Area were basically in line with the pollutionfree food hygiene standards, indicating that they were not harmful to human body. Harmful elements Cd and Hg were more enriched in the wheat samples from Qiantao Area, but their contents were all lower than the national food standards, indicating that the wheat from Qiantao Area was not harmful to human health. The wheat from Houtao Area was rich in essential trace elements Cu, Zn, Se and K, and long-term consumption was beneficial to human health.
基金This project was supported by the Natural Science Foundation of China(30460125)
文摘An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were captured and identified into 7 families, 15 genera and 21 species in 4 orders (Rodentia, Insectivora, Scandentia and Carnivora), while t4 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura, The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain. The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity, abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking lice and their corresponding hosts. A certain species of hosts usually have their fixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mammal host in different oriented areas of Erhai Lake are homologous. The results strongly suggest a close relationship of co-evolution between sucking lice and their hosts.
文摘Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study ecology from genes to the biosphere. Among this trend, N:P stoichiometry is used actively in ecological interactions since nitrogen (N) and phosphorus (P) are the two most important elements in most ecosystems. This article reviews the application of N:P stoichiometry to the studies of ecological problems at different levels, including ecosystem, community and species. Meanwhile, we also provide the cellular basis of N:P stoichiometry, identify the shortages in the use of N:P stoichiometry theory, and put forward some perspectives for future research to be conducted.
基金the Natural Science Founda-tion of Guangdong Province (021740) and Guangdong Environmental Pro-tection Foundation (2001-18)
文摘According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species di-versity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densi-ties of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Com-paring with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment.
基金Supported by National Natural Science Foundation of China(70933004)Fund on Basic Scientific Research Project of Nonprofit Central Research Institutions(1610332012201)Non-profit Special Fund of Ministry of Water Resources(201201008-02)~~
文摘[Objective] The aim was to review on vulnerability evaluation of grassland ecosystem under climate change.[Method] In the research,vulnerability evaluation methods of ecosystem under climate changes,at home and abroad,and the related cases and research progress in China were reviewed.In addition,the future of evaluation research was predicted.[Result] Ecosystem vulnerability to climate change is an important part of climate change research.It is necessary and urgent to improve evaluation methods and reduce uncertainty of future vulnerability evaluation to make evaluation more comprehensive and objective.Furthermore,evaluation on effects of human activity on natural ecosystem vulnerability should be highlighted.[Conclusion] The research provided reference for establishment of a new management model for ecosystem adaptability to climate and sustainable development of grasslands in northern China.
基金Vegetable Basket Projects of Beijing Vocational College of Agriculture for Improving Scientific and Technological Capabilities of New Business Entities~~
文摘In order to investigate the appIication effects of microbial ecoIogical agents as repIacements for antibiotics in weaned pigIets, a total of 120 28 d oId healthy Duroc ×Landrace ×Large White weaned pigIets with simiIar bogy weights and body fats and cIose birth dates were seIected. They were randomIy divided into three groups, incIuding controI group (CK), antibiotic group (A) and microbial ecoIogical agent group (MEA). The growth performance, health status and economic benefits of the weaned pigIets were measured. The resuIts showed that the A and MEA groups couId better enhance the immunity of weaned pigIets and improve the economic benefits in the whoIe experimental period compared to the CK group (P〈0.01). How-ever, there were no significant differences in pigIet immunity and economic benefits between the A and MEA groups (P〉0.05). It is indicated that the Rujunbao, a mi-crobial ecoIogical agent, can be promoted in weaned pigIet production as a repIace-ment for antibiotic.